subwoofer box install info - experimentation

[amalventano@sc.rr.com (Allyn)]

...so i did some research tonight. rigged up the amp and the old sub box (after
some examination).
it turns out the old box is in fact partitioned (each 10 gets .72 cu. ft). i sat
the box in its old location (up against back seat) and started the test runs:
- pointing at normal location (up/aft, parallel to hatch glass): bass was the
most efficient at this location, had to turn down to minimum setting just for it
to be bearable. seemed a little sloppy due to the resonance of the hatch, but
impact-type bass (drums) sounded very good.
- pointing directly backwards: had to turn gain to middle setting. bass notes
were good, but impact was lacking. i stepped outside, closed the door, and
quickly realized that this location was only good for finding rattles :).
- pointing downwards (2" gap): about the same result as firing backwards, except
impact bass was non-existant, lost out the bottom of the car. would have been
better if i had some way to direct the bass either forwards or rearwards (it was
going both directions the way it was sitting). i had to turn the gain a bit
above half, so this seems to really waste alot of power. when outside, i
realized a completely new set of rattles emerged, and all i was really
accomplishing was rattling everything in the garage (as the bass was going right
through the metal at the bottom of the hatchback, hitting the gas tank, etc).
- firing directly forwards: wow. i was amazed. gain had to be set at 1/4. not
only could i hear the impact of the drum, i could hear detail within each drum
beat. there was some resonance, but i think that was because the box was still
sitting 2" above the hatch floor, effectively making a bandpass with the front
chamber being the space between the speaker and the rear seat, and the port
being the space beneath the box. another side effect of this was the mini-back
massage i was getting. i imagine it would be one hell of a massage for one
sitting in the back seat.
- i then tilted the box, putting the speakers as close to and up against the
rear seat. this got rid of some of the resonance, and i didnt have to mess with
the gain either. now the incredible bonus: NO bass/rattles outside the car, even
at very high volume. once you open the door, you hear/feel bass. its as if the
passenger space is the enclosure.
- the only thing i couldnt test was that suggested by mkiivr6, as the box isnt
shaped that way. i believe a setup like that with the opening facing forwards
may work well, but thats unknown at this point.

    why the heck do i see all of these 'high end' installs with all speakers
aiming towards the back? how do those guys get any kind of clear impact/drum
bass? ...or are they just going for the max 'boom'???
i'm going to do some more experimentation in the morning.
Al

----- Original Message -----
From: "Allyn" <amalventano@sc.rr.com>
To: "scirocco list" <scirocco-l@scirocco.org>
Sent: Saturday, November 30, 2002 12:37 PM
Subject: subwoofer box install info


> i've decided to go ahead with putting my old subs in the rieger. i will make
it
> a quick disconnect type of setup where i can remove the box+amps to get the
> weight/space back if needed. i need some first hand advice/experience as far
as
> the speaker direction is concerned.
> - past setup:
> 2 kicker solo-baric 10's in a sealed box, .7 cu ft. per speaker, no divider.
> speakers located directly behind rear seat, driving upwards at 20 degree angle
> towards the rear (i.e. parallel to the hatch glass).
> - that setup was decent, but it was a little echo-happy. i think it may be a
> combination of me not dividing the box (each speaker also had the other
speakers
> airspace, only became an issue where bass notes were coming from a single
side),
> and the fact that the speakers were driving mostly upwards, using the whole
> hatch as a resonance chamber, which made too much of a peak at certain
> frequencies.
> - proposed setup #1:
> same 2 10's in a new sealed box, with a divider, .8 cu ft. per speaker.
speakers
> driving directly at rear seat (parallel to it, 20 degrees up from horizontal).
> - proposed setup #2:
> same as above, with 10's driving directly at the rear.
>
> when making suggestions, please realize that i am not looking to impress
people,
> i want the most accurate sounding bottom end as possible. i'm driving the subs
> with 800w, so power is not an issue. my main problem is getting rid of the
echo.
> i think my best bet is #1, but i am not sure about the airspace with that
> configuration since there will be added load at the front of the subs (due to
> being right up against the rear seat).
>
> thx in advance for info
> Al
>
>
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