Speaker recommendations for new venture

The inverse square law (SPL falls off with the square of
distance) applies only to the direct sound. In a room,
there are two primary components of the sound field: The
direct sound, and the reflected or reverberant sound.

Unlike the direct sound, the reverberant sound is just about
constant in SPL (approximates a "steady state") throughout
the room. Up close to the speakers, the direct sound is
louder. Then as we move back, the direct sound falls off in
SPL according to the inverse square law, but the reverberant
sound stays just as loud. At some distance they become
equal in loudness, and then at greater distances the
reverberant sound is louder. There is some continued
falloff in overall SPL all the way to the back of the room
as the direct sound's contribution gets weaker and weaker,
but that falloff is asymptotic rather than linear, with the
reverberant field setting the lower limit.

(I've made a few simplifying assumptions here, such as
ignoring room boundary effects, lumping early & late
reflections together, and glossing over the transition zone,
but the general principles described are valid.)

Duke

Duke,

While I completely agree that reverberant sound will mitigate the delta in SPL (from near field to distant listening), I don't think that's the relevant question here. The real question is: Will it mitigate the delta enough to be the optimal solution for the OP's application?

In almost every large commercial space that I can think of: Nightclubs and bars, restaurants, gyms, hair salons, retail stores, etc. - the preferred solution is multiple speakers. Shy of a combination retail/performance space (or possibly a pro-sound store), I'd think that very few retail businesses operating in anything like the OP's 90' by 24' room that would be best served by a single set of stereo loudspeakers - even if the power response of the speaker is essentially perfect over a very wide window.

According to the OP, he is not selling audio equipment. I am curious, are you suggesting that you think a single pair of loudspeakers is likely to be his best solution?

Imo multiple speakers done right might be a better solution, depending on what the OP is trying to accomplish. But done wrong, they would be a worse solution, from what little we know (a TV screen is sometimes involved).

If multiple speakers are used, then we should time-delay the outputs of the speakers that are farther away from the TV end of the room. Otherwise listeners will get clarity-degrading arrival time miscues - they'd hear the side speakers first and then the front speakers, and the ears would localize the sound from where it first arrives, which would be distracting if the sound is supposed to come from the TV screen. Even with such time delay, there may still be areas of good and poor intelligibility within the room.

Unamplified music, from quartets to symphony to choral groups, is "played" from one end of the room only and people seem to not mind. So too with most amplified bands, but the average amplified band is seldom the paragon of clarity.

Without knowing what the purpose of the room is, it's hard to say what the optimum system would be. It may well be multiple speakers, properly delayed.

Duke