AR3 Info & ??'s!!

[Tuquala]

Recently acquired a pair of AR3's from a church rummage sale. I guess you could say I "stole" them, but I got over it in a short while!! In pretty nice shape, wood is a 7-8, grilles are a 1, and they work!! Need to do the pots, had to find a spot where all the transducers worked. Cloth surrounds are in fine shape, planning on doing the "redope" of them soon.

Main question concerns my opinion of their sound. Now understand I am comparing them to speakers I have now in my small collection: L100A's and Klispch KG-1.2. Pretty wide size difference there!! The AR's are wonderful in the mid and upper ranges, very open and musical. But (IMO), the vocals and the lower mid area sound somewhat muffled, muddy??? I have listened to them driven by a Yamaha A-960II and a Sansui 8080DB. Hard to say which sounds better, hard to make quick side by side comparisons.

Having downloaded the pdf for restoring the AR3A, and looking it over, I am wondering about a couple of the items and if they would be applicable to the AR3. By the serial #'s, my pair are after '65, and have the 3rd generation crossover. Are there any mods that are recommended to the crossover, other than doing a recap? Would adding the 1.0mH coil to the woofer circuit be advisable or necessary? Or is this only for the AR3A??

After doing some research, I believe that the crossover from the woofer to mid is at 1000hz in the AR3, and lower in the 3A. Would this contribute to my feeling the sound is muddy as I stated? Is there any mods to change this, or should be left well enough alone?

Sorry if I'm rambling, just wondering if I can make these wonderful boxes even better. Any other ideas or experiences appreciated!!

Gerry

[JKent]

Recently acquired a pair of AR3's from a church rummage sale. I guess you could say I "stole" them, but I got over it in a short while!! In pretty nice shape, wood is a 7-8, grilles are a 1, and they work!! Need to do the pots, had to find a spot where all the transducers worked. Cloth surrounds are in fine shape, planning on doing the "redope" of them soon.

Main question concerns my opinion of their sound. Now understand I am comparing them to speakers I have now in my small collection: L100A's and Klispch KG-1.2. Pretty wide size difference there!! The AR's are wonderful in the mid and upper ranges, very open and musical. But (IMO), the vocals and the lower mid area sound somewhat muffled, muddy??? I have listened to them driven by a Yamaha A-960II and a Sansui 8080DB. Hard to say which sounds better, hard to make quick side by side comparisons.

Having downloaded the pdf for restoring the AR3A, and looking it over, I am wondering about a couple of the items and if they would be applicable to the AR3. By the serial #'s, my pair are after '65, and have the 3rd generation crossover. Are there any mods that are recommended to the crossover, other than doing a recap? Would adding the 1.0mH coil to the woofer circuit be advisable or necessary? Or is this only for the AR3A??

After doing some research, I believe that the crossover from the woofer to mid is at 1000hz in the AR3, and lower in the 3A. Would this contribute to my feeling the sound is muddy as I stated? Is there any mods to change this, or should be left well enough alone?

Sorry if I'm rambling, just wondering if I can make these wonderful boxes even better. Any other ideas or experiences appreciated!!

Gerry

Hi Gerry

Stealing from a church. Tsk tsk Wish I'd done it!

I'm no expert on the 3 but those 40+ year old caps are probably shot. I'll bet if you replace the caps and make sure the pots are clean, you'll be happy.

Beautiful speakers, you lucky dog!

Kent

[Tuquala]

Thought I'd add a pic of the crossover. I am "***uming" that the caps are in the box under the coil. Next step is to pull that and the pots and get busy!!

Any other comments on crossover work or mods for these speakers??

Thanks,

Gerry

[genek]

Thought I'd add a pic of the crossover. I am "***uming" that the caps are in the box under the coil.

Actually, the box is the caps, there are no cans inside it.

