# 6 band EQ mods for bass?



## ficelles (Apr 2, 2021)

Building the 6-band EQ and wondering about mods to make the bands a little more bass-friendly... maybe take band 1 down to 50Hz etc. Any suggestions based on cutoff frequency calculation for the filters?


----------



## Feral Feline (Apr 13, 2021)

BUMP!

Still no suggestions for this?

I'd look at a broad selection of bass EQs to see what's already being done and make a decision based on the aggregate, my intuition and some calculated points that avoid steppin on the toes of other players' instruments' freqs...


----------



## bifurcation (Apr 13, 2021)

I mean, obviously you want to shift some controls more into the lows and in particular in the low mids. You absolutely want a control on 100hz. Back in my recording engineer days, we called 100hz "mud," you always inevitably wanted to dip a little 100hz for clarity.

5Khz is often associated with "sparkle," but it can fatigue the ear _(A common problem is engineers turning up the 5K on hat and cymbals, then an hour later thinking they sound flat, turning it up, etc etc until your mix is a brittle mess.)_ Tiny bumps to 3K can accomplish a similar brightness to bring out the metal in yer bass strings, if that's your thing.

Even with the warning in the mid-range _(800hz to 2.5Khz)_ with your chart above, you probably want to to pop or cut a little honk in yer bass sound.

All of which it to say it kinda depends on what yer tone goals are. Are you looking for metal bass? Jah Wobble? Versatility?

The generic 7-band bass graphic is usually: 50 - 120 - 400 - 500 - 800 - 4.5k - 10k  (but that 10K is fucking useless)

For *versatility*, I'd start at mebbe: 40 - 90 - 250 - 550 - 1500 - 4.1k  _(YMMV)_

But if you really wanna get *your* sound, either breadboard or socket those two capacitors on each band, use a filter calculator and tweek each and play through it. (I think most of your tweeking will be in the 250hz to 1500hz range.)

For reference:

Boomy (40 Hz – 90 Hz)
Fat (75 Hz – 150 Hz)
Thin (40 Hz – 180 Hz)
Power (40 Hz – 150 Hz)
Impact (40 Hz – 150 Hz)
Clarity (190 Hz – 800 Hz)
Presence (800 Hz – 6.5 kHz)
Attack (120 Hz – 4.1 kHz)
Hope that helps.


----------



## Chuck D. Bones (Apr 25, 2021)

A note of fiddling capacitors: for a given band, make the same % change on both caps, otherwise you will alter the Q of the filter.  Doubling both caps moves the center freq down an octave, halving both moves the center freq up an octave.


----------



## Fantasticky (May 23, 2021)

Chuck D. Bones said:


> A note of fiddling capacitors: for a given band, make the same % change on both caps, otherwise you will alter the Q of the filter.  Doubling both caps moves the center freq down an octave, halving both moves the center freq up an octave.


Hey Chuck. Agreed on the calcs for frequency shifts. I made a MS Excel formula to plug and play resistors and caps to target freqs and the right “Q” on another build. However, I have a question on the schematic of the 6 band eq pedal. My experience is limited on this design, was hoping to tap your knowledge. I understand  how they achieved the IC1.1 pot 3 (400hz), IC1.4 pot 1 (100hz), IC2.2 pot 2 (200hz), IC2.3 pot 4 (800hz), IC2.4 pot 5 (1600hz) but how did they achieve the (3200hz)? Was it set as an initial range limit from IC1.3 and attenuated by Pot 6 from R20 (1.2k)  C16 (68n) ? If so, I would like to raise it to the 6k band, what do you recommend I do based on this ? Thank you for your time in this matter.


----------

