DIY Flat Panel Speaker Love

[Fshow]

Re: DIY Flat Panel Speaker Love

Hey! Well, there is no single right way as you have experienced yourself Fred. Your panels do play full-range and play full range very well my friend!

My framed panels... the frames will be glued edge wise so the 1/4" edge is facing to the front and back of the speaker. Or looking at the panels from the side, the frame is 1 1/4" thick. So the frame will be very light. I'm considering this a learning experience to see how a lightweight frame will interact with the panels.

The panels are 24" by 5'4" with 2 exciters per panel and isolated by a routed groove in the back of the panel. The plan is to test the panel and build from there as needed. First to route grooves around the edges of the panel close to the frame. If the panel and frame are still operating in DML mode together, I can add heavier wood frames which *should* remove and isolate the frame so it is not operating in DML mode with the panel.

On a side note, adding black ink to the PVA treatment makes it dry slowly and doesn't seem at hard. Not encouraging. :(

Interesting about the 40Hz coupling of the 2 panels! Have you played with toe-in? Test and check adjusting until the coupling is reduced/goes away? Then maybe play with distance to back wall if the toe in doesn't work? This is excellent learning (those panels are lightweight!) Fred but also speaks to how strong LF output is generated by your panels!!! Impressive!

note : I listen to my panels crossed 1 foot in front of the listening position. This is popular config. for open baffles.

Cheers!
Rich

Hi Rich

Now I understand, should be very interesting build. I am sure we will all benifit from your experience. One thing I think I learned is PVA coatings go on easy but come off hard. Adding coats adds to rigidity, which is good but they also make the panels heavier, which is not so good. I ruined an earlier poster board panel with shellac, the panels got too heavy and were never the same. So take it slow my friend.o

About your suggestion of speaker positioning, I will give it a try but I don't have much room for change.
I hope to sand down my panels some more tomorrow.

Thanks!
Fred

[Kornbread]

Re: DIY Flat Panel Speaker Love

rmeinke: I find KornBread and your comments about comparing to a "reference" a bit harsh, speculative and just as likely... inaccurate.

Mind explaining this further for I have posted, in detail and with measurements, every step of what I've done with these panels for all to see. I posted what was perceived to be happening to go along with the measurements but made it clear it was nothing more than my opinion, and opinions are like butts ... everybody has one; Real and measurable data was posted. Since someone else brought Ziggy into this foray; What I have not done is make bold statements like, "This is the best way..........the only way. There is no other.............do we all get it now???" or claim the latest material the mother of tone only to come back to a previous material and proclaim it the best, even Ziggy comments about the pokes he's getting from his lack of data posted to support his opinions. It was his seemingly contradicting statements that almost kept me (they also had a effect on Unbiasedsound and undoubtedly others) from taking these panels seriously. rmeinke, it was your enthusiastic endorsement, not Ziggy's, that finally convinced me to give them a try. Yes, it was sad to see the post of Ziggy passing but his words still live on the net, therefore, they are still open to scrutiny. Defend him all you may, I will also defend myself as I have posted my work in detail including both my opinions and real measurable data to back or refute my opinion.

[Unbiasedsound]

Re: DIY Flat Panel Speaker Love

Yeah, its fine UBS... I was being a little defensive indeed. The Walmart sound comment and the seemingly, ever changing panel material in the AC thread appeared like a jab at Ziggy and those involved in the thread over those many years. Initially, I didn't see a constructive message in the post but after rereading the post I do see it was in earnest and get what your position is. Of course that was not an accurate assessment as I think it is safe to assume that all involved had an existing system before embarking on their DIY panel journey.

In any event, I wanted to comment on that aspect tonight yet... later UBS..

Oh... before signing off... can you explain more about Bertagni's scalloped edges?? That was one aspect of the Bertagni's that I wanted more info on... I couldn't make out scallops in the panel edge itself. My feelings where that large scallops to the front of the panel combined with grooves all the way around the edges on the back of the panel, this should help to better terminate nodes at the edges/panel to solid frame transition. But one of the pics that I saw the scallops looked to be to the back of the panel????? Can you validate?

