"The clock adjustment is unusually high"

[cvanc]

Hi, is there anything in the attached files that can clarify what I'm doing wrong? I can not escape this error message no matter what I try. Thanks.

 

[John Mulcahy]

Everything looks OK. The clock adjustments are a bit variable, and per the message the adjustment for that last measurement is unusually high, but the measurement still looks good.

 

[cvanc]

The mdat was the exact same measurement repeated 3 times, BTW.

Might increasing the loudness of the fullrange timing ref speaker reduce my variability further? I can add a few dB to it.

To verify, I can proceed & ignore warnings of this type knowing the files are going to MSO?

... and thank you.

 

[John Mulcahy]

"exact same" meaning mic on a stand and no movement of mic or anything else in the room between measurements? There are substantial differences between the measurements, if the mic was in the same place for each they should be very similar.

 

[cvanc]

Please ignore my earlier mdat file, invalid channel routing had bass sweep + pilot tone blended together.

This one has correct audio routing and behaved better. I think I'm OK now but would appreciate your nod. I still need whatever magic timing tightness is needed to make MSO happy in a multi-seat multi-mic rig. Thanks so much and please have a joyous holiday season with family.

 

[John Mulcahy]

Measurements look OK assuming they are from different positions. I'm a little puzzled by the variation in clock adjustment, particularly since measurements 1, 4 and 5 are identical at -91.7 ppm but the others range from -51 ppm to -173 ppm.

Since you are measuring subs you could set the sweep end frequency to 300 Hz, everything above that is in the noise anyway.

 

[cvanc]

Still getting variation. Attached file is just me grabbing samples quickly with no changes at all. Took all of 90 seconds? Errors popped up with quite different values to complain about.

I've wiped & re-installed REW and turned HW acceleration off, I read that might help. No change.

You think I'm OK to grab fresh mic samples with things as they are? And again many, many thanks.


(System details here should you need them)
Mic is a UMIK-2
The system is 2.8 using two cascaded miniDSP boxes (SHD & Flex Eight)
SHD is the main unit; output crossover configured 2.2
SHD bass channels are sent SPDIF to the Flex Eight
Flex Eight is set for unity gain and is there only to hold 8 MSO correction tables
8 powered subwoofers spread all over the room

 

[John Mulcahy]

Those responses are all the same bar the noise floor, so that looks good. Not sure what is causing the timing variations, how is the SHD connected to the main speakers?

 

[cvanc]

I got it fixed.

All this gear is lashed up with a slightly ugly USB network. I went thru the whole thing with D5 & a swab and immediately was able to take the 24 samples I actually need with a consistent error of only ten. So... flaky USB seems to have been the culprit. I'm good to go. Thanks for checking in.

(I'd post the mdat for digestion but holy cow it's 35 Megs)

 

[John Mulcahy]

Interesting, good to find an answer.

 

[cvanc]

I've already washed my mic grabs thru MSO and loaded the results into my shiny new Flex Eight. All went smooth and it's sounding great.

OK, so I've got calibrated bass. I'll get used to this for a couple days, eyeball (uhhh... "earball"?) a main/sub level balance & then layer Dirac Live on top of the whole shebang. Should be fun.

Thank you again.