Help Identify These Woofers

[gal419]

I purchased these woofers a few years ago from ebay and I do not remember what speakers the seller said they came from and I cannot identify them. I'm hoping that they are sutible to put in a pair of AR-3a's that I am restoring. Help me out here guys. Thanks.

[tysontom]

Those woofers are the early version of the AR-1 woofer, dating to 1955. They were hand-made, sand-cast (note the thicker aluminum) Alnico-magnet versions with Henry Kloss' pleated surround and felt dust cap—later replaced by the improved half-round surround (another Villchur innovation). These woofers are basically compatible with other AR 12-inch woofers made up through the 1980s, with approximately the same free-air resonance and excursion and so forth, so technically they could be used with AR-3as as a retrofit. The problem is that the pleated surround is more susceptible to "leaking" air than the half-round version, so usually that has to be addressed. These woofers typically don't withstand the high power of the later version as well, usually with glue separating on the skiver and even the surround, so this should be considered. But in truth, all things equal, they can indeed be used in the AR-3a—with sound very similar to the original. Furthermore, since the AR-3a crossover is lower than the AR-1, the woofer would never get into the uncomfortable range above 500 Hz.

--Tom Tyson

Image of early AR-1 SN 0006, showing the woofer that is similar to the two woofers mentioned here.