You know it Mark, I've made a 8th order or Triple Reflex Bandpass. Very difficult indeed. Any chance of putting the T Line in the jeep for a test bump when it's finished?
My passion for building enclosures using mathematics is the only reason why I graduated college. My classmates always griped about how “boring” math is, but when they came to me to build an enclosure, they finally understood a real-world application that affected them directly.
This is a very simple TL box. The woofer is at one end meaning the peaks and dips are pretty big. Moving the sub down the line can help smooth the response quite a bit. You can also taper the line(bigger at one end) and also play with damping at various points in the line. This is a good explanation but there are many more variables that can be tuned in a TL.
Great video! As a ham radio operator, the concept of a transmission line box for audio really resonates with me. Thank you for making it easy to understand!
I had already known much of this because I have been studying this subject since the 90's. But this was the best simplified explanation of TLine vs ported boxes I have heard to date. Well done.
I've built two T-Lines designed by a guy on the East Coast. One for two 12's (Pretty basic layout) and another for a single 15 (Tapered with a 180 degree kerfed wall). There is nothing like a properly designed T-Line! Also, both of these enclosures were very compact and broke a lot of the "rules" around T-Lines. I got out of car audio for awhile, but I'm hoping to build one again soon! Nice video!
Genuinely one of, if not the most useful video I have ever seen on UA-cam. How did I not find this channel earlier! Always wanted to know how Bose get so much bass from a small speaker and this pretty much sums it up. Top man! 👍🏼
I made a tapering T-line with stuffing. Some tapering enclosures expand, the one I made contracts from equal surface area to about one third. It's half wave with a 12", and my god does it pound at 20Hz. I'd be interested to see what it's like in a car though it's 8' long, this one is just for the home theatre. The idea of the stuffing is also to reduce any port type resonances as the chamber behind the sub is larger, before the stuffing it had a 50Hz resonance and had cancellation at 60-70, the stuffing absorbs the higher frequency waves to reduce cancellation and reduces the type of airflow that a port produces to eliminate that resonance. I also used thin sheet metal behind the driver and at the curve (the design is up and back) with expanding foam behind it to make a perfect curve.
Glad to see you explain the science behind it. When I was in the industry (Got out when Tweeter went belly up) I stayed away from ported as I thought they always sounded sloppy. It was also hard to explain to people how much more work it was.
The first time i ever saw the bose wave radio ad in a magazine showing the port layout inside ive been wondering how it would work in a vehicle. thank you so much for making this video and explaining the pros and cons. Much appreciated man!
I'm keen on this build for a number of reasons, not least because the 6.5" Skar subwoofer I got for a specific application, and planned on a bass reflex enclosure based on an email in which they claimed a "tuning frequency" of 40Hz (which I thought meant resonant frequency) turned out to have a resonant frequency of 64Hz. I am definitely looking for FLAT frequency response (I'm 62 years old and have never been a fan of BOOM BOOM!), and if this takes me down to 32Hz (using you half-below-twice-above-Fs rule of thumb) before things fall off, I think I can live with that. If you're wondering why I'm using a 6.5" sub, the space I'm working with (package shelf of a first series Miata) is very limited in height. While there's not much total volume either, given the SD of 17.52in2, and the relatively high Fs (which, if my calculations are correct, makes for a port length of less than 4.5 feet), I think it's doable. What scares me is the "...once we build the box, we're going to need to do some [testing and] fine tuning". Besides adding stuffing, it's hard to imagine how to fine tune something that is a glued together wooden box. And apart from using my ear, I don't know about testing (I'll be searching this site for videos about that, but if you wanted to shoot me some links, that would be most helpful).
In some more advanced TL theory is stated that the speed of sound is slowed when passing through fibrous material such as poly-fill. This reduction in speed is dependant upon the sound frequency in question. It involves some extra math. However with proper stuffing it is possible to build a much smaller (read shorter line) TL subwoofer cabinet.
Mark, this is honestly one of the best explanations of the basics of enclosure design that I've ever seen. If you just add the qualities of different types of enclosures so people learn what the do to the frequency response (maybe more with the dogfood if Hz doesn't mind ;-) ) there would be a lot of people that would finally understand what's going on in their sub box. Heck, I think even some experienced people would gain by watching this, nailing down some basic concepts that are often overlooked.
