Ever buy commercial spkrs just for the cabinets?

[fvoelling]

I've come across a great deal for the Mirage Omni 550 speakers, and I kind of like the cabinet:



Here are the specs:

OMNI 550 Technical SpecsModel OMNI 550
Speaker System Type Dual 6.5" Magnetically Shielded Omnipolar Tower
Recommended Amplifier Power 10 to 200 Watts RMS
Impedance 8 Ohms nominal (4 Ohms minimum)
Frequency Response 35Hz~20KHz +/- 3dB
Sensitivity (room) 90dB
Crossover Points 700Hz, 2.2Khz
Tweeter: Single 1" (25mm) Aluminum Dome
Woofer section: Two 6.5" Fiberglass Composite
Dimensions (H x W x D) 40.75 x 12.5 x 9.75 inches / 102.24 x 31.75 x 24.77cm
Weight 34.17 lb / 15.5 Kg
Finishes Black Ash

Now I'm not expecting much in terms of sound quality, but is this a viable cabinet to utilize for one of the existing speaker designs here, or does that angled front baffle make it a whole new animal?

BTW, Vann's is selling these for $130 - $170 a pair, depending on finish, shipped! I couldn't even buy just the cabinets for that kind of money, let alone build something this nice.

Frank

[Gir]

The problem is that the cabinet is built like total crap. No bracing, thin walls, and most of the time crappy particle board. Only the higher end speakers get good cabinets, for the most part.

[bonehead848]

I imagine if you added some bracing and dampening that the cabinet would be sturdy enough to use. You may even be able to sell the old woofers on ebay.

[Curt C]

Their published specification for speaker weight of 35 lbs does not suggest robust enclosure construction. It appears it would also require some significant changes to convert it to a traditional monopole design. I'd think it would be better to make some sawdust yourself, or maybe consider one of PE's new curved side cabinets:

C

[Martyn]

I built two pairs of speakers over the Christmas break using PE's curved cabinets - one pair in cherry and one in maple. They're very convenient if you're in a hurry like I was, but they do have some unpleasant resonances. I used the 0.38 cu.ft. boxes, but I would expect the problem to arise in the other sizes too.

The curved sides are laminated from a rather mediocre quality MDF that won't hold a screw, so my attempts to add more bracing in such a confined space failed. I tried various approaches and finally succeeded in reducing the resonances to an acceptable level by employing a little constrained-layer damping. They now sound quite good and they look good too - I particularly like the cherry.

[jdybnis]

What did you use for cld? Did you use any measurement equipment, or just the knock test?

[Martyn]

This was by listening. It just so happened that the resonances beamed out at us from the first test track we used; other test tracks were not so obvious. I have a friend with measuring equipment who also happens to have built the same design in a conventional cuboid box. We intend to compare the measurements of the three boxes (cuboid, curved, and modified curved) - we just have to find a mutually convenient time (we don't live within easy reach of each other).

[jdybnis]

How did you end up damping the resonances? I ask because I've got a set of Modula MT's in those cabs, and I'm about to glue on the baffles.

[Martyn]

I used a self-adhesive mass-loaded vinyl damping material that's intended for damping car body panels and stuck that on the largest internal surfaces, then I glued thin aluminum sheet (construction flashing) to the mass-loaded vinyl using contact cement. The contact cement tended to dissolve the vinyl somewhat, but it doesn't seem to have impaired the bond. This made a very noticable improvement.

[owdi]

Did you use any stuffing or acoustic foam? This makes a huge difference.

Dan

[Martyn]

I used felt and convoluted foam too, but that's not going to affect panel resonance.