The mono bass option explained

Mono bass takes everything in the track below 120 Hz and sums it to the centre, so the left and right channels carry identical low end. It is on by default in the Master & export panel because club sound systems reproduce bass in mono, and stereo information in the sub region causes cancellation and a weak, wandering low end.

Why stereo bass is a problem on a PA

Most club and festival systems feed the subwoofers a mono sum of left and right. If the bass in a track differs between channels, in level, phase or timing, parts of it cancel when summed, and the kick and sub lose weight. Stereo widening effects, chorus on a bass synth, or a wide reverb tail that reaches into the lows all cause this. Even on stereo tops, bass that moves between speakers smears the groove. Mastering engineers mono the lows for exactly this reason.

Music models mix in stereo without knowing where the track will be played, so a render can carry width in the bass. Club Ready Music removes it.

How Club Ready Music does it

The signal is split at 120 Hz with a fourth-order Linkwitz-Riley crossover, built from two cascaded second-order Butterworth stages on each side. Linkwitz-Riley crossovers are used because the low and high bands stay in phase at the crossover point and sum back to a flat response, so there is no dip or bump at 120 Hz. The low band is panned to the centre by averaging left and right. The two bands are then summed again with no level change. The audible result is identical mids and highs, and a solid, centred sub.

The same split powers the optional Bass fades last 8 bars feature, which fades only the low band over the final eight bars of the outro so a DJ can bring in the next track's bass without a clash.

Why 120 Hz

Sub-bass and kick fundamentals live below about 120 Hz. Above that, the harmonics of bass instruments start to carry character and width that you want to keep. 120 Hz is a common choice in club mastering, high enough to catch the whole sub region and low enough to leave the mix's stereo image alone.

When to turn it off

Headphone-only releases, ambient or cinematic pieces where wide low-frequency texture is part of the design, or any case where you plan to run your own mastering afterwards and want the raw stereo field. For DJ use, keep it on.

Mono bass and the WAV

The option applies to both the MP3 and the WAV, since both are rendered from the same processed signal. If you want an un-monoed WAV, untick the option before rendering.