AR90 Phase Anamoly - When it makes a difference

[AR surround]

As many of you know, I have AR9's as front speakers and AR90's as surround speakers in my 7.1 audio system.   It has been documented in this forum, by DavidR for one, that the LMR, UMR and tweeter in the AR90 are wired out-of-phase with the woofers. 

Until today, I did not think that this internal wiring of the AR90 made a difference.  However, I recently acquired a new Marantz AVR which includes Audyssey automatic setup.   When I ran the first test, Audyssey detected that the AR90's were out-of-phase with all of the other speakers and stated that I should swap the polarity of the AR90's wiring.   I did the wire swap on both AR90's, reran the test, and Audyssey indicated that there were no phase problems.

I find this quite bizarre because when playing the "phase test" of a calibration disc specifically made for a 7.1 audio system, the AR9 and AR90 speakers clearly sounded in-phase compared to each other without swapping the speaker wires to the 90's.

Now I'm wondering if I've opened up a can of worms for those of us using AR90's with other speaker models in the same audio system.

[ar_pro]

Huh.

So, Audyssey isn't happy with the woofers of the AR-90s being out of phase relative to the AR-9s, but it's OK with the upper portion of the '90s being out of phase. Is it the phasing of the woofer part of a loudspeaker that Audyssey is most concerned with? 

[AR surround]

Here is the answer straight from Audyssey:

Audyssey MultEQ detects absolute phase for each speaker. Some speakers are designed with intentional phase reversals in the drivers in order to address crossover problems. Audyssey MultEQ will detect and report an error. The best course of action is to simply check the wiring and press "Skip" if it is correct.

So this wiring anomaly is not all that uncommon with certain speakers.

[DavidR]

The tweeter, UMR and LMR are wired out or phase from the woofers on the 90.

AR still used the wire colors so that you will still use (for instance) the yellow wire to the '+' side of the tweeter BUT it actually goes to the negative side and not the capacitor. The blue wire goes to the series cap.

[ar_pro]

Kind of an unusual situation, isn't it? I've certainly heard of manufacturers wiring their tweeters with reversed phase (relative to the other drivers), but not to the extent that AR did with the '90, where the woofers are oop with the rest of the system. I wonder how many other multi-driver speaker designs are like this?

Honestly, I'd forgotten that DavidR had established this peculiarity of the AR-90; also, it's been years & years since I've had an AR-9 and AR-90 running together, and I never would have realized that there was any phase difference.

Audyssey seems like it would be of critical importance in setting up a multi-channel audio system; it's almost like magic.

[DavidR]

Just compare the AR9 schematic to the 90 and pay attention to the wire color and where they go.

For instance the 9 has the yellow wire (+) go to the series caps 4uF + 6uF

The 90 has the blue wire (-) go to the series caps.

As for why AR might have done this I remember modifying a mini pair of Yamaha speakers. The only component that remained was the woofers. I replaced the mids and tweeters and made a whole new crossover. I ended up wiring the tweeter  out of phase for no other reason than it just sounded better; sounded right.

[Stimpy]

I've asked before about the AR90s internal wiring, and if I should wire the woofers in phase with the upper drivers?  Wired like the 9s, since my 90s never exhibited great bass performance.  I'd love to know the reasoning between the 9s and 90s, and why they're wired differently?

Also, I've had the same phase issues with my 90s too, when using them for HT duty.  My Yamaha RX-A3030 AVR, which uses YPAO set up software, identified phase issues with the speakers.  I let the AVR correct the phase problem, and bass response greatly improved.

[DavidR]

I have no problems getting good bass........very good bass. I found that both the Pre amp Amp play a big role. A good current pushing amp does the job. I did find bass improvement, especially in the LMR, with the recap.

I suppose you could try it. As I said above about another pair of speakers. It just sounded right with the tweeter out of phase. It maybe as simple as that.

Perhaps Tom Tyson has some knowledge on this.