Question on Old Coral 8CX-1

Hi all,
I have a pair of these Coral coax drivers. No enclosure. To me they have a way cool retro look and appear to be quality product for their time. But I can't find any information on them. Can anyone tell me about when they were made? What type of enclosure would best suit them? If they are likely worth the effort?

From the pictures you may be able to tell they are pulp cones, pleated surrounds, cork gaskets, Also I there's a 2 mfd electrolytic cap (Nitto?) used for coax crossover. Should I assume this needs to be replaced by now?

Thanks,

I purchased one of those drivers off ebay awhile back and wound up throwing it away. The problem was that the chemical used on the pleated paper section of the surround had become extremely stiff over the years and manually flexing it back and forth with my fingers did not loosen it up. Because of this situation the woofer cone could barely move so the driver put out no bass and instead acted as a large midrange driver. I know some here might argue the driver was designed that way to have a high Q factor, but I don't buy that as other Japanese drivers of the same vintage without the problematic surrounds sound much better and have normal bass output.

I also faced this situation with a Pioneer PIM-6L driver. The paper cone actually separated from the chemically treated surround portion as the cone wanted to flex and the surround would not. I've learned my lesson about these drivers and if I see a shiny chemically treated pleated paper surround which is part of the cone material I pass on acquiring them. The 60's vintage Japanese drivers that used untreated paper surrounds, or cloth surrounds are usually fine.

Definately replace the cap. Have seen their values shift downwards and upwards with age. Either way, it takes the tweeter away from the intended crossing frequency.

SSS.....stiff surround syndrome.
A VERY common problem among older drivers.
No cure that I know of.
Although I heard mention on the Telecaster guitar forum of experimentation with everything from brake fluid to fabric softener?
Maybe if large quantities of alcohol were poured on them....they'd soften up?
Always happened to me!

Steve

Steve

I used Meguires rubber conditioner (for cars) and picked up a healthy dose of bass on my similarly surrounded Coral BX-1001 woofer. I placed the speaker on its back while playing some soft music and spread it around with a Q tip. It took about 10-15 minutes per speaker. These speakers are pretty efficient and don't have much cone movement to begin with so you are never going to get heavy bass out of them.

Pre-treatment it was a mid-range shouter and completely unuseable, even for garage duty. After treatment it's good enough to use on my limited budget mono setup although I just use them for garage duty now.

Scuzzer said:

I used Meguires rubber conditioner (for cars) and picked up a healthy dose of bass on my similarly surrounded Coral BX-1001 woofer. I placed the speaker on its back while playing some soft music and spread it around with a Q tip. It took about 10-15 minutes per speaker. These speakers are pretty efficient and don't have much cone movement to begin with so you are never going to get heavy bass out of them.

Pre-treatment it was a mid-range shouter and completely unuseable, even for garage duty. After treatment it's good enough to use on my limited budget mono setup although I just use them for garage duty now.

Click to expand...

Thanks Scuzzer. I'll give that a shot. No telling how long these sat idle before I got them. Just to give them an initial check I threw them into a pr of bass-reflex 2-way cabinets that I'd pulled the same size woofers out for re-foam. After several hrs of play they seem a bit looser now than when I first got them. Still not much on the low end but the cabinet is not optimal I'm sure.