OB with NoBaffle

JohninCR · « **on:** 28 Oct 2006, 11:59 pm »

I said goodbye to boxes before, but now I say goodbye baffles too.
The only thing I still need to address is edge diffraction (not baffle step).
Here are pics of my NoBaffle test mule and some crude drawings of
the look I'm shooting for. The quickly thrown together test cabs have
1 major flaw, but otherwise work great with bass to burn. The drivers
are a Hawthorne Coax and Augie. Next week I'll have the world's smallest
cab housing dual 15" drivers. The test mule was a little too big.

Brad · « **Reply #1 on:** 29 Oct 2006, 12:14 am »

John - it looks like you can move the drivers right down next to each other to minimize the size

Are you able to mount the drivers securely enough that way?

JohninCR · « **Reply #2 on:** 29 Oct 2006, 01:01 am »

The magnet mount support structure will be in back. The test mules are fine, just
too lightweight. You can't see the larger center brace in the rear center. Once
I get ready to do the real thing, the driver spacing will be determined soley on
asthetics. The mules are at 50cm ctc spacing, which ended up a little more than
I wanted in terms if the visual. Visually these are about the same size as my
Frugelhorns. See the pic below.

doorman · « **Reply #3 on:** 29 Oct 2006, 01:28 am »

John: I say "untie those ropes, let those drivers go!"

Don

Brad · « **Reply #4 on:** 29 Oct 2006, 01:41 am »

John,

Why not hire a coupla guys to stand there and hold the drivers for you?
They would be infinitely adjustable that way

Just kidding - the rear pictures show the full support a lot better.

If you keep this up, we'll have to change the circle to Open/Minimal/No Baffle

JohninCR · « **Reply #5 on:** 29 Oct 2006, 02:40 am »

Nice one Brad. No thanks, I have enough dead wood on my payroll
already. I may have to put some surfer dudes to work though. I
figure that broken surfboard blanks may be the best thing for creating
my "Diffraction Rings". Easy to form and make pretty, plus lightweight
as well for cheap shipping.

Final form will be a very narrow support structure. I have some super
dense and strong almendro wood that will be perfect. I will be some
kind of cross between Jamo's stainless steel rear support and Nigel's
magnet mount for his B200's.

Dmason · « **Reply #6 on:** 29 Oct 2006, 02:46 am »

I have thought for a long time about milled surfboard blanks for baffles. The foiling of a longboard blank is convex on the bottom, symmetrical, and one blank would yield two baffles. Use quality D boatcloth, and usual polyester finishing techniques, and have some spectacular baffles for Iris-size drivers. Nuuk has already built several baffles using Clark Rx density foam, in the UK, so we know it works well.

JohninCR · « **Reply #7 on:** 29 Oct 2006, 03:05 am »

Hey Dan,

I'm with ya. That was my first thought when I saw the Jamo's.
I've just never done any quality fiberglass work, repairs only,
otherwise I'd be whipping them out. My thought is though that
narrow baffles don't do much, and drives floating in the air would
look cool if done right. Plus some kind of strong support piece is
needed anyway, so why no eliminate the baffle. Then even dual
15's becomes very room friendly. These are really comparable,
if not smaller than my Frugelhorns, and you can only imagine the
difference in bass. A giant bass horn may compete SQ wise, but
I'm sorry, nothing else does. You should hear what I'm listening
to now. 15" coax on top of double Augies....WOW! Way more
bass than is needed in any reasonable sized room. I can't wait to
crank them outside. Pics coming as soon as I do some finish work,
but some construction previews are above. Those real wood top
baffles are working out great and make the coax's vanish with my
computer driven XO, EQ, everything program.

Dmason · « **Reply #8 on:** 29 Oct 2006, 03:23 am »

I dont do fine glass work, but the board shapers sure do! Cutouts for drivers would be far simpler to top and tail than cutouts for finboxes and skegs. CNC cutters are in full-swing use for shapers to concentrate on finishing foiling, rails, etc. Ergo, it would be easier to come up with a one off successful baffle set of this variety, than an actual board. Two beautiful baffles, rubbed out, hot-coat, the works, for the price of one longboard, maybe less.

Mounting would be an issue solved with a little creativity. I also saw longboards, when I first saw the Jamo. Then I saw the incorrect choice of drivers, nasty little dome tweeters, I saw well-executed Bauhaus fault, IMO, and then I saw BIG coaxials, use of truly fine C/D drivers, such as the B&C D series, actively XO'd & contoured, the ability to use tasty flea amps like 45, 2A3, SV83, on the C/D, and perhaps Vinnie Signature T amps on the cones for lightning-like rise times, and Uber driver control...

