Sub Calibration 13ms delay vs 0ms...

[motleypixel]

I’m running my Ultra RCA out to a class D amp. This amp has tone controls set to noon aka flat and volume at about 90%. Out of the Ultra I use LFE to my active subwoofer (Definitive Technology Super Cube II). I leave “Fixed Volume Output” off to allow the Ultra to control my volume.

When the phase on the sub is set to 0 and in the Ultra and I run a calibration the results is a 13ms delta (forgot which leads/lags speakers/sub). When I set the phase on the sub and Ultra to 180 and run the calibration they are in sync aka 0ms delta. There isn’t any difference in sound to my ears between the two, but I chose 180.

Is this what you would choose and why? Furthermore, my phase control on the sub is variable, it’s not a toggle switch 0/180 so I can set it to anything between 0 and 180 but the Ultra only has two settings.

Thank you.

 

[harkpabst]

When the phase on the sub is set to 0 and in the Ultra and I run a calibration the results is a 13ms delta (forgot which leads/lags speakers/sub). When I set the phase on the sub and Ultra to 180 and run the calibration they are in sync aka 0ms delta.

Why would you set the phase on the sub and on the WiiM Ultra to 180°? That's the same as leaving both to 0°, so pointless.

The "phase" switch should actually be named "polarity", because this is what it really does, it inverts the polarity of the input signal.

Is this what you would choose and why? Furthermore, my phase control on the sub is variable, it’s not a toggle switch 0/180 so I can set it to anything between 0 and 180 but the Ultra only has two settings.

A continuous phase control deserves the name phase. And the WiiM Ultra has that too. Latency (or delay) and phase are one and the same thing, just expressed in different terms. Adding latency means effectively manipulating the phase, so you don't have to use both, but just one of them. It's usually easier to just change the delay setting in the WiiM Home app then fiddling with a rotary knob on the back of your subwoofer. I'd leave both settings at 0 on the sub and control it all through the app. It's usually the sub that lags behind, so the signal for the mains amp must be delayed for them to match.

A simple recipe:

• Set the "phase" switch and the phase knob to 0 on the sub
• Run auto-sync in the WiiM Home app and write down the latency value
  • == Optional ==>
  • Set the "phase" switch in the WiiM Home app to 180°
  • Run auto-sync in the WiiM Home app. If the value is lower than above, keep the
  • If the value is lower than the initial value continue with the "phase" switch at 180° and the new lower latency value
• Measure the distance between your main listening place and your WiiM Ultra
• For each 34 cm (13.5") of distance add 1 ms to the latency value you found above

You might want to evaluate the final result by the latency value by +/- 1 ms. Whatever results in louder perceived bass is probably better.
The results can be slightly different when using different crossover frequencies.

 

[motleypixel]

Why would you set the phase on the sub and on the WiiM Ultra to 180°? That's the same as leaving both to 0°, so pointless.

Well on the surface this makes sense. But again, I did because the sub calibration resulted in 0ms delay between my sub and mains at 180 where as at 0 they were 13ms. So keeping this at 0 now seems okay because I can adjust the latency with the WHA correct?

The "phase" switch should actually be named "polarity", because this is what it really does, it inverts the polarity of the input signal.

Yes I have read this and it makes sense. My DefTech SuperCube II does not have a separate "polarity" switch and continuous phase control knob. It only has a variable knob called Phase from 0 to 180. So it can be set to anything inbetween.

A simple recipe:

• Set the "phase" switch and the phase knob to 0 on the sub
• Run auto-sync in the WiiM Home app and write down the latency value
  • == Optional ==>
  • Set the "phase" switch in the WiiM Home app to 180°
  • Run auto-sync in the WiiM Home app. If the value is lower than above, keep the
  • If the value is lower than the initial value continue with the "phase" switch at 180° and the new lower latency value
• Measure the distance between your main listening place and your WiiM Ultra
• For each 34 cm (13.5") of distance add 1 ms to the latency value you found above

You might want to evaluate the final result by the latency value by +/- 1 ms. Whatever results in louder perceived bass is probably better.
The results can be slightly different when using different crossover frequencies.

- okay on my sub again only one variable knob so set it to 0
- I have yet to run auto-sync in WHA but will try and write down the delay but I suspect 13ms
- okay now for optional try the same with it set to 180 and again I suspect 0ms
- so if it is 0ms then keep the phase knob on my sub at 180?
- okay so if I get 0ms at 180 which is what I have now, and say my main listening position is 95.5in from my Ultra (not the speakers?) then add 7ms delay? (my listening spot is about 7' from the Ultra).

So now, what about the Sub Calibration with the WHA, just ignore it?

Thanks.

 

[harkpabst]

Well on the surface this makes sense.

Not just on the surface.

My DefTech SuperCube II does not have a separate "polarity" switch and continuous phase control knob. It only has a variable knob called Phase from 0 to 180. So it can be set to anything inbetween.

Sorry, I should have guessed this as subs always have either a phase knob or a "phase" switch. Simply forget any reference to the switch on your sub.

- okay on my sub again only one variable knob so set it to 0

Yes.

- I have yet to run auto-sync in WHA but will try and write down the delay but I suspect 13ms

Where did the 13 ms number originally come from if you didn't run auto-sync yet? Just do it, so we don't have to assume.

- okay now for optional try the same with it set to 180 and again I suspect 0ms

It's optional, you can just as well leave it out in a first step. Just start without this optional step.