An you just blew my mind how you took time to explain all of the math used in the builds, awesome! Please keep up the informative vids, I learn more every vid. Thank you.
Really like these super technical videos. You do such a good job at explains complex concepts and techniques. Could you possibly do a video or even a demo comparing 3 boxes of equal size and volume but one is t line, 1 ported, 1 sealed and measure the response with the same woofer and amp? That would be so interesting to see and would reinforce how much difference a good enclosure can make.
Question, I’m working with a 12 inch speaker that’s 6 inch’s in depth, do I have to make my air passage way more than 6 inch’s or can I stay at 6 inch’s where the speaker would touch the back of the board for the t line build. Looking at dimensions 15” x 38” x20”
Very interesting, I always thought of t-line as sort of a mystery I could probably figure out if I was really interested, but I 'get it' now, and it's not exceptionally difficult. I'm not sure about _tapered_ t-lines, but this is a good starting point. Thanks!
Excellent video! I've been wanting to do something with T-Line myself and your explanation is much easier to follow than some of the other stuff online lol.
Brother thank you soooo very much for this video. you explain everything so well. I just built a TLine for my American Bass VFL 8 and i wish this video was around a year ago when i first decided to build it simply because i wanted it for car and home due to my new baby Boy so he can love it just as much as Daddy!!!
As always, a clear and concise explanation to a subject with lots of technical depth. I've been watching for years and just wanted to say thank you and if you offered online classes or even in person classes I'd be (one of the) first in line. Maybe even selling ~hour long instructive videos on parameters for various applications and the various theories for sound quality etc. Just a thought, I don't mean to be that guy who tells you how to run your business lol. Anyways, superb video just like all your others. Your dog is one adorable lil fella too btw.
T-Lines (or back wave variation) will always be my go to enclosure for SQ or in home and when I can get them to fit, the vehicle environment. There are some good tricks you can employ using these.
Great video Mark....never built one of these transmission line enclosures ...but I’ll now have a better grasp of the construction and math behind one...thanks again
Excellent video, every time I was thinking, "but what about....(tappered, guys who think they add SPL, stuffed, multiple complex mathematical theory formulas, )" man, you had it covered. I think you really covered the basics of a T-line enclosure, with a simple formula to get someone started. 👌 Just like sealed, ported, and passive radiators, you can make full-range T-lines for home speakers. The ones I have seen are usually 6"-8" full-range drivers in a T-line.
This was a really good and informative video about T-line design, I understand the math so much more now that! Thanks as always, looking forward to the build video! :D
AMAZING WORK, ive been looking into trying a T line but just didnt know enough and have mainly built low tuned ported boxes, definitely going to try a build for a single or a single 10. thanks mark
1) there will be a 180° phase change when the sound wave reflects off a hard surface. 2) there should also be a 180° phase change when it transitions from the box to the cabin of the vehicle. 3) this box design tunes the system at the Fs of the driver, what happens when you tune the system for the resonant frequency of the vehicle, say 60hz? What gap does it fill in or does it provide a boosted response at that frequency, assuming the driver Fs is much lower?
You should do videos explaining the difference between ported, 4th order, and 6th order bandpass enclosures and also show how the work and how to build them for people trying to get into spl builds.
So if it's not built 100% mathematically correct, the nice flat frequency will be off. Good stuff. I thought a tline was just a fancy name for a extra long port. I learned something. Thanks
OH man I so miss my T line box in my old wagon... The car was painted flat black, with a coffin shaped outer layer on the box. Figured since it was so big might as well play to the "coffin" thing everyone refers these as :P
You could absolutely get more output with 2 ported 10’s/12’s. But I’ve always been intrigued with how efficient a box can be with little power. I wonder how a band pass compares to a t-line like this.
Question for you Mark: I noticed in your calculations as well as a few of my own T-Lines trying with different speakers, the mounting depth is larger than the 'W' calculation. Now correct me if I'm wrong, but wouldn't this put the speaker through the first wall? Or did i misunderstand the orientation of the 'width'? I also noticed you didn't touch too much on Md in your Thiele Parameters video, which i could also have misunderstood. Thanks -From, a fellow engineer.
