I started a business a year ago building custom bass boxes with 0 prior knowledge but I studied your videos and utilized all the knowledge I took from them. Now I have a solid reputation for my boxes performing perfectly
Most likely you did, you just never applied the science to speakers 🔊 Or you just happen to be sleeping or skip school that day… 😅 Even in health class, you learned about a diaphragm this is working in the same way if you pulled on the diaphragm pulled in air if you pushed on the diaphragm and pushed out air..
My issue with ports- is you come to find out half the songs sound like crap and you find yourself playing the same 5 songs that sound "great" in your range, not the music you enjoy- IF you listen to actual music. Thats why i am going back to sealed box this build.
Hey Jim let me help you out there, you are judging ported enclosures and the mechanism based on poorly made or specifically designed ports. IF you make the enclosure Large enough, and you design the port to have the proper area and length, then you can make better and louder sound across the board. Period. If you make the box large enough and design it properly, then you will have absolutely better sound. The cost is more space needed for the box assuming you design it for “full spectrum”. Mainly, where you tune a subwoofer to in frequency it can be nearly twice as loud with the same or better quality at the same volume level. BELOW the tuned frequency the subwoofer won’t play as it doesn’t have enough “suspension” from the air. That’s the easiest way to explain it. Sealed will make more similar suspension across the board of frequencies. Here is the key: to make it sound better and play louder at good quality, you will need to tune the box to a frequency basically low enough that it’s as low as you would want. Now if you want high frequency sound and you tune a box low, it may sound worse. One thing you can always do is to use a digital or amp filter to remove sounds you don’t like. Now to tune a subwoofer to like 26-28 hertz then you will easily cover most frequencies you would like to hear for most music. The rest would be adjusting the digital filters because songs may have notes or sounds in frequencies that you dont really want and they’re noise. Now if you are super picky you can still port the sub and tune it to 18-20 hertz. That’s as low as a human could hear, and generally it can play much louder across the board up until you get to higher notes which would usually be equal to what a sealed subwoofer would play without clipping or distortion or whatever else. But to design it that low it won’t be as loud as a higher tune at max volume. Many prefabricated boxes and designs tune to 36-40 hertz to get max loudness but they miss the key low notes. They also do this because to port lower you need a larger box with the correct well designed port area and length to match. So look you can easily get louder sound overall with zero loss across the spectrum in any frequency compared to sealed subwoofers as long as you tune it low to the minimum frequency humans can hear at. Anything else you do or want can be adjusted by filters to remove the lower notes for certain music, remove higher notes, and even out the volume across the board even. You also want to ALWAYS cut out certain frequencies on your amp before the sub, which would be anything below hearing level and anything above whatever the recommended levels are for your sub. I dont personally know what the cutoff should be for highest frequencies but it’s below 80-100 hertz for sure for most subwoofers. Anyways, if you have the room for an appropriate ported box and you tune and design it properly with enough size and port design, then you can play much better than any sealed box and louder across most if not all notes. The key there is space for the box, the amp you have, the songs and sounds you like, and the availability or affordability of the subwoofer and it’s RMS level of energy it can take. Like many premade boxes are shitty and can only play to 40hertz and up. A ported box should be studied and compared by sound level and curve, and the type of music that you like to play. Most people end up realizing without clipping they are restricted by the energy their alternator and battery can handle. So the best option is to go for bigger subwoofers, and ported with a large box if they want lower notes and full spectrum. Many people actually want 20 hertz for hip hop. The thing is you can change a port to have a better curve you like and be louder with all of the notes by tuning it higher and cutting off lower notes. Anything below the cutoff curve is a sharp decline and is almost impossible to play after 1-2 hertz below. You MUST program your amp to cut off all frequencies below your subwoofer boxes tuning level, and always should cut off any sounds below the frequency of human hearing capabilities. Mainly, if you know your music you can know it’s okay to tune it to 35 or 40 if you don’t want anything lower to play anyways. You should be cutting off the minimum based on tuning and maximum based on the limits of the sub and the general maximums based on an instrument easy Google search. Then a ported sub is still superior or equal at any given frequency at its tuning level or above to a sealed sub, assuming you build the box correctly and don’t make it too small. But listen many people actually have a subwoofer and amp setup that can play as loud as they want at every frequency they want without clipping their amp or overpowering anything and draining their car. In that case as long as you have a pass through filter you can also use your audio input or the amplifier to adjust the filters to your desires based on what you listen to or even have different filters for different music. There is nothing inherently worse about a ported sub and a ported sub if built to the appropriate size and shape will always be superior in its capabilities even when it’s tuned to the lowest possible frequency of human hearing. If you have more capabilities for clean sound at a louder volume across the board, or in the ranges you listen to, then you can always adjust the filters to decrease the sound signal sent for certain frequencies. If you don’t have room for the large box in your car but have room for larger subs and more expensive subs and have the amplifier and alternator to fuel it, then you would definitely want sealed. It’s also more affordable and more simple and has a generally good sound curve. What we really need to be considering here is not what attributes ported boxes have, but rather what trade offs we need to make and what benefits we need to make. Frankly anyone who wants louder sounds across the board full spectrum and they cannot afford higher watt subs or amps, or their car doesn’t have the electrical output, and they have the room for a bigger box then they will always benefit from getting a ported sub tuned to a lower range especially if it’s done to the lowest frequency that can be heard. Then if someone doesn’t listen to music that uses lower notes, or maybe even they already block lower frequencies because they don’t like them in their music, then they can have louder subs ported to a higher range cutoff with a smaller box. If not, then they could still tune it to a lower frequency if they make a large enough box designed properly. The problem is ported subs are always associated with scam sales of boxes super small with horrible designs that are tuned to 40hz or higher which cuts out major frequencies if not the most important for some, and people don’t realize this so they don’t change their pass through filter higher and their sub free wobbles and bottoms out and damages itself. Ported subs can be very much like sealed subs but louder when designed correctly. The question is whether you have space for a box, whether you need frequencies and how low of frequencies do you need, and whether you want louder noise.
Great description of the beauty of the band pass design. I have rarely heard it so well articulated. Just a pleasure to watch and listen to. Some of us are old hats with some of the science, but hearing it explained succinctly and clearly is still a beautiful experience. Thanks for that.
Wow, super impressed! I've never seen so much correct information condensed into 10 minutes on audio as this. In a sea of audio half truths this was refreshing to see not a single misunderstanding of the physics/engineering of how ports operate. My background is live sound engineer/speaker builder/car audio way back when and I spend more time on the math and physics of audio that I care to admit and you hit all the bases. The only thing I would of added would be some of the pro's/cons/trade off's of ported enclosures. Things like efficiency, size, distortion vs group delay, phase, f3, harmonics.
You are far too kind. As far as the pros and cons, my original plan was to make a video covering that topic. I just haven't gotten around to it yet. But you're exactly right. I need to make that video.
Great video! You covered a ton of material in a very short period. I started studying the body of work by Theil & Small in the early 1980s. I began plotting freq response charts and then building a lot of "tuned" boxes back then. Amazing how much speakers have changed since then. Would like to see you do a video on passive crossovers as well. Most folks do not understand a simple 6dB/octave let alone an 18 dB/octave x-over or when to use each.
I have always wondered how to the TS parameters to generate the plots. I am sure somebody out their has this posted online, or it is in a book. Can you point me in the right direction?
good information but the editing that makes the video sound like you are talking without breathing is really bad. you might not realize it but if you watch your video you will see how excusing it is to listen to these kinds of video editing, I hope you make better editing that makes the viewer watch the video in a more comfortable way.
Just ported a box this weekend after watching your video! I added 3 smaller ports instead of one large one due to the size of the speaker and allowable drilling on the sub box. It sounds amazing. as I added each port 1-2-3 it got better sounding each time. I did the math and found the correct ratio to surface area and volume of the cone in order to convert to smaller ports. I see a lot of air but barely see the subwoofer speaker moving. I would say this is most efficient sound I can get out of my setup. Tuned to 59.7 hz.
