Crossover, speaker alignment, room equalization - what do I start with?

[sm52]

MSO calculated the delay to put on closer subwoofer.

If you want to keep it that way, measure each sub separately. Far sub as is, near with MSO delay, using acoustic synchronization over the same speaker with the tweeter. Then do the addition of the measurements in REW. You will get the measurement of the combined sub. Second option. Turn on both subs together, the far one as is, the near one with an MSO delay. Make measurements with acoustic synchronization over the same speaker with tweeter: combined sub, left front, right front. 3 measurements. Next will be job on choosing the crossover frequency.

 

[Lid9497]

Yes, with timing reference as you did for MSO and yes to XO in place.

Thx! another question if you wouldn't mind what is the correct way to measure subwoofer when using acoustic timing reference? do I set measurement frequency range to operating range of the subwoofer? SVS is 260hz -+3db, do I measure that range? or full range? there is a difference in the delay measured with full range being about 1-1,5ms more, that is quite significant.

 

[JStewart]

Thx! another question if you wouldn't mind what is the correct way to measure subwoofer when using acoustic timing reference? do I set measurement frequency range to operating range of the subwoofer? SVS is 260hz -+3db, do I measure that range? or full range? there is a difference in the delay measured with full range being about 1-1,5ms more, that is quite significant.

No reason to go beyond a few hundred Hertz with the sub.
I don’t understand the delay being different relative to the timing channel with either full range or partial.

 

[sm52]

I don’t understand the delay being different relative to the timing channel with either full range or partial.

Yes. I have not encountered such a thing.

 

[Lid9497]

No reason to go beyond a few hundred Hertz with the sub.
I don’t understand the delay being different relative to the timing channel with either full range or partial.

Yes. I have not encountered such a thing.

Took measurements using 200, 500, 20000hz range, 1,2ms difference, also included mdat file, why is this happening? Mic position is unchanged, only changed frequency measurement range.

 

[sm52]

The difference is not 1.2 ms, but 0.14 ms. The measurements of 200 and 500 are almost the same. The 20k measurement differs by 0.14ms. The Umik-1 microphone does not have its own clock oscillator. It takes the clock rate from the USB bus. Therefore, each new measurement is slightly different from the previous one. This is a well-known fact.

 

[Lid9497]

The difference is not 1.2 ms, but 0.14 ms. The measurements of 200 and 500 are almost the same. The 20k measurement differs by 0.14ms. The Umik-1 microphone does not have its own clock oscillator. It takes the clock rate from the USB bus. Therefore, each new measurement is slightly different from the previous one. This is a well-known fact.

Where are you calculating these values from? 7ms with 200hz vs 8.2ms with 20000hz is 1.2ms? Or is that the wrong delay shown and there is some other place to read the delays?

 

[sm52]

I'm not looking at the numbers you're looking at. I look at the source, at the graphs. Between the first peaks there are 386 microseconds, between the second peaks the time cannot be determined, because the second peak of 20k did not work out. The first and second peaks may not reflect the correct information because subs develop peaks slowly. Therefore, let's look at the third peaks. There is a difference of 0.14 ms. But, if you take another microphone, even Umik-2, there will be no difference.

 

[Lid9497]

I'm not looking at the numbers you're looking at. I look at the source, at the graphs. Between the first peaks there are 386 microseconds, between the second peaks the time cannot be determined, because the second peak of 20k did not work out. The first and second peaks may not reflect the correct information because subs develop peaks slowly. Therefore, let's look at the third peaks. There is a difference of 0.14 ms. But, if you take another microphone, even Umik-2, there will be no difference.

OK I got it, but that still doesn't tell me which of the delays is the correct one, I assume MSO will be working with that absolute value, so which one I feed to MSO?

 

[sm52]

so which one I feed to MSO?

To answer, you have to take 4 measurements. Left main, right main, near sub, far sub. All 4 with acoustic synchronization by, for example, the left main.

 

[JStewart]

To answer, you have to take 4 measurements. Left main, right main, near sub, far sub. All 4 with acoustic synchronization by, for example, the left main.

I think @Lid9497 has used MSO to already set the subwoofers as a group and at this point needs to set subs group to the mains.

I assume MSO will be working with that absolute value, so which one I feed to MSO?

If I’m correct with the first comment, the answer is neither of them. Use the Alignment Tool to align the phase of the subs and the mains at the XO that you would have taken your measurements with. The Alignment tool will provide the needed delay.

Here’s a couple of posts that may help if needed.

Post in thread 'Regarding multi-sub alignment, sub to main alignment and EQ set up'
https://www.avnirvana.com/threads/r...-main-alignment-and-eq-set-up.6107/post-45987

Post in thread 'MiniDSP Sub Setup'
https://www.avnirvana.com/threads/minidsp-sub-setup.6128/post-46617

And a lengthy thread if needed:
Thread 'REW Alignment tool - Guides or Manual?'
https://www.avnirvana.com/threads/rew-alignment-tool-guides-or-manual.6814/

 

[Lid9497]

I think @Lid9497 has used MSO to already set the subwoofers as a group and at this point needs to set subs group to the mains.



If I’m correct with the first comment, the answer is neither of them. Use the Alignment Tool to align the phase of the subs and the mains at the XO that you would have taken your measurements with. The Alignment tool will provide the needed delay.

Here’s a couple of posts that may help if needed.

Post in thread 'Regarding multi-sub alignment, sub to main alignment and EQ set up'
https://www.avnirvana.com/threads/r...-main-alignment-and-eq-set-up.6107/post-45987

Post in thread 'MiniDSP Sub Setup'
https://www.avnirvana.com/threads/minidsp-sub-setup.6128/post-46617

And a lengthy thread if needed:
Thread 'REW Alignment tool - Guides or Manual?'
https://www.avnirvana.com/threads/rew-alignment-tool-guides-or-manual.6814/

I meant what measurement range do I use for MSO for subs only optimization purposes, I am not using it for mains eq. Thx for the links, will read through.

 

[JStewart]

I meant what measurement range do I use for MSO for subs only optimization purposes,

It shouldn’t matter, but there’s no point in capturing a lot of noise. A few hundred Hz should be fine.
To verify all is working properly, use the make measurement from aligned sum button on the tool and then take an actual measurement. The two should be the same.