Most unusual baffle shape?

[madisonears]

While building my new open baffle mid/high speakers, I have been experimenting with a variety of baffle shapes. I have been using The Edge to model them, then building test baffles from a bunch of 1/4" paneling I salvaged from someone's trash. This material certainly isn't ideally stiff or strong, but it was free, I have a LOT of it to use, and it's very easy to cut up.

I have tried some unusual configurations of shapes and driver mounting, and I find that the best sounding shapes are the oddest, with lots of irregular edges. I tried tombstone shape to begin with, and they were awful. Next came some flying wing shaped things, and those were better. Now I have a monstrosity that looks like a jagged piece of alien spaceship, and damn if it doesn't sound absolutely marvelous, with very smooth FR and lots of 3D and great imaging.

Most of the designs I've seen in commercial production or presented here for DIY have very regular shapes. It seems that most designers have not really broken away from the simple enclosure-type shape that usually needs to be coupled to the back of a baffle. Have any of you experimented with really bizarre shapes, or are you aware of any commercial designs that feature something more unusual than the rectangle or triangle with rounded corners?

Once I fine tune this thing, I will gladly share pictures and my design philosophy.

Peace,
Tom E

[PeteMcK]

It was a couple of years ago, but IIRC, a lop-sided pentagon seemed to work well.

For me, it's a matter of getting an aesthetically pleasing shape without being too hard to construct.

I agree, most conventional shapes are boring,

got any pics, even the experimental ones you discarded?

[planet10]

Originally posted by madisonears
[B]While building my new open baffle mid/high speI will gladly share pictures and my design philosophy.

pictures, pictures, pictures...

dave

[Pano]

Yes, please do post photos.

This odd shape thing has been discussed lately over on Audio Circle. FWIW (a laugh) I'm working on baffles of the shape seen below.

[Moondog55]

Coolio!!

[madisonears]

I'll not embarrass myself by posting pictures of these monstrosities. These things turned into a total bust when I connected a xover and tweeter.

Thanks for the tip on the lopsided pentagon. I tried that next, and it's still not working. Frustration level is getting very high now.

After numerous experiments and lots of sawdust and swearing, lots of modeling baffles and mounting drivers and tweaking crossovers and listening, I'm ready to throw in the towel on this OB thing. There are simply too many contradictions involved, and I can't master the subtleties of design required. I also can't accept the use of massive amounts of EQ to get decent FR. Seems that any baffle large enough to produce anything close to decent low or even midrange FR is so large that it completely messes up HF.

What a can of worms! I guess there are many good reasons why most speakers are put into enclosures, Linkwitz notwithstanding. I've heard lots of nice music during my OB experiments, but never anything totally satisfactory. I have also heard (and made) lots of nice box designs that produce great imaging and spatiality along with a smooth FR. Making good boxes has got to be easier and more rewarding than this stubborn OB thing.

Good luck to you guys who are addicted to OB sound. I quit.

Peace,
Tom E

[Cal Weldon]

Tom, sorry to hear of the frustration but remember, the failures make you stronger, or something like that

I must say though that the thought of OB bass has always confused me and I share your concerns. OB to me has been an eye opener when it comes to midrange though. The open airiness of it is something I will try to incorporate in as many speakers as I can in the future, but again, the bass thing I just don't get. The baffles have to be too big and the driver motors too small. Non comprende.

[trusound]

all I do is crazy shapes...

[ultrachrome]

I've never gotten the feeling that baffle shape was a silver bullet. You can make a bad baffle but you can't make one that cures cancer.

Assuming a box/baffle of nominal proportions and thoughtful driver choice, the real work is in the crossover regardless of the alignment.

I've gotten past the feeling that EQ=evil. It seems to me that any full-range loudspeaker has quite a bit of filtering.

As for bass, my Lambda Dipole12 drivers have pretty big magnets. I think folks are exploiting the OB friendliness of less endowed woofers more than a small magnet being a requirement.

[Andy G]

http://members.optusnet.com.au/~gradds55/index.html