How to Mix Your Music Using Psychoacoustics

[hcontunes]

Great information, that first eq trick is op!

[LeonvanBokhorst]

Such an interesting subject 🙂 needs more cow bell

[ghislainyeboua]

Good video,
Can you recommend reference books about psychoacoustic ?

[TirriRino]

cool video buddy, thank you for the information :)

[sergionardozza]

This is the same ir i aply panning on ableton?

[sinephase]

damn that's neat! It really explains why video games with directional audio sound so artificial

[tomlewis]

Ticks are not a good way to judge milliseconds. in 4/4 there are 3840 ticks per measure, but measures are different in length, because the BPM may be 50 or 150 or anything in between, so the length of a tick is not defined. A tick (and a measure) at 50 BPM will be 3 times longer than a tick at 150 BPM.

The echo threshold for human hearing is 40 ms, this according to Dr. Helmut Haas himself in 1949. The speed of sound then dictates that unless your ears are 40 ms apart, about 21 inches, you will still perceive a direct sound off axis as a single sound, and a single sound can only come from one direction.

What direction is it coming from? Since it appears to be a single sound coming from one direction, and since the echo threshold is 40 ms, the difference in timing per ear isn't really all that helpful. And it IS a single sound. Since our ears are more accurately 15 ms apart, the difference in timing has a very tiny effect on echolocation in the panorama in a stereo recording.

The difference in frequency response (head effect) and level in the off-axis ear and the fact that the off-axis ear gets many more environmental reflections which can arrive after the echo threshold of 40 ms, is what can make the difference in real-world echolocation.

But sound in the real world it's not the same as sound in a stereo recording. Stereo can only simulate echolocation in the real world, but it can do this much more effectively in a very simple way.

Generally speaking, the more-obvious and much stronger cue in stereo panning is volume differences per ear. Simply panning something will create echolocation for the listener, based solely on that. That's why we have panning in the first place. Even monaural panning can do this quite effectively. The time delay is ineffective and not at all necessary.

So rather than going through the gymnastics of delaying one track of an identical pair, if the goal is to change the perceived direction a sound is coming from in the panorama, simply grab the pan knob for a single stereo track. That's a complete no-brainer. No need to waste your time with parlor tricks that aren't effective.

In headphones, yes, the relative delay to the off-axis ear is literally absent, yet we are still quite able to echolocate a sound in the panorama simply due to the difference in volume levels, one ear to the other, which pretty much indicates how unimportant that relative delay really is. With stereo speakers, there are room reflections that basically mask any time differences below 40 ms between the left and right ears for the original direct sound. Again, it's room reflections or environmental reflections Beyond 40 ms that allow us to actually perceive the delay and aid us in echolocation, especially if you use a room reverb that reacts to the pan position (I always do).


So the Hass Effect is a fascinating concept, but it's pretty useless in trying to create echolocation in a panorama in a stereo recording, compared to all the other things which contribute much more greatly to echolocation.

If you still want to do this, there is a much easier way to do it. In Logic Pro, which is the DAW you are apparently using, there is a plug-in called Sample Delay, which allows you to delay one channel or the other (or both) of a stereo track by either milliseconds or samples. Is it all that effective to simulate echolocation in a panorama? Not really, and because of the reasons above. It can give the crack of a snare a bit more perceived stereo width, but that's really about it (and it would be unusual for the snare to be very far off center anyway).

But I did find a use for it: Bass and kick often compete for the same frequency space. This creates destructive interference directly in the summed tracks which muddies the sound. If you were to pan one track slightly right and the other slightly left, (as well as carving out a dip and a notch in the EQs and using sidechain ducking for the kick), this minor panning will also diminish the amount of destructive interference a little bit more, depending on how far apart you pan them.

But kick and bass are supposed to come right down the middle.

What I do is put on headphones and pan the bass just a couple clicks to the left and the kick just a couple clicks to the right. If you pan them much further, they will start to sound like they are coming from the left and right, which means you've gone too far. But if you put a Sample Delay plug-in on each of those stereo tracks (kick and bass) and delay the right channel in the right-panned track by 20-25 ms or so, and do the opposite in the left-panned track, that will correct the perception of them being panned left and right, and make them sound more centered, while still maintaining less actual destructive interference.

The end result? Less muddiness.

But there's an even easier and more effective way to do this, which is to use the Tape Delay plug-in on the bass track. Set it to add zero delay, then add as much harmonic continent as you like using the Feedback and Clip Threshold controls, then start playing with the Spread control while listening to the full mix, which somehow does somewhat the same thing as the Sample Delay plug-in yet is much more effective. Try spreading left or right at about 30. If you spread to about 40, it starts to change the perceived pan position a little bit, so that is the point where you have to back off. But as you move this control from about -35 to +35, you will find a spot where the bass dovetails directly into the mix better than if you leave it at zero.

Of course, that's the short answer 😉

[MrKarthik]

I use psycho acoustic in my phone audio