DIY Flat Panel Speaker Love

[rmeinke]

Re: DIY Flat Panel Speaker Love

rmeinke: sorry, it was dollar tree, 99 cent store foamcore, the cheep stuff! I'm in southern Cal - they're at every strip mall. My idea on the magnets would be to place 4 or so on the perimeter and 4 on a frame. I think that GE Silicone II as an adhesive would hold good be a little flexible and damp vibration. I would leave the driver as is.

So I volunteer...since I have all of that....now for a frame....

Cheers, Dave

Hi Dave!

Hey man, it would be plain fun to build a set of totally low cost panels from really common materials. Dollar Tree foam boards or treated cardboard, cheap exciters from PE (I have 8 of the 16ohm exciters similar to yours) and probably throw in some duct tape (because its duct tape!!) to attach the panels to frame. Ridiculously cheap but sound pretty darn good no doubt as you already know... who doesn't LOVE a good challenge.

Hmmmmmm...

[dlneubec]

Re: DIY Flat Panel Speaker Love

I'm planning on doing some experimenting soon. I understand the xps panel treatment with the corner rounding and edge roundover for a panel that is not edge suspended. I wonder if this will still be necessary or beneficial if you are planning to use a compliant edge suspension, on all 4 sides of the panel?

[captainjack115]

Re: DIY Flat Panel Speaker Love

Hey Jack! Yeah, I use my sons older Touch for RTA and different signal generators so all is well with the Touch.

I didn't mean to say that the panels are not good sounding without EQ. I enjoyed them for some time without. I'd still listen to them unEQed over many other speakers. :-)

I wish Apple hadn't changed their port connection, my Pure i20 uses the 30 pin connection, just right for the "Classic". If I replace the Classic I'll probably want a 64 gig, 32 would put me on the edge memory wise. Then there's the need to use the adapter to go from 30 pin to lightning.

I get what you mean about the panels sounding good without EQ, the thing that strikes me is the spaciousness of them. I can stand just at the open door of my listening room and it's like stepping into the venue where music is being performed. There is virtually "no sweet spot"! I can't say that about my MMG's, I have to sit down in my listening position to hear them at their best.

Jack

[rmeinke]

Re: DIY Flat Panel Speaker Love

I wish Apple hadn't changed their port connection, my Pure i20 uses the 30 pin connection, just right for the "Classic". If I replace the Classic I'll probably want a 64 gig, 32 would put me on the edge memory wise. Then there's the need to use the adapter to go from 30 pin to lightning.

I get what you mean about the panels sounding good without EQ, the thing that strikes me is the spaciousness of them. I can stand just at the open door of my listening room and it's like stepping into the venue where music is being performed. There is virtually "no sweet spot"! I can't say that about my MMG's, I have to sit down in my listening position to hear them at their best.

Jack

Yeah, its a bit of a bummer with you all set with the 30 pin... but no looking back now I suppose as the lightning cables are here to stay.

Yeah, +1 on the spaciousness. It absolutely fills the room. The sound stage is just huge; even with small panels. Have some vacation time coming soon (hopefully!) so going to finally do some building!! Sedge is making some noise about big panels over at AC so I might make a traditional, large panel as a bit of a reference build. Hope to report back soon!

[captainjack115]

Re: DIY Flat Panel Speaker Love

Yeah, its a bit of a bummer with you all set with the 30 pin... but no looking back now I suppose as the lightning cables are here to stay.

Yeah, +1 on the spaciousness. It absolutely fills the room. The sound stage is just huge; even with small panels. Have some vacation time coming soon (hopefully!) so going to finally do some building!! Sedge is making some noise about big panels over at AC so I might make a traditional, large panel as a bit of a reference build. Hope to report back soon!

Yeah I'd love to have the room to play with a pair of large panels now that there are higher power exciters. Still can't understand why the Ultras I bought say 20 watts on the back.

I made some panels out of aluminum sheeting of few years ago, stuck some damping on the back. Not bad sound, good highs, less efficient though.

Got on the Apple site and ordered an ipod touch 4th generation. It's a referb with the 30 pin connector, it should do the job as an RTA

[dlneubec]

Re: DIY Flat Panel Speaker Love

After you apply the glue/water coats, do you leave as is, or sand smooth? The ones I'm working on feel sorta like sand paper after a couple coats. Seems like you might want to smooth it out a bit, at least in the area where the exciter attaches.

Has anyone added a paint coat after the treatment and measured before and after? I'm wondering if it would change the frequency response in any significant way.

[rmeinke]

Re: DIY Flat Panel Speaker Love

After you apply the glue/water coats, do you leave as is, or sand smooth? The ones I'm working on feel sorta like sand paper after a couple coats. Seems like you might want to smooth it out a bit, at least in the area where the exciter attaches.

Has anyone added a paint coat after the treatment and measured before and after? I'm wondering if it would change the frequency response in any significant way.

Hey Dan, I only lightly sand the area where the exciter is attached. I've never painted after treatments and to be honest I have not measured the panels with no treatment, single treatment or after 2 coats and compared them closely. From the measurements I've taken, there doesn't appear to be significant differences in measured response. In my opinion, the treatment on XPS is more about sound quality improvements vs. measured performance.

