Compare Decay

[tjcinnamon]

Is there a good way to compare decay times across two (or more) measurements?

 

[sam_adams]

Use the Overlays window and select the RT60 graph. It will display the selected Topt measurements:

The black line is the average between any selected measurements.

 

[tjcinnamon]

Use the Overlays window and select the RT60 graph. It will display the selected Topt measurements:

View attachment 63160

The black line is the average between any selected measurements.

I was using the wrong view. This is helpful!

What should I have the settings at? Filter order, Forward filtering, etc..

 

[John Mulcahy]

Forward filtering, order 6 would be the usual settings.

 

[tjcinnamon]

Forward filtering, order 6 would be the usual settings.

My RT60 on the overlays only goes back to 45Hz but my measurement starts at 10Hz. Is that normal?

 

[John Mulcahy]

Yes, the lowest 1/3 octave filter centre is 50 Hz. To see lower frequency behaviour, which is very much in the modal region where RT60 isn't really a valid measure any more, use the waterfall, spectrogram or RT60 Decay graphs.

 

[tjcinnamon]

Looks like I can't EQ my way out of a lower decay time (very well). Any other strategies? Or is phase cancellation the way to go.

 

[John Mulcahy]

Looks like I can't EQ my way out of a lower decay time

Can you explain what you are trying to do? The decay times above the low end are determined by the room's absorptions. At lower frequencies individual modal resonances will have a strong influence, countering them can help lower the decay in that band but if you want the room to be livelier you will need to alter the surfaces in the room.

 

[tjcinnamon]

Can you explain what you are trying to do? The decay times above the low end are determined by the room's absorptions. At lower frequencies individual modal resonances will have a strong influence, countering them can help lower the decay in that band but if you want the room to be livelier you will need to alter the surfaces in the room.

For bands below 120Hz (namely 30Hz which has the longest decay), I'm looking to try and roll my own Dirac ART to counter act that resonance using a speaker dedicating to cancel the problematic driver. I have 4 subs and will soon have 5. I can safely dedicate one with a MiniDSP to cancel/mitigate the problematic bands (if I can figure out how to do it).