AR 5 Questions

[Shacky]

Just got my AR 5's up and running. All I've done so far is refoam the woofers. Great sounding speaker. A lot more clarity in the mids and hi's vs. older model AR 2AX. Haven't A/B'd them yet with my 2AX's. will let them sink in a bit before doing so.

I have 2 questions:

I had read John O's thread a while back saying the tweeters in 2AX and 3a's were actually same - no difference in 4 ohm vs 8 ohm as previously thought. So is that true of the 3a mid drive in the AR 5? I notice the midrange and hi's are a lot more foward than the older version 2AX and was thinking that if mid is 4 Ohm it could explain higher db relative to 2AX in this area. I had to turn down the mid and hi attenuators (which seem to be working pretty well) to half way or below as they were so bright in my listening area.

Also - since I haven't recapped these yet I'd like to. Is it worth replacing the 74 uF cap in parallel with woofer? Or just the 4 and 24 uF caps?

Imaging with these 5's is best I've heard in my limited AR experience. God I love Vintage AR speakers.

[genek]

I had read John O's thread a while back saying the tweeters in 2AX and 3a's were actually same - no difference in 4 ohm vs 8 ohm as previously thought. So is that true of the 3a mid drive in the AR 5? I notice the midrange and hi's are a lot more foward than the older version 2AX and was thinking that if mid is 4 Ohm it could explain higher db relative to 2AX in this area. I had to turn down the mid and hi attenuators (which seem to be working pretty well) to half way or below as they were so bright in my listening area.

The 2ax vs 3 tweeter thread was about the older, orange-domed tweeters. Tweeters from both these models have been measured at 2.5-3 ohms, suggesting they were the same (though one has surfaced on eBay whose seller claims it measures 5.4, which would make it a nominal 8 ohm driver).

The official parts list story for the 3/4" tweeters is that there are 2 different variants, the -1 at 4ohm used in the 3a and LST and the -2 at 8ohm used in the 2ax, 5 and LST-2. A similar variation exists for the mids, 4ohm and 8ohm versions used in the 3a and 5 (totally different from the mid used in the 2ax).

AR in the pre-Teledyne days seems to have been prone to making quick changes as parts supplies ran out, substituting parts from different models and improvising crossover mods to suit. The only really safe way to know what you have is probably to measure drivers while they're still good.

[RoyC]

Just got my AR 5's up and running. All I've done so far is refoam the woofers. Great sounding speaker. A lot more clarity in the mids and hi's vs. older model AR 2AX. Haven't A/B'd them yet with my 2AX's. will let them sink in a bit before doing so.

I have 2 questions:

I had read John O's thread a while back saying the tweeters in 2AX and 3a's were actually same - no difference in 4 ohm vs 8 ohm as previously thought. So is that true of the 3a mid drive in the AR 5? I notice the midrange and hi's are a lot more foward than the older version 2AX and was thinking that if mid is 4 Ohm it could explain higher db relative to 2AX in this area. I had to turn down the mid and hi attenuators (which seem to be working pretty well) to half way or below as they were so bright in my listening area.

Also - since I haven't recapped these yet I'd like to. Is it worth replacing the 74 uF cap in parallel with woofer? Or just the 4 and 24 uF caps?

Imaging with these 5's is best I've heard in my limited AR experience. God I love Vintage AR speakers.

Hi Jim,

The AR-5 is a nice sounding speaker! I much prefer it to any generation of the 2ax and even, in some ways, to the 3a.

If your woofer circuit has the old Industrial Condenser Corp "wax block" caps, I would replace the 74uf caps along with the others. If they are the large Sprague "cans", you could probably safely stay with those.

I agree with genek, you may have some 3a drivers in the mix. Their appearance is identical, so there is no way to know by looking at them. Having to turn the pots down (especially the tweeters') that much seems excessive in my experience.

