6 replies to this topic

[Keith Dayer]

I am in the process of restoring a pair of Allison Ones. I still need two more 10 inch woofers, which in the A1 are each 4 ohm impedence and wired in series. Does anybody know if 10 inch woofers from a CD9 would work, or are they a different impedence? Alternatively, is there a substitute that I can buy new that is similar? I've seen 10 inch 4 ohm woofers for sale, but don't know if they would mix and match with the two originals I have. Third option - does anyone have two A1 woofers that they are willing to sell? Any advice would be appreciated. It's really the only thing standing in the way of completing the project. Thanks.

[Carlspeak]

Allison A-1 woofer DCR=3.1 ohms. CD-9 woofer DCR=3.1 ohms according to my information. Both have p/n 220-110-0. Is that what your p/n's are?

[Keith Dayer]

The only numbers I see are on the back of the cone. Looks like 310. The outside of the basket reads, "Made in U.S.A." and "Nov 15, 1978"/. They are the sticky surfaced drivers that we all know and love. I checked dcr and got 2.8 and 2.9 ohms on my tester. Sounds like these that I am looking at for sale will work, as they look identical to mine. All of them will need new surrounds. When I do that, I am wondering if I should get the foam ones and then spray the whole thing in a fresh coat of this rubbery stuff, if I can find it.

[Carlspeak]

The cone number is not the p/n of the woofer. It's just the p/n of the cone.

Yes, get the foam ones with the filleted inner edge. I don't think you need to coat the new foam surrounds.

[Keith Dayer]

By filleted, I assume you mean angled. Speakerworks has those. If you meant something else, I would appreciate enlightenment. I have done a number of refoams now, and feel pretty comfortable doing these. Thanks for the help. I bought the two woofers. They look identical to mine.

[Carlspeak]

By filleted, I assume you mean angled. Speakerworks has those. If you meant something else, I would appreciate enlightenment. I have done a number of refoams now, and feel pretty comfortable doing these. Thanks for the help. I bought the two woofers. They look identical to mine.

If you mean 'angled' vs 'flat' attach, no, that's not what I meant. By filleted I mean the inner portion of the roll tapers straight down to the inner edge. These same surrounds are also used on Boston Acoustics woofers.

[Keith Dayer]

Oh duh! I get it, thanks. I contacted M Sound about these filleted surrounds. I never thought about these, but now can clearly see that they are different. Thanks so much. Now I just have to decide what to do with the crossovers and I should be all set. They have exploded parts, mostly caps. Previous owner had subbed 8 ohm woofers and probably overcranked the system to get bass. 2 tweeters were blown also. Anyways, thanks for all your help, I started this project two years ago, and it's time to enjoy them.