DIY Flat Panel Speaker Love

[vlad335]

Re: DIY Flat Panel Speaker Love

Thanks for the wonderful reply and explanations. My basement is fairly big so I think i will go with the 24x30 panels as a 1st timer. Thinking of eventually hanging them from the overhead floor joists. Not looking for critical listening, audiophile stuff right away just intrigued as to what these can do. Years back I purchased a pair of old Magnepan SMGa's off of Craigslist and will never forget the sound of them when first hooking them up. The midrange and highs were pure magic such as I have never heard since. The spaciousness between instruments and the way these reproduced a type of live sound that no box speaker can get close to... That is what I am looking for. If the total cost of $50 can even get part of the way to this experience then it will be worth it.

Long story short the Maggies gave up the ghost a couple weeks later. ( Wires were corroded d/t to the age of the panels.) I considered having them repaired and contacted Magnepan but lost interest and moved on. I really enjoyed the SMG's but also found their limitations. They were terrible as left and right speakers in a home theater role with action type movies. No sonic impact whatsoever. Most likely because they didn't go very low. They needed a woofer and mating one to them was a challenge. However, I was getting close when the panels died. Open baffle bass is certainly the ticket.

My days off are Thurs-Fri. so these will be the days to jump into this. Question: You are gluing the exciters to the XPS board correct? I saw that you referenced the type of glue used on page three of this thread. Havent received my Dayton exciters yet but it appears they have foam with adhesive on them. Do you add the glue to the adhesive side of the foam then stick them on? Sorry, probably a dumb question but want to get this right. Also, heard about the 4/5's rule of placement or something to that effect to cut down on standing waves, where would the optimum placement of these drivers be for a 24x30" panel?

Thanks again for your reply and all your help here.

[rmeinke]

Re: DIY Flat Panel Speaker Love

If you liked your Maggies then I know you will really like these panels. I've always liked Electrostats as well... so transparent and clear, but also very polite and lacking slam (which I hard a hard time with... couldn't full enjoy them due to this). These panels are far more sensitive and while I would never say that a DML panel has slam... they are certainly much less polite!

Imaging is very good like a good line array or large panel speaker. Voices are crystal clear.

I have not gone back to my open baffles since December but there is certain lack of presence to these. I don't remember feeling the same with Electostats or Apogee full-range ribbons but it may have been there as well and a side effect of any large panels diffused sound production. Saying this because it did take me some time to adjust to the presentation of these panels.

In any event... you ought to really enjoy them. I don't do HT but I've been told and have read a number of time that DML's are excellent for HT.

For attaching the exciters to the panel, I just use the VHB tape that is already attached to the exciter. Only after the testing is done or I need to remount, then I glue them on. I use Elmer's Probond Max mainly because that the best glue Walmart had the night I needed to re-glue.


For placement on the panels, its 3/5 from the top and sides. So that would be 18 inches from the top and 14.5 inches from 1 side. I make mirror a mirror imaged pair so 1 14.5 inched from the left on one, and 14.5 from the right on the other.

one last note : You will get some panel self-noise for an hour or so but that goes away and the panel will continue to sound better as the treatment cures. The exciters will also break-in as you listen. The Ultra's sounds pretty darn good right from the start but did improve over time... but just not as much as other exciters. Just keep these in mind as you listen for the first time. I was really disappointed when I first started to listen so just give them a little time like any other speaker.

Hit me up with any other questions. You ought to have some nice sounding panels soon man! Good luck!!!

[LongHorn64]

Re: DIY Flat Panel Speaker Love

rmeinke, I love this line-

"If you liked your Maggies then I know you will really like these panels." Truer words have rarely been mentioned in audio circles. I miss mine to this day. All the best, Mike

[rmeinke]

Re: DIY Flat Panel Speaker Love

rmeinke, I love this line-

"If you liked your Maggies then I know you will really like these panels." Truer words have rarely been mentioned in audio circles. I miss mine to this day. All the best, Mike

Never purchased a set of Maggies, ML's or Apogee's and wished to hell I would have. Had many excellent opportunities back in the day but I listened to more rock and alternative then and they just didn't work as well, in the balance, across all the music I enjoyed.

