Upgrading CS-77's

[krameraxeman]

I recently got a pair of Pioneer CS-77's. I have refinished the cabinets so they look beautiful. They don't sound bad, but I was thinking about upgrading them. The CS-77's are 3-what's with a horn tweeter, mid and a 12" woofer. The speakers are mounted behind the baffle instead of on top. Also these cabs are bass reflex and have a huge rectangular port at the bottom.

Anyone have experience upgrading these? Have any suggestions as to what speakers will fit or other mods for these speakers specifically?

 

[bermnerfs]

The 108 DB efficiency these claim to have should be pretty impressive. Is there a reason why you would replace the drivers? To get that kind of efficiency you will have to shell out quite a bit of $.

 

[krameraxeman]

Oh I know they're insanely efficient. I have them paired up with my SX-1500T, which is 55 wpc rms and they scream with the volume knob set at 9 o'clock. I find these speakers to be lacking in bass and at higher volumes to be a bit on the screechy side. I figured they might benefit from replacing the caps in the crossovers, but I don't know what brand or values to use. I also generally like the sound of silk dome tweets.

 

[89grand]

That 108db number is pure fabrication on Pioneers part. They aren't even close to that. I'd bet 10db less easily in real world testing. That speaker would be 5 times bigger and horn loaded, or it makes zero bass, neither of which are actually the case.

 

[krameraxeman]

I was able to dramatically improve the sound quality of these CS-77's by stuffing about 1.5 lbs of walmart polyfill in each cabinet. I made sure to keep the port clear. I then simply put the speakers up on stands that are about 4" in the front and 3.25" in the back. The polyfill cleaned up the messy sounding mids and the bass tighter, but can go a little lower and is a bit more pronounced. The stands helped with sound staging quite a bit. I think I'll hold of on re-capping the crossovers. They sound good as-is.

 

[BrocLuno]

A co-worker and I did his CS99 a while back. Was a challenge, but they are such nice "furniture" that he wanted to keep them in the living room

We ended up replacing the woofers with ones with larger magnets. Seems he had to ship a few pairs back to PE until we finally got a decent match. AFAIK, there are no published Thiel/Small parameters for the drivers used in these ...

We used oil/paper caps for the woofers, poly's for the others, and added "Acousti-stuff" as a cab filler. I didn't keep notes as they were his project. But they came out very nice

 

[krameraxeman]

A co-worker and I did his CS99 a while back. Was a challenge, but they are such nice "furniture" that he wanted to keep them in the living room

We ended up replacing the woofers with ones with larger magnets. Seems he had to ship a few pairs back to PE until we finally got a decent match. AFAIK, there are no published Thiel/Small parameters for the drivers used in these ...

We used oil/paper caps for the woofers, poly's for the others, and added "Acousti-stuff" as a cab filler. I didn't keep notes as they were his project. But they came out very nice

Very cool. I'd love to know more details. Were his speakers CS-99's or CS-99a's? Did the speakers mount on the front of the baffle or behind like mine? I'd still like to upgrade the woofers and potentially the mid and tweeter too, but really not sure what would fit well and sound good together with my 55 wpc receiver.

 

[BrocLuno]

I don't know which models they were. The drivers mounted from the back. We removed the rear baffle - not easy

He's moved away and I've lost his contact info so no help there.

The woofer was another later model Pioneer driver, but still a paper cone.

I do remember using upholsterer's felt to line the cab first. And I remember gluing in the paper/oil caps that we got at a local electronics salvage shop (now out of business and gone ).

I recall some threads here about rebuilding CS99's - have a search and see what you can find