AR 2AX woofer question (old vs new)

[Shacky]

I was reading that the newer (post '70) 2AX woofer was supposed to be smoother in the upper bass lower miderange. Though the later model lowered the cutoff from 2000 hz to 1400 hz.

My question is would the newer style woofer be able to perform with older coil - i.e. work up to the old 2000 hz cutoff? And if so would this be an improvement on sound quality?

I have a bunch of different drivers and was thinking of making a hybrid set of 2AX's using older crossovers with older tweeters, mids and newer woofers.

[tysontom]

>I was reading that the newer (post '70) 2AX woofer was

>supposed to be smoother in the upper bass lower miderange.

>Though the later model lowered the cutoff from 2000 hz to 1400

>hz.

>

>My question is would the newer style woofer be able to perform

>with older coil - i.e. work up to the old 2000 hz cutoff? And

>if so would this be an improvement on sound quality?

>

>I have a bunch of different drivers and was thinking of making

>a hybrid set of 2AX's using older crossovers with older

>tweeters, mids and newer woofers.

>

Shacky,

The crossover for each version of the AR-2ax-series was optimized for the given drivers of the period. The newer 4-bolt, foam-surround driver will certainly work with the older-style crossover, but the response would probably suffer; specifically, there would likely be a reduction in quality, not an improvement. I also don't believe that the newer woofer cone with its softer compound would respond as well to the higher frequencies necessary as with the older unit, so there may be some attenuation in the upper-bass response with the switch.

That being said, you could certainly give it a try. If you have a way to measure the response of the speaker, even with a crude SPL meter done outdoors, you could probably determine if there was a drop-off in the upper-bass response enough to cause trouble. The fact is that AR did offer that later woofer (as a service-part replacement) with an adapter ring to retrofit to the older 6-bolt speakers, so the woofer's reponse is probably not affected enough to be a serious problem. Service parts are generally to get things going again, not to replicate the exact sound of the original, so a little reduction in quality was the trade-off for restoration of power.

--Tom Tyson

[Shacky]

Thanks Tom! I like the sound of my older 2AX's so much I might not find the motivation to tackle this. I had these 2 newer (post '70) 2AX's and wanted to get them working. I'm just not pleased with their sound.

Jim

[Guest GranPa]

I would bet that the woofer coil was enlarged on the new driver to

tame a midrange peak somewhere between 2000-3000 Hz. I built a

"homemade" AR-2x (same size cabinet) with a foam edge 10" woofer

and had to lower the crossover on it to 1200Hz to fix the midrange

response. Just a guess...