KibbleRTA(tm)! Hahaha, I like it. A well-built T-Line sounds really good, but they can be grossly inefficient, especially for Car Audio. At least with a ported box, you can adjust your tuning frequency to work with cabin gain for SPL or SQ!
Great videos man.remind me of some of the quantum mechanics videos I watch.so many things to think about.its probably so hard for someone like you to settle on and install a personal system in your vehicle.so much to think about...port length ,frequencies,even eventually have to factor on dimensions of your car.....keep ya up at night thinking for months.lol.thanx for the lessons
Thank you so much for this. I used your math to build a regenerative transmission line subwoofer like I saw from wisdom audio. I used 2-3ohm 8" Tymphany woofers with a QTS of .58 and it sounds incredible. The bass hits lower then I could have ever hoped for. I do have a question though as I want to build a giant cabinet to go under the couch. My question is: Would a woofer with a lower QTS yield better results? or are there particular specs you look for when choosing a woofer?
coincidentally this was exactly the video I needed right now xD also I now know a T-line is not for me. regular ported it is :D thanks for another great video!
Good morning, thank you for so much in-depth info. Was curious on where line starts.... Your drawing looks like past speaker,and I've read from speaker Center line and above speaker to port wall?????? Help!!🤯 Thanks again for your time making us educated😁 I will say also I built a 2way ,inspired from this video Not being sure of starting point Of line so I guessed........ I used a Dayton designer series 5" and hivi tweeter (parts express stuff) I hid crossover in the bottom of box in a pedestal. Results were amazing!! My son thought other larger speakers where playing when I showed him them😃 Thanks again man.
LOVE This video dude. I was truly expecting to be correcting you in my head on how/why/etc. I can say my only gripe of the whole video was your handwriting. LOL :)
So I noticed when you were calculating everything out for your box, you have a port dimension of 9.75x5.5". But your sub has a mounting depth of 6". How did you make it fit without the magnet hitting the wall of the port? Im having the same issue trying to calculate a box design for a 12" sub I have.
People. If you have not experienced a 1/4 wave T-line. It is so worth the time to design and build. This isn't a throw together box. You want all cuts tight and precise. Mine was first used in a 2010 ford Taurus SHO. I loved it. it is now doing work no in a 30x50 pole barn. Still the loudest and cleanest single 10" sub I've ever heard. Put my buddies twin 12 Sony Xplodes in a Sony pre fab to total shame. In his own Explorer.
There's an unwritten rule concerning the pole piece vent diameter and distance from there to any surface behind it. I noticed that your mounting depth is 6" and the depth of the line is only 5.75". I realize that the thickness of the baffle (or baffles) will make up for a little of the available depth. Will this cause a problem, or is that just another one of those commonly accepted car audio myths?
I built the tapered transmission line box and the speed of sound needed to be more accurate. You can't really get an exact because just a change in 1 degree F adjusts the speed. 1130 fps is if temp is at 72 deg. Air in a ported box after 20 min is at 100 deg and usually stays around the 100 to 110 deg area, sealed boxes get up to 130 deg give or take. All this changes each sub is different so you can't get a perfect fps speed of sound. Instead of using the standard speed I used the speed at 90 or 100 don't remember. At 72 deg speed 1130 fps at 100 deg speed 1160 fps could almost be fully out of phase. I'm not sure if that would be the case or if it would even be noticeable. Just throwing it out there.
Excellent video as usual. I do have to say though that I was a little disappointed you didn't sneak in a few shots at Doug over at Soundman. He's playfully zinged you a few times in a couple of his videos and hoped for a little banter back and forth =)
Man you explanation of adjusting reminds me of tuning a Floyd Rose/floating vibrato for guitar because as the string tension changes the angle of the bridge changes, knocking it out of whack so the more you change the pitch/tension of a string you throw them all out and have to start the cycle over.. a trick I use, which may can be adapted and applied here, is to overshoot my adjustment, although w/6 strings it's less the further down you are and its something you get a feel for.. so maybe you can estimate what a particular frequency may be, from previous experience with similar specs, and go ahead and factor that instead of the open air value and see if it gets it closer.. hope that makes sense!
