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.

No? If you compare the two extremes that Eddie brings up on his site
(namely, rear of the trunk, opposite orientation vs. front of the trunk,
facing driver), a 4.5 foot difference is easily achieved.

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.

Low-passing does not eliminate the frequencies in question here. It's
common to LPF in the 80-100Hz range, which still delivers quite a bit of
content in the 80-100Hz region to the subwoofer. Most consider 80-100Hz
to be bass rather than midrange, though admittedly the distinction can
be arbitrary.

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.

Pathlength differences demonstrate that this is not true.