Acoustic Research AR Classic 26 series crossover issue

[itsbillgruber]

Auditioning a super-clean pair of AR Classic 26 speakers from 1994. Brought along a few demo CDs....one speaker sounds amazing, the other sounds....less amazing. Checked wiring polarity, CD player interconnects, also used an FM tuner for comparison, and, changed amps....the same problem continued. Very bummed.

The "bad" speaker isn't shrill, buzzing or vibrating.....and, all drivers work....but the end result is a speaker that sounds very muted and very different from the "good" one, as if the highs and lows were gently rolled off on a 10 band graohic eq....but no midrange harshness.

Thought about the problem ....it has to be something to do with the internal crossover network. If any of the woofers/mid-ranges/tweeter were "blown" in that cabinet, they would either (A) make no sound or (B) make obnoxious noises like buzzing, vibrating or squealing.....all those speakers in the cabinet work, and, none make objectionable noises...but the whole speaker sounds nothing like the other, and, it generally sounds dulled and muted.

It is an un-amped passive speaker....could the problem lie with the crossover? Anybody familiar with these pricey, short-lived AR speaker series? Is there a correct replacement crossover out there? Or a very similar-tuned generic replacement parts crossover? Thanks much! Bill

 

[Dennis Murphy]

The "bad" speaker isn't shrill, buzzing or vibrating.....and, all drivers work....but the end result is a speaker that sounds very muted and very different from the "good" one, as if the highs and lows were gently rolled off on a 10 band graohic eq....but no midrange harshness.

Are you saying that the bass is rolled off at the bottom, and the treble rolled off at the top? If so, the rolled off bass has me stumped. A bad crossover part in the bass section would probably cause too much upper bass. But the lowest range should still be there. As for the treble, when you put your ear next to both tweeters, the one in the problem speaker sounds noticeably less strong? If so, it could be either a crossover problem or a damaged, but not dead, tweeter. In any evernt, you should remove the tweeter just to make sure nothing is touching between its input terminals). If it looks OK, you could switch in the tweeter from the good side just to make sure. If it sounds dull, then it's the crossover. I'm not sure where it is in that speaker--you can usually see it if you remove the woofer, but I don't know whether it could be reached and removed easily. If it can, then you might send it to someone to check. I could do that, as could a number of other people.

 

[itsbillgruber]

thanks & more on these Acoustic Research Classic 26 speakers

Dennis….Thanks for the insight! These speakers are still in the possession of the seller, and, I could tell he was a little antsy when I started swapping wires, interconnects and amps at his house….probably wouldn’t be happy if I started disassembling them! All the drivers sound clean, just no robust. I own Vandersteen 2C and Definitive BP2002 and the “good” speaker in this AR pair sounds very competitive with these other two models.

To further expound on the sound of this suspect speaker, my initial reaction was he had his speaker wire polarity wrong…..and that may be an even better sonic description….we’ve probably all made a mistake in our speaker wiring and one speaker in a system has it’s plus and minus wires accidentally reversed…..you know that slightly hollow, weak high&low, lower SPL, “out of phase sound.“

Yes, I should have just said this speaker sounds like an otherwise healthy speaker with the speaker wires reversed. That was the first thing I tried, swapping the plus & minus at the speaker terminals. I was surprised when I fired the amp back up and the speaker still sounded odd.

The price is right and the speakers are in sweet physical condition from a very tidy home….maybe worth the purchase even with this issue to resolve. The owner’s CD collection was mostly jazz and classical music, and, he admitted to mostly using them for background music….it could have had this issue since new and not noticed….when I brought in some Dire Stairs and Steely Dan CDs and cranked them up, the lack of overall punch and clarity from the right channel was obvious.

I’ll sit by and see if anyone else chimes in on this issue, hopefully somebody is personally familiar with these Acoustic Research Classic 26 speakers or, others in the AR Classic series from 92-94.