DIY Flat Panel Speaker Love

[captainjack115]

Re: DIY Flat Panel Speaker Love

Hmm? Any chance you played the NAD into clipping?

I just hooked up a pair of DAEX32EP-4's yesterday and connected them to a little Lepai 2020+. Everything went ok, sounded great and played fairly loud too, peaked out at 90db or so.
Today I connected them to my Emotiva XPA-200 power amplifier, more than 200 watts into 4 ohms. Everything went well, loud and clear.

Jack

[rmeinke]

Re: DIY Flat Panel Speaker Love

I received the 2 Thrusters I ordered from P.E. on Friday.

I found 2 of my old 12x12 panels in the garage and mounted a Thruster on each one. I have to say, the sound is not bad. The panels are leaning up against my MMG's, supported on one side.
I took a photo of of my old and cheap spectrum analyser reading pink noise with both panels running, this was at my listening position.
As you can see from the photo, things look pretty flat to 250 and tapers at 125 hz. Oddly enough tonal balance on most music is quite nice, doesn't sound shallow as the analyser shows. A person could pretty much sit contently and listen for hours.

It's been a couple of years since I've played with exciters, One thing I recall is that the panel edges "really" need to be terminated. Left undampened the ear notices a ringing that's not read on a spectrum analyser. Also more than ever I feel very strongly about using 1 exciter per panel. I remember going as high as 8 exciters on 1 panel, they played really loud but with the addition of each exciter high frequencies became progressively less.

Jack
[ATTACH=CONFIG]58300[/ATTACH]

I was pretty surprised by the performance of my small panels too but I would get those panels off the ground and up and into the room to give them some air. I did give them a bit of EQ but there are some qualities that were really enjoyable... they just disappear. Came home one day from work and switched them on and went up stairs to change and when I came down to listen, I stood in the opening to the living room looking at the audio setup and the soundstage absolutely hung in the air completely unattached from the speakers. If I hadn't known that music was coming from the small panels resting on the chairs it would have been a challenge to pinpoint where the speakers would be in the room... was interesting and further peeked my interest in smaller panel arrays. My 14.5x12" panels are too small but really did enjoy how they performed.

Can you describe the ringing a bit more?

[rmeinke]

Re: DIY Flat Panel Speaker Love

Just got one panel done and was checking out and wow. Running from my little NAD 7125 after about 3 mins of play at 1/3 volume the exciter died. I left everything flat on eq it just stopped. Listening to America Horse with no Name. Damn it sounded good till it stopped sounding. Are all of these this fragile? I really liked the sound but if it won't work but minutes what the heck are they good for? The source was my computer ripped cd thru a Teac UD-301 dac to the receiver . The receiver is only 25 watts IIRC so it wasn't over powered. Kind of disappointed . Would have both of them done but I have a bumble bee nest in the hot tub and they attacked me stinging me on the hand so I retreated to finish the other later. I guess I'll rma this one and see what happens it was the Dayton DAEX32EP-4 Thruster.

That is out of the ordinary with the Thrusters for sure. I have abused my Thrusters on both XPS and plywood and they have been very reliable and play loud. This is the first I've heard a Thruster failing.

How are the exciters connected? I know I've had problems with solderless connectors coming off and did wonder if they played some (small) part of my Ultra's failing.

[buke9]

Re: DIY Flat Panel Speaker Love

Damn third time trying to reply. I keep getting booted off.I did not put the NAD into clipping. It never went over 1/3 volume. I finished the second panel and hooked it up to the same setup and it was just fine. Tried to other driver again and it seems dead no sound. The first one is dead period. Never had anything but the hookup from the NAD.