3a drivers would be more sensitive, and would also alter the crossover points. It wouldn't be difficult to check the resistance of the drivers when you do the cap work. If you find the tweeters and/or the mids are measuring closer to 3 ohms than 6 ohms, they are 3a drivers. IF that is the case, you should adjust the tweeter and mid cap values to nearer those of the 3a. The 3a's 6uf cap value for the tweeter, and 40uf (which is a little less than the 3a) for the mid, work well in my experience. Keep the woofer cap the same. The crossover points would then be closer to where they are supposed to be.

I am about to tackle another pair of 5's, and I believe John O. is as well. Feel free to email!

Roy

[johnieo]

saying the tweeters in 2AX and 3a's were actually same - no difference in 4 ohm vs 8 ohm as previously thought.

Jim:

That thread as noted, was about the 1-3/8-in.-diam. phenolic-dome tweeter (dc resistance nominally 2 ohms) designed for the AR-3 and later used in the old 2ax (sn <125,000). It was not used in the -3a! Sorry if that wasn't clear. That was one of the only cases anyone has seen where AR used the same driver in both an 8- and 4-ohm speaker.

Cheers,

[genek]

Having to turn the pots down (especially the tweeters') that much seems excessive in my experience.

AR tweeter settings are very sensitive to the environment, much more so than any other speakers I've ever had. When I lived in a house with low ceilings, carpeted floors and fabric drapes, I tended to have my 2ax's cranked almost to max. My current listening room has a 14-ft ceiling, wood floors and no drapes, and I've got them turned down almost to the center dot. If 3a mids and tweeters were swapped into a 5, I wouldn't be surprised at all if the sound got brighter, and they do look exactly the same so the only way to know would be to measure them or see if there are part numbers on them. I wonder where the crossover points would end up...

[Shacky]

Thanks all for the feedback. Sorry I was mistaken about the old vs new tweeter reference to 3a.

I'll have to take these apart and examine to make sure I know what I'm working with. I am surprised about the brightness.

[RoyC]

I wonder where the crossover points would end up...

...around 7000hz for the tweeter/mid and 900hz for mid/woofer. It should be 5000hz and 650hz respectively, similar to the 3a. Fortunately the AR-5 crossover layout is identical to the 3a, and the identical AR-5 tweeters and mids simply have higher resistance (and correspondingly lower sensitivity), so adjusting the cap values is not too difficult. Actually, I prefer the higher output of the 3a tweeter in the AR-5...probably due to diminished output of some of those old 3/4" inchers.

I agree, the room can have a big effect on the level control settings.

Roy

[genek]

...around 7000hz for the tweeter/mid and 900hz for mid/woofer.

Interesting, that's pretty close to the original AR-3 crossover points.

[Shacky]

...around 7000hz for the tweeter/mid and 900hz for mid/woofer. It should be 5000hz and 650hz respectively, similar to the 3a. Fortunately the AR-5 crossover layout is identical to the 3a, and the identical AR-5 tweeters and mids simply have higher resistance (and correspondingly lower sensitivity), so adjusting the cap values is not too difficult. Actually, I prefer the higher output of the 3a tweeter in the AR-5...probably due to diminished output of some of those old 3/4" inchers.

I agree, the room can have a big effect on the level control settings.

Roy

If that were the case there'd probably be a hole bwtween 650 - 900 as woofer would have correct crossover. I do remember now that these have replacement tweeters. But originally I was thinking the midrange driver might be similar to old tweeter - not worth making an 8 ohm version. I don't think there were a heck of a lot of 5's sold.

[RoyC]

If that were the case there'd probably be a hole bwtween 650 - 900 as woofer would have correct crossover. I do remember now that these have replacement tweeters. But originally I was thinking the midrange driver might be similar to old tweeter - not worth making an 8 ohm version. I don't think there were a heck of a lot of 5's sold.

Yes, using either the 3a mid and/or the 3a tweeter would create holes at their respective crossover frequencies. Larger caps must be used to compensate. The crossover points I mentioned above are very general approximations of where the lower impedance 3a drivers would roll off (at higher frequencies than the AR-5 drivers did). Even if we use larger caps to compensate, the original inductors used to cut off the AR-5 woofer and mid complicates things somewhat.

