Is Solid Wood Good for Speaker Building? Head to Head Testing - DIY vs Elac
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- Опубліковано 9 жов 2021
- My solid wood speaker build: • How To Make Bookshelf ...
Upgrading the speaker: • Speaker Upgrade - New ...
The notable difference between these two speakers is that the Elac is vented and mine is sealed, and that has an effect on the amount of bass each can produce The measurement starts from 30Hz, so it's a factor but in my opinion a small one, since mine has a bigger woofer.
I would guess that the Elac is braced, but the panels are probably 1/2" thick. The panels in mine (other than the back panel which is 1/2" Baltic birch) are 3/4" thick. There isn't any bracing in mine, but it is stuffed (not heavily) with fiberglass.
Remember that what we are looking at in these measurement is how much the panels are vibrating. Don't confuse that with sound. The vibrating panel produces some sound, but it will be very low and almost impossible to measure since the speaker will swamp it out. The peaks in the measurements look big because the accelerometer is able to pick them out and plot them on the computer.
Regarding stuffing: it is a damping material. It doesn't have the ability to chose whether it will damp the airspace only, or the panels only - it does both at the same time. The more you put in, the more it will damp both the airspace inside the box and the panels. My measurement setup in the last video shows how effective each one is at damping by weight, and this is not something you can do by measuring with a microphone. There might be an obvious difference, but you can't see which one performs the best.
Stuffing can be used in vented boxes - the Elac featured in the video has stuffing inside. The key thing is to not block the vent with the stuffing. A vented box is just a Helmholtz resonator, where the volume of air in the box resonates and that sound exits the port. The tuning of that resonance is determined by the volume of the box (affected by the amount of stuffing) and the length and diameter of the port. There is no airflow involved. The air that pumps in and out of the port is the cone moving in and out, not the sound that the port produces to reinforce the bottom end of the bass range. People often confuse sound with airflow, when they are different things altogether.
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The notable difference between these two speakers is that the Elac is vented and mine is sealed, and that has an effect on the amount of bass each can produce The measurement starts from 30Hz, so it's a factor but in my opinion a small one, since mine has a bigger woofer.
I would guess that the Elac is braced, but the panels are probably 1/2" thick. The panels in mine (other than the back panel which is 1/2" Baltic birch) are 3/4" thick. There isn't any bracing in mine, but it is stuffed (not heavily) with fiberglass.
Remember that what we are looking at in these measurement is how much the panels are vibrating. Don't confuse that with sound. The vibrating panel produces some sound, but it will be very low and almost impossible to measure since the speaker will swamp it out. The peaks in the measurements look big because the accelerometer is able to pick them out and plot them on the computer.
Regarding stuffing: it is a damping material. It doesn't have the ability to chose whether it will damp the airspace only, or the panels only - it does both at the same time. The more you put in, the more it will damp both the airspace inside the box and the panels. My measurement setup in the last video shows how effective each one is at damping by weight, and this is not something you can do by measuring with a microphone. There might be an obvious difference, but you can't see which one performs the best.
Stuffing can be used in vented boxes - the Elac featured in the video has stuffing inside. The key thing is to not block the vent with the stuffing. A vented box is just a Helmholtz resonator, where the volume of air in the box resonates and that sound exits the port. The tuning of that resonance is determined by the volume of the box (affected by the amount of stuffing) and the length and diameter of the port. There is no airflow involved. The air that pumps in and out of the port is the cone moving in and out, not the sound that the port produces to reinforce the bottom end of the bass range. People often confuse sound with airflow, when they are different things altogether.
"A vented box is just a Helmholtz resonator, where the volume of air in the box resonates and that sound exits the port". "There is no airflow involved". That's a confusing if not somewhat false statement as the two are directly connected. Above port tuning frequency, the box acts as a sealed enclosure with little to no reinforcement coming from the port. At port resonance, it's the vibrating air mass in the port that is creating the audible bass extension, and is vibrating 180 degrees out of phase with the driver cone. This is why at max port resonance, the pressure pulse in the port pushes against the air volume behind the cone, and it's excursion drops by 50 - 75%. Above and below tuning frequency, the air mass vibrating in the port is no longer in sync with the air mass vibrating in the enclosure, and acoustic output drops. i'm not sure what programs you're using for enclosure design, but the two I use clearly show the relationship between port tuning, air velocity, group delay, and cone excursion.
By airflow I mean that puff of air that comes out of the port when a big bass note is struck. Most people assume that puff of air is the sound and think the speaker needs to "breathe" freely, which means there shouldn't be any stuffing inside. Imagine trying to breathe with your mouth full of ployfil and that's what most people (who even think about this) think is going on.
They see the driver like a fan that's blowing air and think that's the sound it's making.
I said this because I'm getting comments from people that think that maintaining a clear path for airflow inside a vented box is needed for the port to work, like the port is a register at the end of a run of ductwork. Sound isn't airflow and a resonating mass of air doesn't need to flow.
@@IBuildIt I like your explanation. There are a few examples of commercial speakers that were ported and were stuffed very full. One that comes to mind was the very successful Energy Pro22 monitors in the mid 80s. Before that was the JBL 4340. Later 4343 had less stuffing but the 4340 was crammed pretty full of fiberglass. This was a 4 way vented box with a 15 inch woofer.
