AR 2AX Crossover - Old vs. Newer

[Shacky]

I see in the library that AR changed the crossover frequencies on the 2AX from older 2000 and 7500 to 1400 and 5000 on the newer model - >125,000 SN. I have an old pair a newer non-working pair and I notice that the capacitor values are identical - 4 and 6. How did AR change the crossover frequency while using the same caps and same 15 ohm pots?

[dynaco_dan]

Hi there;

What serial numbers do you have?

Do you have photos of the crossovers?

I do not know with any certainty, that they were exact serial numbers during the transition.

There may have been an overlap from older version to the newer version.

[RoyC]

The woofer inductor was changed from a #5 (1.187mh) to a #7 (1.88mh).

Roy

[Shacky]

My old pr is 9xxx. New pair is 153xxx. Attahced is pic of the newer xover.

Jim

[Carlspeak]

>My old pr is 9xxx. New pair is 153xxx. Attahced is pic of

>the newer xover.

>

>Jim

If the old AND new xovers have the combined 4 and 6 mfd caps, then the upper xover frequency could not have changed unless the tweeter's inherent impedence changed from the old to newer models.

The inductor change noted by Roy would indeed lower the woofer xover point but not affect the tweeter's xover point.

The rheostats only attenuate the volume of the mid and tweeter. They do not change the crossover frequency.

Remember, it's all about the music

Carl

Carl's Custom Loudspeakers

[RoyC]

The older version would have been originally equipped with the cloth surround woofer with the old style alnico magnet (and damping ring), as well as the original AR 1 inch orange dome tweeter. The characteristics of at least these two drivers were slightly different than later iterations of the AR-2ax.

The midrange driver of the last version of the 2ax in the mid 70's appeared identical to the original, but with a dcr that was 3 ohms higher.

AR was tweaking and adjusting things all along the way.

Roy

[Carlspeak]

>The older version would have been originally equipped with

>the cloth surround woofer with the old style alnico magnet

>(and damping ring), as well as the original AR 1 inch orange

>dome tweeter. The characteristics of at least these two

>drivers were slightly different than later iterations of the

>AR-2ax.

Yup, you're right about the older version. I had a pair and salvaged the drivers which match your description. Also, the 4&6 Mfd combo-caps were in mine as well.

I have 4 of these if anyone is interested. Also have (2) original 6 Mfd AR caps if anyone is interested.

Remember, it's all about the music

Carl

Carl's Custom Loudspeakers