DIY Flat Panel Speaker Love

[spasticteapot]

Re: DIY Flat Panel Speaker Love

How about some model airplane rubber? It actually has a very low spring constant, but it stretches like mad.

http://www.faimodelsupply.com/product/18-14-lb-box-tan-super-sport-rubber/

[laserpaddy]

Re: DIY Flat Panel Speaker Love

I noticed pe had a new 40 water http://www.parts-express.com/dayton-...4-ohm--295-235
looked like the fs was 160hz rather than 320hz of the 32ep-4

[rmeinke]

Re: DIY Flat Panel Speaker Love

The Dayton Audio DAEX32EP-4 Thruster is the one I was considering. 40W power handling, and the durable steel spider. Are you using more than one on your panels?

I have tried the 4-arm models from Sonic Impact WAAAAAYYYYY back, and they sounded quite nice on some of this:

http://www.jm.com/content/dam/jm/global/en/building-insulation/Files/BI%20Data%20Sheets/Resi%20and%20Commercial/BID-0151_AP_FoilFaced_DS.pdf

I'll have try the glue or shellac on it to get it damped, but I have some of this still in-house.

Last summer at MWAF they had these "Bongo-ties" in the contestant giveaway baggies, and I think they would help suspend the panels well. Another option would be golf tees and bands.

http://www.platinumtools.com/upload_doc/1371583296BongoTie_PF_ONLINE%20%20TS.pdf

I'm thinking about it....
Wolf

Hey Wolf!!
I am currently listening to a single DAEX32EP-4 Thruster per panel and it is in a entirely different class! more than one causes cancelations.. still sound good I've been told but losses some of the panel magic. Boy, I'd try the glue/water combo first. Shellac unless thinned I've heard is a little too much damping but may be a preference thing. Experimenting is fun with these panels... almost instant gratification.

I want to post about panel treatment. I'll probably add it below if you want to take these panels for a spin.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Wanted to give a quick update for those who might want to try out these addictive panels.

Exciters
My thoughts on the 2 exciters is that the lower Fs model (DAEX32U-4 Ultra) likely gets its lower Fs by using a thinner, more compliant (steel) spider opposed to the Thruster's high Fs from a more rigid steel spider. I believe a stiffer spider will be a better candidate for heavier|stiffer|more rigid materials (like a thin Baltic birch ply panel) as it can exert more pressure on the panel with the stiffer spider. The lower Fs DAEX32U-4 Ultra should be better on a lightweight panel like EPS/XPS. When I first started listening to the DAEX32EP-4 Thruster it had really high-levels of self-noise as it totally dominated the panel. Even at low levels I had to keep repositioning the panels because they nearly vibrated off my high-tech stands...errr...chairs. They settled in after a few hours and sound amazing but hope that the low Fs exciters I have on the way will sound even better. Will report back at some point.

Panel Prep
Whats important to make the EPX/XPS panels sound natural is to remove the panels "skin". 100 grit with my palm sander does the trick. Round the corners (I user a 6 in. diameter Pyrex bowl to mark it with a pen) using a steak/serrated knife leaving plenty of room off the marked pen line to allow for cleanup sanding with the palm sander. I use a 3/8 in. quarter-round bit on my (big) router table to knock off the edges and form a rough contour. You have to hand sand to finish. First with 100 grit in long straight strokes to even up the less then perfect router work. Then feather the panels from the panels surface/edge down along the contour of the quarter-round surface. Finish with 200 grit.

Order of events. 1 - Round the corners of the panel. 2. If you use a router, round the edges. 3. Sand the panel skin off. 4. Finish by hand sanding the edges.

Panel Treatment
Once panels are ready, I currently put 2 coats of 1:1 water and wood glue on the back surface/exciter side and 1 on the front. Use a blow dryer to speed the process... you can treat both panels fairly quickly with a foam roller. When done, you will get a sandpaper like surface. When you brush your hand over the surface... even lightly...it will be amplified and quite loud. It is this surface combined with the ultra light and ridged XPS panel that gives the panel it natural sound. Untreated panels do not sound Hi-Fi.