That's sweet, I was looking for information on the exact same idea, and I figured the ratios were easy to calculate. Looks like you found out it's pretty simple.
@@jimjones3287 it seems so theoretically, I tried a design the same way, but I didn't calculate port noise yet. I would see that as being the biggest difference, but haven't put that theory into practice yet. Did you try to search for answers online?
This was a great video. So much information packed into a few minutes. No fluff just the facts and it was explained in simple enough terms you don’t have to be a engineer to understand this information. This is why I follow this channel. Thank you
DIY - maybe take a look at the latest from the '2 Js' "At DIY Audio Guy AND at jimmie james:" a couple notches down. I'll sit tight pending a comment. Thanks---
It can be any shape you want but it comes at the price of efficiency. A round port is the most efficient design possible, from there it comes down to how much efficiency you are prepared to trade for the design you want.
Great video and great explanation! You're explaining this at next level and I'm certainly going to link this video when people start with the subwoofer myths!
Can you explain in Earthquake Sub. There is NO port and Full air tight encloser. Only Passive Diaphram. How he maintain low upto 16 HZ in Supernova MKV-6
I love all the videos that you make I have a couple questions I need to ask you I have Dayton Audio TCP115-4 4" I have a 2008 Scion xB I purchase four of these small woofer what kind of box do you recommend ported or sealed and if you could help me out a little bit thanks
Are you trying to use them as a subwoofer? I don't think I would recommend them for that purpose. This is really designed to pair with a tweeter in a bookshelf speaker for your home.
Beautifully detailed ❤️. I’m a sealed box kind of guy and have been into car audio for over 25+ years. I remember long before “bazooka” tubes, Kicker actually made speakers back in the late 80s that were of an oblong igloo. What was amazing about that design was it include a port, but sort of a hybrid port/sealed enclosure as it came with a port plug. I’m surprised I haven’t seen them since.
Generally speaking a subwoofer is going to perform better in either ported or sealed alignment and even with some of the fence-sitters you'll wind up with either larger than optimum sealed or smaller than optimum ported by just plugging the port.
Port plugs are still a thing in the home theater world. Each of my 15s, for example, have 3 ports and I have the ability to plug each one. This helps with fine tuning to fit your room acoustics.
Wish I knew all this 20 years ago, so many years of bass wasted. Great video bro. Lots of people don’t know and your video help people build an enclosure the right way before making a costly mistake
I've owned both sealed design speakers or air suspension speakers like older Boston acoustic, and I loved the tightness and defined response of bass, was all that traded for the loudness and efficiency of ported designed speakers? Because I believe the sealed design sound a lot more pleasing.
The main problem is that below the tuning frequency, the port goes out of resonance and DOES cancel the speaker output. It is an acoustical short circuit at very low frequencies. That is why a lowcut is needed with a BR woofer - to not over-excite and damage the speaker.
It was interesting to see what's happening to both woofers and the port of an old JBL Northridge 100 at different frequencies. Both woofers are not always in phase, as I had expected. And I heard a lot of rattles and stuff resonating in all kinds of places, at different frequencies.
Based off of your explanation of port size and pressure at different frequencies would it be possibl to adjust the port length with say a consitina setup which is controlled by a stepper motor for different frequency ranges using a frequency controller, e.g. At higher frequency shorten/lengthen the port a few cm (inches - I work in metric) and then at lower frequencies adjust the port again so that the optimal Fb works over a broader range, and the effective frequency range for maximum bass range is widened? Not sure if you understand the question... I'm not technical by any means, but it sounds like a logical approach to expanding the bass range for full enjoyment without compromising choice of the size of the product. Could be overkill, but does such a active port setup exist? Should not be a massively expensive alternative in my mind. Would be interesting to hear your feedback. Very good video BTW, explaining the port logic, even for a non techie like myself!
The humble paddleball is a representation of this. The paddle is the driver, the ball is the air inside the port (in my case, it's instead a passive radiator) the air inside the cabinet is the rubber band. In the ideal scenario, both the ball and paddle should be traveling in opposing directions for as much of the span of said desired wave, as to transmit the most energy into the action. Same as a driver and port air should do the same. The most phase offset I have seen is up to 170°, which is amazing!
More bass? Sure... But, I don't like that sound. It sounds empty without dinamic... Sealed box produce much better sound. I made for myself 12" inch three way sealed boxes. I use 20mm MDF matterial for boxes, 12" inch MONACOR bass, midfle horn and for high tones bullet like high tone speakers. So strong and so warm and powerful sound at the same time. It cost me about 400€ for all of matterial.
I want to order a sound town KALE-112BPW but im so skeptical about the built since its says made of Plywood,but it still looks like a high quality thick plastic finish,. I have a doubt that the plywood made or wood finish cabinet is not durable than the plastic made cabinet for a PA system. Please enlightened me. Thank you
I'm trying to build a Toby design speaker box for 2 10 inch subwoofers but I can't find anywhere where online about the design and I even contacted Toby out of Fort worth texas and they will not share the details with anyone and most people do not know but Toby subwoofers and boxes are the hardest hitting subs in the United States and a lot of people have never even heard of Toby's. But the secret is in the design of the boxes. So check them out and see if you can figure out what there design is for me.
I simulated a dayton woofer in Speaker Box lite. But the diameter of the port is a bit odd. The closent diameter of tube i can find is about 3mm wider. Would that be ok? Is there a tolerance for speaker port size? TIA
Can you give me advice if what's good design for a Hard Kick bass??? Cause here in the Philippines we commonly use Cerwin Vega Design, and mostly are modified... What should we do to make it more better like more harder and can give more output power?? And should we try to put port in the cover or at the back part of the speaker? Cause it's an enclosed type of design. Your reply will be much appreciated, Thanks!
There's actually 2 resonances. One around the mid band where the driver is moving the most and the port and driver are in phase. This happens from a combination of the driver springing against its share of air in the box and the port springing against its share of air (I'm not sure how this air is divided but it is some fraction that changes with speaker parameters, box sizes and tunings). The second resonance is that of the port springing against almost all the air in the box and the driver barely moving. The port output will be 90 degrees behind the output of the back of the speaker (or 270 behind the front). The net 90 degree phase is still additive, especially when the port is making most of the sound. You can actually see two resonances with a mass on a spring and your hand. One where your hand moves up and down a lot and the weight does the opposite of your hand. The other where the weight does most of the motion and your hand moves only enough to make up for losses and may as well be a fixed point. Below the tuning, the port will be making some sound but will begin to act like a leak in the box, meaning the driver will act like it is in free air. In fact it resonates even more at very low frequencies due to the momentum of the air in the box and the port increasing the effective moving mass of the speaker. You can damage your speaker if it's playing too loud down there. I have pa subwoofers that are tuned between 35 and 40 Hz depending on boundary loading and they can move like crazy at 10-15 Hz with just a handful of watts.
Great video. Erin's Audio Corner also had a talk on use of Finite Element Method for design of drivers and enclosures. In it, they mention at one point when there is a high pressure or low pressure at the surface of the cone. Aside from that recent video, there is something else I've been playing with: Changing the Qa (absorption) value in the advanced settings in the box tuning tab. With an absorption value of 20 (what Unibox and BassBox Pro use for an enclosure lined with insulation), this changes the excursion of the driver in such a way as to suggest the absorption makes the box act more like a sealed enclosure, which also allows for more power to be given to the driver before reaching X-max. That may be a fun video, discussing box absorption and the effects on different types of enclosures, rather than the standard of using it to make the Q of the box seem to approach that of a larger box. But, this means some of the negatives surrounding ported enclosures may be able to be combated through the use of insulation. Either way, love the videos. Hope you are having a great weekend.
Definitely something to think about! At some point I'm going to do some experiments with box stuffing. Just need to do some more research and build some enclosures before I jump on that.
Sounds like fun and what could certainly be an awesome learning experience! Especially since I am probably going to have to build my next box so I can have exactly what I'm looking for! My goodness I can't wait to have a Rocking system in my vehicle again!!
