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[PrinterPrinter]

Hello,
I'm using MC 21 on RPI and loving it.

I have two PEQ filters to reign in the sub i my 2 channel set up.

I use REW to calibrate my system and have a question about the relationship between PEQ filters and volume. For example,when I calibrate my system I put the internal volume on max and disable volume levelling - let's say I get 100db output for the measurements. Let's then say that REW recommends a PEQ filter - for example -10dB @ 60Hz. So now that frequency us 10% lower than the rest of the music - sounds good.

I add this filter and then turn on volume levelling and lower the volume a bit for normal listening, let's say it ends up at 70 volume. The PEQ still says -10db so now instead of having 10% less bass (@60Hz) I now have 14% less bass (@60Hz)?

My question is does the PEQ scale with volume? I suspect not. The bass sounds a bit lacking at lower volumes - I suspect because the EQ was set up at higher levels? Is the correct? did I miss anything?

Please share your thoughts,
Thank you!

[mattkhan]

you need to distinguish between using EQ to handle room issues and using EQ for "loudness" compensation; the former is linear, the latter is not. It sounds like you're referring to the former via your use of PEQ and hence there is no issue to be concerned about. At either level you have cut by 10dB to address a 10dB peak so you have reduced the energy put into the room in the direct signal to compensate for the excess energy "stored" by the room. At either level, the result is the same.

However your last line refers to the latter which is where things like audyssey dynamic eq (or other forms of dynamic loudness compensation) come into play.

[mwillems]

Additionally, your use of percentages suggest you might not understand the way audio "scales."  Decibels use a logarithmic scale because our ears (generally) perceive sound intensity logarithmically.  

A 10dB reduction from 100dB is not a 10% reduction it's a tenfold reduction: 90dB has about 1/10 the energy of 100dB.  But the reduction from 70dB to 60dB is also a tenfold reduction: 60 dB has about 1/10th the energy of 70dB, and so on all the way down.  As Matt noted, all ten dB reductions will result in the same proportional reduction in energy because the scale is logarithmic.

You may perceive the sound slightly differently because of the equal loudness contour (which is what Matt means by "loudness compensation"), but that's a separate issue, and JRiver does offer a loudness compensation DSP option to address that exact issue.

[PrinterPrinter]

OK guys,
Thanks.

So I can assume that the PEQ scales with volume level?


Maybe I'm just clueless ;-)

Here are my measurements:


The dark green line is the speakers without the sub. The golden line is the sub without EQ (I've optimised placement and the sub controls as best as I could). Lastly, the light green is the RTA after EQ - it looks ok, I think.

My understanding - maybe I'm wrong - is that with lower volume the bass peaks I'm looking to tame would be lower and so the PEQ needs to be less aggressive, but if I understand you correctly I shouldn't worry about it?

Thanks for the help!

[fooze]

My understanding - maybe I'm wrong - is that with lower volume the bass peaks I'm looking to tame would be lower and so the PEQ needs to be less aggressive, but if I understand you correctly I shouldn't worry about it?

Yep, you're wrong. Turn the volume on your system down a bunch and re-run your measurements, the EQ you need will come out the same. What's happening is the way the speakers interact with the room does not change with volume, but it will sound different to you because your ears and brain respond differently at different volume levels (the equal loudness contour or Fletcher-Munson curves).

[PrinterPrinter]

Thanks People,
That's helpful feedback. Really appreciate your help.