LSiM 706c out of phase in MCACC

dpowell

Each time I run MCACC on my Pioneer, the utility thinks that my 706c is out of phase. I have not had this issue with previous center speakers and I have triple checked that the wiring is correct. I just select the option to move on and all sounds fine. I'm just wondering if anyone else has seen this issue?

Dennis Gardner

Check polarity with a AA battery to see if Polk actually wired it out of phase. Who knows, they are made by humans.

drumminman

FYI I don't use the auto calibration set up with my Yammy AVR. I do it by ear and find it much more to my liking. I start with all speakers at 0 decibals and adjust levels from there. Also, I run everything large, even the surrounds. I've tried it the conventional way (mains large surround small) and like the way this sounds better.

You might try it manually and see what you think.

gce

Dennis Gardner wrote: »

Check polarity with a AA battery to see if Polk actually wired it out of phase. Who knows, they are made by humans.

I put my LSiM703's in my system and I had the same error. Dennis, how do you check it with a AA batt?

Dennis Gardner

Placing the + & - speaker wires on the + & - battery posts should yield the speakers moving outward when the wires are touched to the post. It is easy to see with the woofers as they move the most. All speakers should move in the same direction, if they don't, they have been wired wrong, or the post nuts have been switched.

gce

Thanks Dennis...I'll bet the tweeter is had to see. I'll check it out when I get home.

gumbay13

gce wrote: »

Dennis Gardner wrote: »

Check polarity with a AA battery to see if Polk actually wired it out of phase. Who knows, they are made by humans.

I put my LSiM703's in my system and I had the same error. Dennis, how do you check it with a AA batt?

Interesting. I had the same error when i ran Audyssey on my 703s today.
I just rechecked the speaker cable connections and once satisfied nothing was amiss, ignored the error and proceeded with the calibration

I am beginning to wonder if i need to do some more investigation.

blehmbo

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

gce

blehmbo wrote: »

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

Really, so this is by design? How did you find this out, by testing or did you read this somewhere?

gumbay13

So i ran Audyssey again.

This time i had one lsim703 and one Rti A7 and again the LSim was the only speaker with the phase error. No errors on the A7
I kept the A7 and swapped the other 703. Error still on the 703.

Ran Audyssey on both A7s. No phase errors.

Replaced them with the 703s, rechecked the cable connections and ran Audyssey and again the phase error.

Previously i had just selected SKIP ERROR and moved on.
This time just out of curiosity, I moved the positive connections to the negative terminals and vise versa (in contrast to the amplifier outputs) and this time no phase error!

So it appears the "issue" is with the 703s.

For what it is worth i have not noticed any difference in the sound IN or OUT of phase.
May be I need to do a bit more critical listening.

Also the last time i had a phase error, when doing Audyssey several months ago, the utility flagged the right rear surround speaker and lo and behold it was correct. I made the correct connection and all was well. I was impressed.
So i am certain the receiver is not the issue here.

WLDock

The 703 and 706 are 3-way designs with 4-way crossovers that have 18dB,18dB,12dB,6dB slopes. It would not be surprising if a driver is wired out of phase to bring things back in phase due to the crossovers.

I've gotten this same error with my current RT3000 right speaker when I had a Pioneer SC unit. The speaker is closer to the wall and I did not have room treatments. It did not fail all the time depending on where I placed the mic. So, mine was more a reflective error.

blehmbo

gce wrote: »

Really, so this is by design? How did you find this out, by testing or did you read this somewhere?

I found this out (speaking for the 703) by testing and looking at the printing on the crossover board, the + of the woofer connects to the negative side of the crossover circuit.

gce

Ok, So if I test the phase with the AA batt. on the lower posts the woofer should move IN and if I test using the top posts the tweeter and mid should move OUT...right?

blehmbo

gce wrote: »

Ok, So if I test the phase with the AA batt. on the lower posts the woofer should move IN and if I test using the top posts the tweeter and mid should move OUT...right?

You shouldn't see the tweeter or mid move since they have capacitors in series which block DC, but the woofer should move inward with + to + and - to -.

Conradicles

blehmbo wrote: »

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

Why?

