Phase Tech 9.1 Speakers

[johnny_fever]

I just bought a pair of Phase Tech 9.1 (4 ohm) speakers from a local woman. She said they were very expensive back in the day. I have never heard of them before. The surrounds are rubber but they used foam to cover the metal center of the speakers. My question is does this deteriorating foam matter or was it used for looks? Thanks Rick

 

[dc270]

More than likely this was a function of the speaker design. Phase Tech is a very good speaker and does not leave much to chance. I think they are still in business somewhere in Florida, contact them about the foam issue. You might post us a pic here and get our thoughts as well.

Phase Tech pioneered the dome tweeter and numerous other designs. Their foam surrounds on the older design are hard to match, but Phase Tech is a well regarded speaker company!
DC

 

[johnny_fever]

The foam does not appear to go under the rubber surround. The center of the speaker where the foam is applied is hard. Not sure of material but its not metal. I don't want to crank up the Marantz 2500 yet. Im not sure what the foam does or did since its not used as a surround. Thanks Rick

 

[dc270]

The foam probably acted as a damping material- at one time. Now that age has hardened it, it is not as as functional as once set in place. I see not real isse as it is currently, so long as the outside surrounds are in good condition I would play them as normal. Should you want to restore them I would find some thin open cell foam and remove the old foam material and replace it. Auto headliner material I bet would work just fine here.

Those look like very nice speakers, well worth some time investment should you want to bring them back to stock condition. As they appear now you could use them with no apparent worry. The hardening foam may perhaps affect a given frequency but that is all. Having the flat face drivers ofers great phase alignment/ coherintcy- one of their well known and desirable functions they were once known for. Take these to the bank- they are winners!
DC

 

[johnny_fever]

Thanks for your help & Time

 

[dc270]

Thanks for your help & Time

You are most welcomed. I have worked on several of the Phase Tech models and found them to be very likable, well built and one of the best thought out audio designs around. I hope you can enjoy yours as they look to be very nice.
DC

 

[backinthelou]

I bought a pair of the PC 40 bookshelf speakers at GW a month ago. Unfortunately, it has foam surrounds. The surrounds and the foam disk on the center is deteriorating. They are the heaviest speakers for their size I have ever seen.

 

[dc270]

The Phase Tech speakers I repaired needed new foam surrounds and the foam on the disc center was flaking off as well. I finally found some foam surrounds that I made work (odd size) and the foam on the cenetr disk I used very light weigh auto headliner material. They came out looking good and sounding even better. I really like the sound of them.
DC

 

[frommerstop]

The foam does not appear to go under the rubber surround. The center of the speaker where the foam is applied is hard. Not sure of material but its not metal. I don't want to crank up the Marantz 2500 yet. Im not sure what the foam does or did since its not used as a surround. Thanks Rick

That open cell foam covers the "solid piston" (as PhaseTech calls it) Styrofoam cone. It's nothing special, I've rubbed it off, and replaced it with thin foam sold at upholstery supply stores... I'm not sure how much it really affects the sound anyways. Those are very good speakers, and are particularly good with dynamic Jazz, & Rock. As long as the surrounds are in good shape, feel free to crank 'um up! :thmbsp:

 

[johnny_fever]

Thanks...LETS ROCK

 

[stumpie]

I bought these 9.1's new back in 2003. They retailed for $1000/ea and were a serious value. I worked for an authorized dealer and got a hell of a discount, we'll leave it at that. They have since been used lightly indoors for the past 13 years and the foam disk is just starting to get to the point of deterioration when fuddled with. The foam piece surrounding the mid-high and tweeter is in good shape.

Conversely, I bought a pair of similar Phasetech bookshelf speakers (PC-2.1) from the list that must be a decade or more older, stored in the attic/garage, and all of the foam is literally flaking off with so much as a breeze. I contacted MSE Audio and they said that replacement disks are relatively cheap and easy fix, but the tweeter surround foam pieces for the bookshelves would run about $70 each. The disks on the pistons have no audio properties, but the tweeter surround acts somewhat as a waveguide. Rubber surrounds are still relatively good shape.