Sunday, May 18, 2008

I Love Multiband Compression

Ashi sent me an email this week, letting me know that he might need a track to be mastered. I don't do as much mastering as I do mix engineering, but I do like to tweak a final render here and there.

He sent an mp3 through the email for me to kind of look at.

Whoever mixed the track was incompetent as hell.

Usually when I work with a final render, the tracks are mixed fairly well. Everything that needs to be compressed, is, and everything that needs frequency balancing is EQed to sweet goodness.

Not this track.

It seems like a lot of producers these days love the muddy bass. They're under the impression that bass fills clubs. OK, so it does, but not muddy sub-100 Hz, 3-second release bass. That kind just sounds like sludge. This track that Ashi sent me sounded so fucking muddy, that I could barely make out anything about 200 Hz. Time to get to work.

For those of you who don't know anything about mastering, let me tell you about the multiband compressor. It is the greatest tool on earth. There are a lot of different multiband compressors out there, but they generally all do the same thing. They separate the audio signal into three different frequency bands (low, mid, high) that you can compress independently of each other. A de-esser is sort of similar to a multiband compressor in that it isolates the highs and then compresses those frequencies while leaving the rest of the music alone. What happens is a nice natural rounding off of harsh hissing sounds.

When you have a multiband compressor, you can isolate any problem frequencies in the audio signal, and squash it out. In this case, the bass was too muddy, the levels for the bass was way off the charts, and on top of it, had a nasty long bass release that bled into the track, causing it to sound dull with no punchiness. Instead of sounding like "boom, boom-cha," it sounded more like "thuuuuuuuuuuuuuuud thuuuuuuuuuuuuuuuuud!" The snare, the instruments, the high hats, everything was obscured by this problem bass.

So how did I fix this one?

I first cut out the low end. Usually, this is not too necessary and it's good to get rid of the most offensive bass rumbling. Everything below 100 Hz, I just cut out. That fixed half of the bass release problem. With one knob turn, I could actually tell rhythm that the bass drum was playing.

Next, I separated the 3 bands. The muddiest bass sits around 0 Hz to about 300-500 Hz. I set it to about 300. At this point, the 0 Hz to 300 Hz frequencies were isolated, so I compressed it. I compressed the shit out of it. I put in -20 dB as the threshold, set the ratio to about 5:1, and tweaked attack and release. I basically wanted the bass drum to sound like "biff biff biff" instead of "bleeeeeh bleeeeeh bleehhhhh." I wanted some definition in that sound.

A few knob tweaks at the low end just did the trick. The bass was nice and tight, and everything worked out well. I tweaked the mids and highs just a tiny bit since those frequencies were OK, but damn! That bass annoyed the hell out of me.

Some more compression here, a bit of brickwall there, and I had something that became 10 times more listenable than the original file.

So remember mix and mastering engies: recording and mixing well is important! If you record and mix well, you don't have to mess around with this kind of fix at the end of the road. But if you have to fix stuff up, EQs, compressors, and the amazing multiband compressor are your best friends.

OK, done with this post. Time to work on more music.

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