I am not familiar with the term scalloped edges but if you are talking about those circle looking things in the front one of them one is used for the high frequency exciter usually in the top corners and the other not sure why its there lol. In certain models some use the piezo electric tweeter and some have a actual hole with only a round card board circle covering it.

This model is probably one ahead of mine as it comes with the peizo electric tweeter on the bottom also with the adjustable frequency control. My speakers do not have a piezo tweeter or a adjustable frequency control.

http://img.auctiva.com/imgdata/1/6/6/4/9/3/0/webimg/561777455_tp.jpg

I also believe those grooves all along the edges may have something to do with the mounting to frames to cancel out nodes. Every thing I say on these panels though is only speculation your guess is probably as good or better then mine lol I just wish Mr.Bertagni himself was here to tell us exactly why he did what he did when making his panels.

If I were to buy another pair of Bertagni speakers I would want to buy one with the piezo electric tweeter with the adjustable frequency control just to hear how much of a improvement they are to my lower model speakers.

[Unbiasedsound]

Re: DIY Flat Panel Speaker Love

Hi Ubs

That's ok about not having the tools, I was just curious.
About the duct tape. I have tried various tape on the panels several different times with always the same result which was negative.
I have the panels with the exciter side facing me, sounds better that way.

Thanks Fred

Which exciters do you own? The exciters with the vents in the back radiate sound from the vents as well which could alter the sound.

The exciters on my bertagni speakers has vents as well. What I discovered is that covering up any one of the 5 vents can change the sound of the bertagni speakers. I am just assuming/guessing that it could happen with any exciter that has vents in the back. That will be one of my next experiments to cover the vents in the back to see how it changes the sound of the panels.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Mind explaining this further for I have posted, in detail and with measurements, every step of what I've done with these panels for all to see. I posted what was perceived to be happening to go along with the measurements but made it clear it was nothing more than my opinion, and opinions are like butts ... everybody has one; Real and measurable data was posted. Since someone else brought Ziggy into this foray; What I have not done is make bold statements like, "This is the best way..........the only way. There is no other.............do we all get it now???" or claim the latest material the mother of tone only to come back to a previous material and proclaim it the best, even Ziggy comments about the pokes he's getting from his lack of data posted to support his opinions. It was his seemingly contradicting statements that almost kept me (they also had a effect on Unbiasedsound and undoubtedly others) from taking these panels seriously. rmeinke, it was your enthusiastic endorsement, not Ziggy's, that finally convinced me to give them a try. Yes, it was sad to see the post of Ziggy passing but his words still live on the net, therefore, they are still open to scrutiny. Defend him all you may, I will also defend myself as I have posted my work in detail including both my opinions and real measurable data to back or refute my opinion.

Hey KB, as I told UBS I was being a little defensive to the comments on the NXT thread and Walmart sound quality comment initially as many folks put in a lot of effort into the panels and supporting the DIY community. But after reading the post, I don't think they were meant as negative as I originally thought and felt.

I was just a little sore... you don't need to defend your position or approach... that was my bad Kornbread! :(

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hi Rich

Now I understand, should be very interesting build. I am sure we will all benifit from your experience. One thing I think I learned is PVA coatings go on easy but come off hard. Adding coats adds to rigidity, which is good but they also make the panels heavier, which is not so good. I ruined an earlier poster board panel with shellac, the panels got too heavy and were never the same. So take it slow my friend.o

About your suggestion of speaker positioning, I will give it a try but I don't have much room for change.
I hope to sand down my panels some more tomorrow.

Thanks!
Fred

Hey FShow!

Oh man... that PVA treatment is tough and resilient is it not!! NOT WHAT I WOULD HAVE THOUGHT. What a pain... even with a palm sander and fresh 100 grit paper!