[tysontom]

Recently acquired a pair of AR3's from a church rummage sale. I guess you could say I "stole" them, but I got over it in a short while!! In pretty nice shape, wood is a 7-8, grilles are a 1, and they work!! Need to do the pots, had to find a spot where all the transducers worked. Cloth surrounds are in fine shape, planning on doing the "redope" of them soon.

Main question concerns my opinion of their sound. Now understand I am comparing them to speakers I have now in my small collection: L100A's and Klispch KG-1.2. Pretty wide size difference there!! The AR's are wonderful in the mid and upper ranges, very open and musical. But (IMO), the vocals and the lower mid area sound somewhat muffled, muddy??? I have listened to them driven by a Yamaha A-960II and a Sansui 8080DB. Hard to say which sounds better, hard to make quick side by side comparisons.

Having downloaded the pdf for restoring the AR3A, and looking it over, I am wondering about a couple of the items and if they would be applicable to the AR3. By the serial #'s, my pair are after '65, and have the 3rd generation crossover. Are there any mods that are recommended to the crossover, other than doing a recap? Would adding the 1.0mH coil to the woofer circuit be advisable or necessary? Or is this only for the AR3A??

After doing some research, I believe that the crossover from the woofer to mid is at 1000hz in the AR3, and lower in the 3A. Would this contribute to my feeling the sound is muddy as I stated? Is there any mods to change this, or should be left well enough alone?

Sorry if I'm rambling, just wondering if I can make these wonderful boxes even better. Any other ideas or experiences appreciated!!

Gerry

Gerry,

If the woofer surrounds do not leak; i.e., if you push in the cone, release it, and the cone slowly returns to center, then you don't need to add anything to the cloth surrounds. In fact, if you do add something you run the risk of affecting the properties of the woofer, such as its damping and resonance, and thus the smoothness of the woofer's response (a new AR-3 woofer measured "flat" within 1.5 dB from 38-1000Hz, but that was fifty years ago, and some changes likely have occurred due to age). If the woofers leak -- and you can tell this easily by pushing in the cone and it returns instantly -- then you definitely need to add something to the surrounds.

The muddiness you note could be due to deterioration in the woofer's foam damping ring or slight changes to the midrange driver/crossover due to age. Overall, the AR-3 always sounded somewhat muted in the upper bass when compared with some speakers, but real music sometimes has less "sparkle" and brightness than reproduced music, so it could be a bit too much energy from Klipsch or the JBLs -- probably a combination of a lack of energy on the AR-3 and an over-abundance of energy from the other speakers.

The 1kHz crossover is too high, granted, but it is not as bad as has been described. The woofer gets quite directional at this frequency, but the 2-inch midrange has excellent dispersion throughout its range, and there is significant overlat in the response of the midrange and the woofer such that the midrange is dipping down quite a bit below that frequency anyway. It would be nice to have the AR-3a crossover frequency, but the 2-inch will not go down to 575 Hz without significant attenuation in output.

--Tom Tyson

[JKent]

Thought I'd add a pic of the crossover. I am "***uming" that the caps are in the box under the coil. Next step is to pull that and the pots and get busy!!

Any other comments on crossover work or mods for these speakers??

Thanks,

Gerry

Hold on Gerry! No need to pull the "box". That is a paper/wax cap and all you do is snip the 3 wires to remove it from the circuit, but leave it physically in place. Replace it with individual caps of the correct values and you're in business.

Kent

[Tuquala]

Thanks, Kent. I was wondering about that!! Info appreciated!

Tom, before pulling the woofer, I did check for leaks, and don't seem to have any. As to the "redoping", just going by what has been discussed here on that procedure using Permatex HiTac for the sealant on cloth surrounds. But tell me about this woofer foam damping ring!! Till now, have not heard anything about such an item. What & where???

Gerry

[tysontom]

Thanks, Kent. I was wondering about that!! Info appreciated!

Tom, before pulling the woofer, I did check for leaks, and don't seem to have any. As to the "redoping", just going by what has been discussed here on that procedure using Permatex HiTac for the sealant on cloth surrounds. But tell me about this woofer foam damping ring!! Till now, have not heard anything about such an item. What & where???

