Sidechaining to subtract out the attack

[Rumfoord]

Totally random thought / theoretical question.. (I have no idea if this is already an obvious technique or something that wouldn't work at all):

If you had a bass with, say, two outputs from magnetic and piezo pickups, then the piezo signal would be much more transient-heavy, right?
And if you sidechained the piezo so that the magnetic pickups are compressed more when piezo is louder, then the magnetic pickup mix would have less transient, right?
And if you just tossed the piezo channel or turned the volume down, would you then wind up with a signal where you have a different kind of control over the transient?

My stupid questions are basically: how stupid am I being?

Would this work like I'm imagining?
Would you expect this to be any functionally different from regular compression?
Would you expect it to give you any greater flexibility than what you might just get from other types of multiple or parallel compression?
Is this already an obvious technique that I just have never heard about?

 

[silky smoove]

In theory this would work, but my guess is that using a higher transient version of your same signal would sound the same as just running a compressor with the threshold set lower. You can always try it and report back. If you don’t already have the bass you’re describing you could do this in a DAW by putting a transient shaper ahead of a compressor to increase the amplitude of transients.

 

[Bob_Ross]

Would you expect this to be any functionally different from regular compression?

my guess is that using a higher transient version of your same signal would sound the same as just running a compressor with the threshold set lower.

"Functionally" different? Only in the purely theoretical sense. Depending on what type of piezo pickup the bass has I'm not sure I'd agree with [edit: oops, I meant @silky smoove ] that it would sound "the same" as just running a compressor with the threshold set lower, but I definitely agree that we're into Splitting Hairs territory. I would wager it would sound slightly different because the attack profile (envelope) of the piezo is usually different from that of a typical magnetic pickup...but not so different that you probably couldn't easily replicate it with the Attack control on a comprehensive compressor.

Yes, it would work. But it would probably be making too much work for you given the expected results.

 

[Wasnex]

I'm not sure I'd agree with @Wasnex that it would sound "the same" as just running a compressor with the threshold set lower, but I definitely agree that we're into Splitting Hairs territory.

? Perhaps you meant to disagree with @silky smoove

 

[Wasnex]

@Rumfoord

I believe this is what you are proposing:

The key (control voltage) is generated from the envelope of the piezo. The magnetic pickup will have no impact on the key.

Assuming the piezo has a stronger attack than the magnetic pickup. I would expect it to duck the attack of the magnetic pickup. However, keep in mind Attack, Release, Threshold, and Ratio adjustments apply. AFAIK, all the controls are associated with the detector circuit, which is part of the sidechain. EQ can also have an impact.

 

[Bob_Ross]

? Perhaps you meant to disagree with @silky smoove

Derp! Yes, you are correct, sorry. Not sure how I came up with your name there. Mea culpa.

 

[silky smoove]

All these people disagreeing with me is destroying my ego

 

[AK Bass Guy]

As others above have said in theory you idea would work but in practice I don’t think you could find compressor setting that would reliably trigger and release cleanly.
You would have to play with a lot of muting and reliable play the same dynamics or your compressor on your magnetic signal could be overly compressed all the time.

Sound like it would be a nice trick for recording something that isn’t too busy and you cold really work the compressor.

 

[Mike Caldwell]

Another compressor side chair key input trick is / was to split the input signal one side goes directly to the the compressor input, the other side of the split
goes to an EQ, the output of the EQ feeds the compressor key input. Adjusting the EQ will make the compressor more of less sensitive at different frequencies. So if you would cut a bunch of the highs on the EQ the compressor would not be compressing the when playing higher frequencies but start compressing when it detects lower frequencies. Yes many have that kind of thing built both analog and digital.

 

[Rumfoord]

Oh interesting! I didn't know about that trick, but that's kind of why I thought it'd be worth asking. Without having tried it, that EQ trick sounds about as much in splitting hairs territory as other forms of attempting to compress differently at different frequencies.


Anyway, cool, thanks for thinking about it with me, everyone!

 

[Mike Caldwell]

Another compressor side chair key input trick is / was to split the input signal one side goes directly to the the compressor input, the other side of the split
goes to an EQ, the output of the EQ feeds the compressor key input. Adjusting the EQ will make the compressor more of less sensitive at different frequencies. So if you would cut a bunch of the highs on the EQ the compressor would not be compressing the when playing higher frequencies but start compressing when it detects lower frequencies. Yes many have that kind of thing built both analog and digital.

Another compressor side chair key input trick is / was to split the input signal one side goes directly to the the compressor input, the other side of the split goes to an EQ, the output of the EQ feeds the compressor key input. Adjusting the EQ will make the compressor more or less sensitive at different frequencies. So if you would cut a bunch of the highs on the EQ the compressor would not be compressing the when playing higher frequencies but start compressing when it detects lower frequencies. Yes many have that kind of thing built in both analog and digital.

Keep in mind you can do about anything you want to with the EQ settings as you never hear what the sound is coming out of the EQ.