Baxandall vs Parametric

BigInThe80s · #1 08-02-2010, 09:16 PM

Do I understand correctly that a 3 band parametric can do anything a two band Baxandall can do (only with more flexibility)?

That is, with the Q of the parametric's high and low bands set very small - say somewhere around 1 - and the high and low band center frequencies set at their extremes?

If so, what role does the parametric's mid band play (if any) in simulating the Baxandall?

Darkglass · #2 08-02-2010, 09:25 PM

The difference is as you say it, flexibility... specially for dialing in, or scooping mid frequencies, para, or even semi parametric is a very nice option... having in mind that the cut/boost range is the same as a standard baxandall (from +-12, to 15dB).
For lows and Treble, I dont think is that necessary though...

Regards

Doug.

Eric! · #3 08-02-2010, 09:35 PM

Baxandall to Parametric is like a Muff to a Pitchfactor (don't get nitpicky about tone or anything, just an example).
Baxandall, you can boost or cut two preset frequencies, whereas the Parametric, you set the (in this case, 3) frequencies within a range you want to boost or cut. You could simulate a Baxandall with a Parametric, leaving the mids at zero, and dialing the Q of the high and low to what the Baxandall's frequencies are. But why would you want that when the Parametric is dimensions greater?

bongomania · #4 08-02-2010, 11:13 PM

You'll want to check out the EQ article in my FAQ. Once you read the definition of "parametric", you'll understand very clearly what the deal is compared to a Baxandall.

Worth noting: a Baxandall can be made with 3 bands, not just 2.

Eric! · #5 08-02-2010, 11:15 PM

Quote:

Originally Posted by bongomania

You'll want to check out the EQ article in my FAQ. Once you read the definition of "parametric", you'll understand very clearly what the deal is compared to a Baxandall.

Worth noting: a Baxandall can be made with 3 bands, not just 2.

Well, still the whole point is fixed frequencie vs variable, right?

bongomania · #6 08-02-2010, 11:22 PM

Nope, the center/corner frequencies of a Baxandall are variable. They change fluidly as you alter the levels of each band.

JimmyM · #7 08-03-2010, 05:22 AM

Quote:

Originally Posted by Eric!

Baxandall to Parametric is like a Muff to a Pitchfactor (don't get nitpicky about tone or anything, just an example).
Baxandall, you can boost or cut two preset frequencies, whereas the Parametric, you set the (in this case, 3) frequencies within a range you want to boost or cut. You could simulate a Baxandall with a Parametric, leaving the mids at zero, and dialing the Q of the high and low to what the Baxandall's frequencies are. But why would you want that when the Parametric is dimensions greater?

because it's not?

seriously, i find the baxandall controls highly musical and very versatile. yes, you can't just pinpoint a frequency and boost it, but i can't dial in a bad tone with the baxandall, whereas i can dial in many bad tones with a parametric. some want freedom of choice, i want freedom FROM choice.

Swift713 · #8 08-03-2010, 05:33 AM

ooh, I love a good Devo reference.
I don't understand how a Baxandall eq works, whereas the parametric is very logical and straight forward. I'm think you can make a parametric imitate a Baxandall but not vice-verse.

Darkglass · #9 08-03-2010, 05:38 AM

Quote:

Originally Posted by bongomania

You'll want to check out the EQ article in my FAQ. Once you read the definition of "parametric", you'll understand very clearly what the deal is compared to a Baxandall.

Worth noting: a Baxandall can be made with 3 bands, not just 2.

I once tried it, and the (unwanted) interaction was a disgrace!
For my pedals I actually use 2 band Bax, and an independent Opamp for the mid(s) control(s).
But actually in my rack stuff, I almost always use independent circuits for each band, to avoid any interactions... well, I don't that's cumpulsory, bit I am quite picky with these things

.

Swift713 · #10 08-03-2010, 05:49 AM

So do the SABDDI and VT Bass both have Baxandall stacks?

RCCollins · #11 08-03-2010, 05:51 AM

the bands of a baxandall EQ are interactive and their interaction would be very difficult to emulate with a 3-band parametric.

I like parametric EQ but JimmyM makes a great point - you can get great sounds out of a baxandall with very subtle adjustments. parametric EQ is powerful but it van be a lot trickier to dial in all-prupose sounds

JimmyM · #12 08-03-2010, 05:57 AM

Quote:

Originally Posted by Swift713

So do the SABDDI and VT Bass both have Baxandall stacks?

nope. and not surprisingly, they're both harder to dial in tones. not for me, of course...i've had over 2 years experience with it by this point

but that vt is a real pita at first.

