Your personal experiences with various cabinet designs.

[Drjay]

One of the great things about this forum is the experience and expertiese of its members. A couple of years ago I started a post asking about the "Real world importance of cabinet bracing" in a 1CF box and learned a lot about the topic. However, the discussion got pretty esoteric and my final decision after studying 6 pages of posts was to line the cabinet with ceramic tile and use the following bracing scheme. " I plan to glue in a side to side and front to back brace centered on the tiles. These braces will be 3/4 X 1 1/4 plywood. Each brace will consist of two pieces, overlapped 4" and glued with a 1/8" thick layer of silicone glue as shown in post #56 to load the flexible glue in shear."
While there was one comment that this seemed like a good plan, there were 3 of comments which suggested that it would be better to use a thin layer of construction adhesive instead of a 1/8" layer of silicone because the silicone would be too flexible. Of perhaps greater inerest to me, were comments that there would be little or no audible difference between this approach and no bracing at all (!) and comments that even simple fore and aft braces might result in the speaker sounding worse. There was consensus that an inert cabinet is always desireable, but much disagreement on theoretical grounds about how to get an inert cabinet.
So (without going into too much abstraction) what is your real world experience as to what you would do in order to build a 1/2 to 1CF cabinet that colors the sound minimaly? I know that the tile lined Keremiskas are outstanding, and that Rasmus' (if I remembe his name correctly) super heavy lead lined speakers won the InDIYana theme contest and that Ben has used a super stiff, mass loaded cabinet to good effect. I THINK that bracing of some kind probably results in some audible improvement, but have never compared or measured any speaker I have built with vs.without bracing. I THINK that a doubly thick baffle (1.5 ") might result in reduced cabinet coloration but have never A-B tested or listened to a speaker with a single thickness vs. double thickness baffle.
Many of we DIYrs like to experiment, and I'm betting that some of you have personal, real world experience in what matters and what doesn't in terms of building an excellent, if not state of the art, 1/2 to 1 CF cabinet. Your knowledge and personal experiences are hearby requested.
Best,
Jay

[billfitzmaurice]

I never use exotic constructions. If it exists at some point I probably tried it, and I always came back to 1/2" plywood well braced. I do this in cabs as large as 20 cu.ft. and it always works well. With something as small as 1/2 to 1 cu. ft. it's a pretty simple affair.

[DeZZar]

I'm curious as to what the prevailing theory was behind lining a cabinet with ceramic tile? I would have hypothesized that adding an even more reflective internal surface was a bad idea. Think bathroom acoustics.

I take the perspective that anything that vibrates is making sound. So if your speakers are banging away and you place your hand on the side panel and its vibrating away - its making sound - it effectively is another transducer in the mix.

Personally, I use a minimum of 1 inch material (made from two layers of 1/2inch MDF) along with solid internal bracing. Depends on box size but I generally space the bracing at around 6 inches. Using 1/2 inch stock I make the baffle and top 3 layers and the base 4 layers.

The combination of layering, overall thickness, the naturally less resonant MDF and the bracing makes a sufficiently inert box.

Here's an example of the layering and bracing on a current, not quite finished, project (which is actually a refurb). In this example the side panels are curved and layered so that they are around 1inch at the front and back but reach out to 2 inches thick in the middle. Tapping on these boxes sounds like tapping on concrete.



This is generally the sort of bracing I work with:

[Steve Lee]

I LOVE your commitment to bracing!

[Steve Lee]

Consider for a moment the density and weight of ceramic tile.

It has inherent inertia.

It's application to the inner walls of the cabinet slows/slews the rate of the cabinet walls movement/reaction to the sound pressure waves delivered by the speaker then it is reducing resonances.

The reflective component of the the sound waves at higher frequencies from the tile surfaces can be damped by the addition of absorbent/diffusive material like goose feathers/pillow stuffing and shag carpet.

Or am I way off bass, here?

[djg]

Orange shag.

[DeZZar]

I get that the ceramic is heavy/dense etc...its just that my initial gut reaction to the idea was wondering if it introduces more than it removes...but hey, if it works, fantastic, I've just never thought about tiling the inside of my speakers before!

[djg]

No personal experience with exotic stuff. The KEF LS50 has some interesting construction, and Wolf's Stance interests me enough to maybe build. I was thinking of drywall as the wall stuffing for those.

[PEB]

Drjay, is that pre-veneered MDF on those large cabinets? What is the plan for the front and back panels?

[billfitzmaurice]

Tile...
It's application to the inner walls of the cabinet slows/slews the rate of the cabinet walls movement/reaction to the sound pressure waves delivered by the speaker then it is reducing resonances.

True, and if you don't mind the added weight and construction complexity it works. However, the OP is asking about personal experience. IME it works no better than well braced plywood, or MDF if you should choose that if you're doing veneer. It's not that complex constructions can't work, it's that, again IME, they don't work better than when you adhere to the principle of KISS.

[DeZZar]

Drjay, is that pre-veneered MDF on those large cabinets? What is the plan for the front and back panels?

I'm assuming you were perhaps referring to the images I posted?

No it isn't pre-veneered MDF. The sides of these cabinets are made from multiple layers of radiused MDF pieces - so the whole side is essentially "end grain" MDF. The veneer you spotted is actually just a cheap "backing" veneer that I have applied as a first player. A second layer of makore is planned for these. The idea of the first layer is to provide a smooth surface that "seals" the underlying MDF to make sure the layers do not show through to the final layer of veneer which will be finished in high gloss.

The back panel will be fixed in place and given the same treatment before the final veneer is applied.

[Wolf]

Yeah, my little Stance's 'tank-box' as they were referred to really did the job well.

1- You have to brace, period. Brace well. Even reinforcing corner density with battens can stiffen a panel.
2- If you can mass-load, this also helps. Tile, mass-fill, troweled glop; whatever
3- damping or absorptive materials finish it off.

I know some people have used self-adhesive floor tile. It's basically a rubber/mass base, and it can do the job well.
CLD? Never tried it, but not sold on it from hearing others' attempts.

Later,
Wolf