How do I preserve mono low end while adding stereo width to highs?
Marketing Director & Bass Music Mentor
I use Serum 2's Splitter Mid/Side effect to preserve mono low end while adding stereo width to the highs by selecting 'side' mode, adding a low cut EQ to remove phasing from the low end, then applying Hyperdimension or detuned voices to widen only the high frequencies. This keeps your bass locked in the center while spreading your highs across the stereo field without creating phase issues. I show this exact technique in my Serum 2 course where I demonstrate routing voices through the splitter to maintain punch in the low end.
Frequently Asked Questions
Why does stereo widening mess up my low end?
Most stereo widening tools work by creating differences between the left and right channels, which is exactly what the low end in a properly mixed track should NOT have. Bass frequencies below roughly 100 to 120 Hz should be mono for several reasons: they translate poorly to mono playback (phones, clubs, small speakers), they cause phase cancellation issues, and excessive stereo low end can cause rumble on vinyl. A mid/side split lets you widen only the frequencies where stereo information is safe.
At what frequency should I split when preserving mono low end?
A common starting point is around 100 to 150 Hz. Below that, keep everything in the mid (mono) channel. Above it, you can add width to the side channel. Adjust by ear: listen on a mono speaker and confirm your sub and kick fundamentals are hitting cleanly. Some producers split as high as 300 Hz for genres where a very focused low-mid is important for translation.
Are there other tools besides Serum 2 for mid-side frequency splitting?
Yes. Fabfilter Pro-Q 3 has a mid/side EQ mode that lets you cut the low end of just the side channel, which achieves the same result. Ozone's Imager has a frequency-specific width control. In Ableton, you can route signals through the Utility plugin in mid/side mode and add EQ afterward. The technique is the same regardless of tool: isolate the side signal and roll off the low end of it.
Max Pote
Marketing Director & Bass Music Mentor
Max Pote is a professional bass music producer who performs and releases under the name Protohype. He has more than a decade of releases on major bass-music labels (Firepower Records, SMOG, Never Say Die, Rottun, Deadbeats), festival appearances at EDC Las Vegas and Lost Lands, and a feature credit on Tom Morello's 2021 album The Atlas Underground Fire. He was an early Icon Collective alumnus and later returned as an instructor before co-founding Futureproof Music School. He leads marketing at Futureproof and mentors students on sound design, songwriting, and finishing tracks.
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