Mismatched woofers in a AR2ax pair- advice needed

[mrbruce4]

I've been given a pair of 2ax speakers and it looks like they will become a project. Person said he was the original owner and bought them in '72. He told me when I was loading them up that one woofer was "repaired". The one still in the cabinet (S/N AX100085) has a cloth surround and would appear to be the original since the seal seems to be the black putty I've seen in my pair of 4x. The woofer removed from the cabinet (S/N 100143) has a masonite trim ring and the foam surround is gone. Numbers on the magnet are 561 7731

The puzzling things to me are I've understood from what I've read here that the AR2a used the woofer with the SN 100085. Also, is the woofer I removed from the cabinet worth keeping, after a new surround, and using in this pair?

Separately, it looks like I will need a pair of tweeters. I've cleaned up one pot (disassembled the pot and cleaned with D5 first and then Faderlube), but the tweeters both measure open off the tiny wires coming out of the domes. I get 1.8 ohms on the push button terminals for each of the tweeters. I'm familiar with the pot corrosion problems but since I'm measuring the tweeters as open, I'm not having any hope for them.

Advice on the woofers and suggestions for the replacement tweeters would be greatly appreciated.

Thanks

Bruce

[RoyC]

Advice on the woofers and suggestions for the replacement tweeters would be greatly appreciated.

Thanks

Bruce

Hi Bruce,

Your speakers are the first version of the AR-2ax (late 60's) with the cloth surround woofer and the orange dome tweeter (the same tweeter, incidentally, used in the AR-3).

Your woofer with the deteriorated foam surround is a 1977 AR replacement woofer with a ceramic magnet, and is unlikely to have the same response as the original cloth surround/alnico magnet version. The earliest 2ax woofers (cloth surround and first iteration foam surround) had unusually wide mounting flanges, which is why a masonite adapter was used with your later replacement woofer. Further, the #5 (1.20mh) woofer inductor used in your cabinets is not as compatible with the later woofer, which was mated to a #7 (1.88mh) inductor.

Now for the good news...I believe your tweeters are OK. They are supposed to read 1.8 to 2 ohms as you have measured at the posts. It is very difficult to get readings directly from the aluminum lead wires. Be very careful, as those leads are extremely fragile, break easily, and are very difficult to repair.

My guess is that the pots are still the culprit. They almost never respond to cleaning fluids. You must physically clean the interior contact surfaces to remove tarnish and/or corrosion to make them usable again.

Roy

[mrbruce4]

Hi Roy - Truly appreciate the background on the woofers AND the tweeters. I didn't know the 2ax used the same tweeter as the AR3. I've been looking for tweeters so this will help. Guess I will now also start looking for a woofer.

I did take the one pot apart for the tweeter and cleaned the green corrosion but I'll keep after them before declaring the tweeters lost. The mid range pots did work acceptably well without cleaning but I still plan to clean those up as well.

Thanks again.

[soundminded]

I've been given a pair of 2ax speakers and it looks like they will become a project. Person said he was the original owner and bought them in '72. He told me when I was loading them up that one woofer was "repaired". The one still in the cabinet (S/N AX100085) has a cloth surround and would appear to be the original since the seal seems to be the black putty I've seen in my pair of 4x. The woofer removed from the cabinet (S/N 100143) has a masonite trim ring and the foam surround is gone. Numbers on the magnet are 561 7731

The puzzling things to me are I've understood from what I've read here that the AR2a used the woofer with the SN 100085. Also, is the woofer I removed from the cabinet worth keeping, after a new surround, and using in this pair?

Separately, it looks like I will need a pair of tweeters. I've cleaned up one pot (disassembled the pot and cleaned with D5 first and then Faderlube), but the tweeters both measure open off the tiny wires coming out of the domes. I get 1.8 ohms on the push button terminals for each of the tweeters. I'm familiar with the pot corrosion problems but since I'm measuring the tweeters as open, I'm not having any hope for them.

Advice on the woofers and suggestions for the replacement tweeters would be greatly appreciated.

Thanks

Bruce

These must have been early production units. I've got a pair of AR2as (not restored) and AR2axs (I finished restoring.) The giveaway is the size of the opening for the woofer. The AR2a woofer was the cloth surround cast frame design. It is routed for a slightly larger opening than the AR2ax stamped frame foam surround, hence the adaptor ring. IMO the cloth surround design is the better of the two. The tweeters are the fried egg tweeters similar to AR3 and used in AR2a. The newer version had tweeters similar to AR3as which IMO are much better. Mine seem to work perfectly. The midrange is the 3 1/2" sealed back driver used in AR2ax. AR2a had two four or five inch table radio type drivers in a sealed plastic sub enclosure. Mine have warped cones. When I spoke with Bill Degaulle at Miller sound he had a pair in for repair and the owner wanted an authentic restoration. He rebuilt the cones for the guy. I bought another pair of AR2ax midranges on e-bay. When I get around to it, I think I'm going to replace the AR2a midranges with the AR2ax midranges. I don't know what I am going to do with the tweeters. I don't think mine have much output. I may just leave them in the cabinet and add more outboard tweeters. I don't look for authenticity, just the best sound I can get. Sometimes you can find these tweeters on e-bay. Usually prices run high if they work well and the seller knows he has a rare item a lot of people want.

Fully restored and carefully equalized, I found AR2ax to be an excellent speaker. Mine sound better to me than any I'd heard commercially when they were on the market. I think it's worth the effort. BTW, I used ordinary non polarized electrolytics to recap mine.