I listen to acoustic, jazz, blues, etc. and would be PERFECT for nearly all the music I listen too now. This is why I really enjoy these panels; they have many of the same qualities. Not the same transparency nor the soft or delicate delivery. I do miss those aspects of a Maggie but on the flip side these DML panels are very sensitive and have more authority into the lower mid-range/upper base region... just sound more ballsy; not as delicate... But in a good way!

Cheers!

[Fshow]

Re: DIY Flat Panel Speaker Love

Hi all

Thought I would post a little more. I had a dip in response at 40 hz. I noticed if I lifted the panel off its feet the dip was reduced, so I put a small block of wood under each corner of the existing legs. This helped, see image below. I also included an image of a pair of double stacked Advents and double stacked Bose 901's just for some kind of reference. Ignore the gradual slope in response as the freq increases, it's not real, the program doesn't have a microphone calibration.
I was listening to an organ piece illustrating the pedal notes, and I was enjoying the depth and articulation, when Michael Barones voice came on to deliver a short monologue. I was startled by how real it was. I don't think I have ever heard any thing more real on any speaker that I have heard before.
I also noted that on songs that had very quiet passages and loud passages, that I could hear every detail on the quiet parts. Before I would have to turn up the volume for the quiet passages then be blasted away on the louder passages.
The thing I would like to improve on theses panels is to be able to run them without an equalizer.










Have fun
Fred

[rmeinke]

Re: DIY Flat Panel Speaker Love

Looks good Fred!
Detail is impressive on these panels. I'm still discovering detail on recordings I've listened to 100's of times. What is impressive is that they deliver this detail in a smooth and very natural way. Even poor recordings that can otherwise sound etched and harsh are more listenable on the panels. Definitely not typical.

While I enjoy the panels more with EQ, they still sound fine without. In the 7+ years of experimenting over at AC, no one has really been able to produce a panel with a perfectly smooth response. Read over the later posts... there is a white paper that does a good job showing some different suspension methods and the resulting freq. response. A "Fully Rolled" suspension provides the a perfectly smooth transfer function. The resulting freq. anomalies are then the result of the panel material and exciter.

You can try different edge treatments. Felt dots, other patterns, etc. I'm sure you could smooth a bit more. But folks have spent a lot of time trying to smooth the response but with no meaningful breakthroughs. Can chase squiggly lines day and night... switchbacks and roundabouts my friend. Even if we can't get them superbly flat, whatever small improvements can be made will mean less EQ... that's a good and reasonable goal Fred!

[Fshow]

Re: DIY Flat Panel Speaker Love

Looks good Fred!
Detail is impressive on these panels. I'm still discovering detail on recordings I've listened to 100's of times. What is impressive is that they deliver this detail in a smooth and very natural way. Even poor recordings that can otherwise sound etched and harsh are more listenable on the panels. Definitely not typical.

While I enjoy the panels more with EQ, they still sound fine without. In the 7+ years of experimenting over at AC, no one has really been able to produce a panel with a perfectly smooth response. Read over the later posts... there is a white paper that does a good job showing some different suspension methods and the resulting freq. response. A "Fully Rolled" suspension provides the a perfectly smooth transfer function. The resulting freq. anomalies are then the result of the panel material and exciter.

You can try different edge treatments. Felt dots, other patterns, etc. I'm sure you could smooth a bit more. But folks have spent a lot of time trying to smooth the response but with no meaningful breakthroughs. Can chase squiggly lines day and night... switchbacks and roundabouts my friend. Even if we can't get them superbly flat, whatever small improvements can be made will mean less EQ... that's a good and reasonable goal Fred!

