In many musical performances, there is electronic amplification of musicians that move around. This might be a band with an electric guitarist that walks up close to a drummer while waving his or her long hair and leaning backwards or it might be a barefooted vocalist who dances, skips and sings with a wireless microphone.

In the age of stereophonic, quadraphonic and otherphonic amplification and recording, it seems strange that you can not, as you could with plain acoustics, hear where the musicians are.

I propose a system that does this, that tracks the location of a musician and the amplified output sound is balanced accordingly.

I would like to do this with short wave radio. The musician carries a low power transmitter that emits a very steady signal. Receivers along the perimeter pick the signal up and phase shifts are compared to determine the X location (stereo) or X and Y location (quadraphonic) of the musician. The wavelength is chosen to be larger than the stage. The location of the musician is then used to adjust balance of the amplified signal. The listener will be able to hear where the musician is.

If the number of moving musicians becomes so large that bandwidth becomes an issue, transmitter and receiver are reversed: transmitters are fixed along the perimeter of the stage and receivers on the musicians determine their location and transmit this information as a digital signal (in a completely different band).

This will make concerts with moving musicians much more real and alive.

An improvement to this system would be to also reflect direction of the musician. It might be possible to do this with the same system, by looking at the absolute intensity of the radio signal. That would even produce shadows if another object is placed between transmitter and receiver, which would only serve to make the sound signal more real.
-- jmvw, Dec 11 2006

Bose L1 PA system http://www.acoustic...yle.com/BosePAS.htm
Cylindrical radiators obviate stage monitors [csea, Dec 11 2006]

Soundfield Microphone http://www.ambisonic.net/sfexp.html
Spatial recording [csea, Dec 11 2006]

L1 White paper http://www.bose.com...Bose_whitepaper.pdf
scroll down for combo example (but read the entire paper for interesting guitar history!) [csea, Dec 11 2006]

What problem are you trying to solve, exactly?
-- Abusementpark, Dec 11 2006


Wouldn't this mean that anyone standing, as I was a couple weeks ago, at stage right in front of the guitarist, would hear him much louder than the keyboard player at the other side of the stage? And when he wandered off the duet with the other guitar, I'd hear the bass and sod all else?
-- angel, Dec 11 2006


It would more resemble an acoustic setup, without amplification. Sure, musicians would need to become more aware of where they are standing, but I think this would give musicians an extra opportunity to add depth rather then detract.

A soloist might be able to become dominant by walking to the foreground and subside back into the fabric by stepping back. A walking drummer can pan from left to right and audibly approach groups in the audience. A dancing flute player can float around in the soundscape as if moving through a forest, disappearing and reappearing.

Sound reproduction would be more natural, while retaining the benefit of amplification.
-- jmvw, Dec 11 2006


Another problem with this approach is how one would handle stage monitors (so the musicians can hear themselves.) Possibly in-the-ear monitors, but again the sound tech would have to balance the signals to these as [BrauBeaton] and [Angel] point out.

As an alternative, Bose make an interesting PA system, which is said to obviate the need for monitors, and each performer gets one speaker system. [link] This should improve the spatiality without causing undue headaches.
-- csea, Dec 11 2006


A second thought - if what you're after is spatial recording, one elegant technique is a soundfield microphone [link] in which the mic. has 4 elements in a tetrahedral configuration, from which one can derive any number of signals representing directional microphones.

If one records the 4 signals (so called "B-format"), one can in fact derive the signals after the recording, and adjust balance after the fact.
-- csea, Dec 11 2006


[csea]: While the Bose system appears fine for solo performers, I doubt it would be much use for a band. Stage monitors rarely have either the same mix as the PA, or the same mix as each other. The guitarist of whom I spoke earlier asked the sound guy for more of the other guitar in his own monitor, then for less of the other guitarist's synth. The singer uses in-ear monitors, which would probably have her own voice louder than anything (to overcome the sound of the back-line).

When my own band was in action, I would vary my place on the stage so as to get the best from each monitor.
-- angel, Dec 11 2006


[angel], don't be mislead by the first link showing one performer. Here's a white paper with much more background, scroll down for an example with a typical guitar / drums / bass combo.

I'm actually not a fan of most Bose products, but with this, I think they're onto something.
-- csea, Dec 11 2006



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