I've only re-sanded 1 set of panels and of course had to be one of my original large 2x4 panels. Never again... I build new panels now! Worth the cost of a $13 4x8 sheet of foam.

Good luck with the sanding Fred! :(

[Kornbread]

Re: DIY Flat Panel Speaker Love

The comment about WalMart sound quality was related to the concept that, in the general populous, most people are completely clueless to what is truly possible in audio playback. They may have the latest 4k high def TV but their sound system satisfies only the hearing impaired. Simply put, they think louder is better, more speakers are better, there's nothing else to be gained. It was not directed at Ziggy, or audio forums in general; although, online it does take some reading between the lines to get a feel for the preferences of other posters. YMMV

So I guess we can kiss and makeup now! :eek:

There are a pair of non-functioning Bertagni sm100's on Ebay for $40. Seem to recall someone replacing the exciters with Dayton parts.

Since wood glue is water soluble, would it be easier to soak the coating then wash it away?

One month later and no reply from PartsExpress on substitution, refund, or replacement of the Dayton DAEX32EP-4's. Too bad, was wanting to try the white 1" styrofoam that 'tapped' so good at Lowes.

[Fshow]

Re: DIY Flat Panel Speaker Love

Which exciters do you own? The exciters with the vents in the back radiate sound from the vents as well which could alter the sound.

The exciters on my bertagni speakers has vents as well. What I discovered is that covering up any one of the 5 vents can change the sound of the bertagni speakers. I am just assuming/guessing that it could happen with any exciter that has vents in the back. That will be one of my next experiments to cover the vents in the back to see how it changes the sound of the panels.

Hi Ubs

I am using the Thrusters. When I first saw them I thought that they were way to stiff of suspension, but it turns out that they are just about perfect for me.

Good point about the vents, could be why I like to listen to the back side of the panels.

How low do your Bertagnis go?

Fred

[Fshow]

Re: DIY Flat Panel Speaker Love

Hey FShow!

Oh man... that PVA treatment is tough and resilient is it not!! NOT WHAT I WOULD HAVE THOUGHT. What a pain... even with a palm sander and fresh 100 grit paper!

I've only re-sanded 1 set of panels and of course had to be one of my original large 2x4 panels. Never again... I build new panels now! Worth the cost of a $13 4x8 sheet of foam.

Good luck with the sanding Fred! :(

Hi Rich

Ya it is tough, fortunately I only had to take off some on the back and just took off the roughness on the front. I have my bass back now and as a bonus the response is flatter.
Fred

[Tin Ear]

DIY Flat Panel Speaker Love

The comment about WalMart sound quality was related to the concept that, in the general populous, most people are completely clueless to what is truly possible in audio playback. They may have the latest 4k high def TV but their sound system satisfies only the hearing impaired. Simply put, they think louder is better, more speakers are better, there's nothing else to be gained.

;) As an Easily-Offended Profoundly-Deaf-American with Analysis Paralysis . . .

I don't know about the rest of the Hearing Impaired, but I've always truly appreciated High Fidelity.

Crap of *any* description is for whom some refer to as The-Easy-To-Please, but whom with no small measure of Irony I call The-Infinitely-Baffled, which is more apparent as we hurtle toward the apparent Ideal of Idiocracy.

The Horror. The Horror. *shudder* ;)

-

It seems to me that, be they ever so slight, variances in thickness of Sanded Panels and/or WaterGlue at Specific (Fractional) Wavelengths would have an appreciable effect on THD & SPL Peaks and Valleys that occur at Various and Sundry Frequencies.

The question then becomes, what Fraction/Wavelength Ratio is there for Molecular Material (EPS, Birch, et al) that Good, Good Vibrations must travel to and thru to deliver the Measurable Equivalent of a Full Wavelength?

- Kudos

[rmeinke]

Re: DIY Flat Panel Speaker Love

;) As an Easily-Offended Profoundly-Deaf-American with Analysis Paralysis . . .

