Multiband compressors on monophonic tracks

I have been experimenting with using a multiband compressor on my bass and guitar tracks individually to tighten up some loose playing with nice sounding results. I am generally setting the crossover frequencies to 200Hz, 800Hz, 5k and 8k and I am compressing 4:1 with each individual threshold set so that the compressor kicks on and off, so relatively gentle for this kind of thing, I think. I asked Google what other people are doing with this and I am seeing a lot of responses of people saying they use them for mastering, polyphonic tracks or groups of instruments and there's not much mention of people using them in the manner I am experimenting with. Is anyone else here using a mulitband comp in this way? Maybe you experimented with it, but don't do it? Maybe you used to do it, but you don't anymore? I suppose there are no rules and a person is free to mix and use effects however they see fit. Still, if there are 'common knowledge' reasons that these compressors shouldn't be used this way, I'd like to know why. Right now, I don't really see the downside. I am getting extraordinary control over the dynamics of the instruments.

The only thing that matters is that you are getting the result you are after. You should use whatever tool that gets the job at hand done. 'Common knowledge' can be very useful as a guideline, or to learn from. That doesn't mean they are commandments :) I've used multiband compression on almost every type of track...

I used a MBC on a slap bass track where the pops where a lot louder than the thumps succesfully. I usually only use a MBC if there is a problem because I usually do more damage than good. cam

multiband has nothing to do with mono or stereo or polyphonic. most instruments have alot of harmonics and frequencies thankfully :)

Okay good. I just got the impression reading around the net that it is most commonly used on non-monophonic sources for whatever reason. I didn't really understand this de-facto 'restriction', so that is why I was asking to make sure I wasn't missing something. Perhaps I was reading into it wrong. Perhaps people discuss multiband compressors with full mixes (for example) because a traditional compressor, although possibly a great choice for a particular mix, just doesn't support the same degree of precision and flexibility. I was inferring a rule to avoid using it for 'simpler' sources, but maybe that was an incorrect inference. Seems as if I have confirmed that it is 'okay' :) for me to use it the way I am using it. I would have likely done it anyway, since I like how it sounds.

Every instrument also has a harmonics range and being able to control fundamentals and some harmonics independently is how an MBC (admittedly mostly with only a single band active) can be a fine sound design tool. (Famous example: Compress the hell out of the treble range (and maybe boost the side signal of that a bit to get the image even wider) on a choir or string sound... or backing vox... percussion...where you see fit... for that special "airy" sound, generally leading to less level needed for the instrument to "stay in the mix". You can't do that with an EQ alone.)

I've gotten accustom to using ReaXcomp coupled with ReaEq. I just recorded a mono bass line from a Rickenbacker and there was some fret noise we just couldn't get rid of on the guitar setup. I lowpassed on ReaEq until the fret buzz was almost gone, then send it to ReaXComp to even out the bass freqs and then compressed the shit out of the highs. Ended up with a nice thick bass tone from a dirext track (no amp model). And I barely know what I'm doing :)