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Eddie Runner wrote:

...large snips .....

Nousaine wrote:

Again, in a vehicle the interior volume and dimensions are such that the
pressure-region where the speaker displacement pressurizes the cabin
instead of
setting up standing waves begins somewhere around 50-60 Hz depending on the
vehicle size.

My definition of pressurizing the cabin would have to be a wavelength where
the
vehicle cabin would be no more than about 1/16 to 1/8th of a wavelength, so
that
nearly the entire cabin could have the same pressure level at the same
time...
in a vehicle that has a 6 or 7 ft front to back interior and a side to side
width
of about 5 ft... It might happen at 20Hz where the 1/8 wavelength is about
7ft and
the 1/16 wavelength is 3.5 ft.... the difference in 3.5 ft is 22 degrees...

Moving up in frequency to 40Hz, the 1/8 wavelength is about 3.5 ft and the
1/16
wavelength is less that 2 ft.... Geez, it seems like a real pressure wave is
kinda
hard
to have in a normal sized car at 40Hz Tom...!!! ???

You seem to be making this up as you go along Eddie. Cabin-Gain in vehicles is
a well known and establish phenomenon. You can planing see from the near-field
lab measurements and in-car frequency response measurements from my woofer
tests it begins at 60 Hz in a Corvette or other car with similar interior size.
BTW this car has a 25 ft3 hatch area so acoustically it's larger than a CRX and
about the same as an Integra or similar vehicle.

It's also well known that pressure effects begin below the frequency of the
lowest axial mode in any given space (which is 60 hz in this car and 26 Hz in a
22-foot long listening room.) One can see from the graphs that providing the
speaker has adequate displacement I get nearly 30 dB of low frequency
reinforcement at 8 Hz.

Pressure gain is harder to realize in a larger space such as a living room
because it begins at a lower frequency and the space itself requires much more
speaker displacement to energize. There is also more low frequency absorption
in a larger space especially with stick-frame construction.

For example it's not that hard to get 120 dB SPL @ less than 20% at 12-62 Hz
distortion from a good 10-inch speaker in a 1-ft3 or smaller enclosure because
of pressure reinforcement (Cabin Gain). In my 7600 ft3 Home Theater it takes 8
15-inch TC Sounds woofers in an infinite baffle to get 120 dB over this range @
2 meters listening position.

Now you can put your 1/8 wavelength back in your butt Eddie.