Using reverbs and delays as return effects is more a less a essential part of mixing. The only problem with these effects set ups is that longer reverbs and delays can sometimes confuse a clear mix. Luckily there are a few things we can do to keep things tight and make sure you mix remains intelligible and punchy.
Cut Those Lows
If you have read my other tutorials you may be aware that I'm quite a fan of cutting low frequencies all over my mixes. As long as it it approached with caution the high pass filter can be your best friend in so many mix scenario and this is one of them.
Often larger delay and reverb effects will mask the actual audio your effecting but using a simple high pass filter about 200 Hz (or above) much of this problem can be eradicated, or at least controlled. Adding delay or reverb to low frequencies often causes a real problem and can create a confused low end mix, this simple technique should really help.
Removing the low end from a reverb based effects return channel.
Simply strap a dedicated (non resonant) high pass filter, or EQ that features in built filters, directly after the reverb or delay on your return channel. Now remove those low frequencies until you hear any adverse effects. You can usually get away with quite a bit of subtraction here before you lose transparency.
A vocal treated with reverb with no high pass filtering.
And the same mix with the reverb filtered.
Side Chain, Side Chain, Side Chain
Another way to keep your return effects in check is to you use side chaining to beat a path through the noise. Often using a percussion element in your mix to trigger gain reduction in a simple compressor will make things clearer. Of course you don't want to push things too hard or you'll get obvious pumping effects but 4 or 5 dB of reduction on your return channel should work well.
To achieve this effect you'll just need to insert a side chain capable compressor straight after the effect in question. Then feed the key input of the compressor with a percussion element of your choose. The kick drum is always a favourite here but you can try using high hats and snares as alternatives.
A delay return treated with side chain compression.
A really clever trick here is to actually use the signal your treating as the key input for the side chain circuit. This means when your vocal (or any other signal) is firing your effects will be reduced in level. When they are not in the in the mix you'll hear you effects more clearly. Nice!
Our vocal is treated with a side chain delay... using the vocal as the key input!
And the same vocal in the mix.
Shorter, Less and Lower
It may sound obvious but by using shorter reverbs and delays, and lower effects levels you can really clean things up in your mix. The amount of mixes I get to work on that have huge reverbs layered over them and use very high send levels is pretty astounding. By simply using some restraint here you can make your mixes cleaner and punchier.
Remember if your effects are turned up to 11 all the time you won't have any room for movement, so go easy and when you use them they will be that extra bit special. Also try automating your effects in specific sections of your tracks, as opposed to them being on all the time.
In this case less really is more!
Simply choosing a shorter reverb or lower feedback setting can help keep things clean.