4 speakers vs 8 speakers

[WolfWings]

Originally Posted by talnlnky

thats theoretical...
+3dB if you double cone area
+ 6 dB if you double cone area & rms

Human brain/ears perceive 6-10dB (different for each person) as a doubling in sound, not 3dB.

What I've left out so far tho is that for tones above 200hz you start to have issues with cancellation of the sound waves when you run more than 1 speaker. The more speakers you put in the car, the more convoluted the situation becomes..

You get sound wave interference at all frequencies, actually. There's a reason the current world's loudest car is a single speaker driven by four amps in parallel to provide the power. Not even a pair, or a quad, just a single massive subwoofer.

6db is roughly twice the physical sound pressure change, but it's 10db for an apparent sound volume doubling for our ears, that's what the scale is actually calculated against: Every 10db = double the loudness to our ears, which ends up being about 3.16x the physical pressure at each doubling of apparently loudness.

And you get a lot more than 2% of the sound from the rear speakers, the problem you have to bear in mind is that sound is not a single fixed entity: You have various frequencies to deal with, and the most easilly damped frequencies are the highs. Those get muffled severely by your front seats when played through the rear speakers, though you can adjust for that. You are still (in effect) playing the speakers through a pillow, so it's vastly less efficient than using a good set of front speakers.

A single pair of front speakers is the most efficient setup for stereo listening.

I'll say that by itself so it's clear I'm not trying to say otherwise. But it is possible to set up a pair of rear speakers to sound very good too, if you have a reason to invest the added expense and time to do so. It's far more expensive either in time or seperate equalizer components for the rear and front than just slapping a good pair of speakers in the front and calling it a day.