You would have to treat all surfaces and edges to protect the XPS and have to believe that the treated edges would reflect waves back into the panel. The water:PVA and black pigment/ink/dye are probably the best sounding alternatives but if you don't mind risking some sound degradation experimentation might be needed to validate the changes in sound quality. If it was me, I would build a set of panels using more traditional construction then move on to a painted skin after getting some listening time to the panels.

But experimenting is quick and fun so its always easy to build another set of panels if it doesn't turn out as well as you would like.

[buke9]

Re: DIY Flat Panel Speaker Love

I'm on my way to build a set of frames for the panels. I'm looking for options on isolation to the frames. I'm thinking memory foam might be too dense. I don't want to go with duct tape (sorry Captain Jack) . I want too make a dado recess in the sides and top and bottom to put something in I just haven't decided what. Going to make a prototype out of pine and then a finished pair out of walnut that I have a lot of.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Are you intending to add suspension around the entire panel or just small attachment points? If you want the most out of panels, I would consider lightly suspending them so they are not over damped. You can always add more suspension points if there are any panel resonances that must be dealt with.

[buke9]

Re: DIY Flat Panel Speaker Love

Are you intending to add suspension around the entire panel or just small attachment points? If you want the most out of panels, I would consider lightly suspending them so they are not over damped. You can always add more suspension points if there are any panel resonances that must be dealt with.

I was planning on small as needed points of attachment. Still looking at the right material for this.

[buke9]

Re: DIY Flat Panel Speaker Love

A few ideas for material.
http://www.ebay.com/itm/NEW-RV-DOOR-...-/331481792192
http://www.zoro.com/value-brand-foam...u6/i/G0885945/
http://www.findtape.com/product812/3...ve+Adhesive%5d
Just for starters.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Sedge over at AC mentioned sponge as an suspension material and I agree that it should be very good to isolate the panel from the frame. So you are on the right track!

I spotted these out on eBay and may head in this direction though but might try simple high density foam used for upholstery... not much different from these however these *should* be more dense and stronger.

Hope to start my next project late tomorrow when we get back home. I'm fired up!!!

[captainjack115]

Re: DIY Flat Panel Speaker Love

Sedge over at AC mentioned sponge as an suspension material and I agree that it should be very good to isolate the panel from the frame. So you are on the right track!

I spotted these out on eBay and may head in this direction though but might try simple high density foam used for upholstery... not much different from these however these *should* be more dense and stronger.

Hope to start my next project late tomorrow when we get back home. I'm fired up!!!

After much listening and tweaking I think I'm ready to make some acceptable looking panels.

Acceptable looks also requires that the panels are properly damped/suspended, I find this to be a daunting task. I've been running a series of sweeping sine waves through my panels and it seems to be a good way to see where buzzing may be hiding. It appears that the panels like a firm but compliant hold, too firm and reflective waves raise resonance problems. Not firm enough and buzzing rears it's ugly head.
I promised my wife I'd make the panels look like my MMG's, that means grill cloth. That could be a good thing as grill cloth could hide a multitude of unattractive underlying cosmetics, dare I say duct tape.................The mystical science of Red Green!

Jack

[rmeinke]

Re: DIY Flat Panel Speaker Love

I think that is a good, concise summary and my feelings exactly to this point in the journey if I understand it correctly. Stated another way... I prefer as minimal suspension as required to prevent panel resonances/self-noise. Any more suspension and the sound quality is impacted. Although, as you know, they still sound good with full suspension.. plenty of folks who enjoy their panels in that configuration.

This is the largest challenge of DML panels in my opinion and why I enjoy the smaller/small multi panels as they tend to NOT require as much suspension to sound their best. I can tell a difference when even holding a panel with 2 fingers on each side. They sound better with the least suspension required to produce a quiet panel. I still would like to try to build a single large panel with minimal suspension yet in an attempt to get the benefits (smoother freq. resp.) of a more controlled panel but I'm having a hard time committing time and effort with the likelihood that sound quality will be somewhat compromised as a result. I'll do this as some point and have some ideas but am backing away from that as one of my next builds.

CaptainJack... or shall I say Capn' Duct Tape!! Okay... some might criticize duct tape but I think its rather brilliant in simplicity and even the performance ought to be quite good so long as it can hold the panel in place for an extended period of time. LONG LIVE DUCT TAPE.

On a side note... I picked up some items from Ikea this weekend while in Chicago so will have a DML Ikea hack coming soon. :-)

[captainjack115]

Re: DIY Flat Panel Speaker Love

In my head I see the suspension for my project being something with mild elasticity, something akin to a rubber surround on all sides.

Duct tape does tend to buckle at random points here and there and is far from an ideal material, this I freely admit. It is a step up from having the panels laying about, anything they touch in a casual way causes buzzing.
It's really quite remarkable the way the panels build up excursion as excitation travels to the edge, kind of like shaking a rope and seeing how much it;s moved at the other end. I can truly understand how a large panel surface can produce considerable low frequency output. I think Oliver Gobel had good reason to use just one panel for all of his speaker models. We're all curious about how his panels are made, but for me more so about how he suspends the panels.

Jack (AKA Capn' Duct Tape)