Hi Mark, Thanks for the awesome video but i have a question. The begin of the line length is the bottom left of the schematic or the center of the magnet? And if so, does mounting location matter? Thanks
I've been waiting for this video for a while! I want to build one for two 8" Sundown X-8s. I want to build it for the experience. I've built ported and sealed boxes but I've been curious about the actual build for T-Line boxes.
Hi there, Mark. I liked your video for explaining things in very easy terms to understand for a newbie like myself. Got a question - let's say you target frequency was 60 hz using a driver with a response of 48Hz - 22000Hz. So, 60 hz is higher than 48hz. But what would happen if your target were 35hz? Would the accordingly calculated enclosure work with the same driver?
You mentioned a "tapered" box. Does this mean that the chamber does not need to be equal all the time? Is it simply the cubic feet volume that you're concerned with? Keeping the chamber the same height and width is easier to find that volume, but could you theoretically change the dimensions as you go? I would think the corners would have some variation in them that isn't accounted for. (minimal at best) I'm not sure why you would do this, but I'm just curious about the math behind it.
Newbie question: how does one determine which frequency to use? Is there some sort of natural resonance for each speaker, or is it a personal preference, rather than based on the actual speaker? Also, I have not seen the effective bandwidth of the TL mentioned. I am a ham radio operator and use the same principles when designing antennas and transmission lines...our calculations provide solutions that can only work for about + or - 10 percent of the center frequency.
Who's ready to see the build video? Let's see if we can get this video to 1,000 likes for the next video to be released! Thanks for watching! - Mark
heck yeah!! i'd also love to see the other side of the spectrum. like maybe an aperiodic bi-chamber, or a 4th order, or something!!
You know it Mark, I've made a 8th order or Triple Reflex Bandpass.
Very difficult indeed.
Any chance of putting the T Line in the jeep for a test bump when it's finished?
CarAudioF
abrication
T/L subs are awesome!! Thanks for the quick tutorial on the math. Had them with my ESL's in my home rig.
CarAudioFabrication Of course why not!
My passion for building enclosures using mathematics is the only reason why I graduated college. My classmates always griped about how “boring” math is, but when they came to me to build an enclosure, they finally understood a real-world application that affected them directly.
I'm currently a mechanical engineering student and my car audio hobby makes most of what I'm learning pertinent.
This is a very simple TL box. The woofer is at one end meaning the peaks and dips are pretty big. Moving the sub down the line can help smooth the response quite a bit. You can also taper the line(bigger at one end) and also play with damping at various points in the line.
This is a good explanation but there are many more variables that can be tuned in a TL.
Car Audio, bagging a dozen parameters … not a problem.
Great video! As a ham radio operator, the concept of a transmission line box for audio really resonates with me. Thank you for making it easy to understand!
I had already known much of this because I have been studying this subject since the 90's. But this was the best simplified explanation of TLine vs ported boxes I have heard to date. Well done.
I've built two T-Lines designed by a guy on the East Coast. One for two 12's (Pretty basic layout) and another for a single 15 (Tapered with a 180 degree kerfed wall). There is nothing like a properly designed T-Line! Also, both of these enclosures were very compact and broke a lot of the "rules" around T-Lines. I got out of car audio for awhile, but I'm hoping to build one again soon! Nice video!
Justin Vetter
Ehm, when you brake a lot of the "rules" for a TM build, is it still a TM? And how about frequency curves, doesn't that hurt?
Genuinely one of, if not the most useful video I have ever seen on UA-cam. How did I not find this channel earlier! Always wanted to know how Bose get so much bass from a small speaker and this pretty much sums it up. Top man! 👍🏼
Really good visual explanation using the dog food. Good stuff!
I wanted to have a way to visually represent it, I hope it helped! Thanks for watching.
CarAudioFabrication it did the trick
Stuart Wood I find the wet dog food yields a smoother response.
@@CarAudioFabrication Agree! What if you horn-load the sub? Does that add to the number of dog foods, due to higher efficiency?
