DIY Flat Panel Speaker Love

[rmeinke]

Re: DIY Flat Panel Speaker Love

It has been suggested but I'm not sure that anyone has implemented a multi-panel/all DML speaker at this point using different panel material that are selected to perform best in a specifically frequency range. It certainly is something to try for sure.

I'd post ask over at AudioCircle so see if they know of anyone who has tried.

Happy New Year all!!

[Chaz_H]

Re: DIY Flat Panel Speaker Love

Yeah, I'd be curious to know if anyone's tried it yet. Bass panels might even be "tuned" by adding mass.

[Squidspeak]

Re: DIY Flat Panel Speaker Love

Lets just say back when I was a young budding hifi noob that was the forum I found, and subsequently followed the advice of the "experts" over there. The a$$ wiping and flushing of several thousand dollars down the toilet was a lesson well learned about the audiophool world. It did push me to learn way more about audio then I might ever have, being the simpleton paint slinging aircraft maintainer that I am.

Jay, I don't know about the other sub forums on Audio Circle but the OB forum is pretty good. I also built a modified Hestia project
that was well received at the NY/NJ DIY 2014 event back in November. I have read a bit of the thread on the exciters in the OB forum. Someone
brought a pair to NY/NJ 2013 that sounded pretty good, the panels looked like menu boards at a restaurant.

[Jay1]

Re: DIY Flat Panel Speaker Love

I stopped checking in over there a long time ago, my experiences come from the 2001-2004 time frame. Just holding my grudge.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Jay, I don't know about the other sub forums on Audio Circle but the OB forum is pretty good. I also built a modified Hestia project
that was well received at the NY/NJ DIY 2014 event back in November. I have read a bit of the thread on the exciters in the OB forum. Someone
brought a pair to NY/NJ 2013 that sounded pretty good, the panels looked like menu boards at a restaurant.

Hey Squid!
Congrats on the modified Hestia. I saw the pics and read the entire thread from the NY DIY event to see how everyone liked the OBs. They look great and sound just as good I understand. Well done man!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Yeah, I'd be curious to know if anyone's tried it yet. Bass panels might even be "tuned" by adding mass.

Right on brother! Tectonic add weights to their panels I understand... kinda fun to tweak such a setup to see what exactly you could get?!?

[rmeinke]

Re: DIY Flat Panel Speaker Love

it sounds very intriguing indeed. I wonder how distortion changes with the material used, or with the number of transducers. What about a speaker like this, where different panels are optimized for bass or treble production?

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I was so interested in the link to see what panel design might be hidden only a link away that I didn't respond to the rest of your post. :(

Panel material is a huge determining factor to the finished panel. The material should be light, reasonably damped and ridged. Like traditional driver development its a trade off. Commercial panels are honeycomb using Nomex and other light and ridged high-tech materials. KEF used XPS foam board for their DML speaker. EPS or XPS foam insulation panels are cheap and available and make a great material for DIY DML speakers.

What I have found if the treatment of the panel also has a HUGE impact on the sonic characteristics of the panel. For instance, using the same panel material and panel treatment (1:1 water and wood glue), my small XPS 2ft x 2ft panels are detailed, crisp and crystal clear compared to my 2ft x 4ft panels that sound slow, dull and have significant self-noise. The small panels sounded also sounded this way the first few days however after the treatment cures, the sound improved greatly. I thought that I was just adjusting to the panel sound but after 5 seconds of switching to the larger panels did I understand what a HUGE impact the treatment of the panels surface has on the sound quality/characteristics. Exciter break in also contributes I am sure but it is not clear to me exactly how much it contributes to the self noise and improves sound quality. So given the fact that the panel skin appears to have a profound impact on the final sound characteristic there may be other materials to try (epoxy and shellac have been tried and sound good. There has been less experience with epoxy is my impression.

A lot of panel materials and treatments have been used (see the "Open Baffle" section over at AudioCircle in thread "NXT.......rubbish??....THINK AGAIN!" for details). All kinds of shapes and sizes. Over 4 years of experimenting in that thread.

But to conclude I think the best sounding to date is sanded EPS and XPS insulation board treated with 1:1 water and white/wood PVA glue. Birch plywood is also reported to sound very good but that material needs more time and attention and stronger exciters have been introduced that might make that material more viable so time my rewrite all previous statements.

I'm very satisfied with my small 2ft x 2ft panels. Combining a smaller panel with a Open Baffle sub would be heavenly. Might want to go with a larger panel to integrate better with a traditional sealed/vented sub woofer. To listen more full-range the panel size ought to be 2ft x 4ft minimum.

