Mixing in a home studio can be hazardous to your music. Over the past few years, I’ve finished and mixed a number of synth instrumentals, but I never took the essential step of burning them to a CD and listening to them on other playback systems. Big mistake.

Recently I decided to put all that music on a CD. I expect to sell no more than 100 copies, but even so, I want it to sound as good as possible. By now, the original sequence files were long gone, so remixing isn’t an option. Even if I had the files, the older pieces use hardware synthesizers I no longer own. All I had were the 16-bit stereo masters.

When I burned a test CD (using the nicely-designed Project page in PreSonus Studio One) and listened to it on the stereo in my living room, I noticed two things. First, the bass and kick were oppressively loud for anything other than electronic dance music. Second, the mids had a boxed-in, claustrophobic quality — they didn’t breathe.

EQ’ing the lows down would be easy, but was there some way I could open up the rest of the mix and give it some air? I loaded the first tune into Image-Line FL Studio 9 (reviewed Apr. ’10) and tried adding a bit of room ambience — but only to the mids and highs, not to the lows. With careful adjustment, I got pretty good-sounding results. Of course, it’s easier to add reverb than to take it away. If your mixes have too much reverb, the techniques I used won’t help.

I also didn’t want to smother the mix in ambience. The goal was to produce an effect so subtle that listeners wouldn’t even notice it, though they would notice if it were missing. To test the settings, I listened to the mix while muting and unmuting the aux send channel where I’d placed the ambience plug-in. I wanted to hear the mix open up in a pleasant way when the channel was unmuted, without sounding thick or blurry.

Now that I’ve learned this technique, I’m using it in new compositions. Putting room ambience on an aux send helps hand-percussion loops and lead synth lines blend in, for instance. I’m listening to the low end more critically, too.

In future, I plan to make stems (submixes) of my new music while finalizing the mix. This is extra work, but it’s good insurance if I should need to change anything years later, on a different computer, in a galaxy far, far away. For now, here’s how to retrace my steps if you too need to breathe some life into a “legacy” stereo audio file.

Step 1. Load the mix into your DAW. In FL Studio, this takes three easy steps. In the Channels menu, create an Audio Clip (left). In the Channel Settings box, click the folder button to open a file dialog box, and select the audio file (center). Then, use the pencil tool to add the clip to a track in the Playlist window (right). No need to match the tempo of the song to the mix, unless you’re planning to overdub new MIDI tracks.

Step 2. In an aux send channel, use a multi-band EQ to get rid of the low frequencies. FL Studio’s seven-band parametric does the job nicely.

Step 3. Add a reverb to the send channel. Set it to 100% wet, and dial the decay time back to less than a second. The idea is to go for room ambience, not concert hall echoes. Experiment with adding a tiny bit of pre-delay.

Step 4. Assign the audio clip to its own mixer channel if your DAW doesn’t do this automatically. (FL Studio assigns new channels directly to the mixer’s master output, so this is a separate step.) Then raise the send level for this mixer channel until the meter in the aux channel starts to move.

Step 5. Since the snare backbeat is likely to be one of the loudest parts of the mix, it may have too much added ambience. To tame it, insert a limiter on the aux send channel, putting the limiter between the multi-band EQ and the reverb. Lower the limiter’s threshold until it’s squashing the snare. This reduces the amount of ambience added to the snare, without affecting the rest of the sound.

Step 6. If there are sections of the song that you want to be more dry, add automation control of the aux send channel’s output fader. You may want to pull the output down in exposed sections while bringing it up when the whole band is blazing.