[RoyC]

These must have been early production units. I've got a pair of AR2as (not restored) and AR2axs (I finished restoring.) The giveaway is the size of the opening for the woofer. The AR2a woofer was the cloth surround cast frame design. It is routed for a slightly larger opening than the AR2ax stamped frame foam surround, hence the adaptor ring. IMO the cloth surround design is the better of the two. The tweeters are the fried egg tweeters similar to AR3 and used in AR2a. The newer version had tweeters similar to AR3as which IMO are much better. Mine seem to work perfectly. The midrange is the 3 1/2" sealed back driver used in AR2ax. AR2a had two four or five inch table radio type drivers in a sealed plastic sub enclosure. Mine have warped cones. When I spoke with Bill Degaulle at Miller sound he had a pair in for repair and the owner wanted an authentic restoration. He rebuilt the cones for the guy. I bought another pair of AR2ax midranges on e-bay. When I get around to it, I think I'm going to replace the AR2a midranges with the AR2ax midranges. I don't know what I am going to do with the tweeters. I don't think mine have much output. I may just leave them in the cabinet and add more outboard tweeters. I don't look for authenticity, just the best sound I can get. Sometimes you can find these tweeters on e-bay. Usually prices run high if they work well and the seller knows he has a rare item a lot of people want.

Fully restored and carefully equalized, I found AR2ax to be an excellent speaker. Mine sound better to me than any I'd heard commercially when they were on the market. I think it's worth the effort. BTW, I used ordinary non polarized electrolytics to recap mine.

Hi Soundminded,

The 2ax began being manufactured in the mid 60's, and it wasn't until around 1970 that the foam surround woofer (initially with the same wide flange as its cloth surround predecessor) showed up, along with an 8 ohm version of the AR-3a 3/4" black dome tweeter. The AR-2a cloth surround woofer and orange dome ("fried egg") tweeter were used in the 2ax up to that point. Many thousands of 2ax systems were manufactured with the 2a woofer and tweeter. The 2ax midrange mounted on a 6 1/2" x 10 1/2" piece of plywood was later available as a 2a to 2ax conversion kit to replace the 2a mids you described. (As an aside, only the series leg of the pot was used for those original 2a midrange drivers.)

Similarly, the AR-3a used the AR-3 cloth surround woofer until about 1970, when the foam surround version was introduced.

If you decide to replace your AR-2a tweeters they will sell quickly, as they are getting scarce, and are sought for AR-3 restorations. One of these tweeters sold for $62 yesterday on Ebay.

Roy

[soundminded]

Hi Soundminded,

The 2ax began being manufactured in the mid 60's, and it wasn't until around 1970 that the foam surround woofer (initially with the same wide flange as its cloth surround predecessor) showed up, along with an 8 ohm version of the AR-3a 3/4" black dome tweeter. The AR-2a cloth surround woofer and orange dome ("fried egg") tweeter were used in the 2ax up to that point. Many thousands of 2ax systems were manufactured with the 2a woofer and tweeter. The 2ax midrange mounted on a 6 1/2" x 10 1/2" piece of plywood was later available as a 2a to 2ax conversion kit to replace the 2a mids you described. (As an aside, only the series leg of the pot was used for those original 2a midrange drivers.)

Similarly, the AR-3a used the AR-3 cloth surround woofer until about 1970, when the foam surround version was introduced.

If you decide to replace your AR-2a tweeters they will sell quickly, as they are getting scarce, and are sought for AR-3 restorations. One of these tweeters sold for $62 yesterday on Ebay.

Roy

The cloth surround woofers for some reason sound better to my ears than the foam woofers. Regardless of what the measurements say, the deepest bass notes have a penetrating quality that seems totally without any boominess. I am aware that there may be other variables operateive here. I have a hunch it has to do with the higher compliance of the surround. I was astonished at what a fine woofer the AR2a cloth woofer actually is. I have to confess I haven't given the AR2ax woofers a fair "workout" under identical A/B conditions to compare them since they were refoamed.

The AR3a type small black dome tweeter is another surprise. First of all I was surprised to discover that mine worked perfectly. A raspy sound was traced to one of the midrange drivers which I also replaced. The AR2ax midrange driver although better than the two table radio speakers in AR2a strike me as nothing special yet they perform quite well. Their dispersion less than the AR5 dome tweeter may actually be closer in character to the tweeter, I don't know but I see no reason to look for better.

Placed about 2 feet above the floor catty-corner at 45 degrees in the corners on the short wall of a room about 12 x 15 feet, the midrange level set slightly lower than halfway, the tweeter levels full up, and equalized with a -3d cut at 500 hz, 6db boost at 60 hz, 10db boost at 30 hz, 4db boost at 8khz and a 10 db boost at 16khz, the speaker has sounded remarkably accurate to my ears. High frequency dispersion is by far the best of any single tweeter I've ever heard and is completely without any harshness or strain yet it is crystal clear. No more rolloff. High frequency balance and stereo imaging are uniform throughout the entire room. I never imagined this speaker could perform so well. All of the demos I'd ever heard them in including hearing them often at a friends house who had bought them new (mine were rescued from a sidewalk curb) were inferior.

High frequency response in this installation sounds so good, I'm tempted not to even experiment with augmenting the system even though I've got over 500 tweeters to play with.