I made a tapering T-line with stuffing. Some tapering enclosures expand, the one I made contracts from equal surface area to about one third. It's half wave with a 12", and my god does it pound at 20Hz. I'd be interested to see what it's like in a car though it's 8' long, this one is just for the home theatre. The idea of the stuffing is also to reduce any port type resonances as the chamber behind the sub is larger, before the stuffing it had a 50Hz resonance and had cancellation at 60-70, the stuffing absorbs the higher frequency waves to reduce cancellation and reduces the type of airflow that a port produces to eliminate that resonance. I also used thin sheet metal behind the driver and at the curve (the design is up and back) with expanding foam behind it to make a perfect curve.
UniCrafter In the South, we don't use Stuffing... We make dressing on the side... Will that work? 😂
Glad to see you explain the science behind it. When I was in the industry (Got out when Tweeter went belly up) I stayed away from ported as I thought they always sounded sloppy. It was also hard to explain to people how much more work it was.
The first time i ever saw the bose wave radio ad in a magazine showing the port layout inside ive been wondering how it would work in a vehicle. thank you so much for making this video and explaining the pros and cons. Much appreciated man!
I'm keen on this build for a number of reasons, not least because the 6.5" Skar subwoofer I got for a specific application, and planned on a bass reflex enclosure based on an email in which they claimed a "tuning frequency" of 40Hz (which I thought meant resonant frequency) turned out to have a resonant frequency of 64Hz. I am definitely looking for FLAT frequency response (I'm 62 years old and have never been a fan of BOOM BOOM!), and if this takes me down to 32Hz (using you half-below-twice-above-Fs rule of thumb) before things fall off, I think I can live with that.
If you're wondering why I'm using a 6.5" sub, the space I'm working with (package shelf of a first series Miata) is very limited in height. While there's not much total volume either, given the SD of 17.52in2, and the relatively high Fs (which, if my calculations are correct, makes for a port length of less than 4.5 feet), I think it's doable.
What scares me is the "...once we build the box, we're going to need to do some [testing and] fine tuning". Besides adding stuffing, it's hard to imagine how to fine tune something that is a glued together wooden box. And apart from using my ear, I don't know about testing (I'll be searching this site for videos about that, but if you wanted to shoot me some links, that would be most helpful).
Alan Johansson did you ever do this? I too have some spare 6.5 woofers around
Bry Ytab Not yet. Considerable life has happened since.
Alan Johansson understandable..it will be cool to see, if you ever attempt it
Usually tuning is adding wood in the "chamber" or creating a narrow "throat" to distinguish where the chamber ends and the port begins
In some more advanced TL theory is stated that the speed of sound is slowed when passing through fibrous material such as poly-fill. This reduction in speed is dependant upon the sound frequency in question. It involves some extra math. However with proper stuffing it is possible to build a much smaller (read shorter line) TL subwoofer cabinet.
Hey Mark, Great intro to T-lines. Please consider doing an advanced math video for T-Lines as well.
Cheers
I really wanted to design a tline but didn't know where to start. Thanks for the info bro!!
Thanks for watching!
Interesting followup, the differences between quarter wave, half wave, full wave, ect.
I have worked with Mark in making a custom box for my 12's and everything went great.
Right now I'm having him build another for some DDX-12's
Daniel Lanning can you let me know what you come up with for yr ddxs I'd really appreciate it thanks
Mark, this is honestly one of the best explanations of the basics of enclosure design that I've ever seen. If you just add the qualities of different types of enclosures so people learn what the do to the frequency response (maybe more with the dogfood if Hz doesn't mind ;-) ) there would be a lot of people that would finally understand what's going on in their sub box. Heck, I think even some experienced people would gain by watching this, nailing down some basic concepts that are often overlooked.
An you just blew my mind how you took time to explain all of the math used in the builds, awesome! Please keep up the informative vids, I learn more every vid. Thank you.
Really like these super technical videos. You do such a good job at explains complex concepts and techniques.
Could you possibly do a video or even a demo comparing 3 boxes of equal size and volume but one is t line, 1 ported, 1 sealed and measure the response with the same woofer and amp?
That would be so interesting to see and would reinforce how much difference a good enclosure can make.
Car Audio.etc i
This isn't super technical, its basic.....