@@IBuildIt I get where you're coming from that a fully stuffed ported cabinet can still function properly and under certain circumstances may be even more desirable. I also see where others are coming from as the amount of stuffing in a box does have an effect on overal output, resonant frequency, and port air velocity. While it's true the air is not flowing through the duct like a jet engine, it is alternating back and forth at a very high velocity, which above a certain level (>22 m/sec) is audible as "chuffing". Port air velocity is definitely subject to variables in the pressure pulse driving it, along with molecular friction and surface skin effect of the duct itself. Using an Eminence based box and driver combo in WinISD, I compared cone excursion to port velocity at several frequencies with the cabinet both empty and what it considers to be fully stuffed, and the change was fairly significant. Using a constant input of 40w in an "empty" box, at 70 Hz cone excursion was shown to be 3.5mm, and port velocity was 6.0 m/sec. At the port tuning frequency of 44 Hz (max port gain) cone excursion dropped to 0.96 mm and port velocity increased to 13.45 m/sec. At 32 Hz, cone excursion rose to 6.46mm and port velocity maxed out at 16.4 m/sec. Using the same parameters with a fully stuffed box (Qa
These mentions should be in the video! After I saw the video,I was prepared to hit you with these facts that you mentioned in your comment but forgot to tackle them in the video! I'm glad I've decided to read your comment before I leave mine!
I can tell you for a fact, inside elacs there’s sheets of poly glued to the sides, one 45degree angled brace between the side panels, and is glued together with flexible glue, all 45deg joins (not butt joins) all round, 20mm MDF. I’ve taken several apart and rebuilt them from the drivers up. 👍🏻
You’re doing exactly the content I’m looking for in my projects. Thanks!
At my brothers job, that I work at on the week ends, I have access to a fairly large vacuum chamber (big enough that a front door of a house will fit) for drawing air out of composites and 2 part compounds epoxy's, I pulled a stunt about 6 months ago, I submerged my hardwood pre-glued up planks, in some 6 to 8 hour cure time "hard but thin" epoxy, just flooded over the entire pile of my boards. Ran the vacuum down, then allow the outside pressure to equalize, run the vacuum down again, etc... I did that I think 7 or 8 times, until no more bubbles where being released from the grain of the wood. Pulled the boards out, ringed them off lightly, but not by squeggying with a yellow spatula, as I was unsure if the boards would either pulling more epoxy in on a shrinkage theory or push out any from with-in, I was unsure what would happen. Allowed to fully cure, and found time to get back to this a few weeks ago, to build a pair of satellite speakers for the house. Having no clue how they would sound or the performance of them, using a material like this, I just jumped into it with both feet, and took a chance, and used a design that I have already proven many times to work in standard regular building materials. Each cabinet has a pair of 8 inch sub's, pair of mid range, and pair of tweeters. Each on heavy cut passive crossovers on approach and roll off, again, on a proven designed crossover from 20 years ago that I designed, now with higher quality elements (chokes, caps) of today's brands.
My point is, I really like how they sound, They are not as boomy as the previous pair that were made, of the exactingly the same design and transducers, just with regular wood materials, and is pretty hard to hear with the naked ear, if a pair made with plane ole knotty pine wood, vs any of the heavier hard woods, out side of throwing them in the lab to seeing the overlay of the RTA patterns being compared. BUT, the epoxy saturated hardwood pair, sound strange. Clearly, I can tell a huge difference from the normal wood models. I will not be able to explain the "what", but, as stated, the often times controllable boominess is gone, but the sound in these stupid hard materials sound exceptionally accurate. It is like any of the sound, you get, is purely only what the speaker is putting out. Yes, there is the sound from the back side of the speakers coming through from the enclosure through the cone, but, it just sounds fast or accurate, sharp, again, the echo type boominess is gone. Yes, there is the bass spectrum there but it is as if, I digitally attenuated the base by 50% or more. Sounds kinda flat in the lab on the RTA. This is whee I am lost, the RTA shows a flat spectrum low to high, straight across, yet, what my ears hear, is completely different then what my eyes see on the RTA. STRANGE. How is that possible? What it sounds like, the RTA should show, the low end drooping WAY down from the center flat line? yet, that is not the case. I am lost on this one, but now, I am wonderfully curious of this. When I put them in my entertainment room, you do gain some of the lower end of the audio spectrum, but again, it is weird to hear these. I am speculating that the speakers are forced to do their job or rather, are allowed to do their job, and not have to drive the units so hard to keep things in check? They are exceptionally loud, and still accurate. The sensitivity at 1 watt at 1 meter or pink noise/white noise, is 98.8 dB Explain that? That in "E theory", is not even possible, especially with 48dB slope passive crossovers. The other standard wood units, are only a 89dB units which adds up perfectly, just not as efficient units, but sound great and sold many pairs of my proven design, but these new units, I am lost. They are wonderfully bright, even EQ'd flat. I must say, I do not think these material can be manufactured in a cost effective manor though, with out having a dedicated manufacturing process and time required to deal with slow cure times of the epoxy and the $200K vacuum machine and chamber the size of a small car and enough epoxy to submerge that amount of wood, and the willingness, to sacrifice tripped off epoxy that may not get used or can waste, which was approx 40 gallons, while noting, it is estimated, that only 10 to 15 gallons was pushed into the wood or saturated into the wood as the remaining was poured into molds that made parts that my brothers company makes for the boating industry. Normally that epoxy is fast cure for the production factor. But I wasn't sure or didn't want to have that 40 gallons trip on me in one huge brick weighing 100 to 200 lbs. and possibly go into a self ignition fire of thermal run-away by using fast cure.