What I mentioned on Erin’s video is that steady state the cone moves outward and at it outermost displacement you have the lowest pressure in front of it, not the highest. A big misconception but often not of much consequence. The current video here is really good, great job.
@@Rene_Christensen - The way I remember it is thinking about the system in a ported enclosure. When the cone is at its innermost, it creates the highest potential or vacuum within the enclosure (lowest pressure) which then pulls air in to fill the low pressure as the cone moves outwards. Meanwhile, when the cone is at the outermost displacement, inside the box has the highest pressure at that point because it just filled the box and now that air is pushing back against the cone that is at its peak excursion outwards. But that is just how I think about it to keep it straight. And obviously, what is true on one side is the opposite on the other side (so when low on the inside of the enclosure, it is high on the cone on the outside of the enclosure).
Great science video Mr. DYI. I have an H2 Hummer and want to feel the sound pressure of deep bass. I'm not looking for competition but want to feel the bass pressure not just hear it. This is the equipment I am thinking of getting. Subwoofer = Skar Audio VXF-12 D2 12" 3000 Watt Max 1500 Watts RMS Power Dual 2 Ohm Amp = Sundown Audio SFB-1500D Monoblock Amplifier 1500 Watts RMS Box = ported Box. Maybe i can future-proof and get Sundown Audio SFB-5000D Monoblock Amplifier 3200 Watts RMS. If I plan to get a second subwoofer later on. What do you think? Will one 12-inch at 1200 to 1500 watts give me the Bass pressure I want to feel? Thanks Carlos Exotic
So a subsonic filter can help from playing to low of frequency and bottoming out your subs in a ported box. Is it true that a sealed enclosure wouldn’t need a subsonic filter to be set since there is no port to push all the air out and therefore you always have that air suspension on the subs?
Looking for an opinion on 'sealed' vs. ported and having multiple speakers in the same cabinet, each with what I feel are slightly different specs due to simply that NOTHING is exactly the same as the one right next to it. If a cab has 2 or more in it, should they or should they NOT be 100% sealed apart from each other, EACH ported on a speakerless side of the cab if it is to BE a ported cab and also connected such that they are wired EXACTLY as one unit and NOT from separate channels? I see this all the time and it bothers me that a group of speakers is allowed to act as though there is no care for unity and 100% simultaneous speaker movement. I feel that a group of speakers in a 'sealed' cabinet but not divided as I said allows any of the speakers to act even slightly more of its own accord. An exact replica of what I propose is to take a sample number of identical cabs and connect them together appropriately as above and a couple feet apart and compare the SPL, 'feel' and simultaneous motion of all via slow-motion video. Thanks for any response---🍀😐😵💫
That's a good question. Definitely something that has a much more involved answer than I could possibly give in the comments section. We might want to talk about it in our next live stream.
Thanks for answering - I consider myself 2 b halfway smart so we'll round up today and so I subscribed to this and the Toids channel and if I can't figure out how to watch, comment and such I'll just be happy with what is discussed and the resulting comments. I'd click on 'Live' and/or 'Streams' on each channel Monday night at 8 PM. I don't wanna join Facebook or anything. YT is enough, lol! PS---"...and compare the SPL, 'feel' and simultaneous motion of all via slow-motion video." Shoulda said 'and compare the SPL, 'feel' and simultaneous motion of all TO THOSE OF a multi-sub, undivided cab's subs via slow-motion video with the same exact program material. 🌵🍄🍗
Such a great info-dump. Totally new to this, so trying to pick up some bits. I know you covered a lot, but as I sip information, and don't get a chance to swallow, my thimble just chokes then overflows. I'm left with a bit of the flavor, but most of the nutrition is gone (when people cover advanced topics and go _so_ fast!) I realize for much of your audience this is all 'old hat', nothing new, no need for pace-pause-repeat [[Teaching -->Learning]] because they all know it already. Hey, maybe I can watch 6 more times, keep stopping it and take notes! Meanwhile, thanks for putting the info out there.
Is that decoupled from sea level pressure or not? As I can imagine that all of the weight from the air on top might increase the weight? Or am I completely misunderstanding how pressure and weight work?
@@DeltaNovum Sorry, I meant to say at sea-level. Most people live at elevations closer to sea-level. I believe one reason the number of 14.5 psi is used as one Atmosphere / bar, because that measurement would be accurate to a larger number of people, slightly above sea-level, whereas 14.69 psi is the measurement at sea-level. I like to mess around with these numbers when thinking about work problems, with vacuum pumps, and air compressors, but awhile back, I wanted to make a really cool Bass cabinet and I ended up making a sealed cabinet, because the math for a properly ported speaker would be more difficult to get right. Now you can get cabinets that have all the math worked out, and you just use the types of speakers they specify.
@@DeltaNovum It's also pretty interesting that you can measure how much air weighs, by weighing an air compressor tank, both empty to atmospheric pressure, and compare it to a full tank of known volume and pressure, like in gallons, which is 231 cubic inches per gallon. With some tanks, you could see a difference of approximately 2 pounds, just by pulling a vacuum on a 200 gallon tank, weigh it, and let the air back in, and it will pull 2 pounds of air, back into the tank. But a tank that large is very heavy, so 2 pounds is such a small difference, compared to the heavy steel air reciever / tank. Go make a cool speaker cabinet for yourself, it will be interesting.
From my experience, with a 12 inch kicker sub, I’ve tried both ported and non ported. Non ported hit harder the the system I have and there’s a lot more resonance. Maybe the ported box I tried was made for a lot more power, idk
I am doing now a x2 12 inch Kickers L5, and DIY a ported box with a port in the middle. I had one of them in a sealed box, and sound was good, but heard same speaker in a ported box, and the sound and bass was 10 times more intense and deep then mine. So now i building it.
....Also.... Could you perhaps do a video like this about Transmission Line designs? I think there are very few ..and letting people know why that is .. or how it works differently could be of value to Audio fans. =)
Hey thank you I needed this video I'm doing a spl build for next year and this put everything into perspective, very detailed 👌 been following you for a year now and always something to learn 😀
About the lower end of frequency spectrum you mentioned, I've been looking for cheap subs, and noticed that some of these specify lower limit as 50 or even 60 Hz. Isn't this very high for 8" diameter sub? Or are these manufacturers the rare example of cheap manufacturer posting real specs? (Taga TSW-60 vs Jamo 210 )
Hey I got a question: If the air vibrating in the tube or port is vibrating at the same frequency as the speaker cone, why doesn't this cause phase cancellation? In other words, if the "push" of the cone is depressurizing the enclosure space and thus sucking in the air that is in the port, this would seem to my layman understanding like it would be the same as having a cone that is out of phase with your primary cone. Why is it that this is not the case and that we instead are getting a result that is in phase with the action of the cone? Thank you for the great video.
At the tuning frequency they are both in phase. Starting at the tuning frequency. If you start to decrease the frequency, the two will gradually become out of phase. This is why the drop off in output is so dramatic below the tuning frequency.
I had a doubt How do people tune a box with like a 3" port which isn't long enough like 30cm, and still achieve low HZs Cause in WinISD, it says like make the port 1m long I saw a build with Tang Band W6 in a 26.6L box , 3" port and 29cm long flared port Still achieves 31hz when same on WinISD says something like a 932mm port
Whether the out of phase sound from the back of an element cancels out the sound from the front will depend on the length of the path it has to take. You can theoretically tune an enclosure to get these two waves in sync at certain frequencies, and even though we don't do that and the sounds we play are rarely just a single frequency - we'll probably very rarely see 100% destructive interference
I'm a newbie at home theater and have a question. I have a vented port on my sub and have "chuffing". Will the polyfill reduce the amount of chuffing? Thx and enjoyed your vlog!