RCCollins · #13 08-03-2010, 06:34 AM

two dirt pedals that DO have baxandall tone stacks are the catalinbread SFT and the xotic bass BB

BigInThe80s · #14 08-03-2010, 07:02 AM

Ok, I should mention that I am not a complete neophyte. I am very familiar with how a parametric EQ works have used semi-parametric EQ's on various boards and preamps over the years. I have used fully parametric EQ quite a bit in Sonar and Cubase.

The unknown factor for me is the Baxandall. I suppose I am going to have to mock up a version on a breadboard and play with it with a spectrum analyzer.

A parametric set with a very low Q is going to have a nice slope.

I guess I am a bit of an audio skeptic. I read glowing reviews of pedals like the Barber Linden, how it is nearly magic and you can't get a bad tone from it and it makes me wonder where the "magic" is coming from.

RCCollins · #15 08-03-2010, 07:09 AM

well it really IS hard to get a bad tone from a bax. The idea of the Linden is that it gives you the tone stack from an Ampeg fliptop as a preamp: 2-band bax

I'd get an xotic bass RC booster over the barber, though - just a little more than an EQ

BigInThe80s · #16 08-03-2010, 07:35 AM

An excerpt from The Secret of the Mastering Engineer by Bob Katz:

Quote:

You can simulate a Baxandall high frequency boost by placing a parametric equalizer (Q= approximately 1) at the high-frequency limit (approximately 20 kHz). The portion of the bell curve above 20 k is ignored, and the result is a gradual rise starting at about 10 k and reaching its extreme at 20 k. This shape often corresponds better to the ear's desires than any standard shelf.

RCCollins · #17 08-03-2010, 07:39 AM

Quote:

Originally Posted by BigInThe80s

An excerpt from The Secret of the Mastering Engineer by Bob Katz:

yes but that doesn't interact with the low band to produce a midscoop like a baxandall would

sure, you can use another couple bands of para to do that, but the beauty of a bax stack is that you don't have to - and while it can't do all the tricks that a multi-band true parametric EQ can, most of the time, it doesn't NEED to do tricks

rumblinbass · #18 08-03-2010, 07:59 AM

I'm not going to try to start a flame war here but I don't necesarily agree with all that has been said.

A fully parametric eq allows for greater flexibility. You have control over boost/cut, frequency, and Q. Q allows control over the frequency range that is affected when boosting or cutting. A wide Q affects a lot of frequencies, a narrow Q affects less frequencies.
A fully parametric is not usually offered in bass amps.

The Baxandall tone control is more commonly offered. This is normally offered in 2 to 4 bands. The 700RB I owned had a 4-band tone control and all circuits were Baxandall circuits. Theoretically you can have as many Baxandall circuits as you want. Will it sound good? Don't know you would have to try it out.

With all eq networks one thing to consider is the slope of each circuit and how they interact with one another.

Also mentioned was that the Baxandall center/corner frequencies are variable. That depends on how the eq is spec'ed. If you are measuring boost/cut from 0; no, that is not true. If you are measuring from boost/cut level; yes, that is true. However with some clever switching you can make corner frequencies variable.

Also, note that Baxandall circuits are typically shelving filters. They can be made into a quasi-peaking filter and even into what some could consider parametric but with added complexity.

BigInThe80s · #19 08-03-2010, 08:18 AM

Quote:

Originally Posted by rumblinbass

Also, note that Baxandall circuits are typically shelving filters. They can be made into a quasi-peaking filter and even into what some could consider parametric but with added complexity.

Ok, now I am confused. I thought the Baxandall had continous gradual curves instead of a shelf:

rumblinbass · #20 08-03-2010, 08:37 AM

Quote:

Originally Posted by BigInThe80s

Ok, now I am confused. I thought the Baxandall had continous gradual curves instead of a shelf:

I would say that the slope on a Baxandall is not quite as steep but I certainly would not consider them a notch type filter that would be typically used in a parametric.

More often than not, Baxandalls are used and Low and High shelving circuits and are spec'ed with one corner frequency. These circuits affect a range of frequencies and are not characterized with a center frequency.

There are a lot of ways to spec a filter, eq, or tone control circuit. But you can design just about any topology to be as flexible as you want it.

It's up to you though. If you prefer to differentiate between a Baxandall curve and a Shelving then by all means...
Having designed a few Baxandall circuits I know that when designing a Low Frequency filter you pick a corner frequency and all frequencies below that are affected (that is what I would consider a shelving filter). It does have an inherent curve but that is what makes it sound the way it does. By adding a High Frequency corner in the right place you can create a bandpass filter of they are placed correctly you can create a notch filter. By switching or varying capacitor or resistor values you can make the corner frequencies variable...