Playback volume impact on room correction

[guyinoz]

Hi, I am thinking of getting a Dirac live based room correction processor. I noticed the instructions say do correction in certain dB level (say 75 dB as measured by REW at listening spot) . I fiddle a lot with my volume on my integrated amp or DAC specially when listening to streaming services. So if that changes the SPL to say 60 dB or 85 dB does that negate the room correction which was done at 75 dB ( maybe because phase or amplitude distribution has changed across the spectrum ?)

Sorry if novice question but I couldn’t find an answer

 

[Wombat]

I would think that clad walls and other room items would have frequency and level dependant absorptive, reflective and resonant qualities.

Does DSP address it all? Good question.

 

[ernestcarl]

Well, it shouldn't... unless you increase the volume high enough (to run out of headroom), or decrease the volume low enough e.g. 55dB and below

Sometimes peaking EQs (if gain is set high enough) can excite stuff in your room causing you to hear audible resonances you previously haven't noticed before.

 

[guyinoz]

Well, it shouldn't... unless you increase the volume high enough (to run out of headroom), or decrease the volume low enough e.g. 55dB and below

Sometimes peaking EQs (if gain is set high enough) can excite stuff in your room causing you to hear audible resonances you previously haven't noticed before.

Great thanks so much. Appreciate the answer.can you point out where my logic was flawed specially in thinking correction was different at different dBs.

 

[ernestcarl]

I you have a calibration microphone like UMIK-1, download and install REW. Take measurements sweeps, say, from 45-100 dB at 5dB increments (use some smoothing) with all your PEQs engaged. You might see some compression or deep notches develop as you reach either end of said SPL extremes. Distortion also will significantly rise above, say, 90-95dB...

Just an older image for illustration:

You can see some compression in the sub bass region above the red line. If I remember correctly I don't believe I have used EQ here. But say, if I added a +12dB peak PEQ at around 30Hz or 40Hz, you would likely see compression as you increase the volume. And if you add negative gain, say, -6dB or more at some point, as you lower the volume enough, this could cause a deeper notch to develop.

...

 

[guyinoz]

Great thanks so much. Appreciate the answer.

I you have a calibration microphone like UMIK-1, download and install REW. Take measurements sweeps, say, from 45-100 dB at 5dB increments (use some smoothing) with all your PEQs engaged. You might see some compression or deep notches develop as you reach either end of said SPL extremes. Distortion also will significantly rise above, say, 90-95dB...

Just an older image for illustration:
View attachment 37516

You can see some compression in the sub bass region above the red line. If I remember correctly I don't believe I have used EQ here. But say, if I added a +12dB peak PEQ at around 30Hz or 40Hz, you would likely see compression as you increase the volume. And if you add negative gain, say, -6dB or more at some point, as you lower the volume enough, this could cause a deeper notch to develop.

...

View attachment 37517

View attachment 37518

Excellent explanation. Thanks so much for taking the time and effort to do this.

 

[ernestcarl]

Excellent explanation. Thanks so much for taking the time and effort to do this.

No problem!

Just so you know, I don't use Dirac anymore so I wouldn't really know how much EQ it applies. But you need to take into consideration what speakers you use as some will simply not tolerate that much EQ before distortion becomes apparent.

Here's the EQ I most currently use for the KH120:

And here's the effect at the listening position:

Low enough that it's not really audible to me.