How do I use per-channel room correction?

[Taiga]

I am thrilled to have per-channel room correction for my Pro Plus, but I don’t understand how the measurement procedure differs from the previous stereo version. The steps in the Room Correction sub-menu are identical and don’t have an option to select the channel for measurement. I have a two channel system. How do I tell the software to measure the left and right channels separately and what is the method for them to play back the corrections simultaneously for each speaker? I searched the forums and the WiiM support sections and did not find a procedure. Step-by-step instructions would be nice if the answer is not something simple that I am overlooking. Thanks!

 

[Wiimer]

I am thrilled to have per-channel room correction for my Pro Plus, but I don’t understand how the measurement procedure differs from the previous stereo version. The steps in the Room Correction sub-menu are identical and don’t have an option to select the channel for measurement. I have a two channel system. How do I tell the software to measure the left and right channels separately and what is the method for them to play back the corrections simultaneously for each speaker? I searched the forums and the WiiM support sections and did not find a procedure. Step-by-step instructions would be nice if the answer is not something simple that I am overlooking. Thanks!

I don't think RC per channel has been implemented yet. PEQ per channel.

 

[Taiga]

Thanks. I thought the RC is what set up my parametric EQ curve?

 

[Burnside]

PEQ was available before RC and you could manually set it, perhaps using it to input a set of values obtained from an external app like REW. RC then came along which automatically set a set of PEQ values. Now we have per channel PEQ, I’m sure per channel RC will follow in time.

 

[Taiga]

So simply using the Wiim ap without a 3rd party system for measurement, I’m basically shooting in the dark to set per channel PEQ?

I’m not complaining because RC has made a noticeable improvement to the lower frequencies in my room. Just wondering whether or not it would take me a step further when correcting for separate channels. I’m using KEF R11s and the mid and highs are smooth and defined across the room without any correction. I only listen to music, no HT.

 

[Burnside]

As I say, WiiM doesn't yet support per channel RC, and we'll have to wait until they do unless you can derive the set of values externally.

 

[jmudrick]

Even if it's offered I doubt you should be using it unless WiiM gets a lot more sophisticated in its abilities in both measurement and Auto EQ. Our ears do not hear separate L/R and separate measurement of L/R does not reflect how sound waves interact in a room.

 

[Schmidlapper]

I used HouseCurve to determine both a left and right set of adjustments, and then entered them manually. No auto L R adjustments built in as of yet. What I want to know is what are the new preamp adjustments they mentioned? Do they now auto compensate a preamp setting to avoid clipping, do I stop manually compensating?

 

[jed1]

Per-channel room correction may sound straightforward. However, in order to make it right, phase alignment between left and right is perhaps more important than amplitude-only correction. Amplitudes may get adjusted to target curve. If left and right channels arrive out-of-phase, it will cause undesirable effects. I do not expect WiiM to match performance of a dedicated room correction processor like Arc Studio.

 

[Schmidlapper]

Per-channel room correction may sound straightforward. However, in order to make it right, phase alignment between left and right is perhaps more important than amplitude-only correction. Amplitudes may get adjusted to target curve. If left and right channels arrive out-of-phase, it will cause undesirable effects. I do not expect WiiM to match performance of a dedicated room correction processor like Arc Studio.

Are you saying WiiMs two channel PEQ is causing phase misalignment that they then aren't addressing? Or, that the phase misalignment is already present and they don't address it? I suspect speakers set up well symmetrically would not suffer too much of this playing stereo music, maybe with matching test tones coming from both speakers.

 

[jed1]

Yes. Peak, LS, HS-only PEQ based room correction can cause phase misalignment. PEQ changes not only amplitude but also phase (so time-domain response).

 

[Schmidlapper]

Yes. Peak, LS, HS-only PEQ based room correction can cause phase misalignment. PEQ changes not only amplitude but also phase (so time-domain response).

would this affect primarily higher frequencies, or full range? I suspect higher frequencies, with their shorter wavelengths. I limit my PEQ to below 500 HZ.

 

[jed1]

would this affect primarily higher frequencies, or full range? I suspect higher frequencies, with their shorter wavelengths. I limit my PEQ to below 500 HZ.

It depends on how different PEQ parameters are between left and right. You need to compare phase plots. Arc Studio has a linear phase option which preserves phase relation between left and right, and only changes amplitude in frequency domain (but at a cost of latency, i.e. more computing heavy).

 

[harkpabst]

would this affect primarily higher frequencies, or full range? I suspect higher frequencies, with their shorter wavelengths. I limit my PEQ to below 500 HZ.

I think it's not too helpful to think about phase relations in the lowest bass octaves. Long wavelength signals won't be so much out of phase, unless you invert polarity in one channel. But the placement of speakers and/or subwoofer(s) starts to play a big role concerning the excitation of room modes.

If you could have the entire front wall move as one big subwoofer cone it would really impress the sound pressure into the room. Room modes could develop in one dimension, only, between the front wall and the back wall and would be easy to mitigate. Moving your MLP Up and down or left and right wouldn't be suffering from room modes at all.

Things are probably least complicated in the highest octave where phase correlation is of little interest, anyway. I want.to repeat once more that correction for speaker anomalies (e.g. based on spinorama data) should ideally be done independently from room correction.

 

[MCG555]

I think it's not too helpful to think about phase relations in the lowest bass octaves. Long wavelength signals won't be so much out of phase, unless you invert polarity in one channel. But the placement of speakers and/or subwoofer(s) starts to play a big role concerning the excitation of room modes.