- so if it is 0ms then keep the phase knob on my sub at 180?

No. Don't touch the phase knob on your sub. Ever. Just leave it at 0°, no matter what.

say my main listening position is 95.5in from my Ultra (not the speakers?) then add 7ms delay? (my listening spot is about 7' from the Ultra).

Yes, that's what I said. But after rethinking this I must say that I spoke too soon. I'm very sorry.

I now propose that you rather just try to vary the auto-sync value by 1 or 2 ms both ways (plus and minus).

 

[motleypixel]

Where did the 13 ms number originally come from if you didn't run auto-sync yet? Just do it, so we don't have to assume.

I skipped "calibrate audio path latency" and instead I got the 13ms delta between mains and sub from the sub calibration when the sub in WHA was set to 0 and the phase on the back of my sub set to 0. Then when I tried 180 on both the WHA and the sub the was 0 delta, perfectly in-sync.

Thanks.

 

[harkpabst]

I skipped "calibrate audio path latency" and instead I got the 13ms delta between mains and sub from the sub calibration when the sub in WHA was set to 0 and the phase on the back of my sub set to 0. Then when I tried 180 on both the WHA and the sub the was 0 delta, perfectly in-sync.

Thanks.

Sorry, I still don't understand. There is no separate sub calibration procedure in the WiiM Home app.

 

[cristoo]

Hi

If I may also join discussion especially for @harkpabst advice

I have quite budget friendly 2.1 setup with Mivoc Hype Sub. It is placed right by my left main speaker.

My listening distance from Speakers and Ultra is about 2,5 m

When I recently did sub auto sync it measured 2 ms. As far as I remember it was with 0 phase set.

Than I did some test and for my ear 180 sounds maybe quieter with bass but less boomy and more thight which I found overally better.

So i changed sub phase and wiim app settings to phase 180.

I recievied pretty good frequency response when I measured in HouseCurve.

But now I am a little bit lost:
1. Did I set phase properly ?
2. Should I re run sub sync and what results should be expected? Should I rely on Wiim measurements or correct it by manually calculations ?

Thanks in advance.

Krzysztof/Cristoo

 

[motleypixel]

Sorry, I still don't understand. There is no separate sub calibration procedure in the WiiM Home app.

 

[motleypixel]

Hi

If I may also join discussion especially for @harkpabst advice

I have quite budget friendly 2.1 setup with Mivoc Hype Sub. It is placed right by my left main speaker.

My listening distance from Speakers and Ultra is about 2,5 m

When I recently did sub auto sync it measured 2 ms. As far as I remember it was with 0 phase set.

Than I did some test and for my ear 180 sounds maybe quieter with bass but less boomy and more thight which I found overally better.

So i changed sub phase and wiim app settings to phase 180.

I recievied pretty good frequency response when I measured in HouseCurve.

But now I am a little bit lost:
1. Did I set phase properly ?
2. Should I re run sub sync and what results should be expected? Should I rely on Wiim measurements or correct it by manually calculations ?

Thanks in advance.

Krzysztof/Cristoo

My 2.1 setup is almost exactly the same (doubt our room and room treatments are the same) but my sub is just to the left in a corner of my left main speaker and I sit about 2.5m from them. To me the audible difference between 0 and 180 after the WiiM corrects the 0 phase with 13ms delta sound pretty much the same. At 180 where the system finds 0 delta it may sound, IDK how to say it, louder but oh man every so slightly. So I still have mine at 180 on the sub and 180 in the app where the sub cal runs with a zero delta/delay.

@harkpabst "maybe" the sub and speaker sync under "Subwoofer" section is actually the same thing as the main audio sync, the app devs just put a way to reach it under Subwoofer settings???

Thank you.

 

[harkpabst]

OK, I think I see where you're coming from. There's a calibration between different devices for multi-room music, which has nothing to do with subwoofer management. And then there's subwoofer and speakers sync, which is all about subwoofer management.

If subwoofer and speakers sync (automatic sync) gets you a 13 ms latency it is well possible that inverting the polarity either on the Ultra or on the subwoofer results in a 0 ms latency. It just depends on the placement. If this is what you did, then you actually did perform the optional step from my list. In this case I'd simply go with the inverted polarity and the 0 ms latency.

Again, if you want to you can try to ad 1 ms or to to the main speakers and check if this results in louder bass. It may just not. If it does, make sure to vary the sub level in the WiiM Home app by 1 or 2 dB and stick with whatever you like better.

 

[harkpabst]

I have quite budget friendly 2.1 setup with Mivoc Hype Sub. It is placed right by my left main speaker.

My listening distance from Speakers and Ultra is about 2,5 m

When I recently did sub auto sync it measured 2 ms. As far as I remember it was with 0 phase set.

Than I did some test and for my ear 180 sounds maybe quieter with bass but less boomy and more thight which I found overally better.

So i changed sub phase and wiim app settings to phase 180.

I recievied pretty good frequency response when I measured in HouseCurve.

But now I am a little bit lost:
1. Did I set phase properly ?
2. Should I re run sub sync and what results should be expected? Should I rely on Wiim measurements or correct it by manually calculations ?

Hi @cristoo,

after changing the polarity setting you should definitely re-run the speakers and subwoofer auto-sync. However, the goal of this whole exercise is to get a smooth and flat transition between main speakers and sub. If the HouseCurve measurements don't show any dip in the crossover area, then you're done. Depending on what "pretty good" means there might or might not be potential for further improvement.