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More => Old Versions => Media Center 16 (Development Ended) => Topic started by: justsomeguy on March 09, 2011, 07:29:11 pm

Title: Not sure parametric EQ is working right.
Post by: justsomeguy on March 09, 2011, 07:29:11 pm

I've been playing with the parametric eq a little today and am not sure the results are correct. I have downloaded and installed a VST plugin "EasyQ" from here http://www.rs-met.com/ (http://www.rs-met.com/) that Lunatique suggested in another thread as it has a graphical interface. What I've been trying to do is get settings from EasyQ and translating them into MC EQ. For example I set EasyQ to a center freq:20kHz gain:8db and bandwidth:2.00 octaves (just as a test) and hear a noticeable change in sound. I then set MC eq to 20kHz 8db and .667 Q (which is the equivalent to 2 octaves). When I switch between using the two different EQ's it is obvious that the MC eq is much less pronounced, like either the gain isn't right or maybe the bandwidth is wrong.

I would like to use the new MC eq as I'm guessing it may be of higher quality? I'm not sure of this as I don't know how the processing is done internally in EasyQ and how that compares to MC. Any ideas?

Title: Re: Not sure parametric EQ is working right.
Post by: Matt on March 09, 2011, 07:42:41 pm

You might try the Analyzer DSP to see the change.  Play pink noise (make with Media Editor) or play with Room Correction > Test Tone.

Let us know if you learn anything.

Title: Re: Not sure parametric EQ is working right.
Post by: justsomeguy on March 09, 2011, 08:28:14 pm

Ok did a quick test with those settings and here are the results....

URL removed, bad site.

MC eq...
URL removed, bad site.

EasyQ...
URL removed, bad site.

Something is obviously not right with the bandwidth in the MC eq.

Title: Re: Not sure parametric EQ is working right.
Post by: justsomeguy on March 09, 2011, 08:53:13 pm

Here is the same setting but at 10kHz....

MC eq...
URL removed, bad site.

EasyQ...
URL removed, bad site.


here is at 1kHz...

MC eq...
URL removed, bad site.

Easyq...
URL removed, bad site.

You can still see the slope on the 10k is too steep at least on the right side of the curve, left side looks like it may be right..
The 1k it looks pretty close.

Title: Re: Not sure parametric EQ is working right.
Post by: Matt on March 10, 2011, 01:02:11 pm

Thanks for the screenshots.

The issue is that the equalizer filter we're using will always have a gain near zero at the Nyquist frequency (half the sample rate).  This means the slope on the right side will flatten a little as you approach those high frequencies.

For now, the solution is to use a higher sample rate in DSP Studio if you want to make adjustments.

I'm looking into using a filter that stays more natural near the Nyquist limit.