Shacky, if your tweeters are 3a tweeters, replacing the original 4uf cap with a 5 or 6uf cap should make things right. The level control will do the rest.

Roy

[Shacky]

Yes, using either the 3a mid and/or the 3a tweeter would create holes at their respective crossover frequencies. Larger caps must be used to compensate. The crossover points I mentioned above are very general approximations of where the lower impedance 3a drivers would roll off (at higher frequencies than the AR-5 drivers did). Even if we use larger caps to compensate, the original inductors used to cut off the AR-5 woofer and mid complicates things somewhat.

Shacky, if your tweeters are 3a tweeters, replacing the original 4uf cap with a 5 or 6uf cap should make things right. The level control will do the rest.

Roy

Will hopefully look into these drivers by weekend. I just put my '65 version 2AX's back in rotation. Had been listening to EPI 202 for several weeks. Then the AR5's for couple of days.

Immediately know I prefer the 2AX's. They are like Yankee Pot Roast, Mashed Potatoes, and Hot Gravy!!!! I'm sure some folks would not like them but to me they are the perfect speaker - so far. Don't know why I keep trying others

[Shacky]

I just checked tweeter on one. The wires on the replacement tweeter are inside the cabinet. Measuring across the from metal parts of the tweeter leads and with tweeters in place I get 4.4 Ohms. Is this an accurate reading with tweeter in place?

I can't get measurement on the Midrange leads - too much paint on them.

[RoyC]

I just checked tweeter on one. The wires on the replacement tweeter are inside the cabinet. Measuring across the from metal parts of the tweeter leads and with tweeters in place I get 4.4 Ohms. Is this an accurate reading with tweeter in place?

It doesn't sound right. You should disconnect it from the crossover to measure it. It should be around 6 ohms (or 3 ohms if it is a 3a tweeter).

A properly functioning 5 is a very smooth sounding speaker. It would be more open (better dispersion) and detailed than a 2ax, with at least as much bass response.

Roy

[Shacky]

It doesn't sound right. You should disconnect it from the crossover to measure it. It should be around 6 ohms (or 3 ohms if it is a 3a tweeter).

A properly functioning 5 is a very smooth sounding speaker. It would be more open (better dispersion) and detailed than a 2ax, with at least as much bass response.

Roy

I'm wondering now if it's an air seal issue. I used some stick on foam on rear of woofer to seal. And I've had these in and out a couple of times. Maybe I should use moretite like on my 2AX's.

[Shacky]

I'm wondering now if it's an air seal issue. I used some stick on foam on rear of woofer to seal. And I've had these in and out a couple of times. Maybe I should use moretite like on my 2AX's.

I reseale the woofers with Moretite. Foam I had been reusing was FUBAR.

While great speakers, I'm not that keen on them. To forward sounding to my ears.

I much, much prefer my old version 2AX's - purchased from Andy - what 3 years ago? Recapped, resealed. I have been through at least 10 speakers since gaining these from Andy. And the 2AX's remain my favorites. Close second are Dynaco A-25's. AR knew what they were doing in mid 60's

[RoyC]

I reseale the woofers with Moretite. Foam I had been reusing was FUBAR.

While great speakers, I'm not that keen on them. To forward sounding to my ears.

I much, much prefer my old version 2AX's - purchased from Andy - what 3 years ago? Recapped, resealed. I have been through at least 10 speakers since gaining these from Andy. And the 2AX's remain my favorites. Close second are Dynaco A-25's. AR knew what they were doing in mid 60's

I have restored a number of pairs of AR-5's, and they are by no means a "forward" sounding speaker. They should sound similar to the AR-3a without the very deepest aspects of the 3a's bass response.

I would take a careful look at the details of that restoration...or send me an email if you would like to unload them.

Roy