I recently started watching your channel. First rate work , fairly easy to understand , should be very helpful . I recently started the planning stage for a low power bass cabinet (20 watts ). Being low power, efficiency will be a big deal . When installing 2 different speakers (2-4'' mid bass and a single 10'') in the same cabinet . How do you determine the port size ?
3 questions: 1. What if we placed the port OUTSIDE of the box? (literally thinking outside the box, pun intended) 2. Can a port be bend too? Gradual bend vs. abrupt bend? 3. Would it be beneficial to dampen the port by glueing anti resonance material to the outside walls of the tube?
@@DIYAudioGuy 1.) Anything special to consider when the port is outside? 2.) Does the bend in a port have a big effect on something (if so, what?)// like can I make a "snake shaped" port which is flat on top of my box? 3.) I was thinking about that material which you can use to dampen the inside of car doors for example.
Liked the video. But something that is kinda irksome to me is this notion that Everyone has the same ears, and cannot hear below 20 Hz or above 20,000 Khz. That is simply not true as I can hear down to around 12 Hz, and up to 26,000 Khz, proven by not one but 2 ear doctors. Now even though I can hear above 20K herz it isn't pleasant I must say. But the lower frequencies are enjoyable. Not to mention even if you can't hear them you can feel them. And music is meant to be felt not just heard.
Speaker port's for speaker port's but the science here is strong! So strong that I haven't come across science channels that get it this correct! Buddy, I'm impressed... The scientific community could learn something from this video and then some... The majority of people don't know how much mass is weighing apon them... And a tube is never empty!
Hey Guys, im Planing to make a small Jukebox for my soon to be born daughter. I was wondering if a Port makes sense for a full range 3" speaker. My Plan was to put two Speaker oposit to each other but in seperate chambers. Each speaker has its own Air Mass. Im Planing to 3D Print the Enclosure so Geometry can be wild. Modeling it is also not an issue.
Is there any difference between the resonance frequency of the port itself and the resonance frequency of the system (i.e., the box plus the port)? I have come across some texts that describe them as distinct frequencies. Thanks for your help!
I have found that the recommended enclosure on the Memphis website is a very goo design. If you want a custom design you can find my prices here: diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html
Will it work if I parallel two identical subwoofers, but put it in 2 different 4order bandpass enc. box that the ports of each is tuned in different frequency range i.e. one is tuned to 20hrz and the other is at 60hrz?
Why is it so hard to find a decent box for two 15s. I cant even find a local builder that will do a 6 cubic foot box tuned to 32hz. Find a few way too small inclosures thats it. Theres much more choices for 12s. But i already own my 15s ones got a 2.5 cubic foot box sealed the second 0ne i had built 3 cubic foot tuned to 32hz sounds great but my sub is a single coil 4ohm. I want the second to drop to 2ohm.
I want to build 2 speaker boxes for outdoor activities and I want to use 2 15" subwoofers for each box with 2 midrange speakers and tweeters in each box how box should the box be ty
That's a question for Toids DIY. That kind of build is right up his alley, you can join his forum and find helpful people that can help you figure out how to do it.
So much awesome info. I always built boxes to hrtz by size I would degree the main port tunnel. From opening it up to a smaller opening or a very small opening to a larger opening. It works phenomenally well and just a few degrees makes a huge difference
you say its not for making more sound they you say its for resonating like a speaker cone, so it does in fact produce its own sound if this is correct. i have always felt like its there to make better sound and alleviate the air pressure from effecting the sub. you can always feel the air moving from the port.
If your port is being blocked does it reduce proformance? ( I have a dual 12 build, my port is facing towards the back of my seats with little to no room left between the seat and the box.
Yes, but, seats are not brick walls so sound does make it through. If you can move the box (even just to test it) try moving and seeing if there is a difference.
Give me a link to understand how to make my home sub. the speaker is jbl a1300hi.. what is the best box plan for this one? I want to take a big spl output in low power low moving.
I built a huge sub box for 2 15 inch subs but ran out of 3 quarter mdf wood for it so I left on side open and just have tucked it against the back seat of my van tbh I dont know what to do make it sealed put in a port or a crazy idea make a port that goes under the seat atleast it souds good and vibrates my guts the way it is lol
Great vid as always. I’m always learning and experimenting and learning some more. I like a 25-28 hz tune for the lows ya some day it’s a waist but I’m always changing my port tuning about every 2 months or so anyhow. Motorized port??
I think it would be cool to build a box with a removable panel, just cut a hole in the panel and stick in an arrow port. Then you could swap out ports anytime you wanted.
I started a business a year ago building custom bass boxes with 0 prior knowledge but I studied your videos and utilized all the knowledge I took from them. Now I have a solid reputation for my boxes performing perfectly
That is awesome! Nice work.
That's really cool! More power to ya! 👊
This awesome..
what about custom bass guitar cabs?
Why some boxes have membrane instead of ooen hole?
How come we never had this in school ?
Most likely you did, you just never applied the science to speakers 🔊 Or you just happen to be sleeping or skip school that day… 😅
Even in health class, you learned about a diaphragm this is working in the same way if you pulled on the diaphragm pulled in air if you pushed on the diaphragm and pushed out air..
My issue with ports- is you come to find out half the songs sound like crap and you find yourself playing the same 5 songs that sound "great" in your range, not the music you enjoy- IF you listen to actual music. Thats why i am going back to sealed box this build.
Hey Jim let me help you out there, you are judging ported enclosures and the mechanism based on poorly made or specifically designed ports. IF you make the enclosure Large enough, and you design the port to have the proper area and length, then you can make better and louder sound across the board. Period. If you make the box large enough and design it properly, then you will have absolutely better sound. The cost is more space needed for the box assuming you design it for “full spectrum”. Mainly, where you tune a subwoofer to in frequency it can be nearly twice as loud with the same or better quality at the same volume level. BELOW the tuned frequency the subwoofer won’t play as it doesn’t have enough “suspension” from the air. That’s the easiest way to explain it. Sealed will make more similar suspension across the board of frequencies. Here is the key: to make it sound better and play louder at good quality, you will need to tune the box to a frequency basically low enough that it’s as low as you would want. Now if you want high frequency sound and you tune a box low, it may sound worse. One thing you can always do is to use a digital or amp filter to remove sounds you don’t like. Now to tune a subwoofer to like 26-28 hertz then you will easily cover most frequencies you would like to hear for most music. The rest would be adjusting the digital filters because songs may have notes or sounds in frequencies that you dont really want and they’re noise. Now if you are super picky you can still port the sub and tune it to 18-20 hertz. That’s as low as a human could hear, and generally it can play much louder across the board up until you get to higher notes which would usually be equal to what a sealed subwoofer would play without clipping or distortion or whatever else. But to design it that low it won’t be as loud as a higher tune at max volume. Many prefabricated boxes and designs tune to 36-40 hertz to get max loudness but they miss the key low notes. They also do this because to port lower you need a larger box with the correct well designed port area and length to match. So look you can easily get louder sound overall with zero loss across the spectrum in any frequency compared to sealed subwoofers as long as you tune it low to the minimum frequency humans can hear at. Anything else you do or want can be adjusted by filters to remove the lower notes for certain music, remove higher notes, and even out the volume across the board even. You also want to ALWAYS cut out certain frequencies on your amp before the sub, which would be anything below hearing level and anything above whatever the recommended levels are for your sub. I dont personally know what the cutoff should be for highest frequencies but it’s below 80-100 hertz for sure for most subwoofers. Anyways, if you have the room for an appropriate ported box and you tune and design it properly with enough size and port design, then you can play much better than any sealed box and louder across most if not all notes. The key there is space for the box, the amp you have, the songs and sounds you like, and the availability or affordability of the subwoofer and it’s RMS level of energy it can take. Like many premade boxes are shitty and can only play to 40hertz and up. A ported box should be studied and compared by sound level and curve, and the type of music that you like to play. Most people end up realizing without clipping they are restricted by the energy their alternator and battery can handle. So the best option is to go for bigger subwoofers, and ported with a large box if they want lower notes