Direction needed properly hooking up AR-1W's

[Guest postjob62]

I thought I finally had it all figured out hooking up my AR-1W's to use as a sort of subwoofer (since my deal on the Janszen 130's didn't pan out I figured this was a good interim use). What I did was to hook the 1W's directly to a second receiver, into which I was running the tape output signal from the first receiver.The first receiver powers a pair of 2ax's and of course supplies the source material to the second receiver. I figured this would not strain either receiver since the one powering the 1W's can easily handle 4 ohms, and I further figured I could balance the relative volume with the control on the 1W's receiver. So far so good.

But either my 1W's have a problem or I need to somehow run the output signal from their receiver through a crossover, because the sound is extremely distorted through each of them. They are beautiful speakers and have not ever been into, but of course that's no real indicator I suppose. I cannot see the surrounds through the nylon grillcloth, but as cloth I'm assuming they're good.

Back in the days when these were run parallel with the Janszens, did the Janszens somehow contain a crossover back to the 1W's?

I guess I just (naiively?) figured that they would simply reproduce sound up to the upper limit of their range and then no more, but I'm wondering now if the higher frequency incoming signal is causing this distortion. Or, is it more likely that I have a problem with the 1W's?

Any thoughts are appreciated-I'm too deep into this now to give up!

Thanks,

Ed

[johnieo]

Ed:

The AR-1 (not AR-1W) contained an internal crossover for its woofer and tweeter. The woofer crossover was simply a series 0.4 mHy coil (the unlabled AR 143-turn inductor). In fact all variations of the AR-1 with tweeter--AR-1x etc--used that same woofer crossover coil. These schematics were (are?) in the Archives.

I cannot find a schematic for the AR-1W, so do not know if it had any internal crossover components. If it did not have any crossover, then you might wish to try the series inductor externally. That value set a 1,000 Hz crossover to the Altec 755 tweeter.

First; however, it might be best to remove the grille and examine the driver and crossover. The grille must be removed with great care as it is glued place. It is possible that glue attaching the cloth surround to the cone has dried and separated in one or more spots. That would be the most likely cause of the distortion you hear. These areas can be reglued easily with latex surround glue. If the woofer is not airtight after reassemly, there may be air leaks through the cloth where the butyl rubber is no longer present. A dilute solution of Loctite brand Butyl Rubber and hexane can be applied with a small brush in a very thin coat to restore the cloth surround's integrity. It must not be applied in a thick layer lest it affect f sub s of the driver.

[Guest postjob62]

John,

Thanks much for your response to my dilemna.

Given what seems to be the daunting nature of grill removal coupled with the low probability of success in so doing with these old AR's with the moulding around the grills, I would like to leave that as a last resort. My guess is that even if one were successful at getting the grills off in one piece, that they would somehow never look the same again and these are so nice!

I will, of course do that before letting these go unused. But maybe in the meantime other opinions or ideas to try may emerge from members who have used these 1W's over the years.

Thanks,

Ed

[tysontom]

>I thought I finally had it all figured out hooking up my

>AR-1W's to use as a sort of subwoofer (since my deal on the

>Janszen 130's didn't pan out I figured this was a good interim

>use). What I did was to hook the 1W's directly to a second

>receiver, into which I was running the tape output signal from

>the first receiver.The first receiver powers a pair of 2ax's

>and of course supplies the source material to the second

>receiver. I figured this would not strain either receiver

>since the one powering the 1W's can easily handle 4 ohms, and

>I further figured I could balance the relative volume with the

>control on the 1W's receiver. So far so good.

>

>But either my 1W's have a problem or I need to somehow run the

>output signal from their receiver through a crossover, because

>the sound is extremely distorted through each of them. They

>are beautiful speakers and have not ever been into, but of

>course that's no real indicator I suppose. I cannot see the

>surrounds through the nylon grillcloth, but as cloth I'm

>assuming they're good.

>

>Back in the days when these were run parallel with the

>Janszens, did the Janszens somehow contain a crossover back to

>the 1W's?

>

>I guess I just (naiively?) figured that they would simply

>reproduce sound up to the upper limit of their range and then

>no more, but I'm wondering now if the higher frequency

>incoming signal is causing this distortion. Or, is it more

>likely that I have a problem with the 1W's?

>

>Any thoughts are appreciated-I'm too deep into this now to

>give up!

Ed,

The AR-1W does not have a crossover except for a 3.2-ohm, wire-wound resistor that can be added in parallel to change the output impedance from 4 to 8 ohms. There is no inductor in the circuit such as in the AR-1.

I am not clear on the efficacy of your receiver-to-receiver connection -- and it is suspect -- but what you are doing has certainly been done in the past, and should work fine with everything connected properly. Remember, too, that you cannot control the output level of a receiver's preamplifier through the tape loops if I remember correctly; I believe it is a straight-through proposition controlled by the tape recorder or other device. That signal from the first receiver might be overdriving the second amplifier/AR-1W combination. Therefore, before you blame the AR-1W on the distortion, you might try to simply connect the speaker to a known *good* amplifier or receiver by itself, and play some music with deep bass content, and listen to isolate any noises or distortion that might be coming from the AR-1W. Organ music or orchestral music with bass drum can be a good test. It will certainly sound dull and muted and muffled, but that's to be as expected: no frequencies above about 1 kHz will be reproduced. In the bass, however, you should not hear any distortion or other unruly noises. If you hear rattling or gross distortion, then there is cause for suspicion that the driver surround or skiver masonite has separated from the aluminum frame assembly. Don't connect through the tape loop at this point; you simply want to isolate the AR-1W to see if it has a problem.

--Tom Tyson

[Guest postjob62]

Thanks much for the tip, Tom. I'll do just that and report back with my findings.

These are the "unfinished pine" and are in great shape. I'm sure they aren't as valuable as the finished veneers, but they're perfect for my basement shop. The grills are really nice and I just hate the thought of disturbing them after them making it all these years.

Ed