The purpose of the center channel is to enlarge the area where stereo imaging could be heard.  Instead of a “sweet spot” as we had with two channel systems the good listening area is expanded into a sweet triangle as depicted in our drawing.  The LCR Position Tool shows an estimated sweet triangle (the green triangle).

Computer modeling the Sweet Triangle (right) is possible, but there aren’t any handy programs to do this for most integrators.  A useful approximation involves noting that the Sweet Triangle is a function of the distance between the LCRs.  More precisely, the listening angles between the center and each LR speaker.  In reality, the true width and shape of the Sweet Triangle is also a function of the directivity of the front speakers.  If we use wide dispersion speakers, the triangle will be wide enough for most rows.  However, it’s always worth estimating as our tool does.   The possibility exists of listeners being outside of the triangle on the edges of wide rows.   Especially if the row is nearer to the front.  Keeping as many listeners as possible inside the triangle is recommended.  Of course, the MLP is always the best location.