Anyway, Hearing a speaker work vs slop around projecting noise from the front and echo from the enclosure on through the speakers cone in some what of a muddy sound, of what is basically a muddy delayed sound, now to be eliminated and only hearing what the speaks electrically reproduce, I am telling you, this is strange. It kinda reminds me of being in an anechoic chamber as a child on a family day, that General Electric employees (my father) could bring in their family's to show them what they do for a day. That sound proof room was crazy scary and I was 9 years old and to be in a large square room that the look-out platform that was suspended in the middle where the floor appeared to look like it was 20 foot down below my feet, looking through the metal grate expanded steel holes, that was creepy in itself. It looked like the machine that the X-MEN movie had called Cerebro. One person at a time, they would close the doors behind you, and you could talk or scream at the top of your lungs, and at age 9, I ran out of that room so fast. To hear a non returning echo or rather no echo at all, creeps the mind out, and it did to anybody who ever went into that room, that was not trained for dealing with that room. Again, more of something that can not be explained and only can be experienced to understand it. That room not only didn't bounce or return any sound back to you, it absorbed sound from you. The voice you hear in your ears and head from your voice, sounds like somebody is screaming in your ears, because that is louder then the voice being normally rebounded back off of normal surroundings, like walls. "NOT IN THAT ROOM". Really scary room. Well, a cabinet that doesn't move, or flex, is strange sounding, Please note, I like it. My next mission, I want to stack up several layers of preformed 1/8th inch (0.1250") thick tight weave carbon fiber sheets for a building material as board planks, I ordered enough to make 1.000" thick sheets when epoxied layers are clamped together and cured.
Building with carbon fiber, well, this is also costly, but not as costly, as per the vacuum machine. The clamping system I will be using is two granite precision surface plates, that I will invert one, via the over head hoist crane in the shop. I'll spray mold release spray on both, to manage the epoxy spillage from between the sheets and let the weight of the 24 x 36 x 8 granite surface plate handle the flatness, and the weight alone to squeeze out any excess. (Such a wise investment and use for precision granite surface plates, LOL) I might even throw kitchen wax parchment paper on the top to aid in snapping loose the removal of the top surface plate. Pardon the novel, but have been watching your stuff for a while now, and thought, you would find this interesting. and maybe venture down this avenue to monkey around with building materials that force the speakers to do their jobs, instead of the back side of a speaker to do allot of muddy work. as we always have done in the past, in fact, planned for. I am telling you, it will trip you out. Lastly, I can not see this being any advantage in car audio either? Just due to the nature of how sloppy the automobile is. Unknown to me, even if, one would be able to tell a difference of standard type materials for enclosures vs materials that do not flex or allow vibrations from the enclosure itself to give feed back of echo of a boomy sound, unless going for SPL or sound quality?.... may even hinder what most typically desire in a automobile set up? I do not know this yet. I might set them in the Jeep Cherokee, to see but that would require me ripping out allot of junk that make up the system in it now. That would require me to be in a really good mood to pull that off any time soon. I kinda wish the old school type of speakers were still offered like the "FREE-AIR" stuff. I am wondering what something like those that hate enclosures would do. But finding a FREE-AIR 8" sub woofer these days, not likely.. I have on order a set of 4, paper cone units coming, kinda like, if you'll remember the white paper cones from FISHER, the UDT's, those couldn't handle any heavy measure of wattage, above 20 watts, but dang were those efficient and loud for a 20 watt woofer. I have the part coming to build something like those. single 1.1 oz single layer spider, single layer wired paper voice coil, to eliminate any of the flux dampening in today's aluminum voice coil formers, 1.3 mm accordion paper surround, cast aluminum frames, and the magnets are pretty dinky, but, are adjustable poll pieces, I hope that aspect doesn't screw with the efficiency factor? This is gonna be interesting to see what happens, instead of the 8" Alumapro aluminum cone dual VC's crap. Oh, and the voice coils are 16 ohms each as well. lower accoustical output, but as you know, offer more control on accuracy. Good luck.
Would be reaaally interesting to see a video of this construction. It all sounds like an amazing project.
I really like the idea of solid wood speakers mainly for the aesthetic value, I came up with some plans to build a set of bi-wired bookshelf speakers and sub woofer using 1" thick Australian blackwood and Dayton rs100-8 4" full range speakers Dayton tweeters and the sub woofer was similar construction with a Dayton sub woofer. They are going to be mounted on gold spikes and the sub would have a in built amp. I've had the first bookshelf cabinet and now working on the second when I get time in the wood shop.
@mtozzy11 Wood veneer MDF gives the same look with better acoustics. Think about how loud a grand piano sounds, amplified by solid wood resonance. The more expensive speakers have inert boxes for good reason. You don't want your speaker boxes ringing (resonating), because it can only muddy the sound.
Head to head testing was the most interesting part of this video
Well reasoned presentation.
Thanks for sharing, very inspiring.
Hi John.
What accelerometer are you using to do your measurements?
How would you connect and do the setup in REW?
Thank you for your videos. Fantastic.
This is really good!
Always just found MDF as more consistent, but it depends on what you are after.
As any instrument the components make a difference..I have built a few solid wood speakers ..2 way..3 way and a 5 speaker set..I personally love real wood..but my audiophile friend says otherwise..great job and excellent analysis..Thanks
It would be interesting to see a solid wood speaker of the same dimensions as the retail one and move the crossover and the drivers and everything else between the two enclosures and then do the measurements. Great video. Thank you.
