UM1-K has arrived - now to get started, but sweep and moving mic measurements don't line up.

[Erici]

If you want feedback on measurements, it works best to click the capture icon (small camera) at the upper left of the display window to get a screenshot that will display all the information....

 

[antcollinet]

So - a mixed bag so far. EQ at the desk position has worked really well. Since then I've been trying to do the same for my listening position (other side of the room)

Still using MM Method.

But a low frequency peak is made significantly worse after EQ. I've tried quite a few variations, including extending filter range down to 20Hz from the 35 I was using previously. Screenshots:

1 - EQ for left channel (which seems to be the worst). Showing FR, Predicted and Target with Filters.
2 - FR before (red) and after (purple) EQ. Problem seems to be post EQ spike at 48Hz

Results are more or less repeatable. I guess I'm doing something stupid, but not sure what.

(Note - filters are being exported as WAV and used in LA convolver AU plugin in Soundsource on a mac)

 

[antcollinet]

I could add a manual filter at 48Hz? Filter list is:

 

[Jdunk54nl]

Your scales are all different on the x-axis making these very hard to compare.

 

[antcollinet]

Your scales are all different on the x-axis making these very hard to compare.

I can improve if needed, but I was hoping comparison between the two was not needed, due to the pre EQ FR plot being on both charts.

Hang on though...

 

[Jdunk54nl]

Which one is pre and which one is post? Include that information in the chart or above each chart.

 

[antcollinet]

Hopefully this is better. Still learning this stuff.

Green is target plus filters
Red is Pre EQ and predicted after (lower plot is predicted - sorry couldn't work out how to get two colours.)

Green is pre EQ, Blue is Post EQ

 

[Jdunk54nl]

Two guesses, and that is really what they are...
1) When you export/enter the filters something isn't getting entered correctly.

2) 48hz is a room mode and that other peak at ~75hz (like 1.5 octaves up) was helping slightly cancel it out. Now that you have cut it, the room mode can excite more.

 

[antcollinet]

I like your room mode guess (Mainly because there is nothing I can do to fix point 1 - it is literally export wav file, import into convolver.

I'll try a manual 48Hz filter. Costs nothing to see what happens.

That is for tomorrow though. Bedtime here.

Thanks for looking - it is very much appreciated.

 

[Jdunk54nl]

Try entering the filters manually in convolver and see if you get the same results.

 

[antcollinet]

Interestingly - wavelength of 48Hz is just over 7m which is about double the length of my room. 1 half cycle therefore fits across the room length. I think I might have a resonance/standing wave.

 

[antcollinet]

So I finally got to it.

49Hz
-7dB
Q : 4

Both channels fixed it. Started with -9dB then -6 before settling on -7 as seeming to kill the boom without killing the bass.

I might try another EQ, but with the partial port bungs back in. I'll wait for the new amp though before second pass.