[captainjack115]

Re: DIY Flat Panel Speaker Love

I was pretty surprised by the performance of my small panels too but I would get those panels off the ground and up and into the room to give them some air. I did give them a bit of EQ but there are some qualities that were really enjoyable... they just disappear. Came home one day from work and switched them on and went up stairs to change and when I came down to listen, I stood in the opening to the living room looking at the audio setup and the soundstage absolutely hung in the air completely unattached from the speakers. If I hadn't known that music was coming from the small panels resting on the chairs it would have been a challenge to pinpoint where the speakers would be in the room... was interesting and further peeked my interest in smaller panel arrays. My 14.5x12" panels are too small but really did enjoy how they performed.

Can you describe the ringing a bit more?

The ring is something of a hollowness for lack of better description. If I clamp my fingers around the perimeter the hollow sound goes away and bass gets way better and cleaner.
This is why I feel that dampening the edges is very necessary with DML's, you just can't have destructive energy coming back on the exciter.
When I made the prototypes a few years ago the 4 panels were floating on all 4 sides with duct tape, apparently the thick tape is enough to absorb and dampen reflective energy waves. In my current situation I wouldn't have enough room to set a couple of chairs in front of my MMG's. I'd like to just go ahead and build a new set of DML's using Thrusters or maybe Ultras, whichever works out the best. I still have a WAF to deal with, as she absolutely hates the look of the previous prototype. If I stay with the old design, I'll have speakers that handle 160 watts and high sensitivity.
If I go with a single larger panel, I'll be using 1 exciter. This will give me less handling power power with sensitivity that's still pretty decent all things considered.
In reality 1 larger panel (about the size of the MMG's) using 1 exciter wouldn't be a total heartbreak given my very small listening room.
I use 2 subs with my MMG's to get deep bass, I'd do the same with DML's too.

For an older guy I'm a little bit of a Basshead, I like clean low bass to 20hz. My subs sit on lots of isolation, I don't want to hear the room reacting through mechanical contact.
I custom built my listening room in my old house, I had 4 Titanic woofers built into a free standing wall in an infinite baffle, bass was outstanding!

I should be getting the Ultras next week, I'll make identical panels for them and make a comparison between them and the Thrusters. This will help things along with my decision making.

I know what you mean about the soundstage hanging in the air, I've noticed that when walking into the room, no need to sit in the sweet spot the magic is right there, everywhere! Incredible stereo effect, great depth with imaging that goes beyond left and right. All this and the center stays naild where it belongs.

Jack

[captainjack115]

Re: DIY Flat Panel Speaker Love

Damn third time trying to reply. I keep getting booted off.I did not put the NAD into clipping. It never went over 1/3 volume. I finished the second panel and hooked it up to the same setup and it was just fine. Tried to other driver again and it seems dead no sound. The first one is dead period. Never had anything but the hookup from the NAD.

Wow, that's a tough break very frustrating!

I'm sure it's just a fluke. P.E. is pretty good about taking care of situations like this. It's good to know that you like what you heard, I haven't heard much in the way of disappointment on here.

Jack

[buke9]

Re: DIY Flat Panel Speaker Love

Wow, that's a tough break very frustrating!

I'm sure it's just a fluke. P.E. is pretty good about taking care of situations like this. It's good to know that you like what you heard, I haven't heard much in the way of disappointment on here.

Jack

They took care of me and are shipping out a new one. The only problem is they are now on back order and won't be in till July 7 . What can ya do. I guess I'll have to wait a little bit longer to hear them in stereo.

[buke9]

Re: DIY Flat Panel Speaker Love

Well since the Thrusters are out of stock and have to wait till July 7th till they are to be in I ordered a set of Ultras. I think I will try a smaller set of panels this time. Still need to figure out how to mount them in a frame. Do they need to be isolated from the wood frame ? I have seen duct tape and pool noodles. What is the preferred way (if there is one) if at all needed ?

[captainjack115]

Re: DIY Flat Panel Speaker Love

Well since the Thrusters are out of stock and have to wait till July 7th till they are to be in I ordered a set of Ultras. I think I will try a smaller set of panels this time. Still need to figure out how to mount them in a frame. Do they need to be isolated from the wood frame ? I have seen duct tape and pool noodles. What is the preferred way (if there is one) if at all needed ?

