Distributed Mode loudspeakers - Have there been any discussions?

[Robert Freemond]

Hi Everyone, I haven't been around for a while I've been taking a break from Guitar building & building other things. I have recently found an interest in DML's
& don't know if they have been discussed here.
Most of the non-pro versions I've heard sound too bright & lacking in low end.
I'm starting with two 2' x 2' extruded Polystyrene panels. & am waiting for two Dayton Audio DAEX32EP Exciters.
My first question will be about the placement of (Dampers ?) on the back to address the frequency problem or the use of other materials like Spruce.

I ask for help here rather than a speaker forum because those guys make my head spin

....Thanks

[David King]

I looked into them for a project years ago. WHat's your purpose? Those particular exciters are designed for heavy objects like tables and solid core doors not styrofoam panels. What amp are you planning to drive them with? You probably need to match the load to the impedance etc. These are super handy for near-field talking exhibit panels where you have to use battery power. Not the first place I'd look for quality music reproduction.

Tuning your dampening is going to be tricky. Classic dampening is a rigid plate attached with elastic putty i.e. .060" aluminum plate glued in place with a layer of silicone or other elastomeric compound. It's dampens everything, basically a big attenuator.

[Robert Freemond]

Thanks David, I just wanted to build some inexpensive speakers for the house that might be better than the bookshelves I have. I'm using a Hafler DH200 amp & preamp.

I have watched several videos using various materials & thought I'd start here. I'm anxious to try the Spruce next.

[Randolph Rhett]

There is a guy on YouTube that did an exhaustive test of different materials and exciter/dampener placement. It is impossible to know what they sound like from a YouTube video, but the whole thing was less than $50. Worth the experiment. A crossover and a subwoofer would fix any low end issues. There is a YouTube on making your own crossover too.

I was thinking of putting together just such a system for the pure fun of it, but I don’t need speakers and usually only listen to music with headphones.

[Robert Freemond]

Randolph, That's what I'm doing.
I have seen that video plus many others & am in the process of constructing a pair.
A guy named Rich at Parts Express wrote this article on his build & I'm following it. http://projectgallery.parts-express.com ... at-pannel/

I bought the 24"x24" foamular panels & two Dayton exciters for starters. although he says the 24" x 32.5" (Golden Rectangle) sound warmer.
I'm not expecting the sound I heard from some Electrostatic speakers, but this should prove to be a fun project - especially when you consider the cost.
If you should try it, keep in touch, I will be interested in what you find.

[David King]

I'd recommend a small class -T (tripath) amp for these which could be embedded right in the panel (90% efficient). These have a low end bump that works quite well with the DMLs. You used to be able to buy the amps as a kit, I'm not sure what's available these days. Then add a nice Li-po 12V battery pack and you'd have a fun way to take your music wherever you want to go. A quality yet inexpensive Li-po battery would be the ubiquitous 18250 3.7V cells that are used in flashlights and E-cigarrettes and electric cars.