Quote Originally Posted by RGA
Further Kex -- just some other interesting things that the adds fuel to Peter being comparatively in left field. Lots here for him to be attacked on know doubt but let's just purge it from the system -- This is fairly long so get a Sleeman's Honey Brown and a nice cigar and have a good read or laugh etc.
You've got to respect this guy's passion for what he does, if nothing else. I think he's got a great approach (not that I'm much of an authority on the subject), the product speaks for itself. But there's a lot of PR in Peter's philosophies. I don't see anything necessarily left field or revolutionary here, despite the great efforts to present the ideas as totally unique.

in other words we let the cabinet release the energy as fast as possible rather than hold on to it and release it later at lower ampliitude as happens in a damped cabinet.
The benefit is overall improved efficiency (upto nearly 1 dB) and a sound that is far less restrained by the cabinet in a way that heavily damped cabinets are not.
Myth 1 - cabinets are damped to store more energy and release it at lower amplitudes. While damping can do this, I'm not aware of many speakers that actually use damping with this "goal" in mind...nor am I convinced that this is the result obtained more often than not.. In cheap, entry level speakers I suspect it's used like this more, but to be fair, it's a worthwhile compromise usually.

Consider my old Paradigm Monitor 5's. They had an ungodly amount of stuffing in them - Dacron or polyfil, I can't remember exactly. The cabinets aren't the greatest, but typical of that price-point and performance level. Here it is used to compensate for resonances as Peter suggest. But there's a benefit too. The Monitor 5's cabinets should probably be significantly larger than they are. The damping allows you to avoid making an even bigger box of the same cheap materials, thereby reducing size, cost, and the problems that would come with an even larger somewhat poorly made box. Eliminate the quality of the cabinet construction for just a minute. Each woofer calls for a range of box sizes - there isn't one really, various properties will be "optimal" at slightly different volumes. Using damping material gives you the flexibility to try to make it so the woofer "sees" as many of these optimal values as possible. If my woofer calls for a 45 L box for flat response, and 40 L box for better efficiency and transient behavior...I'll make at say, 41 L and add damping material to make the woofer see 45L. The mass of the damping material isn't nearly as much as the added mass that the larger cabinet would have (as you add a few inches HxWxD of MDF, birch ply, or whatever)...back to the Monitor 5's, you damp out cabinet resonances, avoid an even bigger crappy box that you would have needed (that would introduce more problems), probably keep costs lower, and get closer to universally "optimal" size. Not really a bad thing.

You have to remember, Peter doesn't build speakers for the guy who wants a $400 speaker that Rawwks hard...he's catering to a more discriminating crowd. I think he'd sooner put a bullet in his head than meet the demands of people for whom the Monitor 5 is just what they're looking for. (even if we could argue they'd get a more refined speaker in the AX-2 for a bit more cash).

But there's value in what Peter says. Ed Frias, who owns EFE Technology, designed the ar.com DIY speaker. Since I've paid attention to it, the biggest initial "problem" most people have with the speaker when they first here it is it sounds "muffled" or (as you put) though someone was covering it with a towel...the problem is the damping. Madisound sends them acoustic damping foam, or upsells them Acousta stuff, and then instructs buildiers to use 1/2 lb of it....killing some of the speakers sparkle and snap (transients I guess) while dramatically adding to the apparent volume. Ed instructs a very lightly fluffed, loose handful of polyfill ($3 per 3/4 lb, enough to do 20 speakers or so), just enough to line the rear wall and damp any cabinet resonances, internal waves etc, because it sounds better.

Totem use a different damping altogether...borosilicate material (not cheap). It effectively eliminates the tangential (spelling?) and oblique modes...axial modes are pretty much ignored (much like AN's designs), and aren't a big deal in their small cabinets

That's what designers should be doing...strategically placing the damping material to compensate for the 3 kinds of modes. Peter seems to use bracing to address this. Too many companies just fill the bejeezus out of the cabinet and say "there, we damped them all".

To make this design philosophy possible and effective a designer cannot use drivers with high mass, long throw or large diameter, they are simply too "slow" and release too much energy into the cabinet, so rather than seek a piston effect, I seek a "pressure resonator" behaviour with minimal cone movement.
Agreed...low xmax drivers sound better to me than high xmax drivers. Long-throw is great for car audio buffs who want you to hear them coming, not so great for sound quality though (IMO).


I say, let's keep the box, but use it according to the laws of physics (meaning wide baffle and shallow depth) to reduce difraction and internal cancellation effects.
He uses an age old "golden rule" cabinet ratio. The dimensions will act the same regardless of which side the woofer is mounted (for the most part) The wide baffle doesn't reduce difraction effects though, instead it just shifts it lower in frequency. A good crossover compensates for this though, in both slim and fat box speakers. Fat box advantage is the ability of the cabinet/driver properties to compensate for baffle step loss more than slim lines, this can aid in keeping efficiency high. The advantage of slim cabinets is reduced edge diffraction and superior imaging and clarity. I think the real advantage in slim boxes is the imaging/soundstaging improvements, when combined with the increased placement flexibility you'd get in most rooms. Still, I don't think one is inherently superior to the other. Proper execution is required of both.