I bought a pair of Thrusters because P.E. was out of Ultras. I have since ordered Ultras and they're in the mail as I write this. Theoretically the Ultras should have lower bass due to their lower resonant frequency. When I made my first set of DML's I mounted the panels in a wood frame and suspended them with duct tape on all 4 sides. I'm not positive if there is a preferred way, but I am sure that the panels should be dampened, especially if there's low frequencies involved.

Jack

[captainjack115]

Re: DIY Flat Panel Speaker Love

As luck would have it the same thing happened to me as buke9.

I was just sitting here listening to my test panels, and one channel sounded like the adhesive was coming loose between the Thruster exciter and the panel.
I gave a little push thinking that it just needed to reseat itself, the sound was clear until I let go and things got all buzzy again. I pushed down again and the exciter went silent.
After checking with an ohm meter my suspicions were confirmed, it has an open voice coil.

Can't help but wonder how many people not on this forum have had similar issues. I think Dayton Audio should look into this situation with their supplier in China.
Rmeinke had the same think happen with an Ultra exciter and I believe he's hit the nail on the head that the wires to the voice coil are breaking off due to excursion.
I was powering the Thrusters with a little Lepai LP-2020+amplifier running flat, there's no need for this kind of delicacy.

Well, in the mean time I have couple Ultras coming in a day or two.

Jack

[buke9]

Re: DIY Flat Panel Speaker Love

That seems like a lot of failures in a small community mine made no unwanted sounds and just quit (open coil here also). Got to be something a little better looking than duct tape ( whatever works for you though no offense meant) I would like something a little cleaner.

[captainjack115]

Re: DIY Flat Panel Speaker Love

That seems like a lot of failures in a small community mine made no unwanted sounds and just quit (open coil here also). Got to be something a little better looking than duct tape ( whatever works for you though no offense meant) I would like something a little cleaner.

No offence taken.

You may have seen the photo of my old prototype, I didn't think it looked so bad but my wife absolutely hated the looks of it.
Yeah the duct tape seems to work ok soundwise, but I'm going to have to find something a whole lot better looking if I want to have a set of DML's sitting in the room for all to see.
I also thought about covering the panels with a wood pattern contact paper, that idea was promptly shot down too.
She's right though, I have strong tendency to get a prototype tweaked the way I like it, and just live with it as is. She's ok with my Magnepan MMG's, if I could just find a way to make a pair of DML's that looked just like them I'd be ok.

Jack

[rmeinke]

Re: DIY Flat Panel Speaker Love

No offence taken.

You may have seen the photo of my old prototype, I didn't think it looked so bad but my wife absolutely hated the looks of it.
Yeah the duct tape seems to work ok soundwise, but I'm going to have to find something a whole lot better looking if I want to have a set of DML's sitting in the room for all to see.
I also thought about covering the panels with a wood pattern contact paper, that idea was promptly shot down too.
She's right though, I have strong tendency to get a prototype tweaked the way I like it, and just live with it as is. She's ok with my Magnepan MMG's, if I could just find a way to make a pair of DML's that looked just like them I'd be ok.

Jack

I'm intending to wrap the panel frame in black grill cloth then add thin wood side caps. I hope to make mine look like the MMG's with the black wood sides. :-) What would prevent us from building that??

I just read comments above about suspension... I'll reply to one of the posts above.

