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Mark Zarella
wrote:

But Eddie and the woofer-direction folks aren't talking 90 Hz.

What gives you that impression?

Because that's not what he talks about.

But I'll agree
that many people will interpret changes at 100-200 Hz as "Bass" effects.

As they should be. Furthermore, there's quite a bit of information
under "100-200Hz" yet above 20Hz. Wouldn't you agree?

Sure but most of that, generally below 60 Hz or so depending on vehicle size,
is happening in the pressure zone where woofer location and direction are
irrelevant.

What is interesting is that with the woofer facing the listener it's quite
likely that there will be significantly more low-midrange output. This can
either be an advantage or a problem, depending.

But the argument in this thread is that simply facing the woofer toward the
rear of the car delivers more bass.

Not the way it's been stated by Eddie. Eddie has simply pointed out
that it provides a difference, not that it's necessarily better. He's
mentioned that people TEND to like it the other way, and he's described
the source of the difference.

No he doesn't.He never mentions any frequency other than 60 Hz. He has shown no
understanding of the physics involved and the true acoustical nature of what's
happening.

His description is straightforward and
obeys the laws of physics, yet he's never gone into the specifics of the
effects on the spectral response.

It doesn't obey the laws of physics at all. The 'effect' he describes is not a
standing wave effect at all and it doesn't occur at 60 Hz as stated in his
example with the physical distances stated.

The 'effect' he describes is best described as a single wall reflection
interference notch or a floor bounce with a tower speaker where the effect with
a 60 Hz signal will occur at.150-300 Hz.

It can only do that when you consider
upper-bass and lower midrange(usually 80 hz and above) as the key elements.
Depending on the intended woofer operating range this may or may not be
important.

It's almost always important.

But the general population seems to simply classify any change in sound as
more/better "bass" when it's not.

I think it's useful to break down these Urban Legends into component
factors
and focus on what's really happening acoustically.

Yes, it's worth an in-depth description. I think Eddie's webpage
provides a general description, but it's hardly a comprehensive one.
His website is geared towards users with a certain level of expertise,
and I suggest that someone further describes the effect. Preferably,
someone who's actually made the measurements. But to come in and say
that the effect doesn't exist flies in the face of the common
observations made by just about everyone that's installed a subwoofer.

I've fully described what actually happens on this newsgroup. I've also done
the experiment a number of times and I've replicated the Eddie example outside
with a single wall reflection with a 12-inch woofer in a small sealed
enclosure.

In his example one can see an interference notch with his suggested 3-feet
distance that occurs at 280 Hz. Other than that the basic "difference" between
the woofer faced directly into the wall compared to the same woofer facing away
from the wall was approximately 9-dB more output above 400 Hz.

I've never said that no effect occurs. I've simply described what actually
happens and at what frequency it occurs.

Eddie's description is very misleading and he seemingly hasn't actually ever
done the measurements or he would know that his description is incorrect.

I'm sending an e-mail to you with "woofer direction" measurments actually taken
in a hatchback car where the response and Max SPL capability are graphically
described.