Intro to Q Filters & Low Pass recommendations

[maclamb]

Can anyone recommend reading and maybe a not too expensive box so I can begin to play with and learn about Q-filters/low pass filters?

[crgaston]

LOOK HERE, HERE, and HERE... all from the Must Reads section of the forum.
 
Have Fun!

[maclamb]

kewl - thanks so much

[jags]

yes thanks charles.  dave and i like the same sound and i enjoy it very much,unfortunately too much and just popped something in my swr triad.  i hope i can get it fixed.  

[maclamb]

Ok, so from my reading it appears the difference between a pass filter and parametric EQ  (simply put) is the  pass filter removes or blocks some frequencies and parametric boosts freqs.
It would seem, therefore that if the frequency range I like most for my bass in the 3-5 Khz range, then a high pass filter would cut off those freqs below this.
Reminds me of synthesizer theory from years ago - two ways to create tone - additive  and subtractive. It seems pass filters build tone by subtracting.
 
Why is a pass filter  better than parametric? I say better (on this site) as Almebic chose this.
It would seem a combination of the two would be best - block freqs below the desired range with a low pass filter and then boost certain freqs of what's left.
 
It would seem a band pass filter set for my desired range would be the way to go for a filter.

[lidon2001]

It appears you are looking for Alembic's Swiss army kinfe of tone, the SF-2.
 
Alembic recommends this unit when more tone control is required.

[adriaan]

The filter is indeed subtractive, and it's more about voicing your sound. EQ is about levelling the perceived volume of one rig against other sound sources.
 
Alembic offers the Europa package, which includes both a filter and boost/neutral/cut switches for bass and treble. You can also have them add the filter to the Epic/Orion package (bass and treble rotaries).
 
I would advise against a multi-band graphic EQ simply because you're splitting the signal into little bits of sound, and in the end you're merging those bits together again - beware the Humpty Dumpty syndrome. Or buy studio-grade stuff.
 
Do try and experiment with a minimum of EQ - you might notice that too much EQ can actually get you lost in the mix.

[maclamb]

yes, it occurred to me the sf2 is an option, though I am trying to do it all on board.
 
I will buy a parametric eq to test some of my theories. Graphic is not needed.
 
Not sure what is meant by voicing the sound.  
 
It seems that pass filters would not work for me because I think I need all the freqs in the tone (due to the complex nature of the sound I want) and then boost select ones to get my sound. You can hear my sound in the post in search of the perfect tone on this page.
http://club.alembic.com/Images/393/37037.html?1173105345

[maclamb]

in my more weird moments I envision this: 7 knobs
 
1 - overall pickup volume
2 - pickup blend(neck and bridge)
3 - stacked bass boost / cut = +or- 15db @ 50 - 100 Hz
4 - stacked treble boost / cut = +or-15db @ 8 - 9 Khz
5 - stacked mid 2K - 3K range
6 - stacked mid 3K - 4K range
7 - stacked mid 4k - 5k range

[maclamb]

found this interesting...
 
http://www.bgra.net/2004/review.php?id=123&type=preamp

[adriaan]

The proof of the pudding is in the eating ... don't write off filters before you've actually tried them.
 
Also, past the attack part of the note, most of the high-frequency range disappears very quickly. While the note is sustaining, you can turn the filter pretty much shut (and open again) without much difference.

[maclamb]

I don't have $1000 to drop on experimentation. (at least right now...)
any suggestions for less expensive alternative to learn about voicing filters?

[lbpesq]

Joe:
 
While it's true that the low pass filter doesn't add anything, don't forget about the Q switch.  This does add a boost at the cutoff frequency, usually 6 or 9 db.  I'm also in the don't knock it 'til you try it school regarding the filter set up.  The bottom line is that you can get an amazingly variable palette of sound just by moving that lil 'ol filter just a little bit.  And when used in conjunctiuon with a Q, the possibilities are expanded.  I already spend too much time futzing with my knobs (ask my band mates).  On a set up like the one you describe above - 7 knobs controlling 12 functions - I personally would still be adjusting while the rest of the band would have already finished the song (and we play long songs).  This might work in a studio environment, but the realities of playing live create, at least for me, diminishing returns if the controls get too complicated.
 
As for the SF-2, I can't recommend it strongly enough.  GREAT unit, and you should be able to pick up a used one off of ebay or other source for about half the price stated above, or less.
 
Bill, tgo

[maclamb]

Good point bill - also my eyes may be bigger than my stomach, so to speak.
So, I plan to get a para eq ro begin experiments and see if I can find a SF2.
 
7 knobs  would cause a rerouting of the bass - so for now I would go with 5:
vol/blend, stacked bass, stacked treble, stacked mid
hopefully I'd have it worked out before gigs ;-)
 
But I get your point. this picture of lesh kinda says it all
http://club.alembic.com/Images/393/37419.html?1173745621

[edwin]

Don't forget the way the filters are constructed. A parametric or graphic style eq seems to introduce a lot more phase shift. The Alembic style filter (actually in use in synthesizer modules before Alembic) seems to not have this problem as much.  
 
While it can seem that a parametric offers more options and thus might be more useful, I have discovered that the filter setup offers a way to really get into the resonance of the instrument/pickup synergy that a bass/mid/treble doesn't do and a parametric also doesn't quite nail.  
 
Edwin