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Double Bass Graphic EQ

G

gypsydjango

Jul 9, 2009
460
71
UK
#1
Have any of you fellow bassist's had successful​
results in getting a nice, fuller sound using a graphic EQ?
I have a Gallien Kruger MB150s combo amp. and a 31 band graphic EQ.
My question is:
Having so many 'adjustments' on the graphic where is the best way to start '[DEL]twidling[/DEL]'? to bring out the best sound/tone from each string? Is there a chart somewhere for guidance on this? Your knowledge most helpful.
Mike
 
#4
klem.gote said:
I've never used a parametric EQ. I've heard they can be better for bass, but also harder to learn how to use. True? And if so why? Thanks.
Click to expand...

A graphic EQ is easier to explain, and easier to learn, because the positions of the controls allow the user to visualize the changes he's imposing on the signal. With a graphic, the range extending from about 20 Hz to about 20 kHz is divided into more-or-less equal "bands," each of which can be increased or decreased by raising or lowering a fader pertaining to a specific frequency band; the arrangement of the faders mimics a frequency response graph. The greater the number of subdivisions, the narrower the range controlled by each fader; some graphic Equalizers may provide only 6 to 10 bands, while others may provide 15 (two-thirds of an octave per fader) or 30 (one-third of an octave per fader); a graphic EQ that operates in the digital realm can offer many more subdivisions.

Instead of using faders, a parametric equalizer uses three knobs per band, which allow the user to (1) select the center frequency, (2) increase or decrease the amplitude of the signal in that range, and (3) select the "Q" [width/slope]. A typical parametric unit may provide 3 or 4 user-selectable bands. A semi-parametric EQ usually has unadjustable Q, and allows the user to adjust only the center frequency, and amplitude.

Using a parametric EQ requires the user to approach the task of equalization with a greater understanding of the concepts involved because the interface (three knobs) is less intuitive and more cognitive. Digital EQ often provides a graphic display that shows the effect your knob twiddling is having on the signal. I've never seen an analog rack-mounted parametric with a graphic display.

A parametric EQ enables the user to cut or boost narrow or wide slices of the frequency spectrum with surgical precision, and leaves adjacent frequencies relatively unscathed. The fixed bandwidth and center frequencies of an analog graphic EQ make far coarser adjustments, and the pre-selected bands and bandwidth may be too approximate to meet your needs.

Hope that helps :)
 
#5
Nice job, Jazzdog! I also prefer a parametric tone-shaping circuit. As for how to learn to use them effectively, perhaps this will help. An occupational hazard (or benefit) for me is being able to listen to the response of a system and identify quite well, by ear, the frequency region and magnitude of a peak or trough. With a bit of training, you can really enhance your use of those tone-shaping circuits.

For the geekazoids, the definition of "Q" (stemming from "quality factor" in the radio days) is center frequency/bandwidth. Graphic EQ circuits are typically designed with "non-constant-Q" filters. That means that as you increase the amount by which a band is boosted or cut, the Q changes. Specifically, the Q increases (the relative filter width narrows) as the amount of boost or cut is increased.
 
#6
drurb said:
Nice job, Jazzdog! I also prefer a parametric tone-shaping circuit. As for how to learn to use them effectively, perhaps this will help. An occupational hazard (or benefit) for me is being able to listen to the response of a system and identify quite well, by ear, the frequency region and magnitude of a peak or trough. With a bit of training, you can really enhance your use of those tone-shaping circuits.

For the geekazoids, the definition of "Q" (stemming from "quality factor" in the radio days) is center frequency/bandwidth. Graphic EQ circuits are typically designed with "non-constant-Q" filters. That means that as you increase the amount by which a band is boosted or cut, the Q changes. Specifically, the Q increases (the relative filter width narrows) as the amount of boost or cut is increased.
Click to expand...

Thank you, kind sir. One of the things I like most about my iAmp800 is the semi-parametric EQ. One of my pet peeves is equipment manufacturers who use vague terms, instead of numeric values, as labels for their EQ/tone controls.
 
#8
Parametric is definitely the ticket. You may want a broad correction for tone reasons, or a very narrow correction to kill that hot note that's driving you crazy (or even feeding back). Parametric can do either. Graphic EQ may fix the hot note, but it will also reduce the level of several notes on either side of it (if you are lucky and the hot note is right in the middle of a graphic band - if not - good luck!).
 
#9
Many thanks you guys for your fund of knowledge--as always great info. from you all. I bought the 31 band graphic EQ thinking that the more sliders you have would solve problems--but have learnt a lot from my thread question--bassically (No pun intended) a Parametric EQ
is the way to go.
Mike
 

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