Few years back, I was in a room with over 5000 LP's, the owner, audiphile of some serious extent, had his speakers and tweeter built in brick enclosure. Volume and clarity, crispness, and the overall expereince was overwhelming. I wanted to stay and listen to every LP. Most of his LP's were German polydoor! My speakers i like to build in solid wood at least 3/4" thick, natural wood looks nicer! Thanks for all your video's you post, you make a lot of sense!
Getting a pair of speakers made locally with real wood cabinets. Dual horn design. Measurements look great too.
I used 3/4 mdf for all my car speaker and bass boxes. Mdf resists flex but rather allows flexing waves to flow through much like a car crash test would look. This destroys most unwanted resonants from the wood box which would multiply the speaker spikes. It really levels out the graph AND I always put 200% the packing because it adds a certain tone quality that you just have to hear. I am taking about sealed boxes and tube vented boxes.
"flowing" resonances are exactly what you do not want. MDF sub boxes always require more bracing than plywood ones, as plywood has a much higher point of self resonance per weight.
A friend made some speakers with recycled oak sheet.
They cracked in several places when placed near central-heating radiators one winter.
I hate mdf just for dust reasons. I use birch plywood now. Also wondering about panzerholz that should work wonders with resonances according to some. But it is expensive so maybe only for front panels.
I have been doing car audio builds for over 30 years for SPL competitions. When you get into SPL builds you will lose a lot DB using hardwood. When you get onto home theater builds I think hardwood sounds better in homes.
One word of warning. If you pop your woofer out to fill the cabinet with some stuffing, put something around the back of the woofer to stop the filling from making contact to the cone!
I think it's important to mention that the reason that stuffing virtually increases the box size is because the stuffing actually slows the down the sound waves. The higher the stuffing density the slower the sound waves travel.
Not really important to know what causes something to happen, as long as you know it will happen.
Like it's not important for a person that drives a car to know how the engine works, or someone who's building a house to know how brick is made.
Well yes and no. If you're designing a transmission line loudspeaker it's especially useful to be able to calculate the speed of sound through a given stuffing density in order to calculate your quarter wave line length. You can also increase the stuffing density in strategic locations in order to dampen standing waves. :-)
Yes, but those are two different things. Knowing that adding stuffing will increase box volume is all that's needed to design vented or sealed boxes. Sound doesn't propagate in a controlled way through either of those like it does in a TL.
@@IBuildIt Stuffing and lining are actually two different things in that. Stuffing as in loose fiber in the cabinet has the effect of slowing the movement and propagation, as you assumed. But stuffing is not really the appropriate approach for a vented loudspeaker, as it has a lot of drawbacks. That's where lining is still a thing, which is a sheet of the poly stapled or glued sparsely on the box. These panels are places where standing waves are expected to be formed, but it's important to remember a vent is a resonator (Helmholtz Resonator.) Damping the resonances there will not really help. Neither would slowing the air speed, as this needlessly complicates your box.
First, I assume very little. That's why I test, so I won't have to assume.
Second, argue with all of the major manufacturers (like Elac, the speaker featured in this video is stuffed) that use stuffing in vented boxes. If it's such a bad approach, why are they doing it?
Third, since this channel and everything I show on it has to do with building your own speakers, you can easily work the stuffing into your design modeling software and see the effect it has. You can tailor the response to be exactly what you want it to be. This isn't me telling the average Joe to pop the woofer out of his retail speakers and throw in a wad of fiberglass. It's me trying to talk to people who are interested in building their own.
When you stuff a vented box you just have to be careful to not block the port opening. The box will still resonate and that sound will still come out of the port. Nothing complicated about it at all and I've been building speakers since I was 13, back in the late 70's.
Hey! I would like to advise you to run tests like a sine test on 120,100,90,...down to 20 and every test has to run like 5 sec. Here is why: when the source starts resonating(speaker) the material needs time to get those resonances and send the impulse back to the source. If it's not continous it will not start properly resonating. You can see those experiments with the salt on a surface. It takes time to properly resonate a surface. A simple sweep is too quick and temporary so the box cannot build up frequencys or cancel out.
I just got a bunch of oak hard wood flooring I want to get 3/8 mdf and build my boxes and then wrap it with the oak. I was wondering if that would sound good
Hi thanks a lot for this very interesting test I have the feeling that side panels vibrations contribute is very low in level I know that also at Stereophile magazine lab use to check that
The very critical panel in a speaker looks to be the front baffle It's design and construction is decisive for a great sound (and soundstage)
And if i remember rightly at B&W they used Laser Interferometer devices with the measurements mirrors stuck to the front baffle to check for any baffle micromovements.
I read somewhere a very nice and telling analogy. It is like reading a newspaper held in front of us by a friend If the friend starts moving the paper back and forth the reading becomes extremely challenging because letters are much more difficult to put in focus
And something similar could happen with sound if baffle does not stay still. And in most commerical cheaper speakers it moves I am sure of that
Changing just the cabinet of a cheap speaker can make wonders A friend of mine did just that with surprising results
Kind regards, gino
John is right. Measuring resonance with a microphone or DATS would be useful to know if the damping is helping reduce resonance that impacts the woofer and thus audible noise. If you wish to measure what the box is doing, you have to measure the box.
Solid wood warps more often, can have voids/knots/etc that impart flaws. Also harder on tools, cost is much higher.
Tiny miniscule quantum amount of improvement that could be imparted in other ways with baffle changes.
That being said. Zero resonance might not be as good as a correct amount of resonance, much like an instrument.
