[sdiy] equalizer

[Steven Cook]

A state-variable filter with fixed frequency and q set at minimum would be
an easy way to split audio into three bands.

Steven Cook.

http://www.spcplugins.com/
steve at spcplugins
sales at spcplugins

> From: cheater cheater <cheater00 at gmail.com>
> Reply-To: cheater cheater <cheater00 at gmail.com>
> Date: Fri, 7 Oct 2005 17:31:20 +0200
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] equalizer
> 
> On 10/7/05, Seb Francis <seb at burnit.co.uk> wrote:
>> Sounds like you need to use combinations of high-pass / low-pass filters
>> to get total-kill, rather than just EQ cut.
> 
> You are totally right.
> 
> On 10/7/05, Amos <controlvoltage at gmail.com> wrote:
>> I'm a little rusty on my filter architecture right now... but a band-stop
>> filter should be just as easy as a bandpass filter, as it's basically the
>> same thing from a different perspective.  I remember that a cheesy way to
>> increase the Q of your filter is to use an identical one in series... you
>> can gang them to the same controls, and then I think total band kill is a
>> definite possibility.  For some reason most of the band-stop/bandpass
>> filters I can think of rely on inductors.... but there must be a cheaper R/C
>> version of the same thing, I just can't think of it.  I'm away from all my
>> books right now.  And actually, should probably get back to work... ;-)
>> 
> 
> No, a typical band pass/reject filter won't do - it'll "kill" just the
> center frequency. The rest of the dip won't be that big.
> 
> Cheers,
> D. 8)
> 
> 
>> 
>> On 10/6/05, cheater cheater <cheater00 at gmail.com > wrote:
>>> Tempting! It seems to have nice features.
>>> However, I'm not sure if it has the feature i need most...
>>> can it totally cut ("kill") each of its bands?
>>> 
>>> Best regards,
>>> 
>>> Damian
>>> 
>>> On 10/6/05, ken mosley <keninverse at gmail.com> wrote:
>>>> sorry hit send way too fast:
>>>> 
>>>> how about the Calreq pq1549 project at the gyraf audio site:
>>>> http://gyraf.dk/gy_pd/calreq/calrec.htm
>>>> 
>>>> PCBs can be purchased from gustav here:
>>>> 
>> http://prodigy-pro.com/forum/viewtopic.php?t=233&sid=ef77164249ee072a50c4ad83
>> 18d132fa
>>>> 
>>>> 
>>>> 
>>>> ken m.
>>>> 
>>>> On 10/6/05, ken mosley <keninverse at gmail.com> wrote:
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> On 10/5/05, cheater cheater < cheater00 at gmail.com > wrote:
>>>>>> yes!
>>>>>> schematics anyone? :>>
>>>>>> 
>>>>>> On 10/5/05, dustin sedlacek < dustin.sedlacek at gmail.com> wrote:
>>>>>>> i personally would love to have a EQ killer or at least know how
>> to
>>>> build
>>>>>>> one , thats a really cool unit i think
>>>>>>> 
>>>>>>> 
>>>>>>> On 10/4/05, cheater cheater < cheater00 at gmail.com> wrote:
>>>>>>>> Hey,
>>>>>>>> very interesting find indeed!
>>>>>>>> $199 is definitely prohibitive for me :(
>>>>>>>> 
>>>>>>>> On 10/4/05, Danjel van Tijn < syntheticdan at gmail.com > wrote:
>>>>>>>>> Have you ever looked at the electrix EQ Killer? I highly
>> recomend
>>>>>>>>> incorporatng that design into a DJ mixer. You could actually
>>>> reverse
>>>>>>>>> enegineer one if you got it (not such complicated circuitry)
>>>>>>>>> 
>>>>>>>>> Cheers,
>>>>>>>>> Danjel
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> On 10/4/05, cheater cheater < cheater00 at gmail.com > wrote:
>>>>>>>>>> Hi guys,
>>>>>>>>>> 
>>>>>>>>>> I'm looking to build my own DJ mixer [as, frankly, nothing
>> on
>>>> the
>>>>>>>>>> market is anywhere near what I'm looking for.... :( ]
>>>>>>>>>> 
>>>>>>>>>> the first step would be to build a good equalizer: something
>>>> that's
>>>>>>>>>> four-band and can totally cut out each one of them. I'm
>> looking
>>>> for
>>>>>>>>>> the same kind of thing that's in, for example, the Pioneer
>>>> DJM-600
>>>>>>>>>> (this one's 3-band, though), or the Vestax DCR-1200 PRO
>> (which
>>>> is a
>>>>>>>>>> stand-alone equalizer).
>>>>>>>>>> The Pioneer's EQ, for example, drops the whole band to -36
>> dB.
>>>> Without
>>>>>>>>>> weird resonance. Nice!
>>>>>>>>>> I haven't personally used the DCR-1200 PRO, but from
>>>> stories&tales it
>>>>>>>>>> seems it's the thing I'd want in my mixer.
>>>>>>>>>> No, I'm not buying 6 of those >:(    ;)
>>>>>>>>>> 
>>>>>>>>>> I've searched the archives, but not come up with a lot of
>>>> stuff....
>>>>>>>>>> some nice reads queued, though :)
>>>>>>>>>> 
>>>>>>>>>> If anyone could point me in the right direction, perhaps
>> assist
>>>> me...
>>>>>>>>>> [I've never made a complicated circuit like that, but I'm
>>>> definitely
>>>>>>>>>> NOT shy of my soldering iron ;) ]
>>>>>>>>>> 
>>>>>>>>>> Best regards to everyone,
>>>>>>>>>> 
>>>>>>>>>> Damian
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> --
>>>>>>> Dustin
>>>>>> 
>>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> 
>>> 
>>> 
>> 
>> 
> 
>