hi everybody,

have been doing research about transveral constant Q topology and so far i have not been able to have difinitive explanation of this kind of circuit like what major parameters to consider in designing and its accompanying formulas to use. i know it involves formulas for high/low pass filters, but there is some aspect like the Q & K factors which beclouds my knowledge about filters.

this is not a new techno but it has never gained popularity since it cost so much to build. basically am very much impressed with this techno.

so any guys out there that have stumbled on any site or maybe books to consider, pls help out.

am planning to build a 30 band 1/3 octave graphic EQ. so far there are only two US company that makes this EQ and they are not willing to share knowledge!

 

Hi Mozikluv,
I have some doubts. Even if we use constant q topoloqy, i believe we will encounter the side band amplification and the non-true amplification responce of the frequency spectrum. isn't it?
and bye the way what is the need of 1/3 octave equilizer, when human ear response to amplitude and frequency are logarithemic and it can minimum distinguish one octave and 3db? What is the need of a 30 band EQ when we can cover the full band of 30 Hz to 16Kz( where in we normally use the EQ cut in and cut out.) using a one octave 10 band?
I think if you really want a filter with brick wall responce and constant q the best way is to use DSP.
Bipin

 

hi bipin,

honestly, am not too keen about using equalizers for my music system. however i would like to build this one just for kicks and would really like to hear how it works by playing around with the particular frequency. i agree that what matters is we like what we hear.

i know dsp will do but i still prefer this. can you imagine having 60 slide pots at the face plate for stereo effect?

ha, ha, ha

 

hi bipin,

what really gets me curious is the claim that this set up has an amplitude function that is independent from passband function, which i do not find from the usual EQs. you are right about the side or adjacent band amplification. it has been my observation thru test of several EQs that adjacent control do not show step response but rather only combined peaks in any direction.

before i do make this gizmo, i still have to brush up about this thing.