[Bakpayn]

Hiya.  Looked at a bunch of cabinet builds using almost exclusively MDF. Don't think I've seen any with plywood and wondered why.
I've worked with wood for over 50 yrs now and one of the most stable products I have used has been Baltic Birch plywood 3/4".
It is Multilayered and the "grain" is perpendicular to each other. Virtually no voids in the layers like you find in Construction grade Ply.
Also each layer is Birch not just some cheap filler or seconds material. Last time I bought a 4x8 sheet it was marginally more than good quality construction Ply.

So. How come it isn't used more often? Higher end speaker boxes would hugely benefit from its Properties??
It's not that much more expensive and its way better product.  Marine grade Ply is even better...

Before I found you guys and GR-Research I've been watching a Youtube channel, "Tech Ingredients", the guy is unreal at least I think so.
I knew he had done some research a while ago on materials and some speaker stuff, I just had to find it. I did.

If your interested Mr. Richie and all others please watch the Video, warning, they are almost an hour each but very informative. At least I think so.
Seeing them again really helped me understand much better what Danny Richie talks about in some of his Videos.
Maybe GR-Research could build a set using the existing Drivers but with some alternate materials to see if there is any difference to the standard builds, anyways enough Yakin' here are the 2 Links.

https://www.youtube.com/watch?v=EEh01PX-q9I
and
https://www.youtube.com/watch?v=jjZHFIdfUFk

Hope you enjoy.
Erik.

[EdwardT]

These are quarter sawn Cherry veneer over Baltic birch cabinets from Peter J.

They sound really good.

[Bakpayn]

THOSE are what I need for my Workshop...

[Chewbacca]

I believe MDF is used due to its density and non-resonant properties. The added resin and pressing the board goes through really makes it a hard and consistent material throughout, from one board to the next - you can expect them to be consistent. Especially Super Refined/Paint Grade/Plum Creek. In addition of course to its easy availability, low price, ease of working, ease of finishing, etc.

I've always thought that making a cabinet out of Solid Surface would be quite interesting. Or Corian, to the common folk... Tissue, Kleenex, you get the point. Definitely stays along the lines of me - quite dense

I've designed some fairly elaborate fixtures/displays using it before. Curious how it would sound. Certainly wouldn't be too hard to make a cab out of it.

Here's an example of what can be done with it (not my work):

[mgalusha]

Before I found you guys and GR-Research I've been watching a Youtube channel, "Tech Ingredients", the guy is unreal at least I think so.
I knew he had done some research a while ago on materials and some speaker stuff, I just had to find it. I did.

I'm using the decidamp and thin plywood CLD he demo's in the video, those panels are really dead in comparison to the 18mm BB plywood that is the base layer.

[Argoncat]

Are you "gluing" up the laminate with Decidamp and then trimming to final dimensions?  If so, does the Decidamp foul the saw blades?

[routlaw]

I haven't built any speakers in a long time, but the subject line on this thread caught my interest. A few years ago I read an online article where someone ran accelerometer test on various but common building materials and found MDF to be one of the poorest performers and baltic birch to be the best. So as the OP suggest its interesting why baltic birch isn't used more often if for no other reason it structural integrity is on an order of magnitude better than MDF. Hope this helps.

I suspect someone could google the article mentioned above. I don't recall who performed the test but they seemed as though they knew what they were talking about.

[doorman]

Having built numerous pairs of speakers, Baltic birch is my go-to, there’s other very plausible options of course, including apple ply, stranded bamboo etc. (I’ve seen but not used some of these examples)
I avoid MDF totally, whatever positive attributes it may have, the dust alone is a deal breaker.
Ymmv, as always.

[planet10]

Hiya.  Looked at a bunch of cabinet builds using almost exclusively MDF. Don't think I've seen any with plywood and wondered why.

MDF is cheap (in may ways), and a substantial myth about its suitability for building speaker boxes have been brilliantly promoted by the marketers, so much so that even many very talented speaker  designers are still in its thrall.

Bob Berner of BigWoodStudio does BB flat-paks. A growing number of available diy designs.

Baltic Birch plywood 3/4"

It should be noted that these days, callin git ¾” is only a convoence for tose still living in the only significant holdout from the metric system of measurement. BB comes from the Baltic, it is a nominal 18mm (vrs ¾” = 19/05 mm)

It is Multilayered and the "grain" is perpendicular to each other. Virtually no voids in the layers

That is a good description of “quality” plywood. Default choice around here. The BB we used started getting inconsistent so we switched to Murphy ply whixh adds maple veneers to the quality cores the get from the Baltic.

The only “wooden” panel material that u grade higher is stranded/fossilized bamboo plywood. It could be further improved (you’d either have to order A LOT, or make your own). Once th ehemp industry gets off the ground, using the lng fibres of th ehemp plant in a similar manner should be a furtehr improvement — and that stuff will grow almost anywhere,

Higher end speaker boxes would hugely benefit from its Properties??

Many would. And some do. Have you seen the video of them making the plywood shell for the big B&W nSeries.

