AR2a capacitor oddity

[nickdinatale]

Yesterday I re-did the crossovers on a mismatched pair of AR2a's.

I was a bit puzzled to find that the older speaker (c.1961) had the normal values I've seen elsewhere for 2a's - a 6uf and a 4uf wax covered cap. However, the newer one (probably c.1966) had a capacitor that was marked as having a 6uf and a 2uf. I followed this for my replacements as I just happened to have an extra 2uf cap laying around.

Now that I'm listening to them, the speaker with the 2uf is noticeably dead compared to the one with a 4uf. Should I go back inside and replace that 2uf with a 4uf? Kind of curious as to whether anyone else has encountered this in the past.

 

[GD70]

Yesterday I re-did the crossovers on a mismatched pair of AR2a's.

I was a bit puzzled to find that the older speaker (c.1961) had the normal values I've seen elsewhere for 2a's - a 6uf and a 4uf wax covered cap. However, the newer one (probably c.1966) had a capacitor that was marked as having a 6uf and a 2uf. I followed this for my replacements as I just happened to have an extra 2uf cap laying around.

Now that I'm listening to them, the speaker with the 2uf is noticeably dead compared to the one with a 4uf. Should I go back inside and replace that 2uf with a 4uf? Kind of curious as to whether anyone else has encountered this in the past.

View attachment 1097342

Put the 4uf in and see how it sounds. Don't even solder yet, twist the wires to the cap leads and tape for a temporary test. Go back in and solder if you like it.
One question, are the tweeters different? That could be why there's a different value.

 

[45rpmspinner]

That's odd.
AFAIK, all AR2a's with double 5 inch mids and dome tweeters are the same.
Even when they became AR2ax's with a single 3 inch mid in 1964, the same cap values were used.

Without checking schematics, I'm wondering if the smaller cap value points to the AR2/AR2x which in original form had no tweeter.
AR sold upgrade kits for the 2's, 2x's, 2a's...both tweeters and mids...so you could turn them into 2ax's.
Not sure if it actually makes sense, but maybe someone didn't upgrade the caps after adding a tweeter?

Other than that, I agree with GD70, put the 4uf in and see how it sounds.

Edit: I just checked the schematic for the AR2, it does indeed show 6uf and 2uf caps. I'm thinking it was probably the same for the later AR2x.

 

[stupidhead]

I wonder if you have an issue with the pots? Not mentioned in OP so just wondering.

As Glenn said, is there any difference in the drivers? If you are still able to get inside a pic of the backside of the drivers might very well reveal dates which might help put this anomaly in perspective.