and full spectrum. Many people actually want 20 hertz for hip hop. The thing is you can change a port to have a better curve you like and be louder with all of the notes by tuning it higher and cutting off lower notes. Anything below the cutoff curve is a sharp decline and is almost impossible to play after 1-2 hertz below. You MUST program your amp to cut off all frequencies below your subwoofer boxes tuning level, and always should cut off any sounds below the frequency of human hearing capabilities. Mainly, if you know your music you can know it’s okay to tune it to 35 or 40 if you don’t want anything lower to play anyways. You should be cutting off the minimum based on tuning and maximum based on the limits of the sub and the general maximums based on an instrument easy Google search. Then a ported sub is still superior or equal at any given frequency at its tuning level or above to a sealed sub, assuming you build the box correctly and don’t make it too small. But listen many people actually have a subwoofer and amp setup that can play as loud as they want at every frequency they want without clipping their amp or overpowering anything and draining their car. In that case as long as you have a pass through filter you can also use your audio input or the amplifier to adjust the filters to your desires based on what you listen to or even have different filters for different music. There is nothing inherently worse about a ported sub and a ported sub if built to the appropriate size and shape will always be superior in its capabilities even when it’s tuned to the lowest possible frequency of human hearing. If you have more capabilities for clean sound at a louder volume across the board, or in the ranges you listen to, then you can always adjust the filters to decrease the sound signal sent for certain frequencies. If you don’t have room for the large box in your car but have room for larger subs and more expensive subs and have the amplifier and alternator to fuel it, then you would definitely want sealed. It’s also more affordable and more simple and has a generally good sound curve. What we really need to be considering here is not what attributes ported boxes have, but rather what trade offs we need to make and what benefits we need to make. Frankly anyone who wants louder sounds across the board full spectrum and they cannot afford higher watt subs or amps, or their car doesn’t have the electrical output, and they have the room for a bigger box then they will always benefit from getting a ported sub tuned to a lower range especially if it’s done to the lowest frequency that can be heard. Then if someone doesn’t listen to music that uses lower notes, or maybe even they already block lower frequencies because they don’t like them in their music, then they can have louder subs ported to a higher range cutoff with a smaller box. If not, then they could still tune it to a lower frequency if they make a large enough box designed properly. The problem is ported subs are always associated with scam sales of boxes super small with horrible designs that are tuned to 40hz or higher which cuts out major frequencies if not the most important for some, and people don’t realize this so they don’t change their pass through filter higher and their sub free wobbles and bottoms out and damages itself. Ported subs can be very much like sealed subs but louder when designed correctly. The question is whether you have space for a box, whether you need frequencies and how low of frequencies do you need, and whether you want louder noise.
Great description of the beauty of the band pass design. I have rarely heard it so well articulated. Just a pleasure to watch and listen to. Some of us are old hats with some of the science, but hearing it explained succinctly and clearly is still a beautiful experience. Thanks for that.
Thank you!
Wow, super impressed! I've never seen so much correct information condensed into 10 minutes on audio as this. In a sea of audio half truths this was refreshing to see not a single misunderstanding of the physics/engineering of how ports operate. My background is live sound engineer/speaker builder/car audio way back when and I spend more time on the math and physics of audio that I care to admit and you hit all the bases. The only thing I would of added would be some of the pro's/cons/trade off's of ported enclosures. Things like efficiency, size, distortion vs group delay, phase, f3, harmonics.
You are far too kind. As far as the pros and cons, my original plan was to make a video covering that topic. I just haven't gotten around to it yet. But you're exactly right. I need to make that video.
Great video!
You covered a ton of material in a very short period. I started studying the body of work by Theil & Small in the early 1980s. I began plotting freq response charts and then building a lot of "tuned" boxes back then. Amazing how much speakers have changed since then. Would like to see you do a video on passive crossovers as well. Most folks do not understand a simple 6dB/octave let alone an 18 dB/octave x-over or when to use each.
I tried reading the original papers. I don't have enough background in the subject to understand them.
I have always wondered how to the TS parameters to generate the plots. I am sure somebody out their has this posted online, or it is in a book. Can you point me in the right direction?
good information but the editing that makes the video sound like you are talking without breathing is really bad. you might not realize it but if you watch your video you will see how excusing it is to listen to these kinds of video editing, I hope you make better editing that makes the viewer watch the video in a more comfortable way.
Yes, I took Science classes in school, but, no, I don't remember much of it at all. I'm a prime example of youth being wasted on the young.
Now that I'm old I understand what is meant by that. Yep youth was wasted on me as well.
I flip my speaker box cone facing up, place some rice on the cone and play a test tone. When the rice stop moving that's my tuning frequency.
Yep!
Just ported a box this weekend after watching your video! I added 3 smaller ports instead of one large one due to the size of the speaker and allowable drilling on the sub box. It sounds amazing. as I added each port 1-2-3 it got better sounding each time. I did the math and found the correct ratio to surface area and volume of the cone in order to convert to smaller ports. I see a lot of air but barely see the subwoofer speaker moving. I would say this is most efficient sound I can get out of my setup. Tuned to 59.7 hz.
That's sweet, I was looking for information on the exact same idea, and I figured the ratios were easy to calculate. Looks like you found out it's pretty simple.
is adding an extra identical aero port the same as making the original port longer?
@@jimjones3287 it seems so theoretically, I tried a design the same way, but I didn't calculate port noise yet. I would see that as being the biggest difference, but haven't put that theory into practice yet. Did you try to search for answers online?
Why do you have it tuned to 60 Hertz?
This was a great video. So much information packed into a few minutes. No fluff just the facts and it was explained in simple enough terms you don’t have to be a engineer to understand this information. This is why I follow this channel. Thank you
Thank you!
hes like bill nigh the science guy... only cooler!
Yes, much cooler.
Bill bye, Justin HEY!
DIY - maybe take a look at the latest from the '2 Js' "At DIY Audio Guy AND at jimmie james:" a couple notches down. I'll sit tight pending a comment. Thanks---
Got down off my horse. Man I couldn’t get to the stop button until almost the end of the video. My ears are hurting.
Can it be a Hexagon or Star shaped port? Even my initials? Good video.
Yes.
Manufacturers are forever playing with their port sizes, lengths, flares, openings and whatever else they can come up with.
Speaking of Stars,BEARDIE IN THA HOUSE!!!!
It can be any shape you want but it comes at the price of efficiency. A round port is the most efficient design possible, from there it comes down to how much efficiency you are prepared to trade for the design you want.
Any suggestions for getting a slot port to stop chuffing without completely redesigning my box?
Great video and great explanation! You're explaining this at next level and I'm certainly going to link this video when people start with the subwoofer myths!
You are far to kind!
Can you explain in Earthquake Sub. There is NO port and Full air tight encloser. Only Passive Diaphram. How he maintain low upto 16 HZ in Supernova MKV-6
I am not familiar with that subwoofer. Sounds like it is a passive radiator. ua-cam.com/video/v4rAkxck2_Q/v-deo.htmlsi=kEcg2rGPtA70vIdV
I learned a lot, thanks.
Glad to hear it!
I love all the videos that you make I have a couple questions I need to ask you I have Dayton Audio TCP115-4 4"
I have a 2008 Scion xB I purchase four of these small woofer what kind of box do you recommend ported or sealed and if you could help me out a little bit thanks
Are you trying to use them as a subwoofer? I don't think I would recommend them for that purpose. This is really designed to pair with a tweeter in a bookshelf speaker for your home.
Love the bass use to enclosures in the 90s on my metro
Beautifully detailed ❤️. I’m a sealed box kind of guy and have been into car audio for over 25+ years. I remember long before “bazooka” tubes, Kicker actually made speakers back in the late 80s that were of an oblong igloo. What was amazing about that design was it include a port, but sort of a hybrid port/sealed enclosure as it came with a port plug. I’m surprised I haven’t seen them since.
I remember those.
Generally speaking a subwoofer is going to perform better in either ported or sealed alignment and even with some of the fence-sitters you'll wind up with either larger than optimum sealed or smaller than optimum ported by just plugging the port.
