Is Solid Wood Good for Speaker Building? Head to Head Testing - DIY vs Elac

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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[IBuildIt]

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.

[bryzabone]

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. 👍🏻

[chrisAclaes]

You’re doing exactly the content I’m looking for in my projects. Thanks!

[drubradley]

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.

[BlueTJay]

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!

[mtozzy]

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.

[wobblysauce]

Always just found MDF as more consistent, but it depends on what you are after.

[glenncurry]

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!

[_Reacts]

Getting a pair of speakers made locally with real wood cabinets. Dual horn design. Measurements look great too.

[scor]

Head to head testing was the most interesting part of this video

[groverbaker]

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

[KipdoesStuff]

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.

[didamnesia]

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.

[christianratajczak]

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.

[allanmorris]

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……

[Darkmatterme]

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.

[Synthematix]

I find that stapling carpet tiles to the inside walls gives the best results

[Clobercow]

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.

[JohnLee-dbzt]

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.

[staLkerhu]

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. 😕