Tom, you keep saying you have tested this, and you say you are right because
you tested it, but yet you have not PROVEN anything because you have not
SHOWN us those tests. For them to be valid tests we would need pictures,
documentation, and WITNESSES to each stage of your test. Otherwise, your
words are just that, words. Words of a man proven wrong consistantly by
Eddie Runner. You say one thing, and argue it, and use obscure references,
and then when Eddie shows you the error in your argument by posting actual
pictures of the references you are using to prove your side, and showing
that they support his argument, you immediately change your tune, and start
arguing in another direction.
You can talk (argue) all you want, but you have not proven anything, any
further than everyone else here has by merely SAYING that they've had z
results from doing x test. Dozens of people have already stated that they
have had significant increases in bass output when turning their enclosures
around, but you say it doesn't happen. Are you calling everyone liars, or
just saying that they are hearing things? They aren't making it up, and they
certainly didn't DREAM it (they weren't just hoping so much that it would
increase that they imagined that it did, trust me), so how do you explain
it? I guess maybe you define bass differently than the average consumer.....
Let's make up our minds already.
Although, I could care less what Tom Nuisance has to say, since we know the
REALITY of the whole situation since we're the ones doing the real world
testing every day, and we DO notice the increase when switching the box
around.
I know we're mainly focusing on sealed enclosures at this point, but I have
a little story to provide as well, and I will share it in just a moment. My
story involves ported enclosures though, and while it doesn't necessarily
support Eddies (or anyone elses) view 100%, it certainly doesn't support
Toms either. In my case the results varied depending upon what change I
made, and proved that there was a difference between forward firing and rear
firing, but that there were other variables to contend with.
Here goes:
Ok, I have a 1994 Honda Accord LX with no major interior modifications,
other than I cut the back deck to port through. I started out with 3 JL
8w6's in a box with 2 4" ports of the appropriate length for this setup, and
an Xtant 2140c running them (bridged), with the subs firing FORWARD into the
back of the backseats, ports extended up so as to pass through the holes cut
in the back deck. I drove around a while with it like this, and it sounded
great, but I wanted a change, and wanted to show off the subs from the rear,
so, I turned the enclosure around, and changed NOTHING else. I merely
rotated the box so that the subs fired to the rear, and the ports still
fired up through the back deck. The sound (bass response) was much more
muddy, and the response was lacking greatly. Before I could play anything
from about 33hz up and it was pretty responsive, after switching the box
around so the subs fired back, I lost quite a bit of the low end response,
and some of the higher frequencies were lacking as well. I think from that
point I noticed a huge difference from 33-47hz, but from 48-63hz wasn't too
bad, and from 64-100hz was sorta ****ty as well. So, I decided to experiment
further with things, and I merely swapped the 2 4" ports out (removed the
top of the enclosure) with a single slot port, still firing up through the
back deck like before, which of course was in a slightly different location
than the 2 4" ports (2 4" were about 6" apart centered across the back deck,
the slot port was now dead center in the back deck). The response improved
greatly with the subs firing to the rear, and everything was almost as good
as when I had the subs firing forward with the 2 4" ports. So, out of
curiosity I rotated the box back around so the subs fired forward into the
back of the back seats. This muffled things again, and made the response
very similar to the 2 4" port setup with subs firing back.
So, I have not found it completely true that firing subs BACK entirely
improves the "bass", but I HAVE, most DEFINITELY, found that changing the
position of the enclosure, and the direction the subs fire, makes a HUGE
difference in output, perceived or otherwise, and that there are often other
factors (ports) involved that can also greatly affect the output.