[rmeinke]

Re: DIY Flat Panel Speaker Love

The ring is something of a hollowness for lack of better description. If I clamp my fingers around the perimeter the hollow sound goes away and bass gets way better and cleaner.
This is why I feel that dampening the edges is very necessary with DML's, you just can't have destructive energy coming back on the exciter.
When I made the prototypes a few years ago the 4 panels were floating on all 4 sides with duct tape, apparently the thick tape is enough to absorb and dampen reflective energy waves. In my current situation I wouldn't have enough room to set a couple of chairs in front of my MMG's. I'd like to just go ahead and build a new set of DML's using Thrusters or maybe Ultras, whichever works out the best. I still have a WAF to deal with, as she absolutely hates the look of the previous prototype. If I stay with the old design, I'll have speakers that handle 160 watts and high sensitivity.
If I go with a single larger panel, I'll be using 1 exciter. This will give me less handling power power with sensitivity that's still pretty decent all things considered.
In reality 1 larger panel (about the size of the MMG's) using 1 exciter wouldn't be a total heartbreak given my very small listening room.
I use 2 subs with my MMG's to get deep bass, I'd do the same with DML's too.

For an older guy I'm a little bit of a Basshead, I like clean low bass to 20hz. My subs sit on lots of isolation, I don't want to hear the room reacting through mechanical contact.
I custom built my listening room in my old house, I had 4 Titanic woofers built into a free standing wall in an infinite baffle, bass was outstanding!

I should be getting the Ultras next week, I'll make identical panels for them and make a comparison between them and the Thrusters. This will help things along with my decision making.

I know what you mean about the soundstage hanging in the air, I've noticed that when walking into the room, no need to sit in the sweet spot the magic is right there, everywhere! Incredible stereo effect, great depth with imaging that goes beyond left and right. All this and the center stays naild where it belongs.

Jack

About suspension... I don't hear any ill effects from my very lightly suspended panels but think that the large rounded corners of my panels help to properly terminate the edges. But more so, I think the hollowness you mention may be a result of materials used. What material did you use Jack? I tested my XPS panels with tighter suspension and some of the detail and "air" went away so I, after that, prefer light suspension. I know a good number of the guys over at AC prefer light suspension as well. Given all of this... makes me think panel material may have played some part to your sound quality. Thin, floppy ply and foam I have used didn't sound good to me either... I heard more panel self-noise, poor quality bass and sounded a bit "fuzzy" to me. This is what also lead me to add more coats of the panel treatment than what was recommended to me over at AC.

I am planning on using felt on top and some type of material on the bottom of the panel that provides tension to tighten the suspension in a somewhat adjustable way.

But you are right Jack that some suspension is needed. If you read the white papers, you will see that on light material like XPS if left totally unsuspended you will get 1 deep dip followed by a strong peek in the lowest register. The tighter the suspension, the dip will be less shallow and the peek not as high... I see this through measurements. When I build my next panels with adjustable tension I will be able to see the effects easily and adjust as needed. The plan anyway...

Bummer about the Thrusters dudes. Mine have been very solid... Ultra's not so much and have heard that the design of the Ultra's have been improved. PE needs to figure this out if the failures continue.

[captainjack115]

Re: DIY Flat Panel Speaker Love

[QUOTE=rmeinke;2070566]About suspension... I don't hear any ill effects from my very lightly suspended panels but think that the large rounded corners of my panels help to properly terminate the edges. But more so, I think the hollowness you mention may be a result of materials used. What material did you use Jack?

After trying a bunch of different materials, I built the 4 panel prototype a few years ago. I've continued to use the old panels from that project, the panels are made from 3mm corrugated plastic.
I never noticed a hollowness with them in the past, it could be the loose suspension via duct tape.

Today I built a frame to match the perimeter of the panel, for suspension I used double stick foam to isolate the panel from the frame. A "complete" waist of time! There was nothing near enough suspension to dampen the panel. Excitations from the panel bounced off the poorly isolated frame and right back into the panel. Strong resonance in the 125 to 250hz range, the panel so much better without that particular suspension.

One thing I "can" say about the corrugated plastic, it has plenty of high frequencies, when using a Thruster I measure flat to 16,000 (The limit of my old cheap spectrum analyser)

I took one of my old low power exciters and stuck it on to a piece of common foam core. I have to say it had pretty good bass. I compared it to one of my MMG's and I actually preferred the bass I heard coming from the foam core.

Has anyone on here actually tried the white glue mixture on a piece of foam core? Just curious!

Jack