Gerry

Gerry,

You simply don't need to dope the surrounds if you don't have an air leak. Believe me, that will do more harm than good unless, of course, you have an air leak through the surroud itself. So, why add something to it if it doesn't need it? If those surrounds aren't leaking, you will get very uniform, low-distortion bass response from those Alnico woofers.

The damping ring was added in late-1959, not long after the AR-3 was introduced. The woofer cone was changed slightly as well to add ribs for rigidity, but the foam damping rings (big one close to the apex of the cone and small damping rings around the outside edge adjacent to the surround on the earliest AR-3s) were added to absorb unwanted vibration at the upper end of the AR-3's woofer response around 800-1000 Hz. The rings worked extremely well, but after fifty years the foam becomes brittle (oxidizes like all of the urethane polymer materials) and doesn't do its job the same as before. At one point AR used a rubber product (note the picture of my AR-3's woofer as this has the rubber ring), and those don't seem to degrade as badly.

--Tom Tyson

[tysontom]

Gerry,

You simply don't need to dope the surrounds if you don't have an air leak. Believe me, that will do more harm than good unless, of course, you have an air leak through the surroud itself. So, why add something to it if it doesn't need it? If those surrounds aren't leaking, you will get very uniform, low-distortion bass response from those Alnico woofers.

The damping ring was added in late-1959, not long after the AR-3 was introduced. The woofer cone was changed slightly as well to add ribs for rigidity, but the foam damping rings (big one close to the apex of the cone and small damping rings around the outside edge adjacent to the surround on the earliest AR-3s) were added to absorb unwanted vibration at the upper end of the AR-3's woofer response around 800-1000 Hz. The rings worked extremely well, but after fifty years the foam becomes brittle (oxidizes like all of the urethane polymer materials) and doesn't do its job the same as before. At one point AR used a rubber product (note the picture of my AR-3's woofer as this has the rubber ring), and those don't seem to degrade as badly.

--Tom Tyson

Gerry,

Attached is a better image of the earliest-version woofer with plain-sided cone and no damping rings. A second image shows the "Cut-A-Way" AR-3a with the woofer, showing the damping ring and ribs in more detail.

--Tom Tyson

[Tuquala]

Tom, here pics of my woofers. Cannot in my mind see any "foam" rings on them, even looking inside the frame of the one on the bench. Where am I mentally deficient on this?? They look identical to the first picture you posted of your woofer.

One more ?, is there any advantage to new wires? ie the woofers, they seem to be pretty small guage!!

Gerry

[tysontom]

Tom, here pics of my woofers. Cannot in my mind see any "foam" rings on them, even looking inside the frame of the one on the bench. Where am I mentally deficient on this?? They look identical to the first picture you posted of your woofer.

One more ?, is there any advantage to new wires? ie the woofers, they seem to be pretty small guage!!

Gerry

Gerry,

The foam daming rings are the raised portions on the front of the cone, just out from the center dust cap. They don't look like "foam," but they are really "damping" rings. You have them. You're fine, and your units, which are the middle-1960s versions, have the rubber-type damping rings that don't deteriorate. The early AR woofer, which I showed in a subsequent image earlier, has no ribs in the cone or damping rings, but just a plain-sided cone. So your woofers appear to be in very good condition, and I would not worry about them further. Don't put anything on the surrounds at this point. Be certain on re-assembly to carefully replace the Mortite (or use gray plumber's putty) under the woofer flange. Tighten the eight machine screws in a "torque" fashion as though you were torqueing-down a car cylinder head, alternating from one side to the other. Don't over-tighten, but be sure that the Mortite squeezes out a bit around the flange, and that you have the same acoustic seal as before your dissembled the unit.

