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DIY Flat Panel Speaker Love

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  • Re: DIY Flat Panel Speaker Love

    Originally posted by Kornbread View Post
    Then I should mention, all of these measurements and impressions were using one DAEX32EP-4 per xps panel. I do question how reliable they are as one already STB.

    Please list what other exciters you have experience with and your take on them.

    Have another panel curing ...
    Here is what I've listened to on lightly suspended XPS panels of various sizes. This is all going from memory and really would need to do more comparisons and take notes as I've listened to lots of different panel/exciter combinations, treatments and EQ settings so below is a very general recollection. From my favorite to less enjoyable:

    1. DAEX32U-4 (Ultra) - These have not been reliable for me and have lost 4 in total now. These were excellent right from the first listen. The high compliant, floating motor design makes for a panel with less panel noise. A few seconds into the first track you could hear this quality. With a quieter panel, I could hear more detail. It also sounded warmer to me. But now going back after listening to my KEF's, the warmth may be the underlying vibrational character that I really noticed after switching. Not good on heavier panel materials... even light, 1/16" ply. Its magic may be limited to small, lightweight panels. Still my favorite on XPS.

    2. DAEX32EP-4 (Thruster) - These have been reliable for me and have not lost one yet with 2 pairs for what it is worth. This doesn't seem to be the case for others. These were my favorite until the Ultra's came along. These were more detailed, than others before it. The mid-range is good but sounds hotter than the Ultra's so EQ was required on XPS. Works well on XPS and ply and heavier materials so works good on many different panels. Little to complain about on smaller panels.

    3. DAEX25FHE-4 Framed High Efficiency 25mm Exciter 24W 4 Ohm. This was the first exciter that I really started spending more serious time with. It is more efficient than the Ultra/Thruster and seems well built and reliable. I used these on large panels and the original 2'x2' XPS project panels. The large panels were not for me for all the reasons you know well enough now and did not spend a lot of time with them there. The project panels were not rounded; corners nor edges so more panel noise... thought it might be the exciter as it seemed louder (and added more noise to the panel) but that could be the venting too so really want to go back and listen again. Not as much detail as the Ultras/Thrusters but I enjoyed them and just seem solid and sounded good for such a cheap exciter. I kinda want to try these for a larger multi-panel array...cheap and won't break the bank for such a design.

    4. DAEX32Q-4 Dual Steel Spring Balanced 32mm Exciter 40W 4 Ohm. Not a good sounding exciter on 2'x2' XPS anyway but the corners and edges are not as round as my other slightly bigger panels. Regardless, colored right from the start with a nasally, hallow, cupped hands like coloration. Built like a tank and hoping that it is reliable and might sound better on different panel materials!?!?! Sounds smoother than either the Thruster or Exciter but may be due to the hallow sounding mid range. Also seems quiet on the panel so some good aspects and if not for the coloration there is something that I like about this. No amount of EQ helped the sound quality... was able to reduce the coloration but when I went back to the Ultras I was happy again.

    5. DAEX58FP Flat Pack 58mm Exciter 25W 8 Ohm. These spent the least amount of time on a panel and sounded a lot like DAEX32Q-4 (exciter 4) but worse. Sounded awful but didn't even let it break in honestly as it really did sound that bad right from the start. No panel magic at all with these. The thought (over at AC) was that the plastic plate is responsible for the poor performance. Strangely these measured the flattest of all the exciters. I should have given it time to break in and the reason why I stuck with the DAEX32Q-4 for a few weeks to be more diligent unlike my approach with these.

    Next up...
    6. Tectonic Elements TEAX25C10-8/SP 25mm High Power 8 Ohm Frog Exciter. Want to try this in a multi-panel array for a 4ohm load. Hope these are reliable.

