What is Q ?

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grimtraveller

grimtraveller

If only for a moment.....
Could some of you please describe exactly what 'Q' is and how it's applied {if that's the word} ? In plain simple language that a 9 year old could understand. All the explanations I've come across thus far seem to require a Masters degree in deep space interplanetary excavation and a torrid affair with a Phd in medieval linguistics to grasp. And I'm none the wiser.......
 
Q is the steepness of the curve. So a high Q is a steep curve (thin bandwidth) and a low Q is a mellow curve (wide bandwidth).

G
 
Q is said to be omnipotent, and is continually evasive regarding his motivations.
His home, the Q Continuum, is accessible to the Q and their guests, and the true nature of it is said to be beyond the comprehension of "lesser beings" such as humans so it is only shown to humans in ways they can understand.
 
Steenamaroo said:
Q is said to be omnipotent, and is continually evasive regarding his motivations.
His home, the Q Continuum, is accessible to the Q and their guests, and the true nature of it is said to be beyond the comprehension of "lesser beings" such as humans so it is only shown to humans in ways they can understand.
Click to expand...

Nerd. Sorry, couldn't help myself.
 
Q refers to filter quality, as in steepness, probably because the ideal filter would have infinitely steep slopes and the closer you got to the ideal the higher the "quality" of the filter. In peak/dip filters higher Q equals narrower bandwidth.
 
I was just about to come in and say the word quality.

But I got beat. :(
 
sometimes a Q of 2.0 means it covers two octaves, other times it's just a random number...but sometimes low number Q is a really narrow EQ, other times a high number Q is a really narrow EQ. No matter what the numbers represent, it all does the same thing, you'll just have to mess with each EQ.

Grimm, you use Reaper right? I know ReEQ 1.0 means one octave, 2.0 two octaves etc...
 
aaronmcoleman said:
sometimes a Q of 2.0 means it covers two octaves, other times it's just a random number...but sometimes low number Q is a really narrow EQ, other times a high number Q is a really narrow EQ. No matter what the numbers represent, it all does the same thing, you'll just have to mess with each EQ.

Grimm, you use Reaper right? I know ReEQ 1.0 means one octave, 2.0 two octaves etc...
Click to expand...

Using "Q" with a higher number to mean a wider filter is wrong, plain and simple. This is established and well defined scientific terminology regardless of how things may be mislabeled on a consumer product. Probably some marketing idiot thought Q sounded cooler than width and had the label changed without changing the numbers to match.

But it's helpful to know how different products are labeled even if they are wrong.
 
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Mass confusion like this is why I never speak in terms of Q. I just say "wide" or "narrow".

Try a narrow cut at blah blah blah

Doa wide boost at whatever.

Pretty simple.
 
Who is Q...?

The original Q:

q.webp

The modern Q:

Cleese.webp

The universal Q:

Q-Tips-q-star-trek-11220978-676-572.webp
 
The 9 year old that grasps most of that has my eternal, undying admiration ! :D
 
As Q himself says, "It's hard to work in a group when you're omnipotent".

However, what the others have said is right: in practical terms, Q is a measure of the steepness of a filter used for equalisation--and the higher the number, the steeper the filter.

Actually, the maths for working out the Q isn't all that tricky. It's to do with the centre frequency of the filter and the frequencies above and below this where the change is 3dB less than the maximum.

Say your equaliser is set for a +6dB boost at 1000 Hz and the points where the boost is only 3dB are 800 Hz and 1800 Hz. The formula is to take the higher 3dB point and subtract from it the lower 3dB point. In this case, it would be 1800-800 which equals 1000. You then divide the centre frequency by that number, in this case 1000/1000 which equals 1 so the Q of this filter is 1.

Then consider a steeper filter. Let's say it's the same 6dB boost at 1000 Hz but this time the -3dB points are at 1100 Hz and 900 Hz. The maths here would be 1100-900=200. Then divide the centre frequency (1000 Hz) by 200 and you get a Q of 5.

I always think of high Q parametrics as scalpels to perform detailed surgery on a certain problem. Lower Q filters are better to provide subtle boost or cut on a much wider range.

...but then I don't work well in groups!
 
"Q", is the 17th letter in the English alphabet, preceded by P and followed by R.
 
He is that guy that makes all of those cool devices for Bond - James Bond.
 
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