Question, I’m working with a 12 inch speaker that’s 6 inch’s in depth, do I have to make my air passage way more than 6 inch’s or can I stay at 6 inch’s where the speaker would touch the back of the board for the t line build. Looking at dimensions 15” x 38” x20”
Very interesting, I always thought of t-line as sort of a mystery I could probably figure out if I was really interested, but I 'get it' now, and it's not exceptionally difficult. I'm not sure about _tapered_ t-lines, but this is a good starting point. Thanks!
My buddy had 2 10" DC Audio xl's in a t line box, that box was huge and heavy, sounded really good tho, love these boxes
Excellent video! I've been wanting to do something with T-Line myself and your explanation is much easier to follow than some of the other stuff online lol.
Brother thank you soooo very much for this video. you explain everything so well. I just built a TLine for my American Bass VFL 8 and i wish this video was around a year ago when i first decided to build it simply because i wanted it for car and home due to my new baby Boy so he can love it just as much as Daddy!!!
As always, a clear and concise explanation to a subject with lots of technical depth. I've been watching for years and just wanted to say thank you and if you offered online classes or even in person classes I'd be (one of the) first in line. Maybe even selling ~hour long instructive videos on parameters for various applications and the various theories for sound quality etc. Just a thought, I don't mean to be that guy who tells you how to run your business lol. Anyways, superb video just like all your others. Your dog is one adorable lil fella too btw.
T-Lines (or back wave variation) will always be my go to enclosure for SQ or in home and when I can get them to fit, the vehicle environment.
There are some good tricks you can employ using these.
5,5" wide port but subwoofer mounting depth is 6", how did you solve that problem?
Invert the sub that's what I had to do with my old box, didn't make any difference in sound
Brilliant explanation. I saw one once back in 1996 that was a single 18” in the bed of a p/u truck. Took up the entire bed.
Great video Mark....never built one of these transmission line enclosures ...but I’ll now have a better grasp of the construction and math behind one...thanks again
Excellent video, every time I was thinking, "but what about....(tappered, guys who think they add SPL, stuffed, multiple complex mathematical theory formulas, )" man, you had it covered. I think you really covered the basics of a T-line enclosure, with a simple formula to get someone started. 👌
Just like sealed, ported, and passive radiators, you can make full-range T-lines for home speakers. The ones I have seen are usually 6"-8" full-range drivers in a T-line.
This was a really good and informative video about T-line design, I understand the math so much more now that!
Thanks as always, looking forward to the build video! :D
AMAZING WORK, ive been looking into trying a T line but just didnt know enough and have mainly built low tuned ported boxes, definitely going to try a build for a single or a single 10. thanks mark
1) there will be a 180° phase change when the sound wave reflects off a hard surface.
2) there should also be a 180° phase change when it transitions from the box to the cabin of the vehicle.
3) this box design tunes the system at the Fs of the driver, what happens when you tune the system for the resonant frequency of the vehicle, say 60hz? What gap does it fill in or does it provide a boosted response at that frequency, assuming the driver Fs is much lower?
You should do videos explaining the difference between ported, 4th order, and 6th order bandpass enclosures and also show how the work and how to build them for people trying to get into spl builds.
Dog food demo was so on point, couldn’t explain any better great video
I love the dog food graphics! Amazing :D
Nice box!!! Imma call this one "The Tay-lay dog food box" 😋
...I told Rafa's mom
Be nice af to have some of that mobile solutions equipment lol
Love the dog food/total available energy description. I would really enjoy an informational video on aperiodic loaded subwoofer.
I was looking at the box and thinking that it would make a great home theater enclosure. I might have to build one for my home system.
So if it's not built 100% mathematically correct, the nice flat frequency will be off. Good stuff. I thought a tline was just a fancy name for a extra long port. I learned something. Thanks
So glad you covered a t line. I love this part of audio
I actually really enjoyed the way you presented and explained that.
I just designed a T-line enclosure for a DC m3 8" and it was not that hard.
Thanks for the vid.
did you get a chance to measure the response curve?
The dog food explanation ! ...perfect 😎
OH man I so miss my T line box in my old wagon... The car was painted flat black, with a coffin shaped outer layer on the box. Figured since it was so big might as well play to the "coffin" thing everyone refers these as :P
You could absolutely get more output with 2 ported 10’s/12’s. But I’ve always been intrigued with how efficient a box can be with little power. I wonder how a band pass compares to a t-line like this.
