DIY Flat Panel Speaker Love

[rmeinke]

Re: DIY Flat Panel Speaker Love

And another...

Here is why the DAEX32Q-4 doesn't sound so good...

This is on 2'x2' XPS vs. Thruster on 24"x30" Ply:

[Gary.M]

Re: DIY Flat Panel Speaker Love

And another...

Here is why the DAEX32Q-4 doesn't sound so good...

This is on 2'x2' XPS vs. Thruster on 24"x30" Ply:
[ATTACH=CONFIG]62241[/ATTACH]

Be interesting to see the DAEX32Q-4 on ply to see if heavier material works better with it.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Yes, agreed. I want to try it on other panel materials though the difference between the Thruster on ply and XPS were not terribly different. This leads me to think that to heal its woes I may try a light spline mounting and/or heavier suspension.

This will have to wait as I have other exciters and plans ready to go! :(

[Kornbread]

Re: DIY Flat Panel Speaker Love

Adding more sticks to the fire.

After a drying time of three days for the the lacquer impregnated cardboard, response has changed very little if any. The deep peaks and dips, similar to to the xps panel with floating exciter, are still there.

:rolleyes: Someone model this size panel, 37"x51" so I can use the null areas for mounting areas. :rolleyes: Then we can see if mounting the exciter on this panel has the same, or similar effect, as on the xps panel.



rmeinke, can you overlay these measurements with yours? Your graphs indicate an average of 90db, mine average way less. What kind of musical spl levels are you listening at?


Food for thought .....

The Podiums use 5 exciters, "use conventional crossover techniques to limit the signal going to one or more of the drive units", and tunes with "sound bridges."

Discovered something by accident while marking one of the panel corners for trimming. Try this,hold a glass against the panel, move it to other areas of the panel. Just try it. Try things other than glass. What did you find?

With this accidental discovery and "sound bridges" ...

[rmeinke]

Re: DIY Flat Panel Speaker Love

Adding more sticks to the fire.

After a drying time of three days for the the lacquer impregnated cardboard, response has changed very little if any. The deep peaks and dips, similar to to the xps panel with floating exciter, are still there.

:rolleyes: Someone model this size panel, 37"x51" so I can use the null areas for mounting areas. :rolleyes: Then we can see if mounting the exciter on this panel has the same, or similar effect, as on the xps panel.

[ATTACH=CONFIG]62242[/ATTACH]

rmeinke, can you overlay these measurements with yours? Your graphs indicate an average of 90db, mine average way less. What kind of musical spl levels are you listening at?


Food for thought .....

The Podiums use 5 exciters, "use conventional crossover techniques to limit the signal going to one or more of the drive units", and tunes with "sound bridges."

Discovered something by accident while marking one of the panel corners for trimming. Try this,hold a glass against the panel, move it to other areas of the panel. Just try it. Try things other than glass. What did you find?

With this accidental discovery and "sound bridges" ...

Hey KB, shoot me the saved measurement file from REQ (.mdat) and I'll see if was can combine measurements or just remeasure and add my measurements to yours.

It was good to go back a read the Podium reviews... the conventional crossovers high pass some of the exciters. I understand that with each exciter added to a single panel, the high frequency response is cut by approx. 3dB. So having 5 exciters per panel would result in a very bass heavy panel so some solution had to be found. I misunderstood the sound bridges originally... here they are just an area to clamp to the panel to the frame (and damp the panel at that location). That is interesting insight and appears there is a little tweaking that can be done (at least on a hard and rigid panel that "rings") to change the low freq. response of the panel; not a new concept for us but an interesting just the same knowing Podium choose to tune their's with a small number of bridges. I remember that thee can be moved around and adjusted.

A few more quotes from the 6moons article(http://www.6moons.com/audioreviews/podium/1.html)
"... shown at the Heathrow show in 2006 and at Munich in 2007 used 100% free-floating honeycomb panels, the final production model we received had a modification in this respect. Shining the light through the panel revealed four non-symmetrically placed braces or sound bridges where the honeycomb panel was connected to the Oak frame."

"You may be interested to know that I have a design for a Podium 1 which uses a very large number of sound bridges and absolutely no built-in electronics. But I did not like the performance and the complexity of the physical design concerned me so I went with the electronic/sound-bridge hybrid."

Seems he took a balanced approach in the end in regard to the suspension/sound bridges and passive crossover.

[rmeinke]

Re: DIY Flat Panel Speaker Love

"This is exactly it. The thin leads from the exciter to voice coil breaks. I have had better luck with the Thruster than the Ultra but they both appear to suffer from this issue. The leads are solid copper and not flexible,woven tinsel leads like we see on the DAEX30HESF-4. "

Seriously? Thats just nuts. No-one makes any sort of loudspeaker driver with solid leads instead of braided. Its just guaranteed to break. Hopefully all of the returns will make them rethink and fix this.

I took apart the last failed Ultra last night and this one was different. The leads are not solid copper... it is flexible and completely intact so hopefully we have less fail int hat way.

