The truth behind stereo spreading.

[The Chase]

I'm not sure if I agree that bass is non-directional. Not only because you can still clearly hear a pure low frequency sine wave being panned in a well-treated room, but also because I don't see why low frequencies being non-directional would make where they come from indiscernible - the light from a candle is non-directional but you can still clearly see where it is.

But perhaps this is a fallible analogy, since localization is a given with sight but a result of tricky filtering and analysis of the difference of inputs between the two ears with hearing.

Are there any scholarly sources on the net that denote human low frequency localization?

[Kingston]

you can still clearly hear a pure low frequency sine wave being panned in a well-treated room

it's never a pure sine wave in this case. You're listening to room resonances and speaker inaccuracies. we covered this one earlier.

Are there any scholarly sources on the net that denote human low frequency localization?

Here's what we wanted to know:

http://illumin.usc.edu/article.php?articleID=45&page=3

The short version is that brain takes localisation clues from both time and volume differences of the sound coming to both ears. When the sound wave length exceeds the head barrier (approximately 18cm) brain only uses time difference, ie. less accuracy for low frequency localisation.

If you want to get all nitpicky you can calculate the "lower accuracy threshold frequency" from the 18cm head barrier.

[mkdr]

If you want to get all nitpicky you can calculate the "lower accuracy threshold frequency" from the 18cm head barrier.

Let's all measure our heads and calculate

[eduardo_b]

The short version is that brain takes localisation clues from both time and volume differences of the sound coming to both ears. When the sound wave length exceeds the head barrier (approximately 18cm) brain only uses time difference, ie. less accuracy for low frequency localisation.

Interesting, because this is also how those surround sound speaker bars, containing multiple drivers left to right, simulate surround. Obviously at higher frequencies.

[JCJR]

Regardless of perceptual issues, perhaps a practical reason that bass instruments typically are panned center, has to do with limitations of typical playback systems?

Most playback systems out there are not real powerful, and do not have really strong efficient woofers. So if you want a healthy level of bass or kickdrum in the typical end-user's system, then it would seem a no-brainer to take advantage of the power of both channels of the listener's stereo amp, and both of his woofers?

From the dawn of stereo up into the early 1970's, it wasn't unusual to find mixes which have mostly bass and guitar on one channel and mostly drums and piano on the other channel, or whatever. Those are interesting to hear nowadays, 35 years after mixing/pan conventions have become so formulaic.

[eduardo_b]

From the dawn of stereo up into the early 1970's, it wasn't unusual to find mixes which have mostly bass and guitar on one channel and mostly drums and piano on the other channel, or whatever. Those are interesting to hear nowadays, 35 years after mixing/pan conventions have become so formulaic.

Yeah, it's interesting to listen to albums from the 60s and early 70s, and marvel at not just right and left panning, but also what we call auto-panning now -- moving back and forth. I used to tell people to use headphones if they wanted to really hear all the stuff going on in those mixes.