Panel Size
Most of the guys building DML panels over at AC do larger panels (2x4 being on the small side... 2.5x5, 2x6, etc being the norm) for increased bass output but to me, the quality of DML bass (with XPS) was not up to the high standard as the rest of the panel's FR. I kept wanting to go back to my small panels. Its possible that the new exciters will produce better bass on a bit larger panel and I will try it at some point but I'm afraid that the larger panels will always have less than stellar transient response. Smaller will always have speed and dynamics to its advantage. I have REALLY enjoyed listening to the smaller 24 x 30 inch panels so the next step in evolution is to build 2 small panels per side for more output and possibly even more dynamics as the panel will have to move even less. This also allows you to listen at greater distances as it will act like a line array with a focused radiation pattern. Listening within the focused array has removed some of the "distant... sound emanating from behind the panel" characteristic that I do not like about the panels. It is lessened for sure and possibly nearly gone but I have to go back to my open baffles to verify how much that characteristic is reduced.

Low Bass and High Output
For anyone wanting high output, a Open Baffle H, U or even flat panel bass bin/sub would be an absolutely fantastic mate for these panels. If you have not experienced OB bass it is a treat as well. Of course any quality sub can fill in the last few octaves just fine.

Hope this helps, if even a little. Ask any questions!

[rmeinke]

Re: DIY Flat Panel Speaker Love

How about some model airplane rubber? It actually has a very low spring constant, but it stretches like mad.

http://www.faimodelsupply.com/produc...-sport-rubber/

Your on the right track! YES! I have been wondering what rubber would be best and with many different lengths and thicknesses I bet there is a winner here!! Something to try. I still wonder if we would need opposing bands to keep the panel from moving randomly. These new exciters are very powerful.

FWIW, I am still leaning to simple Velcro... might add a little stability to the panel and its random movement. Probably many, many methods. Anything that add little damping to the panel has some stability should work fine.

I want to try both. The opposing band is interesting as you could have one at the bottom of the panel to possibly adjust the damping?!?

[rmeinke]

Re: DIY Flat Panel Speaker Love

I noticed pe had a new 40 water http://www.parts-express.com/dayton-...4-ohm--295-235
looked like the fs was 160hz rather than 320hz of the 32ep-4

See above...

[Wolf]

Re: DIY Flat Panel Speaker Love

The lower Fs model appears to have a plastic more compliant spider, not a steel one.
Later,
Wolf

[rmeinke]

Re: DIY Flat Panel Speaker Love

Right you are. I totally missed that (?????)... new pictures too I see...

I like the durability of the steel sprider. But the removable plate might be useful... just hope the plastic plate doesn't impact the sound quality. Will find out soon enough.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Spent time last night playing with speaker positioning. These panels are a different beast; most like Open Baffle in setup though. You can not get them out into the room more... solid bass as long as they are 2.5-3 feet away from the back wall.

Imaging is very good in most all cases but considerable better listening within the focused radiation as with a line array. I walked around the speakers last night observing off axis response and its bizarre as the imaging is maintained even as you walk between the panels. Bass drops (null) when your perfectly in between the panels but quickly returns as you move just to either side of the speaker. Cool experience... when you have them pulled way out into the room and can walk freely between listening to both sides of the speaker!!

I personally like them toed in crossing about 1 foot in front of you - like an open baffle. The sound stage is expansive with a DML panel. When listening straight ahead with no toe the image, to me, is too big and not quite as focused for the music I listen to. Some listeners might prefer straight ahead and on some recordings (symphonic) I can see how that might actually be more accurate and enjoyable. But with smaller recording spaces I like the extra toe in... at this time anyway.

Experimentation in your own room is critical but hope this helps to act as a starting point. Them move and position to taste.

Enjoy!

[laserpaddy]

Re: DIY Flat Panel Speaker Love

Have you tried hanging them from ceiling face pointed downward ? Like a ceiling fan Maybe 12" from ceiling? Of course over listening / seating positions.

[rmeinke]

Re: DIY Flat Panel Speaker Love

I suppose you could. Absorption of the back radiation helps to improve the LF and sound quality. I played a bit with the panels and even just heavy drapes behind the panel helped. A thin enclosure with your favorite material to absorb the back wave would work. Pulling a foot away from the wall also produced enough low freq. to be useful. All viable as long as a sub is used.

Mounting on the ceiling I'm not so sure... someone would have to spend some time to determine what a good HT config. would be.

I don't do HT but I've read comments about panels used as right/left channels is really good. Urban scenes with honking cars, typical street noise... helicopter overhead is really interesting. I would have to think its an excellent use of DML tech. A tall, thin panel (12" wide?) would yield a very nice R/L monitor. But I think moving it away from walls and ceilings is important to get that excellent ambient field that the panels throw.