Hi Rich

Thanks for your comments and advice,it's greatly appreciated. I certainly agree with your first paragraph it sums up how I feel also, the remarkable thing is they are so detailed but don't irritate .
My previous panels were black poster board, I had the same or similar issues as these panels, when the freq got very low the panels rattled. I tried many suspensions, rubber, paper, wood, cardboard, playing cards etc. in the end I ended up fastening the panels directly to the frame. I was successful taming both panel types. But the price I had to pay was a bloom in mid frequencies centered roughly at 1 kHz. On the poster bd pnls I used 2 notch filters, and that did work. I will probably try this on these panel but I don't think it will work on these because the bloom is so broad.

Thanks again
Fred

[vlad335]

Re: DIY Flat Panel Speaker Love

Bummer. Got these done and wired them up today. One of the exciters is distorting real bad if I turn up the volume. The other plays fine but most of the sound seems to come from the rear. Is this normal?

[rmeinke]

Re: DIY Flat Panel Speaker Love

...

As I said... different sounding. You have to get adjusted to the presentation as the panels are distant sounding after switching from my open baffles. There is a lack of presence and a sensation that the music is emanating from behind the speaker, through the panel, then to the listening space. Once adjusted they are VERY ENJOYABLE and NATURAL sounding. I listened to Muddy Waters "Folk Singer" (on gold disk) and Cowboy Junkies "Trinity Sessions" into the wee hours of the night a few nights ago just enjoying the dynamics and naturalness. Very nice indeed. All from $30 worth of parts and 1 hours time. Amazing honestly. Would be interesting to combine with an open baffle bass panel. Lots of different configurations.

...

Ah man, that is a bummer vlad. The Ultra's can be fragile but PE will replace, just stinks that you will have to wait for it to arrive. For how cheap they are, I keep a few extra around.

See above from my first post. I reacted the same way to the panels as you did... was pretty disappointed after the first few listening sessions to be honest. And it took me more than a few days to adjust to them... but each session got better and I enjoyed them more and more... once they opened up for me it was flippin' addicting... spent late night after late night going through my music collection disc by disc taking in the new presentation and discovering nuances I hadn't quite heard before.

btw - How big is your room? I moved mine from my listening room (approx 12x14) to our large living room and that seemed to make a big difference. I didn't know if it was me adjusting to the sound, the exciters breaking in, panels curing harder but it wasn't until I got them into the living room that I began to appreciate what they had to offer... was about to give up on them... sure glad I didn't.

Just give them a little time vlad.

[Fshow]

Re: DIY Flat Panel Speaker Love

Hi Vlad

Just my 2 cents worth.

When I ordered these 2 thruster exciters, one was distorted from the beginning and a short time later the voice coil opened up. PE sent me a replacement right away and they have been fine.

But I wanted to say be sure that nothing is touching the panel including the speaker wires.

Make sure the exciter is firmly attached to the panel. I put 2 coats of straight PVA under the exciter lightly sanding it with each coat so that the 3m tape has something smooth to grab on to.

Fred

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hello all,
Soooo... once adjusted to the diffused sound of a DML panel, how IS the presentation?

Standing in the opening to the living room (15+ feet from the panels which are pulled 5 feet into the room) and observing the audio system, its very difficult to pinpoint where the music is coming from. Music appears to just float in space... completely detached from the speakers!!

When you first listen to a panel we are conditioned to expect the music to original from a dome or cone of a dynamic speaker. When you listen to a traditional dynamic speaker you know exactly were the speakers are. This is not the case with a DML panel...the very wide dispersion/excellent off axis response and bipolar radiation makes the speaker disappear.

Hope this better explain the presentation and how it sounds after you get used to the diffused sound of a DML panel.

Vlad, let us know how its going. Hope you got your replacement exciter and your back in business!

Cheers!

