LSiM 706C phase issue

gmcman

The 1st speaker that arrived had some cosmetic damage, but I did try the audssey and I had a phase check warning. I never really pursued it as it was going back so I chalked that one up as another possible issue along with cosmetic damage. All the speaker/ RCA leads were correct.

The 2nd one arrived and I went to setup the room eq again and I get the check phase notification for the center.

So I performed the battery test and all the drivers move inward...so this should be out of phase.

I unscrewed the binding post plate and the wires appear to be correct.




I did talk to polk briefly on the 1st speaker and he said that the wires on the speaker cannot be wired backwards due to size of the terminals...however I didn't pull a driver to confirm.

Two speakers? Is this normal for this speaker?

I figured I would ask before I remove a driver as the mounting screws and the MDF is a delicate mix.

gmcman

Curiosity got the best of me. Having my last speaker arrive with one of the screws loose...mind you the 1st speaker was NIB, I didn't want to remove one for no reason.

Not too much thread on each screw but seems to work...just be careful not to strip.



As far as the wiring, I have the grey wire attached to the POS + on the binding plate, however the grey wire is connected to the speaker NEG - .



Not sure what goes on inside, haven't been into the crossover but curious of anyone has pics inside this speaker.

K_M

Very doubtful they were manufactured wrong.

I would think it would be far more likely an anomoly of the measuring software, or the positioning of the centre in relation to the other speakers, making the software "see" a phase issue, when in reality it may be a timing or distance issue in relation to the different channels.

not absolute phase, but relative to the other speakers.
Also check if other speakers for sure are wired correctly.....

gmcman

My main speakers are wired correctly, all drivers move out when performing the battery test.

The 706C drivers move inward performing the same battery test when connecting to the binding plate.

I removed the speaker wires from the driver on the 706C, performed the polarity test and going straight to the speaker, the come moves out.

joecoulson

Seems like Chinese manufacturing is not perfect after all. I’m Having some QC issues with the Elacs also.

gmcman

So I assume polk is still using the black wire as the POS + and the manufacturing process is seeing the black as the negative?

joecoulson

It seems like it might be the other way around? Typically red is positive.

gmcman

The binding posts have a red wire on one of the positive posts. Polk has used black for positive, especially with the SDA speakers. The binding posts also have black on the negative side.

Not sure what is right. All I know is the speakers show out of phase when performing the battery test.

K_M

gmcman wrote: »

My main speakers are wired correctly, all drivers move out when performing the battery test.

The 706C drivers move inward performing the same battery test when connecting to the binding plate.

I removed the speaker wires from the driver on the 706C, performed the polarity test and going straight to the speaker, the come moves out.

You mentioned damage upon receiving them. Were they demos, previously owned or refurbs by any chance?

I would think the grey wire with protective cover would go to the + terminal on speaker, but have no schematic nor a pair to back that idea up.

gmcman

K_M wrote: »

gmcman wrote: »

My main speakers are wired correctly, all drivers move out when performing the battery test.

The 706C drivers move inward performing the same battery test when connecting to the binding plate.

I removed the speaker wires from the driver on the 706C, performed the polarity test and going straight to the speaker, the come moves out.

You mentioned damage upon receiving them. Were they demos, previously owned or refurbs by any chance?

The damage was on the 1st speaker, this is the replacement.

Both speakers were NIB, factory sealed.

Both speakers show out of phase with Audssey, I only checked this one.

joecoulson

seems to me they are wired incorrectly internally.
1. Send back
2. Fix them

DaveHo

This is not an uncommon issue with calibration software. Though that doesn't explain the battery test results.

gmcman

I'm fine with fixing them, I'll get with Adorama and see what they say. I dont want to keep sending them back if I can help it.

I will also get with Polk on Monday if I cannot find a schematic.

Derm

Please keep us updated on the fix if you could.
I plan on getting a 706c as well in the near future so this would help if any of us new owners encounter the same issue.

WLDock

Have you tried to simply reverse the wires from the AVR at the speakers input terminals and re-run audyssey? See what it does and how it sounds.

gmcman

WLDock wrote: »

Have you tried to simply reverse the wires from the AVR at the speakers input terminals and re-run audyssey? See what it does and how it sounds.

That was the next plan. I was hoping this was a simple fix and not have to do a workaround. I will run another calibration tonight with the input reversed at the speaker and see how it does.

I'm curious now to other users if their 706C behaves in the same manner.

mikeyb128

I had out of phase issues with my lsim running audyssey. I never paid much attention to it, as I know some reflections in the room can cause this. I believe there is a thread here about this issue. Something to do with the crossover design. Is your center in a cabinet? Or on a shelf? Perhaps the speaker isn’t at the very leading edge of your shelf? This can cause reflections as well. You might be surprised the leap in center channel performance if you move your center all the way to the edge of the shelf, minimizing some reflection.

I had some serious quality control issues with my lsim’s. I really loved them when they worked. But In the end they felt fragile and I moved to something else. Dam shame!

gmcman

The 706C is on an open stand. My phase issue is just that....the speaker is firing out of phase.

F1nut

Not that you will see this until I'm let out of polk prison, which I'm in for a completely unjustified reason.

Since the gray wire is on the positive binding post logic dictates it should also be on the positive driver terminal.

jeremymarcinko

It’s been discussed here before. It’s supposed to be that way and my lsim center does the same thing with audessey. If it sounds good I wouldn’t mess with it anymore.

My lsim f/x surrounds do the same thing too.

I have adjusted the placement of the center since and overcome the phase error.

dpowell

My LSiM706c does the same thing. MCACC on the Pioneer shows an out of phase error during calibration. Initially it concerned me and I did the wire double-checks. I finally ignored it and let the AVR do what it wanted to do and have not seen any impact on sound because of it.

sgmsmg

My Pioneer MCACC worked fine with mine. When I switched to the Yamaha that gives the out of phase error.

pitdogg2

sgmsmg wrote: »

My Pioneer MCACC worked fine with mine. When I switched to the Yamaha that gives the out of phase error.

My Yamaha did the same on my surrounds. I switched the wires even though they were correct, guess what? Re-ran the room software and it said....
Yep out of phase.
The battery is perplexing though.

dpowell

Check this thread I started when I first encountered the 'issue'.

Ken at Polk says the speaker xo and phase configuration is intentional.

https://forum.polkaudio.com/discussion/165082/lsim-706c-out-of-phase-in-mcacc