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[darkheart]

I have tried values from 1 to 10 and they all look the same after measuring the result with measuring microphone.
Please solve this problem!

[Matt]

The Q value is not used with a low-pass or high-pass.

You can pick 12 dB, 24, 36 or 48 as the slope.

I'll put it on our list to make this more clear in the user interface.

[mwillems]

I have tried values from 1 to 10 and they all look the same after measuring the result with measuring microphone.
Please solve this problem!

To add to what Matt said, I just looked and there's not even a Q setting box under the high and low pass filters, could you be looking at the high and low shelf filters instead?  If so, it's odd that there's no difference in measurement when you change the Q (unless you didn't specify a decibel offset, in which case that's your answer).  

Matt's right though, the high and low pass filters ("Remove High/Low Frequencies" towards the bottom of the list) work well (I've measured them) and don't have adjustable Q (just a choice of four slopes).

[darkheart]

To add to what Matt said, I just looked and there's not even a Q setting box under the high and low pass filters, could you be looking at the high and low shelf filters instead?

Yes, sorry, I thought about high/low-shelf, but wrote about HPF and LPF. I was trying to achieve a steep -6db high-shelf using values greater then "1". I have also tried to simulate a third order crossover using high/low-shelf filters without success.

Topic title edited.

[Matt]

Q is limited to a maximum of 1.0 for high and low shelf filters.

With this form of IIR shelving, anything over 1.0 is not stable, or at least not monotonically increasing or decreasing.

[mwillems]

Yes, sorry, I thought about high/low-shelf, but wrote about HPF and LPF. I was trying to achieve a steep -6db high-shelf using values greater then "1". I have also tried to simulate a third order crossover using high/low-shelf filters without success.

Topic title edited.

Out of curiosity, why does DSP studio let you enter higher Q's if they're not effective? 
  
I did a good bit of measuring, but only with shelves below 1 Q, so they measured correctly, but there's no way to know (from inside JRiver) that higher Q shelves don't work without measuring and finding out.

EDIT: Did they used to function at higher Qs, but it was just too unstable to leave in?  I could've sworn I read about someone approximating a 3rd order crossover with the shelving function successfully.

[darkheart]

I use JRiver DSP equalizer filter with Q of 3 as -6db notch filter @250hz and it works perfect. So Why high/low-shelf filter would be different?

[Matt]

The Q value is not used with a low-pass or high-pass.

You can pick 12 dB, 24, 36 or 48 as the slope.

I'll put it on our list to make this more clear in the user interface.

The Q is no longer settable when picking low or high pass.  So I think this has been addressed.

[mwillems]

The Q is no longer settable when picking low or high pass.  So I think this has been addressed.

I think the concern was the the high and low shelf filters, not with high and low passes (the terms got a little snarled up above).  Currently DSP studio allows you to assign Q's higher than 1 for shelves, but you indicated above (and my previous measurements confirmed) that JRiver ignores any Q value larger than 1.

Customizable Q's for the shelves are great, and I hope they're not going away.  I just thought it might be worth making it clear in the interface that anything above 1 will be ignored (or don't allow values greater than 1 to be entered in the field).

[Matt]

Customizable Q's for the shelves are great, and I hope they're not going away.  I just thought it might be worth making it clear in the interface that anything above 1 will be ignored (or don't allow values greater than 1 to be entered in the field).

There's no way to marshal what number gets entered.  So a user is free to enter 2 or 3 or 300.

I can't think of an easy way around this.

[mwillems]

There's no way to marshal what number gets entered.  So a user is free to enter 2 or 3 or 300.

I can't think of an easy way around this.

Maybe just explain it in the UI: some text in the interface next to the Q setting making it clear that numbers larger than 1 are ignored?  

As it is unless you measure you'd never know that your 2Q shelves weren't working as planned (and might spend considerable time trying to figure out what's going wrong even if you do measure).

[Matt]

Maybe just explain it in the UI: some text in the interface next to the Q setting making it clear that numbers larger than 1 are ignored?  

As it is unless you measure you'd never know that your 2Q shelves weren't working as planned (and might spend considerable time trying to figure out what's going wrong even if you do measure).

Fair enough.  Next build:
Changed: DSP Studio throws a warning when a Q value greater than one is entered into a shelf filter (and switches back to 1).

[mwillems]

Great news!  Thanks a bunch