[vlad335]

Re: DIY Flat Panel Speaker Love

Hey guys, thanks for the help and encouragement. Got the replacement yesterday and when i first hooked it up, same thing. popping and distorting. Let it play for awhile and most of it went away... but not all. Troubleshooting done with switching channels, making sure wire not touching, etc. I think the previous exciter was attached pretty good as I had a helluva time getting it off. Distortion is still there although it will play somewhat louder before farting than the previous exciter. One track I listened to from Trans Siberian Orchestra which consists of just horns distorts badly so its a resonance thing I suspect.

The other one still sounds great. I see what you are saying about the sound, the detail and soundstage is off the charts. It is really quite amazing. Listened to a lot of stuff I haven't heard in awhile last night, albeit at low volume to keep the popping down.

I don't know what to do. Think i will let these play for awhile today. Also considering making another panel to exclude that being the problem. Hard to believe that there is this much of a failure rate with this particular exciter... If true then they are junk and should be avoided.

Should I try the Dayton Thrusters? Or another model?

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey Vlad,
Definitely sounds like there is something wrong here. Did you sand the panels well on both sides before applying the treatment? The fact that there is panel noise with horns (no excessive bass) IS strange!?!? What size panels did you build and how are these suspended? Also, do you have a means of cutting the very lowest frequencies... say cutting output sharply at 30Hz?

When there is strong bass content I also get popping with the Ultra's at higher levels or content with strong bass output. My plan has always been to build a multi-panel array which will help the output of the Ultra's. The output of the Ultra's are certainly lower than the Thruster's due to this popping noise but I really like how they sound and at $14 its a steal. But of you want a single panel/exciter you may want to try the Thrusters.

Update us soon man!

[vlad335]

Re: DIY Flat Panel Speaker Love

Hey Vlad,
Definitely sounds like there is something wrong here. Did you sand the panels well on both sides before applying the treatment? The fact that there is panel noise with horns (no excessive bass) IS strange!?!? What size panels did you build and how are these suspended? Also, do you have a means of cutting the very lowest frequencies... say cutting output sharply at 30Hz?

Update us soon man!

Hello,

I sanded the panels but I wouldn't say I sanded them extremely well. It was very cold and I sanded them outside and wanted to get them done ASAP. Probably could have taken more off.

I made the 24x30" panels. I hooked these up to my computer setup initially for testing which is a Dayton DTA100 amp and Asus soundcard. The drivers for the soundcard have a feature called flex bass which is essentially a crossover. Have this set at 80-90hz so no low bass to the panels.

Something weird now. I hooked these up to the system i am planning on using and the other panel is now making the noise! Distorting and farting when minimal volume applied. This is the exciter I thought was OK! So maybe my Ultra wasnt defective! I placed the panels on chairs supported with foam and used the same amp. I bought a MiniDsp 2x4 for crossover to the sub/panels.

Looking back, I may have not sanded enough and watered down the glue too much. 2 coats applied but it was kinda watery... Maybe what I am hearing is "Panel Noise" as eluded to in the Mega thread at DIY audio. It is not low bass doing this. Like I said, The worst offender of the distortion was a track by TSO called Christmas Concerto which is horns playing only. https://www.youtube.com/watch?v=wu9AvBSHEhM I could barely turn that song up without severe cracking and popping. It has a tuba but I played tracks with much lower bass content.

What consistency did you water down the glue for the panel coating? I am thinking more sanding and thicker glue coating.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey Vlad,

Hello,

I sanded the panels but I wouldn't say I sanded them extremely well. It was very cold and I sanded them outside and wanted to get them done ASAP. Probably could have taken more off.

Since making panels are pretty quick and simple, I'd make another set and sanding them well when the weather gets nice (this week looks great!). I sand off all of the imprinted black lettering on the panels to give you an idea of how deep I sand. For the clean side of the XPS panel, I just make sure that all of the skin is off... there should be no shinny skin left after your done sanding. When you apply the treatment, you will see it absorb into the panel. If you missed a spot, you will see it looking at an angle into the light... it will be shinny and the treatment won't sink in as it did in a well sanded area.

