PreSonus Blog

Friday Tips – Why Mono Matters for Mixing

With the ideal mix, the balance among instruments is perfect, and you can hear every instrument (or instrument section) clearly and distinctly. However, getting there can take a while, with a lot of trial and error. Fortunately, there’s a simple trick you can use when setting up a mix to accelerate the process: Start your mix with all channel pan sliders set to center (Fig. 1).

Figure 1: All the pan sliders (outlined in white) are set to center for a reason.

With stereo tracks, changing the track interleave to mono isn’t adequate, because it will throw off the channel’s level in the mix. Instead, temporarily add a Dual Pan set for the -6dB Linear Pan Law, and center both the Left and Right panpots (fig. 2). Now your stereo track will appear in the mix as mono.

Figure 2: Use the Dual Pan, set to the -6dB Linear pan law, to convert stereo channels temporarily to mono when setting up for a mix.

Analysis Time

Now listen carefully to your mix. Are all the instruments distinct? Monitoring in mono will reveal places where one instrument might mask or interfere with another, like kick and bass, or piano and guitar (depending on the note range).

The solution is to use EQ to carve out each instrument’s rightful place in the frequency spectrum. For example, if you want to prioritize the guitar part, you may need to reduce some of the piano’s midrange, and boost the regions above and below the guitar. For the guitar, boost a bit in the region where you cut the piano. With those tweaks in place, you’ll find it easier to differentiate between the two.

For kick/bass issues, the usual solution is to increase treble on one of them—with kick, this brings out the beater sound and with bass, string “zings” and pick noises. Another option is to add saturation to the bass, while leaving the kick drum alone. If the bass is playing relatively high notes, then perhaps a boost to the kick around 50-70 Hz will help separate the two.

Keep carving away, and adjusting the EQ until all the instruments are clear and distinct. Now when you start doing stereo placement, the sound will be open, with a huge soundstage and a level of clarity you might not obtain otherwise—or which might take a lot of tweaking to achieve.

We’re Not Done with Mono Just Yet…

Okay, now you have a great stereo mix. But it’s also important to make sure your mix collapses well to mono, because you have no control over the playback system. It might play from someone’s smartphone, and sounds mostly mono…or play back over speakers that are close to each other, so there’s not real good stereo separation. Radio is another possibility where the stereo might not be wonderful.

Some processors, especially ones that control stereo imaging with mid-side processing, may have phase or other issues when collapsed to mono. Short, stereo delays can also have problems collapsing to mono, and produce comb-filtering-type effects. So, hop on over to the main bus, and click the Channel Mode button to convert the output to mono (Fig. 3).

Figure 3: The Channel Mode button (circled in yellow) can switch the output between mono and stereo.

Hopefully, everything will sound correct—just collapsed to mono. But if not, start soloing channels and comparing what they sound like with the Channel Mode button in stereo and mono, until you chase down the culprit. Make the appropriate tweaks (which may be as simple as tweaking the delay time in one channel of a stereo delay processor), make sure the mix still sounds good in stereo, and you’re done.