Here is a in room RTA of my fresh 2x4 panels:

In room at listening position:


In room close mic'ed center of panel:


The panels sound full (if not boomy at the moment) and not lacking in bass given the RTA's FR but that might be how the panels interact with the room/mic. However a little EQ to taste may be an option for some. Considering I have $39 into the 2ft. x 4ft. panels an equalizer that could be used for multiple purposes would be a reasonable ask. I use a Behringer DCX2496 Ultradrive Pro for crossing to my Open Baffle bass bins and to EQ the panels and my traditional full-rangers in OB.

Lots of options and is just plain old DIY fun at its core! 1 hour and you can have delicious flat panel sound!

[donradick]

Re: DIY Flat Panel Speaker Love

So I got a couple of 2 x 2 pink project panels and some Titebond II at HD today.....

Those FRs you posted look pretty great!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey Don... Sweet! The 2x2 panels roll off sooner and don't play as low but they do sound very good after the panel treatment cures and the exciters break in. You will enjoy them after a few days but they will hit full stride in a week or so.

You can use a hair dryer to speed drying of the panel treatment. Could have music tonight!!!! But be warned (before break in and curing)... they will sound shallow, fuzzy, veiled and generally crappy ( ) but you *will* hear some of the outstanding characteristics when the music contains it. I have not listened to rock on the panels other than some Pink Floyd DSOTM; mainly jazz and acoustic that really sound nice on the panels. Live recordings also sound very good and a specialty of the panels.

What exciters do you have Don?

[donradick]

Re: DIY Flat Panel Speaker Love

I've got Qty 4 of the DAEX58FP

I must have missed it - how do you attach them to the foam?

[rmeinke]

Re: DIY Flat Panel Speaker Love

I don't think I detailed that.

Elmer's ProBond Advance glue from Walmart is what I used for those exciters. Placed a heavish glass cup on it for 2 hours and used the hair drier in waves to dry it more quick. I let it set for 5-6 hours before I could not help myself any longer.

1 exciter 3/5 from the top of the panel and 3/5 from the left or right (I made a mirror image pair). When listening however, I flipped them so the exciter is top outside corner.

Good luck Don!

[laserpaddy]

Re: DIY Flat Panel Speaker Love

This looks like FUN!! I would try a west epoxy 2 part system it can stick to anything and can be spread extremely thin, resistance to all weather heat etc that you would ever want a speaker to be placed. I used it for high powered rocketry. Going to have to pick some up after more research...thanks

[Silver1omo]

Re: DIY Flat Panel Speaker Love

http://techtalk.parts-express.com/showthread.php?238606-Transducer-surrounds

[rmeinke]

Re: DIY Flat Panel Speaker Love

Morning Don,
Hope you didn't get the DAEX58FP exciter glued in place on the test panels. After listening to them for a few days on larger 2 ft. x 4 ft. panels they were not sounding nearly good as the small panels and were especially boomy and overall plain sluggish. Not the clean sound that I have been enjoying on the small panels. You can follow this disappointing and horrifying development over at the AudioCircle thread on DML panels.

After making a new set of 2 ft. x 4 ft. panels last night and using a single Dayton Audio DAEX25FHE-4 exciter the large panels are now performing very well with plenty of panel magic.

Don't know how the DAEX58FP exciter is going to sound on the small panel but I would ditch them as quickly as I could. The large plastic plate on the exciter really caused issues with transfering the energy to the light XPS panel. Very disappointing.

I would order the Dayton Audio DAEX32EP-4 exciter. It is new but the early reports are extremely positive and to quote one of the listeners... "a game changer" in DML panel technology and sound quality.

[rmeinke]

Re: DIY Flat Panel Speaker Love

http://techtalk.parts-express.com/sh...ucer-surrounds

All I can say is wow... the panels look AMAZING! Your wife is very talented.

Sorry to hear that they didn't sound good. The DAEX58FP exciter is not a good performing exciter and the panel material will not produce Hi-Fi quality sound as you already experienced. For $30 you could make a really excellent performing speaker.

I have heard really good things about DML panels for HT use. This is very believable to me as they perform very well with "live" recordings. This is evident with DIY panels as well as commercial offerings. DML panels with supporting subs might be the ultimate HT setup if there is room for panels. A 2 ft. x 2 ft. panel with a sub would perform well I imagine.

Personally, I have not wall mounted a set of panels but just holding up my small panels the low frequencies disappear. The dipole radiation pattern is disrupted and not allowed to develop when placed against the wall.

Kind regards,
Rich