Why bass mono?

[Touch The Universe]

Rule only applies to sub frequencies

[zerocrossing]

Well, the technical reason is that the low frequencies, i.e. the bass frequencies,
carry the most energy. The converters that we use, i.e. the loudspeakers, monitor
boxes or the PA, almost all have problems reproducing these frequencies with
their high energy. That's why it's important to distribute this high energy evenly
on both sides, i.e. to place it exactly in the middle.

That isn’t necessarily true. Monitoring equipment is really good these days and sub woofers are cheap. It’s more because the wavelengths are longer than the distance your ears are apart, therefore you can’t perceive them as part of a stereo field. Of course, harmonics of that bass part will be directional, but you generally want them in the center anyway for aesthetic reasons. Do you want the “base” of your track to be panned to one side?

Strictly speaking, no. The main reason is the high energy content and the problems
that loudspeaker systems have with it.

Of course, there are good monitors and subwoofers that can also reproduce low-
frequency signals well. But as a rule, you want a song to sound good on all equipment
- including your home stereo or small boomboxes or headphones. That's why it's a
must: the bass has to be exactly in the middle.

Let's assume that everyone has ideal monitoring speakers (which is not the case).
Then there is no reason to always place the bass exactly in the middle. Then,
depending on the genre and style, you could also place the bass all the way to the
left or right - or even alternately. A new style would even emerge, called "left-right
-super-bass-pounder," in which the bass would waft around the room.

But the reality is different: There are lots of small and tiny speakers. In order for a
song to sound decent on them, the bass always has to be placed exactly in the
stereo center.

I didn’t think about it before, but I imagine these days, a large, maybe even majority, of music is listened to on headphones, so having the bass panned would be odd. Also, a lot of Bluetooth speakers where the stereo fierce is negligible or zero. I do music for for VR games, so it’s all coming out of an Oculus or some headphones connected to an Oculus.

[legendCNCD]

I would remove "always" from the specification as a word... you do not _always_ need to mono the low end, it really depends on the production/genre/is it needed?

[Uncle E]

The only exclusions I can think of for not mono’ing subs is headphones and wearable or seat-loaded subwoofers. When playing over speakers, it’s pointless for sub-80Hz to not be mono and can only do harm.

[swilow11]

What is the crossover frequency after which bass directionality can be perceived?

It's odd because if a car banging some doof doof drives past, you can actually perceive directionality but I guess this is because it's moving. And if I hard pan low frequencies, I can get a sense of that but it sounds shit. The bass feeling (rumble in chest) doesn't pan...

Subwoofers are summed mono so it is both psychoacoustically and technically pointless.

[BertKoor]

What is the crossover frequency after which bass directionality can be perceived?

I honestly would not know. It can be dteremined experimentally.
Subwoofers with outputs for the midrange speakers have cross-overs around 120 Hz I think.

It's odd because if a car banging some doof doof drives past, you can actually perceive directionality but I guess this is because it's moving.

My guess would be it's because the 'doof' sound also has a 'clack' component which is high frequency content.

[legendCNCD]

The only exclusions I can think of for not mono’ing subs is headphones and wearable or seat-loaded subwoofers. When playing over speakers, it’s pointless for sub-80Hz to not be mono and can only do harm.

Even in these cases sometimes the under 80hz sounds actually better if its not 100% mono, even something low like 25% of stereo dampening might do the trick. Fex. space ambient type genre.

[Synthman2000]

It's is not an absolute.

Even for vinyl cuts it does not have to be 100pct mono.

The core reason is to avoid phase cancellation and loss of power/bass level /tonal mix changes in mono. And some playback systems can be mono by choice or in error.

Again with most things in audio it depends on your knowledge and ability to know the reality of the audio in your music. Superb monitoring and acoustics provides truthful listening experience.

If you have the monitoring you can very easily produce a mono compatible stereo bass.

In fact it can sound very good. Better than mono, it can add interest and dimension.

"bass in mono" is a good rule of thumb for amateurs who probably cannot hear the reality of what lies on their L/R outputs. A belt and braces approach that quickly removes potential mono incompatibility for people who are fumbling around with audio not really knowing what they are doing.

If you do make stereo bass, it needs to be fairly subtle and tasteful. And you need monitoring accuracy to judge the effect well. Experiment with very subtle amounts of filtered reverb and Dimension D type chorus or multiple oscillators/unison.

The rule here is extremely subtle-y. Best judged in very good acoustics with very good monitoring.

And always keep checking mono compatibility and if the effect of the slight stereo-ification gels correctly with your entire mix down. It may sound better or worse.

Bass can potentially psychoacoustically have a "dimension" beyond mono when harmonics, if rich enough interact with non static, pseudo stereo lead type sounds in your mix.

This may or may not be desirable depending if it sounds good in accuracy.

Experiment, just be over the top cautious and the worse your monitoring and room (and mono compatibility checking discipline) the more cautious you should be.

What you want to avoid at all costs is the fake "I do no know what I am doing" overly wide phasey sound (even if it does sum to mono) cause it just sounds amateur.

Try not to sound amateur.

[Freaqpeak]

The only exclusions I can think of for not mono’ing subs is headphones and wearable or seat-loaded subwoofers. When playing over speakers, it’s pointless for sub-80Hz to not be mono and can only do harm.

Agreed. For sound design in certain scenarios it might be useful but never in music production.

Adding a bit of stereo to ~100 Hz can feel really great depending on the material though.

PLAYBACK with sub in stereo is a another topic, it has benefits in a studio or high quality playback environments though. Sometimes you can't place the sub where it is beneficial for the acoustics in the room, so you need two subs (stereo or mono). You can still hear subs from left and right so..

[Synthman2000]

The only exclusions I can think of for not mono’ing subs is headphones and wearable or seat-loaded subwoofers. When playing over speakers, it’s pointless for sub-80Hz to not be mono and can only do harm.

Agreed. For sound design in certain scenarios it might be useful but never in music production.

Adding a bit of stereo to ~100 Hz can feel really great depending on the material though.

PLAYBACK with sub in stereo is a another topic, it has benefits in a studio or high quality playback environments though. Sometimes you can't place the sub where it is beneficial for the acoustics in the room, so you need two subs (stereo or mono). You can still hear subs from left and right so..

Not discounting the fact that there is such a thing as stereo monitoring that does not need a separate sub. Quite a lot of synth wave has stereo synth bass and 80's synth pop from which it is derived.

You just have to be very careful and know what you are doing and all importantly be able to hear reality, not sonic mis-representations.

[VELLTONE MUSIC]

It all depends,what the composition let or what the artist want to achieve in low spectrum as sonic diversity.
Bass under 100 hz gives nice boom and the save bet is to be mono,but always mono is boring and limited idea imo.
110-330hz is wast area to create,which unfortunately is the area of many other instruments and have to find the way to complete each other or at least to set proper attack and release,not to fktp the mix.
It's more interesting when you have small phase deviations,osc/filter modulations and so on interesting parts to make your base line really dynamic and interesting to follow.
Or you can put simple mono bass 10 min the same and to forget about all problems

[billinder33]

Bass (the instrument) can definitely be stereo, especially in the upper harmonic frequencies.

Bass (the frequencies, specifically sub) should definitely be in mono. Because you don't want the phase cancellation that's created from different sub frequencies colliding. It's the same basic logic for sidechaining or ducking your kick and bass, or why psytrance artists use oscilloscopes to make sure kick and bass don't overlap.