Date:         Wed, 4 Jan 2012 19:58:52 -0500
Reply-To:     Derek Drew <derekdrew@DEREKMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Derek Drew <derekdrew@DEREKMAIL.COM>
Subject:      Re: Sound systems (yet again)
In-Reply-To:  <CAHbJSdUuOEiCqSqQ76_AUgcGrwKMOXvvkvxFU=j5t6Dcste1UQ@mail.g
              mail.com>
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For door drivers, mine are both 6" JBLs, one mounted in the stock
location, and one mounted down near the motor for the power windows.

Both locations require a little metal removal from the door, but not much.

They are rated at 175 to 200 watts each; the top one is with a
separated tweeter, and the bottom one is conventional two-way type
where the tweeter is mounted in the center of the woofer.

For the rear speakers, I have two old Kenwood 6 x 9 drivers that I
selected years back after spending nearly a whole day test listening
to drivers of this size. These are also rated at 175 watts each, and
I'll put them in the traditional Westfalia locations. Even though
they are too big to fit there, I have so much confidence in their
sound I'll force them to using VanagonOwnersAstoundingInginuity tactics.

For anyone else starting fresh, I think 4 x 10s or a size like that
would be much better. I am a prisoner of the findings I had that
listening day.

I researched 6x9s, and it seems that the typical 6x9 likes to be in a
box 0.5 cubic feet.

So, I'll drill a hole for the driver's side rear speaker into the
closet and make a box inside the camper closet at that location so
the total box volume that speaker sees is 0.5 cubic feet, including
the space from behind the speaker itself together with the nook in the closet.

Making a 0.5 cubic foot box out of the space on the rear passenger
side of the westy above the right rear passenger's head looks like
its going to be more of a challenge so I don't know what's going to
happen there, and I ain't doing anything ugly.

Mounting the subwoofers into the rear hatch seems like a piece of
cake because Bostig just announced somewhere that they are going to
build a really expensive custom-fit fiberglass enclosure to fit subs
in the back in a stock-looking way. I told them that I'd get 4 of
them and I am sure a ton of other people on this list want them too
like a group purchase. So, that convinced Jim to do it I'm hoping. I
told Jim I'd researched subs and to just make an opening for two
Alpine Type R,  Alpine SWR-T12 12 inch drivers if the resulting cubic
feet was about 1.0, or openings for 3 drivers if the resulting cubic
feet was about 1.5 feet.  I think Peter at Van-Cafe will carry the
product forward on his site with his traditional partnership model
after the group project is done so it doesn't distract Bostig.

I originally thought, WTFreak, I'll just get free-airs. But after
some research, I cannot determine any good mounting location for the
free-airs so that the backwave doesn't cancel things out when
camping. And then researching further, it seems that the car audio
folks don't have a lot of regard for free-airs in relation to what
can be accomplished with sealed boxes, so that's why I couldn't get
much of a personal-bite-of-interest with the free-air idea.  The best
place I figured to have a free-air firing into is my rooftop storage
box, which after all, is essentially the same as a car trunk. But you
don't have to think about this very long to have images of 12" holes
drilled out of your roofs to try to get a path for the air up into
the rooftop storage box, and then nightmares about what you do when
you want to take the rooftop storage box off, so that kind of killed
my interest in that from a practicality angle as well.

There is one other secret space .... a fairly large box of some
sort.... in the Vanagon which could be used for a subwoofer enclosure
that nobody knows about, which is a strange space near where your
shoes would be when you are walking up the front isleway, but down
underneath the floor (in syncros) somewhat near, but in front of, the
batteries. Its hard to describe, but there is a definite cavity there
in syncros that is hard to get to, and is free space for a time when
we should figure out how to use it.

Most subwoofers seem to say, "yes, you can use it free-air and it
will work great, but the sound handling capacity of it will drop from
400 watts to 80, and the low frequency rolloff point will change, you
may experience boominess, and the sound won't have punch, and don't
play it too loud or you will break it, and it would be better to use a box."

A friend of mine had 10" drivers mounted in his rear hatch (FJ-60)
and they sounded like crap. So I think there is something to the
sealed-box idea as practiced by car stereo folk.

As for bass thumpers/shakers, a more effective system would be to T
the stereo output into the engine ECU and tell the engine to sync the
exhaust notes to the music (or switch to the CVs or center driveshaft
vibrations if you had issues with those, whichever was louder).

I researched the transducers themselves a couple of weeks ago. I got
excited about how easy it seemed but then I found some negative
reviews, and then it seems that for some installations, planning out
power handling capacity, the amplifier, and then the shaker, and
making sure they can scale up to the  maximum  spl of a stereo system
without going nasty before looked more complicated than I wanted it
to be. The issues seemed to hit me when I got into shaker power amps,
of all things. Then, I decided that maybe I'd build the van's new
skid plates out of these bass shaker I-Beams since, if I bash one or
two, the whole bass shaking thing is so goofy anyway I wouldn't miss
them:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-920  The
reviewer says that none of the other transducers have any "detail"
like this one does.

Come to think of it, we could have a competition to see who of us
could have their van shake so much that all the nuts holding the van
together unscrew and the van ends up in as heap of vibrating loose metal.

So, that said, I want the BIGGEST one of these things I can fit under
my seats so I shelved my research till later.

At 05:46 PM 1/4/2012, you wrote:
>Let us know how the alpine amp sounds, those class D digital ones have
>been getting better and slowly making their way out of powered sub
>boxes and into fullrange applications slowly but surely. I'm curious
>to hear about how you like it, the specs are good.
>
>My girlfriend just bought me a pair of front speakers for Christmas,
>and I'm also now considering configurations for the rest of things. I
>think for now I'm going to replace the little plastic hang-down guys
>with something about as small, but much better and make them so they
>can swivel.
>
>There are also lot's of low profile subs kicking around these days
>that might make good candidates for existing spaces, but I'm not sure
>how most of them are setup and if free-air use is possible. It's
>usually easier and more efficient to get want you want with a box...
>but I don't think it would be impossible to do otherwise given that
>your main goal (and mine) is to not take up any additional space for a
>box.  I may play with some free-air subs in the rear hatch or driver's
>side panel areas, but my immediate plan for some thump is to use a
>pair of 50w tactile transducers I already have attached to the front
>seat backs. I have no need to bump around town, and tactile
>transducers really can produce a nice result without huge amps or high
>SPLs.
>
>Anyhow the thought of boxes made for low profile subs for the vans has
>crossed my mind as well, they could be pretty simple in micro-ply kit
>form... such a project would never pay for itself, but if I was going
>to do it anyways... might be a fun distraction (honestly the very last
>thing I need), but I want good sound for once! I'm done with the
>factory cassette deck with missing knob, blown out rears and 3" paper
>cone fronts. I think my cellphone sometimes sounds better.
>
>I have gotten nowhere but frustrated looking at head units. I think
>I'll just go for something under $120 as long as it has front aux in
>and doesn't have a light show as it's major redeeming feature.
>
>Jim Akiba

_______________________________________________
Derek Drew
Washington DC / New York
derekdrew@derekmail.com
Email is best normally but...
PHONE: 202-966-7907 (Call the number at left normally)
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