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Author Topic: Low shelf filter setting in pEQ  (Read 4244 times)

harlington

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Low shelf filter setting in pEQ
« on: April 07, 2014, 12:46:24 pm »

Hi there,
I would like to apply a 3db low shelf filter for bass center at 55hz and do not know what Q value to enter. Can someone help explaining the Q value here? With graph would be very helpful. Thanks.
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mwillems

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Re: Low shelf filter setting in pEQ
« Reply #1 on: April 07, 2014, 01:17:33 pm »

Hi there,
I would like to apply a 3db low shelf filter for bass center at 55hz and do not know what Q value to enter. Can someone help explaining the Q value here? With graph would be very helpful. Thanks.

The Q reflects how quickly the shelf rises as frequency decreases.  Higher Q rises faster, lower Q rises more slowly.  The DSP module ignores Q's higher than 1 for shelving filters (1 is the highest supported Q for a shelving filter in MC right now).

Check out this thread (the linked post has an illustration): http://yabb.jriver.com/interact/index.php?topic=86791.msg594451#msg594451
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mojave

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Re: Low shelf filter setting in pEQ
« Reply #2 on: April 07, 2014, 02:07:03 pm »

If you have Excel, you can download the Biquad calculation spreadsheet from the miniDSP website and click the lowShelf worksheet. You can enter in your frequency, Q, and gain and it will show you exactly what is happening.

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mojave

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Re: Low shelf filter setting in pEQ
« Reply #3 on: April 07, 2014, 02:17:16 pm »

Another way that might even be easier is to download the trial for Voxenglo GlissEQ and install the VST plugin in DSP Studio. Then you can model the filter right from within JRiver. The control B/W is the same as Q. You can even activate the plugin and test settings before using them in Parametric Equalizer. The audio cuts out every 30 or 60 seconds with the demo, but that isn't an issue when testing settings.
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harlington

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Re: Low shelf filter setting in pEQ
« Reply #4 on: April 07, 2014, 02:27:11 pm »

Thanks for all the helpful replies. So with Q value of 1 max is allowed with jriver MC,  if I set it to 1, is it a fast or slow rise?  Thanks. I will read the link.
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mojave

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Re: Low shelf filter setting in pEQ
« Reply #5 on: April 07, 2014, 03:25:39 pm »

I mentioned that the control B/W is the same as Q. They both refer to the slope, but the numbers aren't interchangable. Use this calculator to convert from Q to B/W.

A Q of 1 has a faster rise than less than 1.

Here are a Q of 1 (B/W 1.38) and Q of .5 (B/W 2.54)
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nwboater

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Re: Low shelf filter setting in pEQ
« Reply #6 on: April 07, 2014, 05:46:07 pm »

Another way that might even be easier is to download the trial for Voxenglo GlissEQ and install the VST plugin in DSP Studio. Then you can model the filter right from within JRiver. The control B/W is the same as Q. You can even activate the plugin and test settings before using them in Parametric Equalizer. The audio cuts out every 30 or 60 seconds with the demo, but that isn't an issue when testing settings.

Thanks very much for this great idea. At your recommendation I bought this a few years ago before MC had it's own great PEQ. So I just fired it up again and had forgotten how helpful the visualization is in determining PEQ settings of all kinds. I guess for the pro's that work with this stuff all the time they don't need such graphics. But for many of us that do it rarely this is a huge help.

Also a big thanks for the link on the the B/W to Q calculator.

In closing I hope that someone from JRiver will follow this thread and realize what a big aid the graphics is. It would be a great addition to MC.

Cheers,
Rod
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harlington

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Re: Low shelf filter setting in pEQ
« Reply #7 on: April 07, 2014, 07:00:37 pm »

Thanks. I will try a 60hz LS with 1Q.
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