This one died because the voice coil became unglued to the flange that mounts to the panel. I had another one like this earlier; sounded like something was rattling inside the exciter. That one too must have failed like this and I just assumed it was the broken leads.

This is sad as all the parts and pieces of the exciter are fine... just the adhesive bond failed. Probably a cent worth of adhesive is what is caused this latest failure... now if this can get fixed we will be in a much better spot.

I'm curious... of those of you who had an exciter fail, can you verify the cause?

Broken tinsel lead?

Rattling of the voice coil int he gap?

or ???

[Gary.M]

Re: DIY Flat Panel Speaker Love

I took apart the last failed Ultra last night and this one was different. The leads are not solid copper... it is flexible and completely intact so hopefully we have less fail int hat way.

This one died because the voice coil became unglued to the flange that mounts to the panel. I had another one like this earlier; sounded like something was rattling inside the exciter. That one too must have failed like this and I just assumed it was the broken leads.

This is sad as all the parts and pieces of the exciter are fine... just the adhesive bond failed. Probably a cent worth of adhesive is what is caused this latest failure... now if this can get fixed we will be in a much better spot.

I'm curious... of those of you who had an exciter fail, can you verify the cause?

Broken tinsel lead?

Rattling of the voice coil int he gap?

or ???

A thought/question. Are these failures on heavier material like ply, or on the xps as well?

[Kornbread]

Re: DIY Flat Panel Speaker Love

Put self adhesive light density foam tape, 1/2"x3/4" along the inner sides of old xps frame, mounted treated cardboard panel.

Even though the panel is held in place by light density foam, it changed the sound, free air was better.

Solid mount frequency response cardboard panel.

Solid mount purple vs free air brown cardboard panel.

Tried to locate enough areas of lesser activity in which to leave mounting tabs. Done this by simply dragging a pen down the panel edge while playing music, sinewaves, and pink noise, the pen would rattle against the panel or just sit there.

Gary, both of my exciters that stb show open circuit and were mounted on a large 1" xps panel.

[rmeinke]

Re: DIY Flat Panel Speaker Love

A thought/question. Are these failures on heavier material like ply, or on the xps as well?

Hey Gary, I've had failures on mostly XPS & 1 on ply so nothing related to materials.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Put self adhesive light density foam tape, 1/2"x3/4" along the inner sides of old xps frame, mounted treated cardboard panel.

Even though the panel is held in place by light density foam, it changed the sound, free air was better.

Solid mount frequency response cardboard panel. [ATTACH=CONFIG]62264[/ATTACH]

Solid mount purple vs free air brown cardboard panel. [ATTACH=CONFIG]62265[/ATTACH]

Tried to locate enough areas of lesser activity in which to leave mounting tabs. Done this by simply dragging a pen down the panel edge while playing music, sinewaves, and pink noise, the pen would rattle against the panel or just sit there.

Gary, both of my exciters that stb show open circuit and were mounted on a large 1" xps panel.

Like XPS, and probably more so, cardboard is a pretty well damped material. Probably have said this before... but my personal feeling is that you only damp the panel enough to prevent any panel noise. Any more additional damping reduced the panels "air" and high frequency extension.

But most importantly... how does each sound??

[Kornbread]

Re: DIY Flat Panel Speaker Love

But most importantly... how does each sound??

The cardboard must sound better, I fell asleep while listening. Couldn't relax and listen long enough to the xps panels to do that.


This may be where I'm heading next. http://www.ebay.com/itm/4-ft-x-25-50...8yxIzgX5NQl_Yw

[Gary.M]

Re: DIY Flat Panel Speaker Love

The cardboard must sound better, I fell asleep while listening. Couldn't relax and listen long enough to the xps panels to do that.


This may be where I'm heading next. http://www.ebay.com/itm/4-ft-x-25-50...8yxIzgX5NQl_Yw

What you going to grow something to assist with your appreciation? ;-)

[Kornbread]

Re: DIY Flat Panel Speaker Love

What you going to grow something to assist with your appreciation? ;-)

Stretch the mylar tight on the same wooden frame. Haven't figured out a way to 'tune' how taught the mylar is yet.

Not waf friendly or speaker related but since you brought it up could use a laugh before work. http://joecartoon.com/watch/i1bbbc/S...me=last_7_days

[Gary.M]

Re: DIY Flat Panel Speaker Love

Stretch the mylar tight on the same wooden frame. Haven't figured out a way to 'tune' how taught the mylar is yet.

Not waf friendly or speaker related but since you brought it up could use a laugh before work. http://joecartoon.com/watch/i1bbbc/S...me=last_7_days

Joecartoon.com. I forgot about that, it's been a long time. Excellent.

[Unbiasedsound]

Re: DIY Flat Panel Speaker Love

Here is another link I found of bertagni speakers to help yawl with some ideas for perfecting your designs.

http://www.townwire.net/bes_d120's.htm