Damping and baffles are for abating internal standing waves.
Bracing is for abating cabinet panel resonance.
Your accelerometer test may not so much be measuring the panel resonance as it is the effect of a standing wave. Cabinet dimensions determine standing wave frequencies. The standing waves will emanate out through the speaker cone.
I always use a MDF/ClothPadding/MDF sandwich with internal bracing leaving no more then 8x8 voids.
Could you test something that is designed for this application like no-res or dynamat?
I wonder how much volume (db) you need to make a 6.5" woofer move air like a large woofer. At that lower 6.5" scale, I would think it doesn't really matter that much what material you use. Like at low listening levels, even 1/2" mdf is as good as 3/4". When it gets louder and more air is pressurized, then it would really come into play, I think. Like common sense tells me to not put a 12" woofer on 3/4" baffle.
Just curious, would it make a noticable (audible) difference (in making the panels vibrate less) if you glued straight mats of fiberglass onto the panels or is stuffing well enough?
Stuffing and lining are two different things.
My buddy used to build speaker boxes and swore up and down that down filled pillows worked the best for stuffing for speakers. He would make a bag with this fabric that was almost see through and you could poke a finger through it. Fill the bag with down and us that in the box
Many enthusiast diy'ers utilize certain cheapo Walmart pillows for sub stuffing.
Aside from damping, pillows are easy to handle, retain shape and assure adequate clearance from vents, drivers, etc.
I find that stapling carpet tiles to the inside walls gives the best results
Very interesting....
You really should test some GR Reserch No Rez. It may be something you want to use in your large speaker build. It really improved and tightened up the bass in my CerwinVega speakers. I would like to see your opinion on how well it does at damping
Oh yeah and also the Black Hole 5 clone stuff that PE sells.
Agreed, had a set of xls encores with the no rez, and was the best bookshelves ive ever had, sold my revels and ls50s and kept those, not just due to the no rez im sure, but certainly solid and tonally perfect. Shouldve kept em.
i have xls-215 what did you get from gr research?
@@shangrilaladeda xls encores, full upgrades.
@@JukeboxAlley thank you do you know the price of them and I once went to his site and had such trouble navigating it I couldn’t figure much out
I think the issue with solid wood is structural changes as you mentioned, less of an issue the sound or stuff like that.
these videos have sucked me down the rabbit hole.
There are more comparison's that could be done. various grades of lumber, solid wood (hardwood vs soft wood) vs plywood as Baltic Birch is, coating the inside walls of the box walls vs uncoated.
A home made pair of KEF 104’s using chipboard and real wood veneer started to look scruffy when the veneer began to peel off. Cladding the cabinet in an extra layer of half inch solid oak transformed the sound dramatically for the better. That was 40 years ago, maybe damping is very important……
It's vitally important.
By adding thickness you STIFFENED the panels by the cube of the thickness. This didn't dampen them, it made them less flexible and less transmissive, more reflective of acoustic energy, forcing that energy to be dissipated by other means, e.g. through absorptive "stuffing", moving the woofer cone, or exiting through the port.
I've made a few different speakers using solid red oak and solid white pine and the pine always seemed to sound better.
Is spruce good for acoustic guitar?
Spruce. This evergreen, found in northern temperate regions of the globe, is literally top choice: the ideal wood for the soundboard, or top, of an acoustic guitar. Its look - light in color, even in grain - is appealing though somewhat plain; what sets it apart is its beautiful tonal properties.
We here about MDF or wood, rarely about HDF. What about using HDF?
Where did you get that accelerometer?
Thanks!
can you test bamboo composite material resonace ？
59 experts so far say you are wrong and think you should spend about $4000 and do the test again with exact materials, supported by platinum braces and done on the moon. I guess I'm not an expert because I understood exactly what you were trying to show and I too, saw it.
Agreed. Sometimes we overcomplicate things
btw which accelerometer you have used can you pls tell me the model no
Good to mix and match materials. MDF + plywood veneer is extremely inert.
Years ago a UK company Radford Audio made a speaker whose enclosure was solid Afrormosia ( around 5/8 thick I think ) with some bracing . Thing weighed a ton, it was a medium sized triple driver floor-stander. Sounded very good as I recall.
Expensive; not popular.
Guys get lost in the minutia in nearly everything, but especially in audio. And often manufacturers will run with that by saying certain things are way more important than they actually are. Ultra quiet cabinets are one of those, especially when compared to other factors that are giant sized (but generally ignored) in comparison.
@@IBuildIt the minutia...😀
Like your style.
So you attached your sensor on the veneer
Which is good sound
Where the drivers the same in both boxes?
Even in the case of measuring the same amount of vibrations from the box, a natural material like hardwood (compared to MDF)
could possibly have a nicer tone to the sound that benefits the music. It's worth checking out.
@geminijinxies7258 How so? If that was true you could take the crap shoot method in building musical instruments from random hardwood, thickness, shape.......It's not going to happen. The best materials for speaker boxes (concrete, granite, aluminum.....) are denser and take much more energy than wood to excite them.
A good audiophile has a hard time distinguishing a 5db difference in a sound level across the frequencies.
Even after days of testing speakers on CLIO MLS frequency response I can tell something is different but not what is different.
By then I'm not entirely normal!-)
I think I get it now. I wonder if you could demonstrate somehow how low the cabinet output is compared to the speaker? A mic 1” from the cabinet wall plotted at the same time as a mic 1” from the cone?
