Well, I know this isn't really most of the people on here's style, but thought some of you might appreciate the old-school stuff. This isn't going to be a really detailed build log, but it will show some of the steps we went through building it...
First, the van...1996 GMC Safari (we just call it an Astro)
We determined for the goals of the system, extreme low frequency extension, monster air movement, and pretty good SPL, a large ratio, somewhat peaky 4th order band pass was the way to go. After measurements were taken, we determined a 3;1 would work with 6 cubic feet sealed per three JL 18w6, and 54 cubic feet total for the combined ported chamber. Here's the beginnings of the sealed part, using 3/4" birch. (We went with single layer on most, mostly because the width was very limited.)
The sealed chamber complete, inside the van...(the ported chamber was also started in this pic)
Working on wiring up the subs, after painting of course.
Subs all ready to go..
Braces put inside ported chamber...
After testing for the resonant frequency of the sealed chamber inside the van using a DATS from Parts Express, we determined we wanted to port the front chamber at the same frequency, right about 46hz. Here is a pic of the front loading wall and port. The port is somewhere near 1000 sq inches (Can't remember exactly off the top of my head), and we used three sides of the enclosure for the port, and 4" PVC cut in half lengthwise to round the edge of the loading wall, which is made of 2"x4" sideways and 3/4" on the inside and outside of it.
Picture from outside the van of the loading wall, and it all sealed in to the front of the vehicle.
The start of some center console ideas. It would hold the brain for the marine Kenwood radio, so we could control it with the separate marine controller from outside the van. Also holds the Autotek 30 band EQ, and Audiocontrol crossover/EQ plus various switches for the amps, etc., and storage space.
Top area of the console, where the EQ and crossover will reside.
A picture of the ceiling, we wanted to make it solid, didn't want as much rattle as some of the loud vehicles out there, though we knew there would be no stopping it completely. It's two layers of 3/4", attached to the front brace, middle brace, and loading wall, then a thin layer of 1/8" just as a trim piece.
The beginnings of the amp rack for the VLX-400s, and below it is the rack for the 6 C&D 147 Ah AGM batteries. (There is a smaller C&D battery up front). In process as I do this build log is an Ohio Generator 300 amp alternator.
Test fitting the amps
First show...
First MECA show awards, 1st place in it's class, PHAT Install, and Best of Show
My buddy accepting the trophy and $250 gift certificate for First Place at Parts Express Midwest Audiofest 2012, the Autosound Challenge
It does 153.4 at about 40 hz on only 3500 watts clamped, at 8100 watts it did a 155.9. Eventually it will get an American Bass VFL-1100.1 on the subs, and the VLX-400's will be moved to mids and highs. It should do in the 156.5-157 range sealed up legal SPL style. It is only about 1.5dB down at 27hz too.
Very nice. Did you try out a W6 in a ported enclosure? How'd it do if so?
Humph umph tsk tsk hump umph tsk
Quote:
Originally Posted by MarkZ
It's not Tchaikovsky. But it's still music that people like and that people want to listen to. Therefore, the goal is to meet that demand. When you let your audio system dictate the music you listen to, you've lost.
Very nice. Did you try out a W6 in a ported enclosure? How'd it do if so?
I didn't personally, but another guy I know did. I know they aren't recommended for it, but they sounded good and had no problems with about 1300 RMS each.
Astro van 9 JL18w6, 3 U.S. Amps VLX-400
Linear Mode