@@Mr.Robert1 some were , depending on model some weren’t
What was the model , I never knew and would like to see it if it’s on line
Port plugs are still a thing in the home theater world.
Each of my 15s, for example, have 3 ports and I have the ability to plug each one. This helps with fine tuning to fit your room acoustics.
Wish I knew all this 20 years ago, so many years of bass wasted. Great video bro. Lots of people don’t know and your video help people build an enclosure the right way before making a costly mistake
👍
Next level stuff... Love this videos... Everything Audio makes sense for a sound fanatic as myself... Keep it up...🤩
Thank you! Will do!
Longer is better than Larger
it's all done for impedance matching!
kat knows stuff....goot,,,, so,,, which is most accurate subwoofer,,, no port,, or,,, port
That is a great question, join us on our next live show and we will try to give a detailed answer: bit.ly/3PYKG5P
18inch 103 voice coil diameter what type of box is good for it that will give a big sound
I will depend on all of the TS parameters. diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html
Drums will not sound correctly with a resonant system, it is mainly a loud “boom” box.
That sounds like a testable hypothesis.
Great video but the speedtalking makes me nervous.
I would love a single 15" band pass ported box I can never find one 😢
You'll probably have to build one or pay someone to build one. You're very unlikely to find a prefab 15 bandpass enclosure.
I've owned both sealed design speakers or air suspension speakers like older Boston acoustic, and I loved the tightness and defined response of bass, was all that traded for the loudness and efficiency of ported designed speakers? Because I believe the sealed design sound a lot more pleasing.
A lot of people like that sound.
The main problem is that below the tuning frequency, the port goes out of resonance and DOES cancel the speaker output. It is an acoustical short circuit at very low frequencies. That is why a lowcut is needed with a BR woofer - to not over-excite and damage the speaker.
Yep, very sharp roll-off below tuning frequency.
OMG 10 mins of non stop technical words, need hours to understand the basics of the port, wonderful explanation!! thanks for sharing the knowledge!!!
Glad you enjoyed it!
It was interesting to see what's happening to both woofers and the port of an old JBL Northridge 100 at different frequencies. Both woofers are not always in phase, as I had expected.
And I heard a lot of rattles and stuff resonating in all kinds of places, at different frequencies.
Odd
Great info
Thanks
Based off of your explanation of port size and pressure at different frequencies would it be possibl to adjust the port length with say a consitina setup which is controlled by a stepper motor for different frequency ranges using a frequency controller, e.g. At higher frequency shorten/lengthen the port a few cm (inches - I work in metric) and then at lower frequencies adjust the port again so that the optimal Fb works over a broader range, and the effective frequency range for maximum bass range is widened? Not sure if you understand the question... I'm not technical by any means, but it sounds like a logical approach to expanding the bass range for full enjoyment without compromising choice of the size of the product. Could be overkill, but does such a active port setup exist? Should not be a massively expensive alternative in my mind. Would be interesting to hear your feedback. Very good video BTW, explaining the port logic, even for a non techie like myself!
The humble paddleball is a representation of this. The paddle is the driver, the ball is the air inside the port (in my case, it's instead a passive radiator) the air inside the cabinet is the rubber band. In the ideal scenario, both the ball and paddle should be traveling in opposing directions for as much of the span of said desired wave, as to transmit the most energy into the action. Same as a driver and port air should do the same. The most phase offset I have seen is up to 170°, which is amazing!
That is a cool trick.
More bass? Sure...
But, I don't like that sound. It sounds empty without dinamic...
Sealed box produce much better sound. I made for myself 12" inch three way sealed boxes. I use 20mm MDF matterial for boxes, 12" inch MONACOR bass, midfle horn and for high tones bullet like high tone speakers.
So strong and so warm and powerful sound at the same time. It cost me about 400€ for all of matterial.
I want to order a sound town KALE-112BPW but im so skeptical about the built since its says made of Plywood,but it still looks like a high quality thick plastic finish,. I have a doubt that the plywood made or wood finish cabinet is not durable than the plastic made cabinet for a PA system. Please enlightened me. Thank you
Just wanted to find out what those tubes on my speaker do. This video got me more confused than when I started! 😂😂
😅🎉
I'm trying to build a Toby design speaker box for 2 10 inch subwoofers but I can't find anywhere where online about the design and I even contacted Toby out of Fort worth texas and they will not share the details with anyone and most people do not know but Toby subwoofers and boxes are the hardest hitting subs in the United States and a lot of people have never even heard of Toby's. But the secret is in the design of the boxes. So check them out and see if you can figure out what there design is for me.
I simulated a dayton woofer in Speaker Box lite. But the diameter of the port is a bit odd. The closent diameter of tube i can find is about 3mm wider. Would that be ok? Is there a tolerance for speaker port size? TIA
Can you give me advice if what's good design for a Hard Kick bass??? Cause here in the Philippines we commonly use Cerwin Vega Design, and mostly are modified...
What should we do to make it more better like more harder and can give more output power?? And should we try to put port in the cover or at the back part of the speaker? Cause it's an enclosed type of design.
Your reply will be much appreciated, Thanks!
"..Akleemated.."?! You Yanks speak funny. It's not cleemate, it's climate so "Ak..cl..eye...ma...tized". (Just stirring, we still understand you fine)
Everybody talks about more bass and nobody talks about more fidelity
The struggle is real.
Fidelity is everything.
@@jamesconnors5653. 1000%!!!
There's actually 2 resonances. One around the mid band where the driver is moving the most and the port and driver are in phase. This happens from a combination of the driver springing against its share of air in the box and the port springing against its share of air (I'm not sure how this air is divided but it is some fraction that changes with speaker parameters, box sizes and tunings).
The second resonance is that of the port springing against almost all the air in the box and the driver barely moving. The port output will be 90 degrees behind the output of the back of the speaker (or 270 behind the front). The net 90 degree phase is still additive, especially when the port is making most of the sound.
You can actually see two resonances with a mass on a spring and your hand. One where your hand moves up and down a lot and the weight does the opposite of your hand. The other where the weight does most of the motion and your hand moves only enough to make up for losses and may as well be a fixed point.
Below the tuning, the port will be making some sound but will begin to act like a leak in the box, meaning the driver will act like it is in free air. In fact it resonates even more at very low frequencies due to the momentum of the air in the box and the port increasing the effective moving mass of the speaker. You can damage your speaker if it's playing too loud down there. I have pa subwoofers that are tuned between 35 and 40 Hz depending on boundary loading and they can move like crazy at 10-15 Hz with just a handful of watts.
Yes, I've only barely scratched the surface in this video.
Great video. Erin's Audio Corner also had a talk on use of Finite Element Method for design of drivers and enclosures. In it, they mention at one point when there is a high pressure or low pressure at the surface of the cone.
Aside from that recent video, there is something else I've been playing with: Changing the Qa (absorption) value in the advanced settings in the box tuning tab. With an absorption value of 20 (what Unibox and BassBox Pro use for an enclosure lined with insulation), this changes the excursion of the driver in such a way as to suggest the absorption makes the box act more like a sealed enclosure, which also allows for more power to be given to the driver before reaching X-max.
That may be a fun video, discussing box absorption and the effects on different types of enclosures, rather than the standard of using it to make the Q of the box seem to approach that of a larger box.
But, this means some of the negatives surrounding ported enclosures may be able to be combated through the use of insulation.
Either way, love the videos. Hope you are having a great weekend.
Definitely something to think about! At some point I'm going to do some experiments with box stuffing. Just need to do some more research and build some enclosures before I jump on that.
Sounds like fun and what could certainly be an awesome learning experience!
Especially since I am probably going to have to build my next box so I can have exactly what I'm looking for! My goodness I can't wait to have a Rocking system in my vehicle again!!
What I mentioned on Erin’s video is that steady state the cone moves outward and at it outermost displacement you have the lowest pressure in front of it, not the highest. A big misconception but often not of much consequence. The current video here is really good, great job.
