I have used a pair of second-generation Pentagram P10's as my main speakers for the past 26 years. They are excellent all-around performers, with no major weaknesses. They cost $1800 in 1983, iirc.
If the woofers on your speakers are truly 8 inches, they may be a smaller model which I believe they also produced, called the P8. My P10's have a 10 inch woofer, a 4 inch or so dome mid-range, and a one-inch or so ribbon tweeter (it was claimed to be a ribbon, but I don't recall if it really was one, the alternative possibility being an etched voicecoil leaf tweeter). It also has a 15 inch mechanically tuned passive radiator on the bottom. "Mechanically tuned" means in this case a large rubber band-like thing attached between the center of the cone and a wooden cross-member within the speaker, which holds the cone under a certain amount of tension.
There was an early version and a late version of the P10. They can be distinguished by the fact that the early version had a smaller dome mid-range (around 2 inches, instead of 4), and a mica top. My later version has the 4 inch or so mid-range, and a painted wood top.
Mine is finished in a beautiful light oak veneer.
Specs are as follows:
Power handling 35W minimum, 200W continuous
Sensitivity 90db (1W, 1meter)
Frequency response 24 to 20000 Hz +/- 2db
Impedance 7.2 ohms nominal, 5.7 ohms min
The truncated pyramid design serves two purposes: It time-aligns the drivers with each other, and results in there being no parallel surfaces internally, which eliminates the need for internal damping.
They are a fairly easy speaker to drive, and I've had excellent results with both tube and solid state amplifiers. Their bass is deep, loud (when it should be), and tight. The rest of the spectrum is very well balanced and integrated. Imaging is very good, especially with tube amps. There are no particular colorations in any part of the spectrum, and I consider their weaknesses to be subtractive, i.e., a lack of the kind of detailing that good planar speakers can provide.
I recently had the surrounds redone on the woofers and passive radiators by Bill LeGall of Millersound.net (not .com), who did a wonderful job. They were not rotted or disintegrated, just torn, I suspect due to a combination of age-related loss of flexibility coupled with being driven hard.
The company only existed for around 3 years or so in the early to mid-1980's. Its president was a youngish fellow named Michael Levy, who was the designer, and the speakers were assembled in the garage or basement of his house in Queens, NYC. The cabinet was custom-made to his specs by an outside cabinet-maker, and the drivers were from well-regarded companies such as Seas.
Hope you can get them restored to good shape -- they are excellent performers, especially if they are P10's in the later version, and I feel that you would have to spend perhaps $5K or more to duplicate their combination of bass performance, dynamic range, and overall balance and accuracy with today's speakers.
Regards,
-- Al
