ACOUSTIC DIPOLES : PRACTICAL APPLICATIONS   1. Any place : stereo mix re-imaging 2. Public spaces : integration to columns 3. Public spaces : on top of doors 4. Public spaces : lamp-like dipoles 5. Pseudo-dipoles

 

ANY PLACE : STEREO MIX RE-IMAGING An acoustic dipole, as seen here, distorts the mix by litteraly delocalizing the out of phase informations. Thus, the very use of an acoustic dipole is already an application in itself : it's enough to hang a dipole in the air to get sound coming from anywhere else in the room. ...or how to "project a mix in space" using only two speakers.

 

PUBLIC SPACES : INTEGRATION TO COLUMNS Columns are often easy to find in public places - it's a good idea to install dipoles there.   It's also possible to put four speakers in the column, so as to use two dipoles simultaneously - in this case, it would be a 2D dipole, like the following prototype :   NB : Note that the bigger the column, the less spectacular "+1/-1" effects (see here)

 

PUBLIC SPACES : ON TOP OF DOORS Like this : The speakers are in the wall. If the door is open or if there is no actual door, the two back to back speakers act as dipoles - otherwise, if the door is closed, each speaker acts as a normal speaker anyway. Maximum effect when the listener crosses the doorstep, which may be something excellent in certain cases.

 

*** PUBLIC SPACES : 'LAMP-LIKE' DIPOLES *** A very nice solution is to make "custom dipole boxes" to be put on the walls like a lamp at man's height, or indeed on any surface. Thus, it doesnt get in the way, and the "delocalization / out-of-phase" effect works perfectly well when people walk or stand in front of it. If people are meant to sit, then it's naturally better to put this "sound lamp" lower, so it's still at the same height as the people's head.

 

PSEUDO DIPOLES - 'OBLIQUE SOUND' Placing two speakers side by side can also be interesting.   Unlike what happens with a "strict" dipole, the directivity doesn't strictly follow the "omni - cardio - bi" pattern - but it adds a "lateral component" to the speakers intrisical directivity which may prove elegant and useful. For a start, it can avoid the "in your face syndrom" that happens when someone walks in front of / below a speaker. ... and from another point of view, it can create a "sound halo" close to the wall, a bit similar to oblique light. In general, using pseudo dipoles instead of single speakers, meaning systematically using two speakers instead of one could greatly enhance installations This is an extremely simple trick - even simpler than using dipoles - which can have great effects.