@@Rene_Christensen - The way I remember it is thinking about the system in a ported enclosure. When the cone is at its innermost, it creates the highest potential or vacuum within the enclosure (lowest pressure) which then pulls air in to fill the low pressure as the cone moves outwards. Meanwhile, when the cone is at the outermost displacement, inside the box has the highest pressure at that point because it just filled the box and now that air is pushing back against the cone that is at its peak excursion outwards. But that is just how I think about it to keep it straight. And obviously, what is true on one side is the opposite on the other side (so when low on the inside of the enclosure, it is high on the cone on the outside of the enclosure).
Great science video Mr. DYI. I have an H2 Hummer and want to feel the sound pressure of deep bass. I'm not looking for competition but want to feel the bass pressure not just hear it.
This is the equipment I am thinking of getting.
Subwoofer = Skar Audio VXF-12 D2 12" 3000 Watt Max 1500 Watts RMS Power Dual 2 Ohm
Amp = Sundown Audio SFB-1500D Monoblock Amplifier 1500 Watts RMS
Box = ported Box.
Maybe i can future-proof and get Sundown Audio SFB-5000D Monoblock Amplifier 3200 Watts RMS.
If I plan to get a second subwoofer later on.
What do you think? Will one 12-inch at 1200 to 1500 watts give me the Bass pressure I want to feel?
Thanks Carlos Exotic
You want a pair of 15s in a sealed box with a hellafied amp.
Hexibase did a great job explaining port variations. This is another good example for explanation 👍🏻
His stuff is entertaining.
So a subsonic filter can help from playing to low of frequency and bottoming out your subs in a ported box. Is it true that a sealed enclosure wouldn’t need a subsonic filter to be set since there is no port to push all the air out and therefore you always have that air suspension on the subs?
Looking for an opinion on 'sealed' vs. ported and having multiple speakers in the same cabinet, each with what I feel are slightly different specs due to simply that NOTHING is exactly the same as the one right next to it. If a cab has 2 or more in it, should they or should they NOT be 100% sealed apart from each other, EACH ported on a speakerless side of the cab if it is to BE a ported cab and also connected such that they are wired EXACTLY as one unit and NOT from separate channels?
I see this all the time and it bothers me that a group of speakers is allowed to act as though there is no care for unity and 100% simultaneous speaker movement. I feel that a group of speakers in a 'sealed' cabinet but not divided as I said allows any of the speakers to act even slightly more of its own accord. An exact replica of what I propose is to take a sample number of identical cabs and connect them together appropriately as above and a couple feet apart and compare the SPL, 'feel' and simultaneous motion of all via slow-motion video. Thanks for any response---🍀😐😵💫
That's a good question. Definitely something that has a much more involved answer than I could possibly give in the comments section. We might want to talk about it in our next live stream.
Thanks for answering - I consider myself 2 b halfway smart so we'll round up today and so I subscribed to this and the Toids channel
and if I can't figure out how to watch, comment and such I'll just be happy with what is discussed and the resulting comments.
I'd click on 'Live' and/or 'Streams' on each channel Monday night at 8 PM. I don't wanna join Facebook or anything. YT is enough, lol!
PS---"...and compare the SPL, 'feel' and simultaneous motion of all via slow-motion video."
Shoulda said 'and compare the SPL, 'feel' and simultaneous motion of all TO THOSE OF a multi-sub, undivided cab's subs via slow-motion video
with the same exact program material. 🌵🍄🍗
Such a great info-dump. Totally new to this, so trying to pick up some bits. I know you covered a lot, but as I sip information, and don't get a chance to swallow, my thimble just chokes then overflows. I'm left with a bit of the flavor, but most of the nutrition is gone (when people cover advanced topics and go _so_ fast!) I realize for much of your audience this is all 'old hat', nothing new, no need for pace-pause-repeat [[Teaching -->Learning]] because they all know it already. Hey, maybe I can watch 6 more times, keep stopping it and take notes!
Meanwhile, thanks for putting the info out there.
👍
As I understand it, air weighs an average of .075 pounds per cubic foot.
Is that decoupled from sea level pressure or not? As I can imagine that all of the weight from the air on top might increase the weight? Or am I completely misunderstanding how pressure and weight work?
@@DeltaNovum
Sorry, I meant to say at sea-level.
Most people live at elevations closer to sea-level.
I believe one reason the number of 14.5 psi is used as one Atmosphere / bar, because that measurement would be accurate to a larger number of people, slightly above sea-level, whereas 14.69 psi is the measurement at sea-level.
I like to mess around with these numbers when thinking about work problems, with vacuum pumps, and air compressors, but awhile back, I wanted to make a really cool Bass cabinet and I ended up making a sealed cabinet, because the math for a properly ported speaker would be more difficult to get right.
Now you can get cabinets that have all the math worked out, and you just use the types of speakers they specify.
@@richtomlinson7090 thanks for clarifying and nice! Good luck on your endeavours!
@@DeltaNovum It's also pretty interesting that you can measure how much air weighs, by weighing an air compressor tank, both empty to atmospheric pressure, and compare it to a full tank of known volume and pressure, like in gallons, which is 231 cubic inches per gallon.
With some tanks, you could see a difference of approximately 2 pounds, just by pulling a vacuum on a 200 gallon tank, weigh it, and let the air back in, and it will pull 2 pounds of air, back into the tank.
But a tank that large is very heavy, so 2 pounds is such a small difference, compared to the heavy steel air reciever / tank.
Go make a cool speaker cabinet for yourself, it will be interesting.
Musk approved
👍
🔴So how much bigger should the box be above the manufactured recommended size
Interesting. But plz skip the background muzac.
Wavelength is not measured in hertz...just saying.
From my experience, with a 12 inch kicker sub, I’ve tried both ported and non ported. Non ported hit harder the the system I have and there’s a lot more resonance. Maybe the ported box I tried was made for a lot more power, idk
I am doing now a x2 12 inch Kickers L5, and DIY a ported box with a port in the middle. I had one of them in a sealed box, and sound was good, but heard same speaker in a ported box, and the sound and bass was 10 times more intense and deep then mine. So now i building it.
The fat quality thick bass came from the back of the speaker not in front the hole should be centered on the magnet of the speaker not side etc
I prefer sealed boxes. They don't go as deep, but are faster, better defined and an easier load for the amp.
....Also.... Could you perhaps do a video like this about Transmission Line designs? I think there are very few ..and letting people know why that is .. or how it works differently could be of value to Audio fans. =)
I have downloaded hornresp, as soon as I get it figured out I will post a video.
@@DIYAudioGuy ...🙏🙏🙏.. Ive heard details that lead me to think its a pain in the ass... butt I think it'll be worth while.. I mean.. PMC thinks so..
Whats its the postive and negativ solotion . of sliseport than Aeroport
Wow alot of good info, I never saw a port like a passive radiator before but it makes sense the way you explained it. thanks!
Glad you liked it!
I just discovered your channel. Out-effin-standing work, info, and presentation! New subscriber here!
Welcome to the party.
Hey thank you I needed this video I'm doing a spl build for next year and this put everything into perspective, very detailed 👌 been following you for a year now and always something to learn 😀
Glad it was helpful!
Keep up the good work
About the lower end of frequency spectrum you mentioned, I've been looking for cheap subs, and noticed that some of these specify lower limit as 50 or even 60 Hz. Isn't this very high for 8" diameter sub? Or are these manufacturers the rare example of cheap manufacturer posting real specs? (Taga TSW-60 vs Jamo 210 )
That number means nothing, it is just marketing.
Hey I got a question: If the air vibrating in the tube or port is vibrating at the same frequency as the speaker cone, why doesn't this cause phase cancellation? In other words, if the "push" of the cone is depressurizing the enclosure space and thus sucking in the air that is in the port, this would seem to my layman understanding like it would be the same as having a cone that is out of phase with your primary cone. Why is it that this is not the case and that we instead are getting a result that is in phase with the action of the cone? Thank you for the great video.
