Know anything about Pentagram Loudspeakers?

Al,

Thanks VERY much for the info! I just measured, my woofers are indeed 10" with a 4" midrange. I was able to get one speaker playing today, and I was very impressed by the highs and mids, although the woofers may be a lost cause - the previous owner tried "refoaming" them with, if you can believe it, a strip of foam (like, couch cushion foam) and white caulk, lots of it. But the cabinets seem to have a lot of integrity and I think they could be easily re-veneered. The crossovers are probably the most substantial I've ever seen.

Your post raises a few questions which I hope you don't mind answering: Do your speakers contain any damping material, and if so, what kind and about how much? And, any ideas where on earth could I get a passive radiator that would be a suitable stand-in for the original?

I wonder if this Michael Levy fellow is still around? It'd be interesting to get in touch with him...

Thanks again, and best regards!

Roy

Hi Roy,

The Pentagram's were unusual in that they contained no internal damping material whatsoever. That was made possible by the five-sided truncated pyramid design, which has no parallel surfaces (you'll note that each side is opposite a corner edge).

I'm sure Bill LeGall can effectively repair the damage the other person did to the woofers, for reasonable cost. He is the best in the business at re-coning and repairing surrounds. His phone number and email address can be found at http://www.millersound.net. The main downside would be the time and effort required on your part to remove, pack, and ship the drivers, and reinstall them subsequently.

Before sending him my drivers for repair of the tears I mentioned, I spoke to him at length on the phone (he is a delight to talk to, and very informative), and he actually recalled having listened to the P10's, and commented that they were "very, very musical."

If your passive radiators simply need cone replacement, I'm sure he could do that as well. If they are completely missing for some reason, I have no suggestions to offer other than asking Bill for his advice.

Not sure what became of Michael Levy after his Pentagram days. I haven't seen his name come up ever since in any of the numerous audiophile publications I subscribe to.

Best of luck with them!
-- Al

Some good additional background and information on the Pentagrams is provided in post no. 49 of this thread.

Among many other things, he notes that the P10's were the reference speakers of a reviewer at "Audio" magazine.

Regards,
-- Al

I used to build these for Mr Levy. The P-10 is a 3 1/2 way, incorporating a 15 inch "passive damper" that crossed over mechanically at about 60Hz and was 3db down at 16Hz or so. The woofer was made by Becker. Any 15" (preferably paper) passive can be used to replace the original, but it must have an added 16oz weight hot glued to the center and be suspended from an internal support in the middle of it's linear excursion with 1/4 inch rubber bands, such that it returns to center when flexed. It was attached with t-nuts, so it's easy to remove and install. If you have the original damper you might use the original weight. We used heavy washers and eye bolts. The tweeter is a Panasonic leaf, quite good for it's time. Replacing it will probably require adjustment to the crossover. The speaker sounded best at the time placed 1/3 into the (preferably large) room and driven by high power push-pull amps like the CJ Premier 1 and Quicksilver M190, or really good sand like the Bedini 25/25. Its strengths were great imaging and bass equivalent having two subs. Tonality could be adjusted slightly by toeing them in, but your best bet was to be VERY accurate in placing them, relative to the listening position. In an equilateral triangle with the speakers the base and the listening position the apex, they would disappear.
The cabinets use high quality wood veneers and black Formica tops. Finishes included walnut, light oak, and Brazilian Rosewood, and we made a few with 10 coats of black lacquer painted by a car painter. We had a lot of fun back then, but they were very expensive to make, since Mike used high quality parts, including the best caps and resistors, and parallel leads composed of Kimber Kable and Live Wire, equating to 10ga internal cabling, which required one BIG soldering gun!
That's all folks!
Best Wishes

yes this speaker was manufactured in bayside queens in a garage in the mid 1980's. i was hired to assembled them in a garage