And they would be cheaper to ship.

dave

[mgalusha]

Are you "gluing" up the laminate with Decidamp and then trimming to final dimensions?  If so, does the Decidamp foul the saw blades?

I cut the section pieces to fit the areas of the panels between the dados and where it met the other cabinet parts. Covering every square mm wasn't something I worried about and I expect about 98% is covered. The stuff is thick like frozen peanut butter and once the catalyst is mixed in, it has about 30 - 40 minutes of working time. I did it over three days, two panels each day, each with 4 sections. The front panel is 3 sheets of 18mm BB glued up. Unfortunately I forgot to do the top and bottom pieces of the cabinets, but I had some dynamat and no-rez on hand, so they received a bit of that. Not close to as dead as the decidamp/plywood combo but way better than nothing.

As for saw blades, once fully cured it might not tear them up but I suspect it would make a mess. I had a few areas where some ended up on mating surfaces, it wasn't hard to scrape off, but I think it would stick to a high speed blade, but of course that is pure supposition.

[planet10]

I believe MDF is used due to its density and non-resonant properties.

Density is not an asset. Sometimes it comes along with really stiff (standed bamboo ply) but in itself lighter is better,

And non-resonant is part of the myth i mentioned above.

dave

[planet10]

a cabinet out of Solid Surface

Let me save you the time. It does not work well.

dave

[mgalusha]

And non-resonant is part of the myth i mentioned above.

So true.

[planet10]

stranded bamboo

Perhaps the choice of the somewhat garish neopolitan version was not the best asethetic choice, but it sure stands out.



dave

[mlundy57]

Around here BB is three times the price of MDF. I've used both and each have issues. The biggest one, other than the cost, I've had with BB is blow out when edge profiling even with shallow passes. MDF is messy and edge profiles are more difficult to seal when painting.

[planet10]

Ignoring the fact that we could get as much free MDF as we could, the price differential is not as great here, but 3-4x is well worth it once one adds in all the other costs, it becomes insignificant.

One cannot approach the design or build quite the same way when utilizing MDF or ply.

dave

[GaryPC]

Thanks Erik, I thoroughly enjoyed watching the links and at last know where/what accelerometer (the ADXL335 Amazon $17) I think I can use to measure cabinet vibration.  But to your point, in the 1st video the specific comparison between plywood and MDF that happens at 25:05 minutes is really interesting.  Because of this alone, and also because of the huge dust mess I get into when I work with MDF (even with a 5hp cyclone dust collector that I admit I should learn to utilize better), my next speaker will be definitely be from furniture or marine grade plywood and possibly from the African mahogany Sapelli plywood that is discussed in the video.
 

Hiya.  Looked at a bunch of cabinet builds using almost exclusively MDF. Don't think I've seen any with plywood and wondered why.
I've worked with wood for over 50 yrs now and one of the most stable products I have used has been Baltic Birch plywood 3/4".
It is Multilayered and the "grain" is perpendicular to each other. Virtually no voids in the layers like you find in Construction grade Ply.
Also each layer is Birch not just some cheap filler or seconds material. Last time I bought a 4x8 sheet it was marginally more than good quality construction Ply.

So. How come it isn't used more often? Higher end speaker boxes would hugely benefit from its Properties??
It's not that much more expensive and its way better product.  Marine grade Ply is even better...

Before I found you guys and GR-Research I've been watching a Youtube channel, "Tech Ingredients", the guy is unreal at least I think so.
I knew he had done some research a while ago on materials and some speaker stuff, I just had to find it. I did.

If your interested Mr. Richie and all others please watch the Video, warning, they are almost an hour each but very informative. At least I think so.
Seeing them again really helped me understand much better what Danny Richie talks about in some of his Videos.
Maybe GR-Research could build a set using the existing Drivers but with some alternate materials to see if there is any difference to the standard builds, anyways enough Yakin' here are the 2 Links.

https://www.youtube.com/watch?v=EEh01PX-q9I
and
https://www.youtube.com/watch?v=jjZHFIdfUFk

Hope you enjoy.
Erik.

[Early B.]

Maybe GR-Research could build a set using the existing Drivers but with some alternate materials to see if there is any difference to the standard builds,

If there are sonic differences between MDF and BB, it will likely be hardly noticeable. Nevertheless, even if BB sounds better than MDF, the additional cost may not warrant its use. Besides, there are probably less expensive ways to manipulate the sound quality in speakers. So real wood may be a good option for reasons other than sound.

Also, how much of the enclosure material do you actually hear if it's lined with No Rez or some other product?



 

[lokie]

Working on a new build and went to Home Depot to buy a couple of sheets of Baltic Birch... it was $88 a sheet.

Too cheap to pull the trigger.

[Early B.]

Working on a new build and went to Home Depot to buy a couple of sheets of Baltic Birch... it was $88 a sheet.

Too cheap to pull the trigger.

Wow. Wood prices have skyrocketed.

Plus, BB ain't exactly the prettiest pony when stained, so you gotta veneer it like EdwardT did above if you want your real wood cabinets to look more like real wood.