Any microphone in any position will be swamped by the direct output from the cone. So there's no way to measure how much sound is coming from the panel itself, as far as I know.
Even the accelerometer isn't perfect - it will pick up how much the entire box is shaking along with the panel vibration.
KEF's Laurie Finchum has performed a careers amount of investigation on the cabinet's contribution.
Other major players in the industry have also performed extensive research in this area.
Cabinet panels excitation can manifest in acoustic energy emanating from the panel (relative to driver sizes, a large panel needn't move much to generate output).
KEF's Finchum also details that cabinet panel excitation not only arises from acoustic energy, but mechanical reactionary forces off the driver basket's mounting contaminates the initial direct energy of the driver.
KEF and others have addressed these issues. A recent example is KEF's Blade, and how the Uni-Q coax is entirely isolated physically in it's own sub-assembly ... whereas mechanical transmission is damped both directions; into and out of the coax module.
Currently, in my audio exploration, wherby the two challenges I currently enjoy learning and exploring the most;
Cabinet contributions, distortions and optimization.
Secondly, speakers, room acoustics, and their complex interaction.
Thanks
@@FOH3663 Thanks for the clarity. Some of the wrongheaded logic presented in this discussion was making my brain hurt! It's all about management of detrimental energy, dissipating it inaudibly or turning it to good purposes e.g. with ports. Dr. Geddes could set us straight in a hurry. His day job was quieting automobile interiors.
I'd consider concrete lined with butyl rubber as a cabinet material if my floor could take that weight. Your floor might.
Not trying to be hyper-critical here because honestly I only watch for entertainment, but to compare "apples to apples" wouldn't you have to build two exact same speakers with the only difference being the cabinet materials and not one that you did an exhaustively good job making it as good as practicable to a decent commercially built one?
Mackintosh apples to empire apples, then :)
@@IBuildIt 😂
But the limiting factor for stuffing is volume not weight so filling the box with each and testing would be the fair way and the real world way of testing
Do you have any comments on "world's best speakers" by your fellow youtuber 'Tech Ingredients"? They are flat panels
It depends which wood you use, for mass production solid wood would be impractical
Some say using real wood it sounds more like an instrument as instruments are made from real wood, like a violin or piano.
The unfixable problem is continuous drying. Even proper, quality dried wood is not completely dry, and after time it "moves" a lot, some type more, some type less. My father made one small box from beechwood, and cracks appeared near to the gluing points after 2-3 years, like, the glued surfaces remained intact, but the weaker panel got cracked. Such thing would never happen with MDF or ply. There are some really dense exotic wood types (like Patagonian or Caribbean Rosewood), which also less prone to dry and "move" a lot, but even if available, those things probably cost a fortune compared to MDF or ply. 😕
It is fixable, if you know how to make allowances for the movement.
You'll get cracking when you do something that doesn't allow the wood to freely expand and contract with seasonal moisture changes. Those same allowances are used when making solid wood furniture.
Stuffing is for breaking up high frequency standing waves and would be unwanted port ‘ noise’ and affective in increasing the ‘length of travel’ vs the ‘bee line’ between two parallel panels or structures internally which the air particle pattern of oscillation must navigate in between/in and around, or within the messy hard to travel fibrous filled space. It can even lower tuning -slightly- in a transmission line speaker design from this ‘distance’ it creates of actual travel. Damping’ out vibrations (after the fact) is only going to happen by bracing strategies and added mass like rubber, butyl weighted layers or uneven decoupling layers in the baffle itself? Kinetic energy being handled in either case. One on the ‘V^2’ part if the problem , and one on the ‘M’ . Both similar end product but not exactly related in the way stuffing ‘damps panels’ , that’s not what’s happening (if that makes sense in typing, I hope ) 🤓
I really gotta get an accelerometer like that, So cool! 👍🏻👍🏻
I've decided that it's better for me to not answer the comments that say that stuffing isn't effective for panel damping, since it's a lot like banging my head against a wall.
@@IBuildIt it’s semantics area often and the bulk$h!t is everywhere too! One that even the spelling of the words confuse it. Damping/dampening ? wet? Or a shock or impact absorb or ringing potential , etc . I think we are agreeing, but it still sounds (no pun intended 😆) ‘different ‘ when speaking of the cause or effect or result of .. in other words: prevent from occurring or absorb those that are going to…? Maybe that’s where it gets kinda mixed up? Either way, I think we’re agreeing. I don’t mix the idea up with sealed boxes. There’s a source of confusing the use of stuffing more than anything out there
@@IBuildIt yeah, but then the wall resonates.
and I get a headache :)
@@IBuildIt 😂😂😂😂😂
Concrete Boxes?
You have to dry out the wood like they do in instraments and have it seasoned in an oven for it to work right to take out all the moisture and strenghten the wood. Sonus faber makes a solid wood speaker this way that is sublime. Sonus Faber ELECTA AMATOR III it is called
Sounds like you are talking about torrified wood, which is very expensive and not commonly available.
@@IBuildIt Yea the Sonus Faber are 10 grand for the bookshelf, 15 grand for the towers. So it is expensivce stuff.
@@pennfootball71
Sonus Faber's flagship models are up over $140k ...
And relevant to this video's topic, they employ Tuned Mass Damping, ... pendulum style, down the center of the speaker internally. Not unlike those used in skyscrapers ie., Taipei 101, John Hancock bldg in Boston, CN Tower, Burj Dubai, and hundreds more.
