ESL Panel construction?

[markusA]

My building materials are slowly arriving and soon it's time to start the practical work on the panels.
I have an idea but I'm not sure how to actually build it?

Perforated steel stators, 3m VHB tape spacer, mylar diaphragm.

How can I make holes that go all the way through?
(2x steel stators, 2x VHB tape, 1x mylar diaphragm)
I need something like 8mm diameter holes. I'll probably use M8 nylon screws.

[Calvin]

Hi,

perforated metal features tens of thousands of holes ....why and what for do You need additional holes?? Certainly not to hold things together.

jauu
Calvin

[CharlieM]

A beautiful thing about using 3M foam tape for the spacers is that it also sticks and holds the panels together quite well-- so you won't need any fasteners. For example:

[chinsettawong]

Hi CharlieM,

From your picture, what is a weather stripping?

Wachara C.

[CharlieM]

Originally Posted by chinsettawong

Hi CharlieM,

From your picture, what is a weather stripping?

Wachara C.

It's basically a medium density closed cell synthetic foam rubber material (silicone or other rubber-like material). It serves to isolate the panel from the frame, both acoustically and electrically.

[markusA]

Calvin> I'm thinking about a super simple frameless mounting system.
It might be a moot point if the frame is needed for stability?
Holes in the diaphram will introduce stress concentration points but bolts running through the entire structure will recuce shear stress.

CharlieM> If a frame is needed, your pictures solves most issues. Finding suitable PE-tape and weather stripping might be the hard part? How good is the insulation?
Is it good enough that you could use a metal frame instead of a wooden one?

[CharlieM]

MarkusA,
I use 3M brand foam tape exclusively. I believe I used either 3M #4008 or #4016 tape in 1/16" (1.5mm) thickness on my latest panels. I think any of the 3M #4000 series tapes with acrylic adhesive would work fine. Here the 3M data sheet: http://multimedia.3m.com/mws/mediawe...6EVs6E666666--

Certainly, with appropriate insulation, you could use a metal frame (Martin Logan does). I used wood because it's cheap, readily available, easy to work with and cosmetically appealing. Completely dried wood would have no electrical conductivity at all but to the extent that it absorbs humidity it can become somewhat conductive. Still, I would think that a good stator coating alone would suffice in a wooden frame but some additional electrical insulation can't hurt. Additionally, I always use a medium density synthetic foam rubber cushion (weatherstripping) between the frame and stator for acoustic insulation because the ESL panel vibrates quite a bit when playing and we don't want the panel rattling against the frame or conducting vibrations into it.

[markusA]

I guess one could say I have a fair understanding about materials?
However I do tend to overthink problems and I'm always looking for the perfect solution. Sometimes I need to relax, take a step back and go with "good enough".

In this instance the key words might be "panel ratteling" and "vibrations".
Will I need the frame? Is the frame important?
It will add mass, rigidity and it might change resonance behavior as well.

The panels will be 165x25cm (160x20cm actual active membrane area).
I'll be using 1.0mm Rv 3-4 perf steel stators.
3M 1.6x25mm VHB tape (I'm considering 1.1mm thickness)
(25mm 5962 or 5952 since the stators will be powdercoated)
I'm not decided on the additional tape spacers needed, width and orientation will depend on the thickness of the tape.

I'll try to run them as low as possible (hybrid) without compromising the audiable qualities to badly. X-over <300Hz I think? Exactly how low depends on the final result and I won't know that until the panels are built.

Will the vibrations be large enough to warrant a frame?

And now back to the original question.
I could do it without the extra holes but holes will make a better solution I think.
I need 2 holes for M8 screws on each side (L/R) for each panel. The stands will be mounted near the floor so the holes will need to be located a few inches above floor level.

[markusA]

Instead of starting a separate thread...
Since you have my info above, what do you think about spacer thickness?
Should I stick with 1.6mm or should I go with 1.1mm?
It's a hybrid design and I'll be adding separate bass units.

[chinsettawong]

If you ask Calvin, he would suggest you to use the thinnest spacer you can get.

Wachara C.