At the tuning frequency they are both in phase. Starting at the tuning frequency. If you start to decrease the frequency, the two will gradually become out of phase. This is why the drop off in output is so dramatic below the tuning frequency.
I have seen a 12 inch driver shake the building in the right cabinet.
I had a doubt
How do people tune a box with like a 3" port which isn't long enough like 30cm, and still achieve low HZs
Cause in WinISD, it says like make the port 1m long
I saw a build with Tang Band W6 in a 26.6L box , 3" port and 29cm long flared port
Still achieves 31hz when same on WinISD says something like a 932mm port
I get what you are saying. Hard to no for sure without testing and measuring.
In other words the port makes the mass of air (sound) in phase with the front of the con
Whether the out of phase sound from the back of an element cancels out the sound from the front will depend on the length of the path it has to take. You can theoretically tune an enclosure to get these two waves in sync at certain frequencies, and even though we don't do that and the sounds we play are rarely just a single frequency - we'll probably very rarely see 100% destructive interference
Yep, transmission line.
In Russian the spider would be centering washer
I'm a newbie at home theater and have a question. I have a vented port on my sub and have "chuffing". Will the polyfill reduce the amount of chuffing? Thx and enjoyed your vlog!
Probably not, the port needs to be larger. One option is to turn the sub so that the port faces a wall, then the chuffing may not be audible.
You just scored yourself a subscriber my good man. Amazing video, thank you!!
Thanks!
I recently started watching your channel. First rate work , fairly easy to understand , should be very helpful . I recently started the planning stage for a low power bass cabinet (20 watts ). Being low power, efficiency will be a big deal . When installing 2 different speakers (2-4'' mid bass and a single 10'') in the same cabinet . How do you determine the port size ?
Here is what you want: ua-cam.com/video/yZNeYBYGRKk/v-deo.html
@@DIYAudioGuy Thank you so much
@@Mr.Robert1 Thanks for the input. I like to build my own stuff if I can .
3 questions:
1. What if we placed the port OUTSIDE of the box? (literally thinking outside the box, pun intended)
2. Can a port be bend too? Gradual bend vs. abrupt bend?
3. Would it be beneficial to dampen the port by glueing anti resonance material to the outside walls of the tube?
1) Yes
2) Yes
3) It could not hurt, but it would probably only be worth the money if The porch were made out of something flimsy.
@@DIYAudioGuy 1.) Anything special to consider when the port is outside?
2.) Does the bend in a port have a big effect on something (if so, what?)// like can I make a "snake shaped" port which is flat on top of my box?
3.) I was thinking about that material which you can use to dampen the inside of car doors for example.
Liked the video. But something that is kinda irksome to me is this notion that Everyone has the same ears, and cannot hear below 20 Hz or above 20,000 Khz. That is simply not true as I can hear down to around 12 Hz, and up to 26,000 Khz, proven by not one but 2 ear doctors. Now even though I can hear above 20K herz it isn't pleasant I must say. But the lower frequencies are enjoyable. Not to mention even if you can't hear them you can feel them. And music is meant to be felt not just heard.
You are one in a million.
You’re educational videos are really well done. Your teaching style makes topics easier to understand.
Glad you like them!
Speaker port's for speaker port's but the science here is strong!
So strong that I haven't come across science channels that get it this correct!
Buddy, I'm impressed... The scientific community could learn something from this video and then some...
The majority of people don't know how much mass is weighing apon them... And a tube is never empty!
That is exactly what I was shooting for.
Hey Guys, im Planing to make a small Jukebox for my soon to be born daughter. I was wondering if a Port makes sense for a full range 3" speaker. My Plan was to put two Speaker oposit to each other but in seperate chambers. Each speaker has its own Air Mass. Im Planing to 3D Print the Enclosure so Geometry can be wild. Modeling it is also not an issue.
A port will help with low end extension, but not much sine you only have a 3" driver.
To learn more check out this video: ua-cam.com/video/-yopTneS7g8/v-deo.html
Is there any difference between the resonance frequency of the port itself and the resonance frequency of the system (i.e., the box plus the port)? I have come across some texts that describe them as distinct frequencies. Thanks for your help!
That is a great question, join us on our next live show and we will try to give a detailed answer: bit.ly/3PYKG5P
So, in short, bigger driver, sealed enclosure 🤓
Are u trying to make folks stupid its a port to give the speaker air
I have $9.99 for a bit design.
2door tahoe
Memphis 4ohm MoJo 15.
Whatever u recommend for HiP HoP/reggae/rock low LOW Lows.😁
I have found that the recommended enclosure on the Memphis website is a very goo design. If you want a custom design you can find my prices here: diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html
Will it work if I parallel two identical subwoofers, but put it in 2 different 4order bandpass enc. box that the ports of each is tuned in different frequency range i.e. one is tuned to 20hrz and the other is at 60hrz?
It can work, but it would be a lot of trouble to get it right.
Why is it so hard to find a decent box for two 15s. I cant even find a local builder that will do a 6 cubic foot box tuned to 32hz. Find a few way too small inclosures thats it. Theres much more choices for 12s. But i already own my 15s ones got a 2.5 cubic foot box sealed the second 0ne i had built 3 cubic foot tuned to 32hz sounds great but my sub is a single coil 4ohm. I want the second to drop to 2ohm.
I can't believe a local shop would not build that for you.
I want to build 2 speaker boxes for outdoor activities and I want to use 2 15" subwoofers for each box with 2 midrange speakers and tweeters in each box how box should the box be ty
That's a question for Toids DIY. That kind of build is right up his alley, you can join his forum and find helpful people that can help you figure out how to do it.
So much awesome info. I always built boxes to hrtz by size I would degree the main port tunnel. From opening it up to a smaller opening or a very small opening to a larger opening. It works phenomenally well and just a few degrees makes a huge difference
You mean like a flare. Yeah, that works great.
What your opinion on kerf ports?
you say its not for making more sound they you say its for resonating like a speaker cone, so it does in fact produce its own sound if this is correct. i have always felt like its there to make better sound and alleviate the air pressure from effecting the sub. you can always feel the air moving from the port.
That's not what I said, watch it again.
Yes, more low quality bass... 😂😂😂
I respect sealed speakers only.
Thanks for the info DIY Audio Guy. 🙂
Remember that God loves you!, no matter what you think or what someone tells you to the contrary. 🙂
Thanks!
How could I buy an aero port box for a single 15 inch American bass hd d2 1ohm from you? Or even just a blueprint for a sub like this?
diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html
If your port is being blocked does it reduce proformance? ( I have a dual 12 build, my port is facing towards the back of my seats with little to no room left between the seat and the box.
Yes, but, seats are not brick walls so sound does make it through. If you can move the box (even just to test it) try moving and seeing if there is a difference.
Unless u gota do some comp u dont need any of this inc box
Give me a link to understand how to make my home sub. the speaker is jbl a1300hi.. what is the best box plan for this one? I want to take a big spl output in low power low moving.
ua-cam.com/video/yZNeYBYGRKk/v-deo.html
I built a huge sub box for 2 15 inch subs but ran out of 3 quarter mdf wood for it so I left on side open and just have tucked it against the back seat of my van tbh I dont know what to do make it sealed put in a port or a crazy idea make a port that goes under the seat atleast it souds good and vibrates my guts the way it is lol
Awesome.
I have JBL subwoofer I can't feel any air moving from sub air pipe 🤣 but it just gives killing bass
ua-cam.com/video/mHTGwEHCCRo/v-deo.html
Great vid as always. I’m always learning and experimenting and learning some more. I like a 25-28 hz tune for the lows ya some day it’s a waist but I’m always changing my port tuning about every 2 months or so anyhow. Motorized port??
I think it would be cool to build a box with a removable panel, just cut a hole in the panel and stick in an arrow port. Then you could swap out ports anytime you wanted.
25-28 is the life, low life. That’s where I live