DIY Flat Panel Speaker Love

[Ronin]

Also, it seems like this would have been brought up by now (its impossible to read this entire thing) but just in case-- as any luthier will tell you, scoring and or sanding parts of the panel thinner will emphasize the modes flexing along those lines. Use to smooth out / taylor response. It's a more evolved version of simply putting weights on points.

[Unbiasedsound]

Also, it seems like this would have been brought up by now (its impossible to read this entire thing) but just in case-- as any luthier will tell you, scoring and or sanding parts of the panel thinner will emphasize the modes flexing along those lines. Use to smooth out / taylor response. It's a more evolved version of simply putting weights on points.

Yes utilizing various thicknesses through out the panel can help to smooth out and taylor response....This is one of the methods I have learned from Bertagnis designs....its not really a more evolved version but a different method used to taylor response.....Bertagni's design also uses weights as well.

[Kornbread]

Also, it seems like this would have been brought up by now (its impossible to read this entire thing) but just in case-- as any luthier will tell you, scoring and or sanding parts of the panel thinner will emphasize the modes flexing along those lines. Use to smooth out / taylor response. It's a more evolved version of simply putting weights on points.

Scoring a thin metal is bound to have an influence on nodes, same with cutting grooves/channels in foam board. If we only had some kind of software to model these panels ...

[Ronin]

Re: DIY Flat Panel Speaker Love

I made some panels out of aluminum sheeting of few years ago, stuck some damping on the back. Not bad sound, good highs, less efficient though.

Captain-- I'd love to know details. About how much less efficient? Size? Thickness of aluminum and EPS backing? Which exciters?

[ameuba10]

has anyone tried it on a tall narrow board similar to a tower?


also, looking at daytons buyers guide it states

"Bass and low frequency sound are enhanced greatly when using larger panels or increased areas of substrate. Additionally, using a heavier substrate will allow deeper bass to be achieved, but at the expense of reduced treble output."

With that being said, could one design a board with many perpendicular boards (think heatsink) to create a "subwoofer?"

[Unbiasedsound]

I have used the Balsa and bass hobby wood that is tall and narrow around 2-3ft. but only 4 inches width and 1/8-1/16th thickness....They lack bass so it would best be used as a sat with subwoofer.....To achieve decent amounts of bass the panel would need to be at least 12"X12".

Are bass and low frequency sound enhanced when using larger panels, SURE, but bigger is not always better unless you know how to properly utilize it in ones design....Too big of a panel will make the bass sound muddy and sluggish.

In my opinion, DML/Bending wave technology is like throwing a pebble in a pond and watching the ripples flow to the edges....Bigger the pond the longer it takes for the ripples to reach the edge, the longer the bass travels the muddier/sluggish it will get if the panels are too big because it will take that much longer to reach the edge before stopping.

Treble vibrations are weaker then bass vibrations so the bigger the panel/pond the weaker the treble vibrations get when it reaches the edges hence the diffused sound....the smaller the panel the more focus and pronounced the treble becomes as it has way less area to travel hence the reason why most conventional treble drivers are "SMALL".

[Unbiasedsound]

Since last nov. I have been experimenting and combining XRK's foam board enclosures to my DML panels and it has improved the performance of all my panels especially in the bass region. Who would of thunk to use EPS foam to increase bass response. Props to XRK for this technique.

[panoramer]

Damn. That sucks. Like I said i was just trying to imitate those JMC's, that cost $8k!!! They do use there own type of exciter so maybe that's where the difference is. But for that money they have to sound good.
Maggies have always been a dream of mine to own. Maybe one day.

Thanks for the response.

Hi. I have done a lot of research about the JMC soundboard. Yes they use 8 of them. The ones I saw in the video I posted above are 15 Watts. The producer is http://mechakustik.de/exciter.html Elac brand.

[Unbiasedsound]

Found a video of some old school Yamaha speakers that utilized DML/BMR technology for the bass and combined them with the conventional cone type of drivers for the mids and highs.

I am planning on duplicating those speakers in the near future.....Did yawl see how huge that exciter transducer is on that bass panel?....Now that is the type of huge/robust exciter I wish Dayton would make.

https://www.youtube.com/watch?v=XNGsFul8sXI&t=172s

I just read that someone on Audiokarma said that Yamaha licensed the technology from Bertagni (BES)...no wonder the shape of the bass driver is shaped very similar to Bertagnis.

[nnjones]

Hi all,

I've been reading the threads on DML panels and am thinking about building some.

Here is what I have envisioned:

Dayton DAEX30HESF-4 drivers, 2 per channel in series, two panels per side vertically stacked (EPS or XPS?) 1" thick, 24" x 32", corners rounded, sanded and treated, mounted in a frame using foam weather stripping insulation as a suspension.

Should I mount the driver frames onto a spline/back brace, leave them free standing, or screw them down to the foam panels? It would make sense to me to fix them to a spline/brace so more energy is transferred to the coil/panel, and they would not have coil sag, but mounting them would cause more energy to be transferred to the frame (maybe silicone them to the brace?)

The rest of the details I'll work out around the crossover/DSP but any suggestions or advice would be appreciated.

I'm located in Fox Cities, WI area and noticed there are others that posted on this forum that are nearby, it would be great to hear from you.

Regards,
Nate

[Unbiasedsound]

You seem to be on the right track.....Best results I have found is to mount them to a spline/brace attached to a frame....if mounted securely very little energy is transferred to the frame as the voice coil will push against the magnet which will be stabilized in place by the brace and almost all of the energy will be transferred to the panel....you can use silicone or epoxy glue....I prefer epoxy.

[Kornbread]

I eventually hung carboard panels from the ceiling with string before abandoning the experiment. It started with blue insulation board (xps) mounted in a frame, don't remember what size, but big. Eventually wound up cutting the edge of the foam board leaving only small tabs holding the foam board into the frame. For the most part it resonated freely from the frame. The freer the foam became, the more bass it produced. The exciter was mounted to a brace running behind the foam board which also increased bass output. Most of my experiment, including measurements, and the model number of the exciters which, at times, wouldn't last long enough to get a measurement, should still be on this thread minus pictures that Photobucket hosted.

[nnjones]

You seem to be on the right track.....Best results I have found is to mount them to a spline/brace attached to a frame....if mounted securely very little energy is transferred to the frame as the voice coil will push against the magnet which will be stabilized in place by the brace and almost all of the energy will be transferred to the panel....you can use silicone or epoxy glue....I prefer epoxy.

Cool, that makes sense to me, thanks.

[Unbiasedsound]

This new Lepai 2.1 amp is what I needed for my (BASTAT) DML satellite/sub combo panels.

https://www.parts-express.com/lepai-lp210pa-2x30w-60w-21-channel-mini-plate-amplifier-tpa3118--310-4002

[Vinaudi]

I am interested in DML. I would like to explore various hanging options for XPS. I am thinking of a free standing solution.

I am also interested in ways to power them at the source so a signal can be pushed wirelessly.

Ideas?