# Help me understand eq'ing...???

Discussion in 'Amps and Cabs [BG]' started by rayzak, Aug 17, 2005.

1. ### rayzak

Jan 13, 2001
Louisville, KY
For example:

Bright: +5dB >4kHz shelving
Treble: +/- 13dB @ 4kHz shelving
High Mid: +/- 14dB @ 800Hz peaking
Low Mid: +/- 14dB @ 400Hz peaking
Bass: +/- 18dB @ 40Hz shelving
Deep: +6dB <100Hz shelving

The above may as well be written in brail because I have no understanding of it. Shelving, peaking, etc.
Some are passive eq's some are parametric eq's.... overwhelming to me.
I know how to fiddle until I get a sound I like, but it sure would be nice to know what the hell i'm doing.
Any help is appreciated.
Thanks.

2. ### PilbaraBass

+/- xx dB = cut and boost (xx is the range)
+ xx dB = boost only

shelving = filter is shaped like a "shelf"
peak = filter is shaped like a "peak"

high and low pass filters are "shelving" filters and pass frequencies above a threshhold (high pass) or below a threshhold (low pass)

band pass filters are "peak" filters with the "peak" being the centre of this peak.

the "kHz" thing is the frequency in which these "peaks" and "shelves" occur.

combining all these filters together in various combinations and various amounts of boost and cut, creates a way in which your signal level can be filtered or "EQ'd" according to frequency response and thus give your sound certain characteristics like "bassy" or "boomy" or "trebly" or "mid-rangy"

it is analogous to playing with the "tint" button on your TV...the basic picture is the same, but the colours (in this case, tones) are different.

3. ### PilbaraBass

passive eq's work on RC (resistor capacitor) circuits and have no amplification, hence they can only cut signal

active eq's work on RC circuits combined with signal amplification, hence boost and cut is available.

parametric eq's have the ability for the peak frequency to be moved or "swept" in addition to the boosting and cutting of signal.

Now that you know all of this..."fiddling" is still a good thing.