Help me understand bass compression

[H-evolve]

I'm trying to understand the fundamentals behind bass compression...

Compressors always (at least the ones I've tried) take a lot of bottom out of the tone. I think it's because lower frequencies have more energy for the same volume, therefore triggering more compression? Is that it?

My issue is... There are a lot of time where I am quite satisfied with my tone, however there is still too much dynamic in the bass and I want to even things out. So I'm kinda screwed, as using compression affects the tone I liked...

Is that why people use multiple compressors in succession? (that is, multiple smaller ratios of compression instead of one big ratio).

Or perhaps people prefer using limiters?

Trying to understand the basics I guess....

 

[Old Man Doom]

I prefer limiting, to be honest. I have the JST Finality limiter and it really helps pin those dynamic parts in place. However, I just started experimenting with compression too. I have found that you can get a cool gluing/bouncy effect by putting an 1176 style comp on your bass bus when you're mixing a low and grit track together. Medium-slow attack and super fast release on that comp can really help the two tracks move together as single instrument (if that makes any sense).

I get what you mean about the low end suck. However, I do find that a slammed limiter, like L1 or Finality, can really bring up the sustain and body of the whole bass while pinning down those dynamic parts semi-transparently. Joel Wanasek talks about this approach a lot in his mixing for the URM podcast with Sturgis and Levi.

 

[mva801]

A lot of people mixing in this genre use heavy compression and limiting on the bass. Ermz summed it up really well in his mixing guide.

A limiter IS a compressor, just with a high ratio (above about 20:1) so definitely experiment with different ratios and different compressors. When in doubt, if you don't like what any compressor does to your tone, AUTOMATE the volume of the bass notes that aren't sitting well. Then you keep the tone of the bass and can alter the dynamics how you wish. Andy said it before about automating live kick drums for consistency. It takes time to do that. But don't be lazy

 

[TRUIE]

You can either split your tracks to different frequency ranges if you need more control, or feed an EQed version (less low end) of your signal to the compressor sidechain, so that it won't react that much to the low end.
This second method can be worth to experiment with, if you're after more natural/breathing results but still needs some control on the dynamics.
It's well explained here : https://www.sonnox.com/tips/i-want-more-bass-and-i-want-it-loud

 

[Novocaine]

If you have an internal sidechain in your compressor (Molot and MJUC for instance) you can use the high pass to prevent the compressor from reacting to the bass frequencies. Really opens up the sound.

 

[MrBongo]

i´m slightly puzzled about your statement "compressors take out the low-end". Usually it´s people complaining about a lack of treble when the compression is working. That´s because some compression circuits on hardware units attenuate the high-end when in use, and of course there´s a few plugins emulating it.

Your usual compressor reacts to the total signal amplitude that is fed into its detector circuit (the Sidechain), like the peak graphs in your DAW are showing. It does not care whether it´s low-end or treble (except when the RMS detection time is rather long, but let´s keep it simple for now). However, this peak graph may be altered (EQ´d) slightly or heavily by the circuit components before the detector stage.
Some compressors only have a lowcut in front, so they react less to low frequencies than they would do without that low-cut. Others have a true EQ circuit in front, some even switchable EQ curves.
This can be useful if you want to compress a bus track harder when the snaredrum hits, without affecting the rest of the action much. Feed an EQ´d signal into the sidechain which emphasizes the snaredrum.

To compress electric bass, I greatly prefer multiband compression, because I work with just a single bass track 98% of the time. You can split the track into low-end and clank, of course, it´s basically the same here.
The problem in modern music is the loudness you often want to achieve. Bass frequencies need a lot more energy to create the same level of perceived loudness than higher frequencies do. But we don´t want to mix with a lack of low-end either, because it quickly makes a track sound thin and weak.
If we want to mix a dynamic E-Bass, we are in trouble: it´s one of the most dynamic instruments we have with possible huge transients, and its sonic space mostly lies in the low-end. So the peaks will be far too loud and probably even go over 0dBFS, when we finally get to the average loudness we want it to have. We need to get rid of the peaks without killing too much of the dynamic feeling of the track.
If we fed a bass-less version of the signal into the detector, it would simply ignore the huge low-end peaks and react differently
Enter multiband-compression:
The clank can pass through slightly compressed or even unaltered, while the low-end can be smoothed out a lot more. This preserves most of the dynamics which come from the overtones in the mids and treble, and keeps the low-end under control

 

[H-evolve]

i´m slightly puzzled about your statement "compressors take out the low-end". Usually it´s people complaining about a lack of treble when the compression is working. That´s because some compression circuits on hardware units attenuate the high-end when in use, and of course there´s a few plugins emulating it.

To clarify what I meant, think of an electric guitar on the clean channel. If you use a compressor, I find that the tone starts to be a lot less mellow, and starts to be something like a "twang" sound.

Or if you take a kick drum. Add a compressor on it, and it starts to be less "boomy" and more "clicky". That is what I mean by taking out low end.

I'm sure you experienced the same no? How would you call that phenomenom if not "less low-end"?

 

[Korwent]

That has to do with your attack setting, if the kick is more clicky when compressed it is because you let the attack and compress only after it, increasing its volume compared to the rest of the kick sound.
On the other hand, if you have a fast attack you will reduce the attack too, and possibly even only the attack when setting the threshold high enough, bringing it more under control!
So it's less low end depending on the settings ah ah

 

[H-evolve]

That has to do with your attack setting, if the kick is more clicky when compressed it is because you let the attack and compress only after it, increasing its volume compared to the rest of the kick sound.
On the other hand, if you have a fast attack you will reduce the attack too, and possibly even only the attack when setting the threshold high enough, bringing it more under control!
So it's less low end depending on the settings ah ah

That is a nice explanation thanks, that helps me understand better. With this I can probably figure out a way to compress my bass without affecting my tone. I guess I was not setting the attack fast enough (though in my mind it was already pretty fast, but I guess not enough).

 

[nezvers]

You can go through limiter to shave transient peaks and then go through compressor. In that way you get low-end participating in note punch.

 

[wishtheend]

Use a comp with a lpf, maybe around 80-100hz just to ease some trigger off the lowest end. Or a light multiband prior to main comp/limit for balancing between the bands. If I'm doing the bi-tone (clean/dirt) 2/3 track setup, I do struggle with a single comp/limit combo on the main bass buss. The individual tracks sometimes need different eq/comp settings.

 

[MrBongo]

Korwent already explained it, that´s why I prefer compressors with lookahead and quick attack/release for most things

 

[Phil_ocean]

That is a nice explanation thanks, that helps me understand better. With this I can probably figure out a way to compress my bass without affecting my tone. I guess I was not setting the attack fast enough (though in my mind it was already pretty fast, but I guess not enough).

What you can do is to duplicate the bass track to 2 channels and low pass one of them at about 140Hz and use that as the low end part of the bass while the other channel will be your "tone". Then I usually compress the low end channel in 2 stages and finally limit to pin it down so its consistent. You can do the same or almost the same with your "tone" channel if it doesnt affect your tone too much, but usually i do the same steps to the "tone" channel too for consistency. I can describe exactly how i do it but it will be an annoyingly big post

Edit: 9/10 times i have to flip the phase on one of the channels.