WLDock

Because of phase shift at the crossover frequency. Sometimes you have to reverse the phase of a driver to help the flatten the combined acoustical output.

dpowell

I found the same to be true when I switched the speaker connections to what would normally be "out of phase". MCACC did not find a phase issue in that configuration. I switched the wires back since I did not purposefully want to connect the speaker improperly and just moved on. Glad to hear I'm not the only one that has run into this. Surely Polk must have found this during quality testing and should have some insight or at least put our minds at ease that this is normal.

1Locoweed

I called tech support this morning & verified that this is intentional. Ken said it is due to a second order filter.

WLDock

Due to phase shift. The driver is generally wired out of phase when using a 12dB/Oct crossover.

6dB/Oct = 90 degrees
12dB/Oct = 180 degrees
18dB/Oct = 270 degrees
24dB/Oct = 0 degrees

gce

1Locoweed wrote: »

I called tech support this morning & verified that this is intentional. Ken said it is due to a second order filter.

Thanks for that. Its always good to hear it from the horses month.

mdacompact

gce wrote: »

blehmbo wrote: »

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

Really, so this is by design? How did you find this out, by testing or did you read this somewhere?

So, in the end what did u do with the speaker wires? reverse it or use them as it's design? Kindly advise too, i got the same when connect them with my Yamaha TSR-7850 receiver and it found automatically

Tks A Lot!
mdacompact

ptrooper

I had the same reading with my old yammy Z 11 i sold a few years ago.
The dealer said to not take notice as it was very common.
Before being told this i pulled apart the 706 and all was ok!

Emlyn

I just think of the auto setup phase warning messages as a convenient reminder to double check the amp to speaker wiring with a new setup. Always out of phase, always wired correctly in my experiences.

mantis

Phase can also be measured in room according to the way that signal bounces around the room it can appear out of phase even if it's wire correctly and internally wired correctly.

mpitogo

Oh dang, this is very helpful. I was scratching my head as well when I swapped my LSiM series into my HT. It said all of my speakers where out of phase, 707, 706c and four 702fx, I will have to check all of the wiring again.

mrloren

I had/have the same problem with my LSiM's. Audyssey said out of phase. I did some reading and googled it. Look's to be the norm with the LSiM's.

When I had the Signatures I didn't get the phase error but Audyssey would put the sub out of phase. I'd get 5db more output from the sub switching the phase to 180. now with the LSiM's I run Audyssey get the speaker out of phase warning but the sub is in phase. Sounds great so I just leave it alone.

mpitogo

@mrloren good to know. Audyssey here too. I have both my subs at normal 0 phase, will have to test changing them. They can do 0, 90, 180 and 270.

dpowell

mdacompact wrote: »

gce wrote: »

blehmbo wrote: »

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

Really, so this is by design? How did you find this out, by testing or did you read this somewhere?

So, in the end what did u do with the speaker wires? reverse it or use them as it's design? Kindly advise too, i got the same when connect them with my Yamaha TSR-7850 receiver and it found automatically

Tks A Lot!
mdacompact

I kept mine wired as designed. Been that way since I started the thread and i have no complaints. It sounds great!

mdacompact

dpowell wrote: »

mdacompact wrote: »

gce wrote: »

blehmbo wrote: »

No need for alarm, the woofer in the LSiM703 is wired out of phase with the mid and tweeter by design. I can test my 706c later.

Really, so this is by design? How did you find this out, by testing or did you read this somewhere?

So, in the end what did u do with the speaker wires? reverse it or use them as it's design? Kindly advise too, i got the same when connect them with my Yamaha TSR-7850 receiver and it found automatically

Tks A Lot!
mdacompact

I kept mine wired as designed. Been that way since I started the thread and i have no complaints. It sounds great!

Tks you man!

pawelmwo

Yeah normal. My 705 and 706c had phase errors during Audyssey calibration as well. Sound great.

mpitogo

Thank you op for starting this thread. It’s something you don’t read in a manual.

OK so I put all of them back to proper polarity and needed to set my subs to 180, I had some serious loss of bass due to cancellation. I was wondering why my system went bass shy going from LSi25 -> LSiM707.