BASS PROCESSINGIf your bass is needs to be cleaned up, try using mid/side EQ. You can take out the bass where it doesn't need to be — perhaps create some more focus by reducing the clutter from the stereo field. In mono the bass can poke through much more easily, and should come out a lot less muddy if done properly.
STEREO IMAGEAdjusting the width of a stereo recording usually means making it wider, but an overly wide mix can be narrowed, too. There are plug-ins that can do this, but they need to be handled with care, as they can cause phasing issues and weaken a tough mix. Be sure to leave everything below 100Hz alone, as this area carries no directional information and has a much greater impact in mono than stereo.
A narrow mix can also be widened using mid/side processing, as compression and gain on the outer frequencies will accentuate them. Just be careful not to obscure important parts in the center of the stereo image, like kick, bass and vocals. An overly wide mix can be tightened by compressing the mono signal, then raising its level back up.
ADD PUNCHIf your kicks are cutting through too much yet turning them down takes out too much, try compression with a fast Attack and/or slow Release. Conversely, if your kicks don't come through enough, try a slow Attack to let the crack of the kick through, plus a fast Release.
Multiband compression can prove useful for zeroing in on kicks. Just don't use shelving EQ to boost your kick. When you do this, you are boosting all the harmonics too. Always use notching to just control the thud of the kick. Make sure you actually need to boost the kick, rather than making space for it in your bass using an equalizer and/or sidechain-compression.
Expansion can be useful for pulling some dynamics out of a squashed mix. Expanders work in almost the exact opposite way to compressors, increasing dynamic range rather than compressing it. They can't perform miracles, though, and can in fact add distortion, so if you have to rely on one, perhaps you should think about having another go at the mix.
DYNAMICSKeep your limiter's output ceiling under 0dB. Although you might want your track to be as loud as possible, some CD players can glitch if too many samples hit 0dB, and some disc duplication plants may reject the disc because their equipment determines the 0dB samples to be 'errors'. Set your limiter to around -0.5dB.
Remeber that it is not difficult to make a properly mixed track loud. If you ever wonder how the professional producers get their tracks so loud, it's probably due to mixing techniques used. If you are struggling with overall loudness at this stage, you need to return to the mixing stage.
Some plug-in limiters offer a look-ahead function. This can cut the beginning of your track off completely if your left locator bar is set too close to a zero-crossing. So, if you use look-ahead, leave a second or two lead-in and lead-out for the final file export, then tighten up the start and end of the final after that.
Don't just use one compressor/limiter for everything at once. Have two or three, each doing their part. This allows you to divide the workload between multiple dynamics processing units, which will cause less distortion. Two compressors with 1.5dB of gain reduction could sound louder and punchier than the same limiter with 3dB reduction.
When creating MP3s, you'll often get better results by converting from a WAV that has been mastered to a slightly lower output level than 0dB. We recommend -0.5dB for best results.