The car was only metered twice during the entire time these subs were
installed, once with the 2 4" ports with subs forward (the best sounding
setup), and once with the slot port with subs firing back (almost as good as
the first setup), and the difference between them was - 2 4" ports with subs
forward, 138db, slot port with subs firing back 132.3db. So, firing subs
back in this case lowered my max spl, and the perceived loudness and QUALITY
of the "bass" was quite a bit different. Shortly after I removed this setup
completely, and slapped 6 JL 8w6's into a custom fiberglass enclosure in the
spare tire well (well, extending up beyond the tire well of course), but
never metered it, and shortly thereafter removed everything from the car to
start other modifications, and have yet to reinstall anything.
So, as you can see, in my case firing BACK did NOT really increase the bass
at all, and would not prove either Tom or Eddies theory, but this is just
ONE CAR and one particular enclosure design (well 2 if you count the change
to the ports). This only shows that there IS a difference when enclosures
are moved around. Anyone that argues otherwise is a complete fool. We've
seen SPL vehicles that did one #, and simply sliding the enclosure back a
couple of inches increase the output greatly (.5-3db, and while that doesn't
sound like a lot, it is when we're talking 168+db already).
I guess one of these years when I care enough about car audio again to
actually install anything in one of my vehicles, like maybe my Range Rover,
I'll do a little experiment on this very subject to see if we notice a
difference.
I would say Tom is definitely not "right" though....
Eddie is an annoying bugger, but he's usually spot on (or damn close) in his
information, and he's certainly forgotten more about audio (or has he?!)
than most of us will ever learn. Remember, he's not only one to STUDY
everything he can get his hands on, he's also a hands-on type of guy that
has applied most of these theories in his day to day business for over 30
years. He's an old MF! Did anyone mention he was a figure skater once in his
life? hahaha
"Nousaine" wrote in message
...
Eddie Runner wrote:
Luke Hague wrote:
Why then if it's not the reason that Eddie and I both feel is the
truth,
how
come it still increases bass when the subs are turned around?
Tom says
1) it cant happen!
2) if we think it does happen we dont know the defintion of bass and its
really
highs that get louder, not bass...
ha ha ha
What else I have to add would be that I see you never took physics,
and
that if you used a corvette that it really wouldn't make a difference
anyhow
because there is little trunk space.
My 2001 C5 has 25 cubic feet of hatch space which is larger and has more
movement space than most trunks.
But so what, according to Eddie all the room you need is enough to put the
box
in the car and close the boot. Then you can put it in backward.
But, I've done a full analysis of the effect including max SPL at the
drivers
seat between 10 and 60 Hz with the enclosure face facing the frotn of the
vehicle and with it facing the rear. Plus a set of full-band frequency
response
measurements with the enclosure faced either way.
The ONLY thing that happens is that an interference effect at 188 Hz can
be
seen when the woofer face is facing the rear of the car.
Think about how small a corvette is on the interior, I can barely get my
fat ass into one, so just how much can the woofer box in the back
actually
be moved for the test???
3 feet front to back and 4 feet side to side.
We can scoot a box around in a normal car trunk several feet, in Toms
Corvette piece of **** I would doubt there is enough room to move a box
around more then a few inches...
EVERYONE here can plainly see, but dont expect a reversal
from Tom, he wrote a magazine article for the kiddies and it would
be too big of an embarasment for him to admit he is wrong now..
(human nature I think)
Eddie Runner
http://www.installer.com/tech/
It's human nature for you to continue to posture but not put your claims
to the
test. You are simply very wrong which can be shown through a simple
experiment
with the variables controlled. This I have done before and I did it again
in
the past few days and the experimental evidence shows you are wrong.
A single boundary cancellation will occur in a car but it never happens
below
the lowest axial mode of the vehicle interior space. In a compact car like
an
Integra, CRX, Civic, Spirit, Camaro, Corvette or even a full size X-Cab
pick-up
this cut-off point is 60 Hz.
In a Pontiac Bonneville its a few Hz lower. In a full size van it may be
as low
as 45 Hz.
But, no matter what car you're using this is related to the volume of the
interior and it doesn't cancel deep bass and a single or mulitple boundary
cancellation always occurs at frequencies above the lowest axial mode.