    On the list...
    DAEX30HESF-4 High Efficiency Steered Flux Exciter with Shielding 30 mm Exciter 40W 4 Ohm. Odal3 over at AC likes these a lot... possibly better than the Thrusters. The DAEX25FHE-4 (exciter 3) appears solid and reliable and hope that this might displace the Thruster as it sounds as good but more sturdy.
    Last edited by rmeinke; 11-22-2015, 11:56 PM.

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    • Re: DIY Flat Panel Speaker Love

      If someone can model these dimensions, 45"x32" with the NXT? software I'll cut the other panel free so as to keep the mounting tabs at the null zones.
      http://techtalk.parts-express.com/fo...khanspires-but
      http://techtalk.parts-express.com/fo...pico-neo-build
      http://techtalk.parts-express.com/fo...ensation-build

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      • Re: DIY Flat Panel Speaker Love

        Hi Kornbread. As far as I know no-one has that software here. I'd try mounting at 1/3 in from the corners, or on the halfway point on each side. That looks to be low energy on all the images I've seen.

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        • Re: DIY Flat Panel Speaker Love

          Hey Kornbread... like Gary suggested, I would put them about 1/3 in top and bottom (2 tabs top, 2 tabs bottom). For sides, I'd have 2 tabs per side. With a panel that large I think more tabs will do a better job of reducing the drum resonance. I would also consider using thin foam sheets/adhesive backed felt or ??? to help terminate the edges better unless you can round them appropriately. Even if rounded, you still might want to do it anyway because that panel will probably be pretty lively but will have to see as you go. Oh, and get some damping where the panel is clamped to the frame.
          Last edited by rmeinke; 11-24-2015, 10:19 PM.

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          • Re: DIY Flat Panel Speaker Love

            Originally posted by rmeinke View Post
            That is some elevated low freq. with the Amazing's... doubt they sound the way they measure. I never got what I felt was accurate OB bass measurements and always tweaked levels by ear with my Martin King based OB panels.
            Slightly off topic, but what driver are you using for your Martin King OB's? What' your best Fs?
            In my walks, every man I meet is my superior in some way, and in that I learn from him.

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            • Re: DIY Flat Panel Speaker Love

              Originally posted by captainjack115 View Post
              Slightly off topic, but what driver are you using for your Martin King OB's? What' your best Fs?
              Different vintage drivers (EV Wolverine, SEAS alnico mainly) but currently a pair of MCM 55-2981 10" Pro drivers per side driven by Jung 200W 6db+ plate amps. I'm getting extension unEQed to just this side of 30Hz or flat to 25Hz with +3dB boost (at 25Hz) via the DCX2496. It really didn't matter with 99% of the music listen to so I had removed the boost long before I stopped listening to my OBs. Have 2 sets of RS270-8 10ers waiting for baffles but have been happy with the cheap MCM's and the Jung combo in my small listening room so little motivation... especially since the flat panels have arrived.

              For background on the MCM... these were the mid-range in the original Hestia OB - "an ambitious low cost, 3-way OB design" that Ed over at AC put together. He listened to 8 - 10" drivers for a few months before selecting the MCM for mid-range duties. If they are articulate enough for this design I had no concerns about using a pair for bass duties with their robust construction and 7mm of Xmax. Note: the mfg spec is off and has a much higher Qts due to lower grade ferrite mags. But this works beautifully for OB duties.

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              • Re: DIY Flat Panel Speaker Love

                OK, luck came my way today. I was visiting one of my company's suppliers and noticed some large sheets of twin cush corrugated cardboard. Not just ordinary stuff, but very very high quality. As it happened it had been dropped off to them by someone who gets it as part of the packaging for some industrial equipment from Japan. So this board is made in Japan, nice and light for the size and seems extremely rigid. This will now become my first experimental panel material, and the cost, zero.

                I've only seen mention of treating this with shellac. Has anyone used anything else? What advice?

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                • Re: DIY Flat Panel Speaker Love

                  What a score... very cool Gary!