Damping isn't the reduction in the amount of vibration. It's the reduction in oscillation of the cone. The more damping, the greater control of the cone for quicker, more accurate reproduction of the sound. Amps also have a damping factor
You are talking about electrical damping. This is mechanical damping. Same name, similar idea but entirely different implementation.
Damping = dissipating energy from an oscillating system.
Simply to clarify;
In this instance, damping (acoustically absorptive material in the box), is minimally impactful to restorative forces of the cone.
Such damping is to attenuate the acoustic energy in the box ... resonant and otherwise... thus lessening that latent energy's impact from contaminating the original signal... either thru the driver or thru the cabinet panels.
Alo there's mechanical damping of the cabinet walls... via mass, bracing, viscous and frictional losses, etc.
As you mentioned, electrical damping, ie., an amplifier's control of a driver's behavior.
John's content elicits the best comment discussion.
Wood is a natural substance and thus not uniform. The density can vary considerably throughout a cabinet panel. It is also typically less dense than MDF.
Make one like a bandsaw box, really wind them up.
What the real MDF guys don’t realize is that there is more to removing cabinet resonance than building materials. Some of the best speakers ever designed were built years before the glued sawdust MDaF material was invented. Resonance can be all but eliminated by paying attention to the thickness of the walls of a given cabinet, proper internal bracing and the use of the right damping material, like Rock wool, fiberglass etc. I owned an old pair of cabinets made from cheap fiber board. The crap used in the unseen sides of a hime assembled book shelf. They were nasty sounding in frequencies below 60HZ. The fundamental bass region. I hated them. Then e friend suggest that I stuff the cabinets with inexpensive Fiberglass. I thought he was crazy, but R30 was restively cheap, and I had a partial roll left over from insulating a small add in room in the house I had recently bought. Without insulation it was unbearable to be in year round. After filling the upper ceiling cavities in the attic, it became much cooler. Anyway, having cheap leftover stuff was the rigt price to experiment with. So I lined the walls of the cabinet with the R30, leaving plenty of airspace around the driver. what a huge difference. The bass no longer rang out forever, became much more defined and when I gave the cabinets the knock test which something I tried and found to work. Knocking on a cabinet et wall to see how it sounded told you if there was resonance. A good cabinet was identified by almost no sound being audible. A decent cab was somewhat audible, but can be dealt with, and if the rest of the store can hear your knocks and the salesman ran up to see what your doing, it was unusable. I also thump a woofer, nowhere near the dust cap,but enough to hear the resonance of the driver helps me find a good vs crap driver when no specs are available, still test it to make sure you are right before using it in any build, but useful on the cheap. Anyway, fiberglass helped a crap cabinet immensely. Bracing and anti resonant material allows natural wood to compete with MDF, and most people will never hear the difference. A trained ear, sure. But when minimized to prevent listening fatigue, who cares!
On more quick thing. The Klipsch Corner Horn with the Cornwall and Heresy are often refers to as the best speakers ever made. Although I believe there better better drivers available now, these speakers used real wood construction and resonance is not a problem. I fact this video brought this to mind!
the proper experiment would be putting drivers and electronics of the Elacs into a wooden cabinet, then compare.
Music instruments are made of solid wood because it resonates and guitars and pianos sound good because the solid wood (and thickness) is purposely chosen to resonate in a favorably manner. Put a tiny blue tooth speaker on a solid wood table and the bass amplifies many times. This is with 1 watt (or less) energy. I placed my LS 50s (inert cabinets) on a solid wood desk and they sounded like as$, because the bass was droning through the desk. When I isolated them with sand filled MDF boxes, they sounded great. Everything in the universe has a resonance point, but at very different frequencies and some thing ring much longer. Solid wood rings on and that is why it is chosen for instruments. My hard wood floor also sounds like as$ (worlds most muddy subwoofer) and that is why I decouple my speakers from the floor. I love hardwood, but I don't want it connected to any of my audio system, because it seriously degrades the sound quality, compared to more inert (less resonance) materials.
You have only one peak, but it is huge at + 18 Db if you draw a straight line through your frequency response. That would hurt my brain. I need a flatter frequency response. That said, everything needs to be relative. If you replace a very thin cabinet of particle board with a more solid 1.5 " solid wood cabinet, then it may still sound better. However, a 1.5" MDF cabinet would have much less resonance than solid wood. Rap your knuckles on it, if it rings longer, it's resonating more. Also, I think the glue from the tape would act as an acoustic barrier between the very light mass of the accelerometer and the cabinet. Especially in the higher frequencies. At what level did you do your test? At low volume cabinet resonance doesn't seem to be much of a factor, but when you increase the energy it's a different story.
Damn John,
This one hit your cabinet panel of experts, resonating in an un-damped manner.
I don't need no accelerometer to know ... this one clearly registers "un-damped".
C'mon, everyone knows "critically damped" is the target. Slacker.
If you keep this up, your numbers will continue to go up.
With changing density, your volume changes with weight changes. Your reasoning is fair only if two materials have the same volume and density. It's a war against unwanted vibration, fair is not a factor in war, unless you don't care about winning.
Two things...
One is... a THD plot show better, whats goin on... same drivers, one set in a rigide box, one in a cheap box...
The other thing is...
Stuffing is for enlarge the inner volume... to control the Qtc. right...
But it is not for damping the Vibrations. It is for damping the inner "room modes" of the box, which are damped down with stuffing...
For vibrations, normally material is used, which is stuffed onto the inner sides of the box... In most cases, material from cars ( damping material for the inner sides of doors trunk a.s.o ) :-)
Watch my other videos on damping.
