10:10 May 27, 2011 

Sound is critical to the IMAX Experience. The six-channel, discrete digital IMAX motion picture sound system, with sub-bass, is manufactured by SONICS Associates Inc., a subsidiary of Imax Corporation, and is a world leader in sound system design and installation. The SONICS Proportional Point Source loudspeaker system, specifically designed for IMAX theatres, eliminates variations in volume and sound quality over the entire theatre seating area.
http://www.thehenryford.org/imax/about.aspx

10:07 May 27, 2011 

http://explorethecanyon.com/imax-theater/imax-experience/

Sonics Proportional Point Source™ (PPS) loudspeaker system was specifically designed for IMAX® theatres. The system typically uses 44 laser focused speaker drivers located throughout the theater to fully envelope the audience.

07:20 May 27, 2011 

I think it would more likely be 'à source ponctuel utilisant des enceintes proportionnelles' — however, I stll have the gravest resrevations about describing it thus without being in possession of further technical details of what the system actually involves: I suspect the 'proportional' may be to do with SPL throughout the auditorium, for example — really too risky to take such decisions without more details.

07:15 May 27, 2011 

Comme l'a dit Tony ça ressemble à un nom de produit, mais si une source peut être ponctuelle elle ne peut pas être proportionnelle, l'enceinte par contre peut l'être (linéarité de puissance acoustique en fonction de la puissance d'entrée), donc ce serait une enceinte proportionnelle à source(s) ponctuelle(s)

06:58 May 27, 2011 

To start with, this is I think a proper name of their proprietary system, so it probably ought not to be translated.

Secondly, I'm not entirely sure that 'source ponctuel' properly conveys the meaning of 'point source', which is indeed a standard term in acoustics (etc.) — I stand to be corrected here, but I strongly suggest further research on this point.

If you really feel you have to translate this name, I suggest you research from IMAX what it actually means, since the title seems to me not entirely explicit.