AR3A woofers

[Guest Paul C]

I have a pair of AR3A's originally purchased in 1964. When the woofers became torn I replaced them with Radio Shack 12 inch woofers. I have cleaned the pots and everything works O.K. but I am curious whether I should fork out $160 apiece for original woofer replacements. All comments will be appreciated.

[Carlspeak]

>I have a pair of AR3A's originally purchased in 1964. When

>the woofers became torn I replaced them with Radio Shack 12

>inch woofers. I have cleaned the pots and everything works

>O.K. but I am curious whether I should fork out $160 apiece

>for original woofer replacements. All comments will be

>appreciated.

Are you satisfied with the RS woofers as they sound now? Were you satisfied when you first replaced them? If answer to both is yes, then save your money.

Do you mean the foam rotten when you say 'they became torn'?

Do you still have the original woofers? If so, they can be refoamed.

I believe original AR woofers of that era had the flat sides. How did you get the 12" RS woofers to fit?

It's all about the music

Carl

Carl's Custom Loudspeakers

[dynaco_dan]

Hi Paul;

Hold off buying any other woofers until everyone has had a chance to read your question.

If, and that is only if, you want to replace them, perhaps the eBay route is your best for original woofers.

You might be able to pick up a pair for under $100.00 with very careful shopping and exceptional seller packaging.

Too bad the NHT 12" woofer would not be suitable, AR-3A cabinet is too small, they're very durable and well reviewed.

If I was in your shoes, and I'm not, I would hunt down the older alnico magnet, cloth surround woofers, rather than the foam surround ceramic woofers.

More feedback to follow.

[soundminded]

>I have a pair of AR3A's originally purchased in 1964. When

>the woofers became torn I replaced them with Radio Shack 12

>inch woofers. I have cleaned the pots and everything works

>O.K. but I am curious whether I should fork out $160 apiece

>for original woofer replacements. All comments will be

>appreciated.

There is simply no comparison between the AR woofer and the RS woofer. In fact there are few woofers in the same class made by anyone. What's worse is that those which are, aren't suitable for the AR3 enclosure. To get the bass performance an AR 12" woofer is capable of, you not only need the right woofer and enclosure, you need the correct amount of fiberglass of the correct type and the enclosure must of course be air tight. I think it's around a pound and a half of fiberglass. The fiberglass plays a critical role in the acoustic suspension speaker by controlling damping (overshoot or undershoot.) with too little fiberglass, the speaker will have a bass resonant peak. With none it all, it could bottom out and be damaged. With too much it will have an overly attenuated bass.

When properly installed, the AR3/AR3a woofer in its enclosure has a resonant in box frequency of around 42 hz, a system Q of 0.7 (critical damping) and falls off at 12 db per octave. It will reproduce 30 hz with 5% THD. Even more than 50 years after its first manufacture, you will not find much close in performance and certainly not at anywhere near the price. The driver is nominally rated at about 100 to 200 watts I think but actually will withstand impulse power for brief periods of over 1 kw as reported by Julian Hirsch. About the only woofer which I can think of which is similar and might be suitable as a substitute is the 12" Dayton reference woofer but it does not have the truncated edges to fit into the AR3a cabinet without adapting it.

Whatever you were listening to all these years, it was not an AR3a.

[Guest Paul C]

Carl,

Thanks for your comments. The Radio Shack 12 inch speakers were made to fit with the judicious use of a hacksaw but the bolt holes lined up perfectly. I don't have the original AR woofers anymore so repair is not an option. The RS woofers are 8ohm instead of 4 ohm but the sound quality difference is not easily determined by my memory of the original sound. I did go to a Tweeters stereo store and ask to here my jazz and classical cds on their systems and I was surprised to find that I was not impressed.

[RoyC]

Paul,

I agree with Soundminded...

The AR woofers and associated bass response are at the core of what made the 3a, as well as other AR models, special. Further, any replacement would surely necessitate a crossover change to have any hope of sounding similar to the original 3a.

With that said, I would NOT pay $160 a piece or anywhere near that price for the current replacement woofer, which I assume you were referring to. Much has been written about that woofer here in the forum. Although it is probably preferable to the RS woofer, the "Tonegen" replacement, as it is referred to, is overpriced. Also, the general consensus seems to be that this replacement is not as desirable in the 3a as either version (cloth or foam surround) of the original woofer.

You should pay around $125 to $175 a pair for any of the above in good condition, and I would recommend it. It is likely that the capacitors and level controls need attention at this point as well:-).

Roy

[tysontom]

>I have a pair of AR3A's originally purchased in 1964. When

>the woofers became torn I replaced them with Radio Shack 12

>inch woofers. I have cleaned the pots and everything works

>O.K. but I am curious whether I should fork out $160 apiece

>for original woofer replacements. All comments will be

>appreciated.

Paul C:

If you purchased them in 1964 they would have been AR-3s, not AR-3as, but the woofer system is basically identical. I agree with all the others that you should try to replace the woofers with the original AR 12-inch woofer. It seems impossible that a Radio Shack 12-inch woofer would have characteristics that even resembled the AR woofer, such as ultra-low resonance, heavy moving system and high-excursion suspension. The sound would almost surely have been compromised by using those replacement woofers.

Since the original woofers in that vintage had the cast-aluminum frame, cloth surround and Alnico magnets, you should shop around on eBay to find a pair of those woofers. They do come up on eBay quite a bit as people tend to part-out the big heavy AR-3s, AR-3as and so forth, and so the parts can usually be easily found. The later 12-inch, stamped-basket, flat-side woofer will also work satisfactorily, and these also appear frequently on eBay.

--Tom Tyson

[dynaco_dan]

Hi again Paul;

You've already received some of the best advice available regarding your woofers.

Could you please provide a front photo of your drivers please, so that it can be determined if they are in fact AR-3's or not.

Tom is one of the best person's here with date and data and if you are correct with your date, then Tom is right and they are AR-3's.

The best way to go, if they are in fact AR-3's, is, alnico aluminum cloth framed woofers, which are only available used, of course.

Packaging for shipment is very critical and if that is what you choose to do please write it up here first.

Whereas a KLH and Larger Advent woofer has a reverse roll surround, and can be placed flat against heavy cardboard or better yet plywood, no damage will happen to the surround.

All of the AR surrounds, and most other brands, can be destroyed if placed frame face to cardboard or plywood without adequate spacers.

I guess I was trying to be polite by not commenting on your existing woofers.

Especially if you are happy with them.

With the corrct woofers in your cabinets, you will notice a difference, like day or night.