Mdf is death. Wood has resonance. In a diy speaker book was a info from fostex or coral. Use 2 different layer of material. 16mm and glue inside 12 or 13mm . So no swinging in the enclosure.
Stuffing is better than potatoes from what I hear.
My hypothesis is NO. Less adhesive, more resonance. However, Sonus Faber likes enclosures to resonate like the body of a Cello.
There are so many variables to this subject matter [HiFi & acoustics] it's a wonder anyone can wrap their mind around it. I certainly can't. For instance you all don't want the box to vibrate [resonance?] so you use MDF or ply. To me ply flexes, just a matter over what span. In my mind you'd want to use a very dense wood then. For reasonably price domestic wood that would be hickory. For imported, ipe, cumaru, tigerwood, or teak[$]. I never see speakers made from such woods, so no, I do not get it.
just line the solid wood(or whatever) up with resonance dampening material on the inside. simples
Tech Ingredients channel goes science nerd crazy detail indepth on this topic. Worth checking it out if you're interested.
I think I'll definitely build a pair.... I lost mine in the divorce
Dang bro. That's just spiteful.
I feel you! I lost about 6 or 7 pairs of vintage speakers I had been collecting over the years to a divorce.
Coincidentally, I just ordered my parts for my first speaker build last night: the ubiquitous Overnight Sensations. Prior to watching this video I was planning to build two versions: solid wood and MDF to hear if there are any differences. The plan stays the same because comparing two different speakers is pointless. Sorry John.
Have fun! The OS are a very fun kit to work with
Pour concrete into speaker shaped molds with chicken wire reenfocment... Maybe thicker than chicken wire.....
I "stuck" thin poly w to w carpet inside my T-200's during my rebuild. I wanted a low damp, as the original Radio Shack stock speakers were very "boomy". I got great results on REW tests, looking forward to more builds. Love your vids.
ua-cam.com/users/shortsK_LdBsBYJa8
actually particle board is even better that mdf and solid wood but less lasting
The reasons MDF is popular for speaker building are lower price, consistency of the material and millability.
wood sounds better than mdf
Put styrofoam balls in box like they do in cell phone speaker chambers !
Solid wood is equal to resonance.
Com 4 stats
Comments on much of what I have read below, not just the video. When testing A versus B then outside of the 2 materials on test then everything else must be exactly the same, same drivers, volumes, fillings, electronics cables etc. Also any judging of 'results' thru 'reading' electronically produced graphs and charts is flawed. Your eyes cannot tell you how something sounds. Only your ears can judge differences and one persons like will be another persons dislike. Where materials are concerned many materials are right for cabinets, woods, glass, plastic, concrete, IF YOU THE LISTENER LIKES THE SOUND ITS GOOD FOR YOU. its that simple. I have been buying gear for 40 years and marketing guff has got more and more technical/confusing/distracting and I now just go to the shop and listen and sometimes home test. I don't care what its made of, the tolerances, the graphs, the geometry, the cables, the theory etc, etc. I just listen, my ears tell me if I like it or not. Simple , Buy what you like not what the charts, graphs and latest magazines tell you is this years 'best' . Remember the industry has to keep re inventing product to keep selling new stuff each year to survive , how do you think they do that ? I hope that you and some of your subscribers may agree with some of my points not just on this 'test' but the industry in general. I would finally like to add that the points made by Steve C were very relevant and I thought your dodged an answer with a flippant reply.
The point was to show the terrible monster hiding inside solid wood that makes it acoustically unsuitable for building speakers. Did you see any monster? Monster, not to be perceived as flippant, is a massive resonance that makes the test from the Elac look as flat as a mirror.
You don't need a 100% perfect test procedure to do what I set out to do. You just need viewers who can take a break from trying to find fault with every little thing and lighten up enough to listen to what's being said.
If you want a more scientific test that will meet your criteria, by all means do that test and make a video showing the results. Feel free to post a link back to it here so we all might learn from it.
@@IBuildIt flippant...headache😂😂😂
@@IBuildIt John, You are a true craftsman and technician. What I was attempting to do was to give my reasoned opinion that no electronic test on materials with accelerometers or any other gadget tells anyone what it sounds like. Results given as lines on a graph are purely relative to each other and cannot show which is 'best' . Best is what is best for any individual listener and only thru listening tests with EARS, not electronic graph producing kit. Peoples actual ears decide what is best for them, some people like clinical / flat , some people like warm / full , audiophiles strive for perfect whatever that is. Everyone has their own perfect sound and to say that solid wood is unsuitable for building speakers to me is incorrect. Solid woods of which there are 100's may just suit someone's listening criteria. You have your opinion and you put it out there with bold statements, you should at least accept that others with differing viewpoints will challenge and hopefully debate, all on your channel. More power to your channel. The more debate the better. PS the speakers I use myself and keep going back to are my Yamaha NS44 which are a close relation to the NS10. Why ? They sound good to me. All that matters ????
This is not a valid comparison. Two different speakers with different drivers, volume, dampening. If you want to do a valid comparison, build the same cabinet with MDF and hard wood and then measure. There’s scientific method for a reason.
Nope. LDF is superior than any other type of woods. LDF has the widest range of audio freq response from lower bass to high pitch freq. Please don't mislead people.
Partical board is dead , stable, and easy to work with . Far superior to wood that twists, rings, and harder to work with .
Nonsense comparison. Completely meaningless