                  Boy, I treated some thin cardboard (trifold display sheet from DollarTree) with the PVA and water treatment hoping that it would dry hard quicker than the shellac but still not quite as hard or cured as fast as I had hoped so hard to say at this point what treatment is best... have to see what happens over the next week+

                  For a small panel, i can see an Epoxy being a good choice...and if it sounds good we could move to a larger panel as costs seems a bit prohibitive.

                  I'll report back again soon!

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                  • Re: DIY Flat Panel Speaker Love

                    This board seems to have solid outer surfaces, a bit more than the average packing grade. I will buy some shellac flakes and impregnate with those dissolved in alcohol.

                    Click image for larger version

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                    • Re: DIY Flat Panel Speaker Love

                      Gary, that looks really good.

                      When I did my panels, I also did the flutes (as did the folks over at AC). Its time consuming yes, especially considering the double cushion, but given how nice that panel is I think it may just be worth it.

                      Order:
                      1. Front (dry) and Back (dry)
                      2 Keeping the same orientation, do the flutes by placing the panel at a 45 degree angle and shoot shellac down each flute until just a little come out the bottom (you will get the hang of how much). Keeping the same orientation, flip the panel to the other end and repeat so you are treating the same flutes. You are hitting the flutes that form a troth. (dry well).
                      3. Change the orientation (front to back) and repeat the process as above.

                      Hope this makes sense.

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                      • Re: DIY Flat Panel Speaker Love

                        Originally posted by rmeinke View Post
                        Gary, that looks really good.

                        When I did my panels, I also did the flutes (as did the folks over at AC). Its time consuming yes, especially considering the double cushion, but given how nice that panel is I think it may just be worth it.

                        Order:
                        1. Front (dry) and Back (dry)
                        2 Keeping the same orientation, do the flutes by placing the panel at a 45 degree angle and shoot shellac down each flute until just a little come out the bottom (you will get the hang of how much). Keeping the same orientation, flip the panel to the other end and repeat so you are treating the same flutes. You are hitting the flutes that form a troth. (dry well).
                        3. Change the orientation (front to back) and repeat the process as above.

                        Hope this makes sense.
                        Thanks for the info. I will follow that process...

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                        • Re: DIY Flat Panel Speaker Love

                          I'm not really sure going to this extreme to impregnate the cardboard is required. Thin the shellac considerably, (IIRC alcohol) and apply liberally with brush, roller, or possibly spray on. It soaks in like crazy but since you have double wall cardboard ... who knows, try it on some scrap first.
                          http://techtalk.parts-express.com/fo...khanspires-but
                          http://techtalk.parts-express.com/fo...pico-neo-build
                          http://techtalk.parts-express.com/fo...ensation-build

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                          • Re: DIY Flat Panel Speaker Love

                            This looks like a very nice panel. To make the best possible panel you will need to treat the flutes. Its work, but this has been the best approach over at AC when cardboard was thee material of choice. I've treated many... unfortunately, it takes a long time to harden from my experience.

                            One note Gary, try not to soak it... afraid the flutes might lose their shape. Kornbread is correct, it does soak in pretty quickly. Yours looks thicker but just watch it closely. It might be worth reading over the AC thread on treating cardboard panels but what I explained was the standard approach at the time.

                            Update on the PVS:water treatment... checked my treated panels and now after a week, they are CRISPY! Might be as firm as the shellac already with only a week of curing. The shellac took months and months to fully harden.

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                            • Re: DIY Flat Panel Speaker Love

                              FYI... Posted some measurements over at AC comparing 24"x30" panels using the Thruster on 1/8" ply and 1" XPS.

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                              • Re: DIY Flat Panel Speaker Love

                                Originally posted by rmeinke View Post
                                FYI... Posted some measurements over at AC comparing 24"x30" panels using the Thruster on 1/8" ply and 1" XPS.
                                ... you forgot about us or at least link it.:p
                                http://techtalk.parts-express.com/fo...khanspires-but
                                http://techtalk.parts-express.com/fo...pico-neo-build
                                http://techtalk.parts-express.com/fo...ensation-build

                                Comment

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