AVR crossover settings when using ASIO

BJB

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I just want to verify that my understanding about crossover settings are correct when taking measurements and generating a PEQ for a MiniDSP 2X4 HD. I saw an old post on this but they were not using ASIO and I am.

For subwoofer only measurements if I am using ASIO and HDMI 4/LFE channel, am I correct that I should set my AVR LFE crossover to the highest possible frequency when running a 15Hz to 300Hz sweep so the crossover has no impact? So this would be for Gain matching, polarity, alignment, and an REW measurement which I will use to generate a PEQ for the subs for the MiniDSP 2X4 HD.

Then when running a new measurement (after the PEQ is loaded) on the left, right and then sub with the intention to overlay the charts in order to see how the crossovers and EQ are working and interacting, for that sweep I would want to set my AVR crossover set as normal for LFE so probably 120hz. Also, my understanding is my AVR sub/mains crossover can be left at 80hz for all of this as it is not being used when I send the sub a sweep on LFE HDMI 4.

The only other crossover question I have is the setting in REW "target settings" for the sub to generate the PEQ *without* a house curve. Some say to choose sub and if not wanting a house curve set the slope to zero, others say just choose "none" for speaker type. Perhaps they give the same result but wanted to check.

When generating a house curve my understanding is I would use my AVR crossover for the mains/sub (80Hz) in the Crossover cutoff box in REW.

Thanks,
BJB
 

John Mulcahy

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Measure the sub with the crossover setting it will have when redirecting bass from the mains, so 80 Hz, and use 80 Hz as the crossover setting for the sub target. Adjust the target LF cutoff and LF slope to match the measured sub response. You don't mention which version you are using, the 5.20 beta version have a separate check box to control whether a room curve is added, for 5.19 set the slopes to zero.
 
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BJB

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Measure the sub with the crossover setting it will have when redirecting bass from the mains, so 80 Hz, and use 80 Hz as the crossover setting for the sub target. Adjust the target LF cutoff and LF slope to match the measured sub response. You don't mention which version you are using, the 5.20 beta version have a separate check box to control whether a room curve is added, for 5.19 set the slopes to zero.

Thank you so much for your quick reply!

I am using the most current version but although familiar with audio mixing, a newb when it comes to REW so sorry for the follow-up questions. Thank you for the house curve checkbox reminder. I am also trying not to confuse the measurement settings for REW and AVR from the target/curve generation settings which I was doing for a while.

"Measure the sub with the crossover setting it will have when redirecting bass from the mains, so 80 Hz..." So set my LFE crossover to 80Hz in my AVR when taking measurements via HDMI 4 if I understand correctly as that is the crossover I will use with my mains. Hopefully my LFE crossover is the same order as my sub/main crossover in the AVR.

"...and use 80 Hz as the crossover setting for the sub target" - I believe this relates to setting my target curve for creating my PEQ file from the above measurement. So in the "target settings" box choose "subwoofer" and 80Hz for the crossover which is my usual sub/main crossover (assume AVR is 12 dB/octave). Could I possibly be getting this? :)

"Adjust the target LF cutoff and LF slope to match the measured sub response." This also relates to my target settings so I need to look at my raw measurement graph and see how far down my sub really goes to determine the LF cutoff (I think mine is spec'd at 20Hz). As far as the LF slope, try to match the general shape of my sub response?

Thanks again, hope I got all the above right. Your answer was great, my understanding is the issue.

BJB
 

John Mulcahy

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Yes, all good. A more fiddly alternative is to use the L/C/R outputs when measuring but disconnect the relevant main speaker for the sub response and vice versa.
 
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