I don't know about the rest of the Hearing Impaired, but I've always truly appreciated High Fidelity.

Crap of *any* description is for whom some refer to as The-Easy-To-Please, but whom with no small measure of Irony I call The-Infinitely-Baffled, which is more apparent as we hurtle toward the apparent Ideal of Idiocracy.

The Horror. The Horror. *shudder* ;)

-

It seems to me that, be they ever so slight, variances in thickness of Sanded Panels and/or WaterGlue at Specific (Fractional) Wavelengths would have an appreciable effect on THD & SPL Peaks and Valleys that occur at Various and Sundry Frequencies.

The question then becomes, what Fraction/Wavelength Ratio is there for Molecular Material (EPS, Birch, et al) that Good, Good Vibrations must travel to and thru to deliver the Measurable Equivalent of a Full Wavelength?

- Kudos

Just love your post Tin Ear...

Not just deaf, nooooooooo, *profoundly* deaf. That's like what... 2, or dare I say 3 times more deaf than a "normal" deaf American?!?!? And with a rampant case of analysis paralysis... me thinks there is another IT guy in the house!!

Good, Good Vibrations... you've come to the right place, then, Tin Ear.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Its all good Kornbread!!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey FShow! So, do you have an idea why it might be smoother now? So you sanded the back around the edges of the panel and only lightly sanded the entire front yes?

[Kornbread]

Re: DIY Flat Panel Speaker Love

;)

Crap of *any* description is for whom some refer to as The-Easy-To-Please, but whom with no small measure of Irony I call The-Infinitely-Baffled, which is more apparent as we hurtle toward the apparent Ideal of Idiocracy.

- Kudos

You do know that Google quickly returns http://ibsubwoofers.proboards.com/ when searching for 'the infinitely baffled'. No kidding aside, good info in there.

It sounds like you have some panel suggestions?

[mrmky]

Re: DIY Flat Panel Speaker Love

I have read almost the entire thread, if I missed it I apologize, but is there any reason not to try shapes other than square/rectangular? I'm definitely a beginner, but it seems that if you are rounding the edges, and eliminating the corners because they are areas of high energy/distortion, why not explore different shapes of panels?

I'll be ordering some exciters from PE in the next day or two, this sounds like a really fun project and a great way to get some hands on without having to invest $$$$$.

It seems that the thrusters and the ultras are the two most popular drivers, could anyone make some recommendations on where to start with exciter options? I'll be using an avr to power them, I'm not sure if running a 4 ohm load is a good idea? Should I be looking for 8 ohm exciters to be safe?

Mounting them seems to be an unresolved issue as well. I have read about duct tape, which would not fly anywhere except in the garage with the lady of the house. And seen pics of foam sandwiched between the panels and a frame, which is better visually but still not great with WAF. What about a band of fishing line/string/rope/strap encircling the panel with tie offs to a frame that enclosed the edges without touching the panels. Perhaps with ~1/4" clearance except for the tie off points?

Another thought I had was shaping the panel like a bowl. With a thick enough piece of foam you could remove material to shape it like a shallow cone. If you used a mounting method like mentioned above in a round shape you could use tension in the rope and mounting points to play with dampening at different points.

Please don't hesitate to shoot down any 'silly' ideas, it won't hurt my feelings and if someone knows it will be a waste of time I would rather know before I have wasted it.

I have several panels of 2'x4'x1" that I am going to start shaping into various sizes and shapes while I wait for my parts to be delivered. Really looking forward to another speaker project, especially one that doesn't set me back financially the way my last one did. I love my 'Johnny Sub', but my wife isn't quite as enthusiastic lol. Why aren't most women impressed when you build speakers that can shake pictures off the walls?!.

One last question, is there a good way to take the exciters off and reapplying them to different panels? Or do I need to just order several pairs of them if I want to play with different panels?