[Dragunov-21]

I was hoping someone could help me understand the Q-Value in parametric EQs.  I know larger values correspond to wider frequency bands affected by the gain/suppression you specify, but how are the frequency ranges calculated from the values you set (0.5-6.4 on my Rockboxed Clip+)?  I've tried finding the info myself, but apparently my google-fu isn't good enough...
 
Basically, I've been trying to equalise my SCL2s, and have identified the following peaks:
 
10500-7500Hz, peaking at 8800

6000-3700Hz, peaking at 5000

1000-450Hz, peaking at 850/930
 
The Rockbox EQ allows you to specify Gain, Peak and Q settings for Low Shelf, High Shelf, and three peaks.
 
So I've set the peak frequencies to 890, 5000 and 8800Hz, but what values should I set for Q, for the 650, 2300 and 3000Hz ranges?
 
Cheers in advance for any help
 

 

[Dragunov-21]

Nevermind, just found some conversion formulae...  Ain't it always the way...
 
On the other hand, now I don't have to be corrected on my larger Q = larger frequency comment.
I guess this thread can die now... unless someone can tell me how to work out octaves from Hz? ~pretty please~

 

[Ham Sandwich]

If you have a desktop media player that can support VST effects (like Foobar) you could try one of the various parametric EQs that display a graph of the EQ curve.  That will allow you to see how wide various Q settings are and what the resulting curve looks like.  The question would be whether the VST EQ uses the same Q curves and shapes as the Rockbox EQ.  I don't know the answer to that.
 
One of the VST parametric EQs you could try would be something from DDMF.  The demo ones would be enough for you to get the info you need.