That small-gauge wire is still about twice the diameter of the voice-coil wiring, and since the length of wire is less than 20 inches total, you will not ever have any audible -- let alone measurable -- improvement by putting in large wiring in the crossover. There is no loss or added resistance, so don't worry about that. It's a waste of time. I would, however, think about making sure all the wiring is tied together and that it doesn't move around in the cabinet. Double-check all of the solder connections. I usually use T&B Ty-Raps to hold the harness together once I've finished putting things back together. Since you are have some issues with the lower-midrange response, you could measure the crossover capacitors to make sure they are within reasonable spec (+/- 10-15% is probably fine); you may have a bad capacitor or two, but you probably need to measure to be certain. Also, if the midrange has low output, check the dcr of the midrange driver to be certain that it is still in the 2-ohm region; I've seen those drivers lose sensitivity over time, but that is a hard call. If it is working and you are not hearing distortion, it's probably okay. Most importantly, make certain that you get the level controls as oxidation-free as possible, so that you will then have more latitude with the spectral balance of the speaker, and you can improve things "sonically" quite a bit. I'll bet that if you get the level controls back 100% you will hear a big, big difference.

--Tom Tyson

[RoyC]

Recently acquired a pair of AR3's from a church rummage sale. I guess you could say I "stole" them, but I got over it in a short while!! In pretty nice shape, wood is a 7-8, grilles are a 1, and they work!! Need to do the pots, had to find a spot where all the transducers worked. Cloth surrounds are in fine shape, planning on doing the "redope" of them soon.

Main question concerns my opinion of their sound. Now understand I am comparing them to speakers I have now in my small collection: L100A's and Klispch KG-1.2. Pretty wide size difference there!! The AR's are wonderful in the mid and upper ranges, very open and musical. But (IMO), the vocals and the lower mid area sound somewhat muffled, muddy??? I have listened to them driven by a Yamaha A-960II and a Sansui 8080DB. Hard to say which sounds better, hard to make quick side by side comparisons.

Gerry

Hi Gerry,

I strongly agree with Tom. It is extremely unlikely your woofer surrounds will need resealing. I have been playing around with this issue for some time now and believe that the majority of folks resealing old surrounds are degrading the performance of their woofers. The woofers you have almost never need re-sealing. They look great.

Your AR-3's appear to be in excellent condition. Other than making sure the level controls and capacitors are working properly, there is little else you can do to change the overall character of the sound. Vocals/lower mid area of the AR-3/3a series will never sound the same as the speakers you are comparing them to.

Roy

[Tuquala]

Well, after many months of these just sitting in the garage, I have finished recapping one of them. Used AEON 250V 5% capacitors and mounted them and the coil to the x-over board. Also, disassembled the pots, and cleaned and lubed. Resealed the woofer to the box, and set up to listen and compare to the other one which hasn't been touched yet.

As to the sound, I would have to say - "no change"!!! Both sound pretty much the same, and to my ears they still sound muted and muddy. They are being driven by a Yamaha A960-II in my garage shop. May listen in the house after doing the second one this week. There they would be driven by a Yammy V3000 HT reciever with about the same power as the A960.

Still wondering if they have something further to look at. I know that my other speakers are more the west coast kind of sound, but I also have a set of Cambridge Soundworks Ensembles in the HT setup, and they blow the doors off of these in my mind. More open and clean sounding, but not as bright and in your face as the L100s and the KGs.

Attached a shot of the completed internals of the first one.

Gerry

[genek]

Still wondering if they have something further to look at. I know that my other speakers are more the west coast kind of sound, but I also have a set of Cambridge Soundworks Ensembles in the HT setup, and they blow the doors off of these in my mind. More open and clean sounding, but not as bright and in your face as the L100s and the KGs.

Don't let the "Cambridge" in the CS name fool you, by the time the Ensembles came along both East and West Coast sound had been replaced by "flat" as the prevailing preference, which is still brighter than the AR3s were designed to produce. You have done everything there is to be done, and the sound you're getting is the classic AR3 sound. Turn both speaker pots up full and add about +3dB with your amplifier treble control if you want a "flat" sound. That's what AR recommended back in the day.