These elements are taking shape in my head. I have already had a chance to play around with the CADSurf program, which is owned by a shaper I know. A custom baffle design program right there! Any thoughts on this approach out there?

corloc · « **Reply #9 on:** 29 Oct 2006, 03:27 am »

Your killing me John,

I'm almost finished with what I hoped to be my finished baffles for my B200's. Now I have to screw around with this Idea. I figure my B200's with the Warrior 15's would equal a Silver Iris. My listeing room whent from the living room to a spare bedroom, so room filling bass will not be as hard. I need to find some engineered beams. They should make a great spine to work from. Time to break out the tools.

Chris

Brad · « **Reply #10 on:** 29 Oct 2006, 03:52 am »

Dmason,

I love the idea of the surfboard blanks.
Get them finished in one of the classic surfboard patterns......

Some Dick Dale blasting out of a pair of SI coaxes/Augies on each side

JLM · « **Reply #11 on:** 29 Oct 2006, 10:07 am »

I'd guess that substantial mass in the supporting structure would help counteract the movement of the cone masses, add stiffness, and reduce vibration within the structure itself.

I suppose the ultimate expression of this concept would be suspending the drivers from fish lines.

JohninCR · « **Reply #12 on:** 29 Oct 2006, 09:09 pm »

Quote from: JLM on 29 Oct 2006, 10:07 am

I suppose the ultimate expression of this concept would be suspending the drivers from fish lines.

Sure that's possible. You'd probably want to hang them quite high with woofer very near the
ceiling because the +6db boundary loading is important in the woofer section to conserve some
power and excursion. The primary gain, once you figure out an arrangement that is aesthetically
pleasing, is the ability to totally decouple the drivers from each other and everything else as
long as you isolate the support cables at the ceiling connection and hang the drivers on separate
sets of cables.

Russell Dawkins · « **Reply #13 on:** 29 Oct 2006, 10:41 pm »

I'm imagining a pair of WWMTMWW arrays hanging from the ceiling

JLM · « **Reply #14 on:** 29 Oct 2006, 10:45 pm »

I was sort of kidding about the fish lines as I envision the drivers moving back and forth like wind chimes from the cone movements. On a much smaller scale, the same would be happening if the structure lacks mass/stiffness.

Russell Dawkins · « **Reply #15 on:** 29 Oct 2006, 11:04 pm »

Quote from: JLM on 29 Oct 2006, 10:45 pm

I was sort of kidding about the fish lines as I envision the drivers moving back and forth like wind chimes from the cone movements. On a much smaller scale, the same would be happening if the structure lacks mass/stiffness.

I figured you were, although I'm not sure that JohninCR picked up on that.

Apparently the idea of mounting the drivers from behind by the magnet with a lossy seal to the baffle is good enough for that to be now a standard feature of the Orion.

For that sort of arrangement the surfboard would seem to have better acoustic characteristics than a wood or mdf panel in that it would be light and rigid and thus have inherently higher frequency resonant characteristics.

Dmason · « **Reply #16 on:** 29 Oct 2006, 11:24 pm »

I spoke with a surfboard shaper today I happened onto, and he had built all kinds of things with blanks. The baffle idea intrigued him and he stated he had all the tools to do cutouts and had some ideas about proper mounting as well. He pointed out the CNC cutter could do a surgical job on the holes, as this hadn't occurred to me at all. He thought a dark Anthracite gray metallic type paint with a hot coat would look amazing. He easily envisioned where I was going with the idea, and NOW, I want to do it.

markC · « **Reply #17 on:** 30 Oct 2006, 01:50 am »

And somehow...I know that you Will.

hurdy_gurdyman · « **Reply #18 on:** 30 Oct 2006, 04:01 am »

Quote from: Dmason on 29 Oct 2006, 11:24 pm

I spoke with a surfboard shaper today I happened onto, and he had built all kinds of things with blanks. The baffle idea intrigued him and he stated he had all the tools to do cutouts and had some ideas about proper mounting as well. He pointed out the CNC cutter could do a surgical job on the holes, as this hadn't occurred to me at all. He thought a dark Anthracite gray metallic type paint with a hot coat would look amazing. He easily envisioned where I was going with the idea, and NOW, I want to do it.

Dan,

Go for it! I'd love to see how they turn out.

Dave

JohninCR · « **Reply #19 on:** 30 Oct 2006, 05:40 am »

JLM,

You may have been kidding, but I wasn't. I've looked into some related studies in the
past while researching suspending arrays from the ceiling, and as long as isolate the drivers
from each other the only slight loss is in efficiency. You just don't what a woofer moving
a tweeter back and forth at the woofer's frequency. You could always add mass to the
driver basket to counteract the efficiency loss.