I made the 24x30" panels. I hooked these up to my computer setup initially for testing which is a Dayton DTA100 amp and Asus soundcard. The drivers for the soundcard have a feature called flex bass which is essentially a crossover. Have this set at 80-90hz so no low bass to the panels.

Okay, this seems to rule out heavy bass content if you head panel noise on this system. Though I've had panel noise when I attach a new exciter before... when I first installed the Thrusters, I had very noticeable panel noise but it went away in just a few minutes for the most part. After an hour absolutely no noise as the exciter broke in. I never noticed this with the Ultra's... they were notably more quiet from the very first listen compared to the Thruster. Don't know how long you had the panels connected to this system, but if for at least an hour then its not panel flex or large excursions causing the panel noise.

Something weird now. I hooked these up to the system i am planning on using and the other panel is now making the noise! Distorting and farting when minimal volume applied. This is the exciter I thought was OK! So maybe my Ultra wasnt defective! I placed the panels on chairs supported with foam and used the same amp. I bought a MiniDsp 2x4 for crossover to the sub/panels.

I guess I should have asked this right from the beginning. If you remove the panel from the chair... just holding it in your hand... do you still hear the noise? The foam should be fine but wondering if the panels are touching the chair's back directly? If the panel is touching the chair's back directly that would be a source for noise without a doubt. I have large rubber bands wrapped around the chair's back so the panel is only touching the rubber bands and resting on the socks or foam in your case. The exciters are powerful and if the panel is touching anything that isn't very well damped you will get noise. You probably have this covered, but I'd just check this area just in case.

btw... MiniDsp is a great choose. I'm planning to make a purchase as well as that will take care of any EQ needed and integration with a sub when I decide to add it (if really needed). Looking forward to you getting this all setup correctly and tweaked to your liking and what your impressions are of the MiniDsp/DML panel combination!

Looking back, I may have not sanded enough and watered down the glue too much. 2 coats applied but it was kinda watery... Maybe what I am hearing is "Panel Noise" as eluded to in the Mega thread at DIY audio. It is not low bass doing this. Like I said, The worst offender of the distortion was a track by TSO called Christmas Concerto which is horns playing only. https://www.youtube.com/watch?v=wu9AvBSHEhM I could barely turn that song up without severe cracking and popping. It has a tuba but I played tracks with much lower bass content.

As I said above, I'd build another set quickly for peace of mind and best fidelity. I've listened to a large untreated panel and did get a small amount of panel noise but mainly a "drum resonance" and nothing even remotely approaching the problems you are having. Not sanding might be a contributing factor (minimal) but only on low bass and at high volumes. Much of my problems are that the panels are not suspended in anyway (just like yours) and are subject to large excisions compared to a panel that is suspended to prevent over excision. You might be surprised by the tuba, my "drum resonance" where due to loud male human voice in the 150-300Hz range. Man, if I were you I would download an RTA app on your phone and check so see if you can identify what freq. the tuba notes are playing and verify that you don't have a large peek... good learning to see what is going on with the panel.

But like I said above, I'd check the chair and panels and verify that the panels are not touching a surface that isn't highly damped. This still appears the most likely given everything you have told me.

What consistency did you water down the glue for the panel coating? I am thinking more sanding and thicker glue coating.

I do a straight up 50:50 mixture of water and glue. 1 coat on the front and normally 2 on the back(side with exciter attached). The treatment is very thin, but I've refinished a panel before and have a hellava time sanding off the treatment... so its thicker and tougher that you would think considering its watery consistency.

Bottom-line... make sure the vibrating panel isn't touching any hard/undamped surfaces while playing. A good chance here since the other panel is now also making noise... they can shift easily during a listening session and sometime need to be adjusted on their high-tech stands (ummm...chairs). Fingers cross man...