Question for you Mark:
I noticed in your calculations as well as a few of my own T-Lines trying with different speakers, the mounting depth is larger than the 'W' calculation. Now correct me if I'm wrong, but wouldn't this put the speaker through the first wall? Or did i misunderstand the orientation of the 'width'? I also noticed you didn't touch too much on Md in your Thiele Parameters video, which i could also have misunderstood.
Thanks
-From, a fellow engineer.
KibbleRTA(tm)! Hahaha, I like it. A well-built T-Line sounds really good, but they can be grossly inefficient, especially for Car Audio. At least with a ported box, you can adjust your tuning frequency to work with cabin gain for SPL or SQ!
I have built those for a few years. Hertz is hella cute.
Great videos man.remind me of some of the quantum mechanics videos I watch.so many things to think about.its probably so hard for someone like you to settle on and install a personal system in your vehicle.so much to think about...port length ,frequencies,even eventually have to factor on dimensions of your car.....keep ya up at night thinking for months.lol.thanx for the lessons
The Fab Kitchen is looking good and clean. Good video on t line boxes also.
Thank you so much for this. I used your math to build a regenerative transmission line subwoofer like I saw from wisdom audio. I used 2-3ohm 8" Tymphany woofers with a QTS of .58 and it sounds incredible. The bass hits lower then I could have ever hoped for. I do have a question though as I want to build a giant cabinet to go under the couch.
My question is: Would a woofer with a lower QTS yield better results? or are there particular specs you look for when choosing a woofer?
coincidentally this was exactly the video I needed right now xD also I now know a T-line is not for me. regular ported it is :D thanks for another great video!
Great video!! I understand the making of these much more than reading about them!!!
Good morning, thank you for so much in-depth info.
Was curious on where line starts....
Your drawing looks like past speaker,and I've read from speaker
Center line and above speaker to port wall?????? Help!!🤯
Thanks again for your time making
us educated😁
I will say also I built a 2way ,inspired from this video
Not being sure of starting point
Of line so I guessed........
I used a Dayton designer series 5" and hivi tweeter (parts express stuff)
I hid crossover in the bottom of box in a pedestal.
Results were amazing!!
My son thought other larger speakers where playing when I showed him them😃
Thanks again man.
This was a bit helpful, will be building one for an 8" infinity sub, thanks...
LOVE This video dude. I was truly expecting to be correcting you in my head on how/why/etc. I can say my only gripe of the whole video was your handwriting. LOL :)
i have a double rockford t2 12 in a transmission and it wins alot in db and sound great
So I noticed when you were calculating everything out for your box, you have a port dimension of 9.75x5.5". But your sub has a mounting depth of 6". How did you make it fit without the magnet hitting the wall of the port? Im having the same issue trying to calculate a box design for a 12" sub I have.
+Pat B the thickness of the wood...
People. If you have not experienced a 1/4 wave T-line. It is so worth the time to design and build. This isn't a throw together box. You want all cuts tight and precise. Mine was first used in a 2010 ford Taurus SHO. I loved it. it is now doing work no in a 30x50 pole barn. Still the loudest and cleanest single 10" sub I've ever heard. Put my buddies twin 12 Sony Xplodes in a Sony pre fab to total shame. In his own Explorer.
Wow I learned something today! Kudos! Very well explained, Excellent job!
This is a chalenge I want to build for a JL 8Wo I have laying around.. Gonna give it a run
There's an unwritten rule concerning the pole piece vent diameter and distance from there to any surface behind it. I noticed that your mounting depth is 6" and the depth of the line is only 5.75". I realize that the thickness of the baffle (or baffles) will make up for a little of the available depth. Will this cause a problem, or is that just another one of those commonly accepted car audio myths?
Mark's onscreen voice is maturing.
I built the tapered transmission line box and the speed of sound needed to be more accurate. You can't really get an exact because just a change in 1 degree F adjusts the speed. 1130 fps is if temp is at 72 deg. Air in a ported box after 20 min is at 100 deg and usually stays around the 100 to 110 deg area, sealed boxes get up to 130 deg give or take. All this changes each sub is different so you can't get a perfect fps speed of sound. Instead of using the standard speed I used the speed at 90 or 100 don't remember. At 72 deg speed 1130 fps at 100 deg speed 1160 fps could almost be fully out of phase. I'm not sure if that would be the case or if it would even be noticeable. Just throwing it out there.
