AR 4x efficency

[Guest]

A friend of mine found a pair of 4x ( small bookshelf with 8" and high freqency driver) sitting out for the garbage man. He brought them over and the cabinets are fine, one 8" driver is bad as is the high frequency driver ( same cabinet ). I hooked up the "good one" and it is nowhere as efficent as my old beat up set. How could this be? Where can I get a replacement high frequency driver and is there any hi quality replacements that would work with out modifying the crossover?

Thanks for the help!

[Guest]

>A friend of mine found a

>pair of 4x ( small

>bookshelf with 8" and high

>freqency driver) sitting out for

>the garbage man. He brought

>them over and the cabinets

>are fine, one 8" driver

>is bad as is the

>high frequency driver ( same

>cabinet ). I hooked up

>the "good one" and it

>is nowhere as efficent as

>my old beat up set.

>How could this be? Where

>can I get a replacement

>high frequency driver and is

>there any hi quality replacements

>that would work with out

>modifying the crossover?

>Thanks for the help!

The AR4 1962-1964 was the first (in the world) bookshelf loudspeaker. They sported an 8” CTS woofer and a 3.5” CTS mesh grille tweeter. The AR4X was the upgraded bookshelf model with an improved 2.5” tweeter but the same sized tweeter back plate (1964-1969). The final version was the AR4XA (1969-1973).

The original tweeter is no longer available as AR actual built the driver in-house back then. There is a similar replacement available for your defective 2.5” tweeter from Alex at AB Tech (800) 225-9847) P/N# 12000060 at $34.00 each. Alex told me you would have to replace both, as the replacement tweeter is a bit different in freq. response from the original.

[Guest gioip]

>>A friend of mine found a

>>pair of 4x ( small

>>bookshelf with 8" and high

>>freqency driver) sitting out for

>>the garbage man. He brought

>>them over and the cabinets

>>are fine, one 8" driver

>>is bad as is the

>>high frequency driver ( same

>>cabinet ). I hooked up

>>the "good one" and it

>>is nowhere as efficent as

>>my old beat up set.

>>How could this be? Where

>>can I get a replacement

>>high frequency driver and is

>>there any hi quality replacements

>>that would work with out

>>modifying the crossover?

>>Thanks for the help!

>

>The AR4 1962-1964 was the first (in the world) bookshelf

>loudspeaker. They sported an 8� CTS woofer and a 3.5� CTS

>mesh grille tweeter. The AR4X was the upgraded bookshelf

>model with an improved 2.5� tweeter but the same sized tweeter

>back plate (1964-1969). The final version was the AR4XA

>(1969-1973).

>

>The original tweeter is no longer available as AR actual built

>the driver in-house back then. There is a similar replacement

>available for your defective 2.5� tweeter from Alex at AB Tech

>(800) 225-9847) P/N# 12000060 at $34.00 each. Alex told me you

>would have to replace both, as the replacement tweeter is a

>bit different in freq. response from the original.

********************

Hi,Do you know the freq range of Ar4xa woofer?

Is it linear until 2300hz?

Because i want change the x/o of my Ar4x

Thank a lot

gio

>

>

>

[Guest daveshel]

AR speakers are typically inefficient. I had a pair of 4xs with bad tweeters and I tried some dome tweeters that were modified to be drop-in compatible. I got them on ebay and the same seller has another pair:

http://cgi.ebay.com/AR4-AR4x-replacement-u...1QQcmdZViewItem

What he said about the cone vs the dome rang true from my experience, and I was more interested in having a pair that worked than having them be original. (Even knowing my actions could brand me a heretic here) I was quite happy with the results. The speakers are now somewhat brighter than they should be, but also a bit more efficient. YMMV.

[Guest tdeutsch]

Read some of the AR info in the library section of the web site. As you found out, the AR-4x (and all/most of the early AR's) are power hogs. From what I gather, this was a chief complaint way back then (most people had low-power amps). Every speaker design is a compromise -- the AR acoustic suspension design (used in the AR-4x) soaked up wattage but gave great frequency response in a small package. I recently was given a pair of AR-4x and I initially planned to use them with my father-in-law's original tube receiver (15 wpc) but now I prefer them hooked up to a much more powerful modern Yamaha amp, which I run at about 1/3 volume for just ambient listening. At that setting, my very efficient Pinnacle Monitor 200 floor speakers are quite loud. the AR-4x's seem to "come alive" when driven with a decent amount of power to at least medium volumes. To me, they sound very "reserved" at low volumes.

[Guest tgw]

The AR-4 with the original tweeter had a crossover of 2,000 ohms while the AR-4x crossed over at 1200 ohms. With this in mind you could plan on using the original woofer with a newer tweeter that crossed over at 2,000 ohms. You would need to change the cross over to accomodate the higher cross over frequency.

[pmsummer]

The AR4 1962-1964 was the first (in the world) bookshelf loudspeaker.

Not to dredge up old history (too much), but the Frazier Monte Carlo bookshelf speaker (roughly the same size as an AR4) dates to the late 1950s.

[JKent]

A friend of mine found a pair of 4x ( small bookshelf with 8" and high freqency driver) sitting out for the garbage man. He brought them over and the cabinets are fine, one 8" driver is bad as is the high frequency driver ( same cabinet ). I hooked up the "good one" and it is nowhere as efficent as my old beat up set. How could this be? Where can I get a replacement high frequency driver and is there any hi quality replacements that would work with out modifying the crossover?

Thanks for the help!

Yes--AR speakers are less efficient than many other speakers. Ported designs are more efficient than Acoustic Suspension. But you don't need a whole lot of power for these. My 1st stereo consisted of a pair of AR4x's driven by a dynakit ST-35 (17 wpc) tube amp.

But back to your speakers. What's "bad"? If the woofers have foam surrounds, there's volumes written here on replacing the surrounds. The ARs are notorious for corroded level pots. Try fiddling with the dial on the back and see if the tweeter works. You may need to clean or replace the pots. If you do need new tweeters, maybe a member more knowledgeable than I can steer you toward a good replacement. AB Tech is good but there may be less expensive alternatives.

These speakers are definitely worth salvaging! I am still listening to mine, 40 years after buying them. New caps, pots and grille cloth but well worth it. Download the booklet on restoring the AR3a at the top of this forum--much of the info there will apply to the 4x. Here is the link:

http://www.classicspeakerpages.net/library...ring_the_ar-3a/

Good luck!

Kent

[dynaco_dan]

Yes--AR speakers are less efficient than many other speakers. Ported designs are more efficient than Acoustic Suspension. But you don't need a whole lot of power for these. My 1st stereo consisted of a pair of AR4x's driven by a dynakit ST-35 (17 wpc) tube amp.

Download the booklet on restoring the AR3a at the top of this forum--much of the info there will apply to the 4x. Here is the link:

http://www.classicspeakerpages.net/library...ring_the_ar-3a/

Good luck!

Kent

Hi Kent;

I owned a pair of AR-4X's and used an SCA-35, FM-3 with an AR turntable.

I still consider that to be the ultimate cheap quality system.

Sadly, as always, I needed money and sold the entire system.

That system was adequate for my normal listening needs with 17 1/2 watts per channel, exaggerated, probably closer to 13 watts per channel, clean.

I also used my AR amplifier with AR-4X's.

The AR amplifier was not an awful lot louder that the SCA-35, but now I was able to blow Bussmann FNM 6/10 amp fuses.