HT panel love!

[rmeinke]

Re: DIY Flat Panel Speaker Love

I very much like something about these. Lots of imaging, very wide soundspace.
[ATTACH=CONFIG]53794[/ATTACH]

Hey Don... if your out there... how are things progressing on your panels?

Very curious to hear if the plate exciters you are using are opening up and becoming more clear as the spiders break in!?!? The panels as they cure gives an added touch of HF and clarity. Not eye popping but notable.

Took me a good 30 hours of listening before I said "Hey... I REALLY like these!!". Interested to hear your thoughts as you listen more.

[donradick]

Re: DIY Flat Panel Speaker Love

Hey Don... if your out there... how are things progressing on your panels?

Very curious to hear if the plate exciters you are using are opening up and becoming more clear as the spiders break in!?!? The panels as they cure gives an added touch of HF and clarity. Not eye popping but notable.

Took me a good 30 hours of listening before I said "Hey... I REALLY like these!!". Interested to hear your thoughts as you listen more.

I'm running into the problem I always thought about with panels -
I really can't think of a place for them that will have good WAF.
Right now, they are in the my shop in the basement, and I've mostly been working upstairs, so not a lot more hours on them.
Not an optimal position, but really like the sound, almost like a line array near field.
I've got an order in the PE cart at present, and thinking long and hard about grabbing a pair of the "P" exciters.

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey Don,
That is a challenge for sure... these panels really need space and can get large.

One of the motivational aspects for me to build these panels was the fact that they are very light weight. I wanted something for the living room that I could set up and tear down quickly and move to a storage location out of sight. That is how I will be using the panels. Also a negative aspect... the panel do not sound as good in my small listening room. A larger room is also an aspect that makes for a more challenging setup than your typical box speaker.

I also want to build a thinner panel to handle 150Hz and above with a open baffle woofer to cover the lowest frequencies. After another thoroughly enjoyable listening session last night, I am almost ready to move on such a design so I can have panels in my main listening space. Would be interesting to see if a smaller panel can be used in such a way and still get that panel magic in smaller spaces... have a line array waiting for me but I might have to take a little more time to see what can be done moving in that direction...

If your not in a rush to get the "P" exciters, maybe when I get my next order together I can order an extra set and mail them down to you. I hope to get a QTY of ten and free shipping... might be cheaper for us that way.

That goes for anyone... if someone else wants to try a set of the new high shove/power handling exciters, let me know and we can coop this and do group buy.

Thanks for the update Don!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Exciter update...

I received my DAEX32U-4 Ultra exciters tonight (plastic exciters) and even after a short listening session these *may* sound better than even the Thruster version (metal spiders)... not even broke in they appear louder and with more clarity and mid/upper bass energy. Been listening to them most of the evening and would love to comment more but as the listening session progressed the left panel started making what sounded like panel self-noise on louder passages. Now, some 30 minutes later, the noise has been replaced with just buzzing. Not happy after waiting an uncharacteristically long 7 days after ordering.

While these have potential on lighter panel materials like EPS/XPS I am a bit concerned about the construction. Not because of the failure specifically, but because of its general build quality.

Where the Thruster model feels solid and of very high quality, the Ultra model feels cheap. The spider, as stated, is plastic but to get a lower Fs, there is some form of plastic/rubber spider on the backside connecting the magnet/back plate to the outer plastic housing. This allows the magnet assembly to (firmly) move forward and backward within the outer housing. There is a sticky black substance that possibly attaches the magnet assembly to the spider and outer plastic housing or maybe just acts to dampen where the magnet, spider and outer plastic housing meet. If you look at the product photos it might become more clear. The design is interesting from an engineering perspective but appears to fail in execution. The fact that one exciter failed after a short listening session is a huge concern. Bad luck... I sure hope so... but these feel fragile right out of the box.

I'm going to give them a long assessment after I get a replacement from PE. They seem to have potential and may, in the end, topple the Thruster as the best sounding high-shove, high power handling exciter especially for ultra light panel material like XPS. Just may come at a cost of lower reliability (can I really complain about a "speaker" that costs less than $18).

p.s. As I type this up... listening to a left Thruster panel and a Ultra right panel, it almost sounds like the Ultra seems quieter(?)... like it has a higher signal-to-noise ratio... and cleaner/clearer presentation. I don't want to like these but afraid they do sound better. Arg.

Will keep you posted...