Thanks a lot for this T- line building idea.
the dog food analogy was cool.... now add a sealed enclosure. would it produce a similar line as the T line box?
we were talking abt science and maths..... and suddenly u decided to do some magic 8:45 !!!!!!!!!!!!
Best explanation I have ever seen. Good Job.
Excellent video as usual. I do have to say though that I was a little disappointed you didn't sneak in a few shots at Doug over at Soundman. He's playfully zinged you a few times in a couple of his videos and hoped for a little banter back and forth =)
Man... I loved this video, lots of juicy information, keep going :) I am going to try the math in Excel mode and passing it to european units.
Do a 6th order build log
I have been missing the Dog food! thats why my Violent Bass Air is not so Violent... Great video man
Omg thanks for this vid...there isnt much info about t line enclosures
Awesome video with user-friendly explanations on the technical stuff. Well done. Subscribed.
Man you explanation of adjusting reminds me of tuning a Floyd Rose/floating vibrato for guitar because as the string tension changes the angle of the bridge changes, knocking it out of whack so the more you change the pitch/tension of a string you throw them all out and have to start the cycle over..
a trick I use, which may can be adapted and applied here, is to overshoot my adjustment, although w/6 strings it's less the further down you are and its something you get a feel for..
so maybe you can estimate what a particular frequency may be, from previous experience with similar specs, and go ahead and factor that instead of the open air value and see if it gets it closer..
hope that makes sense!
FINE! subb'd bcuz U did a really good job essplainin' the maths behind a T-line.
Hi Mark, Thanks for the awesome video but i have a question. The begin of the line length is the bottom left of the schematic or the center of the magnet? And if so, does mounting location matter?
Thanks
Great explaination and great workmanship
I've been waiting for this video for a while! I want to build one for two 8" Sundown X-8s. I want to build it for the experience. I've built ported and sealed boxes but I've been curious about the actual build for T-Line boxes.
You ever end up building that box?
Thank you that answered a lot of questions.
Hi there, Mark. I liked your video for explaining things in very easy terms to understand for a newbie like myself. Got a question - let's say you target frequency was 60 hz using a driver with a response of 48Hz - 22000Hz. So, 60 hz is higher than 48hz. But what would happen if your target were 35hz? Would the accordingly calculated enclosure work with the same driver?
You mentioned a "tapered" box. Does this mean that the chamber does not need to be equal all the time? Is it simply the cubic feet volume that you're concerned with? Keeping the chamber the same height and width is easier to find that volume, but could you theoretically change the dimensions as you go? I would think the corners would have some variation in them that isn't accounted for. (minimal at best) I'm not sure why you would do this, but I'm just curious about the math behind it.
I was very entertained by this video, and I learned some good info from it! Keep it up! I like these types of videos, as I'm sure many others do.
You are the best on the line!
Thank you. That’s was a very easy explanation and informative
Newbie question: how does one determine which frequency to use? Is there some sort of natural resonance for each speaker, or is it a personal preference, rather than based on the actual speaker? Also, I have not seen the effective bandwidth of the TL mentioned. I am a ham radio operator and use the same principles when designing antennas and transmission lines...our calculations provide solutions that can only work for about + or - 10 percent of the center frequency.
Great video! Very informative, very easy to understand and to apply!
hi there, thanks for share your knowledge! very nice videos. you have a beautiful workshop, i wish mine was like that ; greeting from colombia.
You the best mark love your videos !!! You the man tnx for sharing
I appreciate that, thank you for watching!
How do I design a T line running multiple drivers in same encloser? Im thinking line array T line for my home theater..???
Hertz is an awesome name for a dog
I love the line box
So my car stereo just needs more evenly spread dogfood, who could have guessed it would be that easy!?!? :-D
this channel is awesome. im addict to it.
WOW Mark , great Video! I will share the heck out of this.
+adam watkins appreciate that! Thank you
The dog is called "Hertz"
Insert jokes and puns here...
Please do a tapered, that would be so cool.
Saw this video before work...instant like!👍