Q ?

H

HearClear2

New member
I just upgraded my mixer and i now have fully parametric mids.
I know how the sweeps work and I have no idea how to use the Q knob. From what I understand it can cut out freq. from 1/16 oct to 2 oct.
Can someone explain to me an average application for this control?
Thanks
Adam
 
I cant get too technical cause I dont know jack, but Ill give it a stab....

first, in case you dont know what Q is, it is how far of a range your selected boost will affect...say you want a 10db boost at 1k with a q of 2.....boost will start at 500hz(?) at 0db and go up along the frquency range until it gets to 10db at 1k and then starts going back down gradually until its down to 0db at 2k(?).....

how you apply it and what q you will need depends on what going on with the track....the best way to see how Q works and what it can do is to let a track play and select a frequency and give it a healthy boost and then move to q around from as low as possible on up and see how it affects the track....keep doing this with a few frequencies.....

and when you are really mixing and using EQ, just use your ears, experiment, sweep frequencies, play around with the Q to get the desired results you are after.....
 
Or. . . Q or Bandwidth gives you conrol over the width of a certain frequency you are boosting or cutting, to include more or less frequencies either side of the fundemental frequency. This is useful especially for notching (cutting) problem frequencies, where you can use the bandwidth to fine tune the group of frequencies being reduced.
 
Q

Q is a measure of the width of the bell-shaped curve -- the bandwidth as some might say. A low Q -- 0.3 is low -- will allow the EQ to cover a wide range of frequencies, while a higher Q -- 5 is high -- will allow you to home in on a particular feature of the sound.
 
Its the same as the bandwidth controll on you parametric eq. I think it will affect how wide of a freqency range you midrange controll will cover.
 
Good explainations so far. I will try to add a little to it.

I am on a little kick of drawing stuff up and scanning it to illustrate what I am talking about. I am no "graphics artists" so work with me here and don't laugh at my drawings! :)

Filters, known as EQ's, can of course effect, and will, frequencies above and below the "center frequency". Your "center frequency" is that which you select with the Freq. knob on the EQ.

Bandwidth, or Q, is how far above and below the "center frequency" is effected. Wide (see Figure 1 on the provided .jpg) in this case is set to 2 octave. Notice though that with a 1KHz "center frequency", that 500Hz and 2KHz are NOT being turned up as much as 1KHz is. So, it is importent to remember that yes, all the frequencies in that 2 octave range are being effect, but the farther away from the "center frequency" you get, the less that frequency is effected. So, turning up 1KHz with a 2 octave bandwidth 6dB doesn't mean that everything between 500Hz and 2KHz is being turned up 6dB. In fact, 500Hz and 2KHz in this case might only be turned up about .1 dB.

Narrow (see Figure 2 on the provided .jpg) shows that again, 1KHz is being turned up (let's say 6dB). But notice that the bandwidth is very narrow, so 500Hz and 2KHz are not effected at all. Like stated earlier, this is very useful for isolating and effecting a certain frequency.

Use Wide to effect a broad band of frequencies (remembering that the farther away from the "center frequency" you get, the less it is effected) and Narrow to effect a limited frequecy. Which you decide, or anything in between is totally up to you in regards to what you expect to accomplish with the equalizer.

Good luck.

Ed
 

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Like Squeezing a Balloon - when you gain you loose.

In the frequency domain Q indicates the bandwidth of a filter, as has been excellently explained here. But in the time domain, Q indicated the level of damping. Low Q means better damping. Hi Q means worse.

It’s like squeezing one end of a balloon. When you squeeze down the frequency range of the filter, the time it takes for the filter to ‘settle down’ blows up at the other end.

So, if you use a hi Q bandpass filter to boost a narrow frequency band, the notes in that band will ring out much longer than they are supposed to – i.e. they are smeared out in time.

The mirror image of this effect is when you use a hi Q notch (bandreject) filter to cut a narrow frequency band. In this case the low damping filter causes frequency response degradation (ripple) and transient degradation (time smearing) in the passband above and below the notch frequency.

EQ always degrades some of the detail of the track you are applying it to. Use it sparingly and push toward the lowest Q filter which will work for a particular application.

Unfortunately we never get something for nothing.

barefoot
 
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