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Nousaine wrote:

Mark Zarella

i have heard putting subs at the back facing forward have more
cancellation issues due to wave bouncing off the back end and
cancelling the front wave...i read it in a website...

You can also read about alien visits on websites too. At bass wavelengths
(17
feet @ 60 Hz and much longer at lower frequencies)

(and shorter at higher frequencies)

there just aren't any
"cancellation" issues going on in the car cabin.

Sure there are. The wavelength is on the order of car size. A 9ft path
length difference is enough to put the 60 Hz wave completely out of
phase. A 90 degree shift requires only 4.5 feet. That can easily be
the path length difference that the poster was referring to.

4.5 feet is not the "distance" involved in deciding which "way" to face the
woofer at subwoofer frequencies.

In your living room the standing wave region will occur in the bass range
(roughly 30 to 300 Hz) but in a much smaller space this is shifted up by
about
an octave (60 to 600 Hz in a small car.)

But even at 60 Hz any 'cancellations' will occur at a fraction of a
wavelength
(200-300 Hz) and not at the fundamental.

You don't need 180 degree differences to create attenuation or any other
response irregularities. Even so, why are you ignoring the importance
of "higher" frequencies?

I'm not. But most people will low pass a "subwoofer" which seemed to me to be
the point of this thread. As I said earlier in a vehicle the standing wave
region is shifted upward in frequency by an octave compared to a listening
room, which is an interesting phenomenon and problem but it generally isn't a
"do I get more/better bass when the woofer faces the rear of the car?"

Bass is the same either way. Midrange can be a factor.