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Posted: Sun Jan 02, 2005 11:37 am
by GlassWolf
on a side note for that calculator, subtract -3dB for aperiodic enclosures, compared to sealed.
we could probably add that calculator to the FAQ section if you like. I'm sure people would appreciate having it around to mess with.
Posted: Sun Jan 02, 2005 11:53 am
by William from NOLA
Man. If I build my new box just right, I should be able to hit about 148 dB. I need to pick up 2 dB!! I'm sure I'll get those 2 dB if I put down my sun visors! lol
Posted: Sun Jan 02, 2005 11:57 am
by Jszar
or add a few stickers on your car, that always seems to do the trick. lol
Posted: Sun Jan 02, 2005 12:05 pm
by 71buickfreak
Have you tested your van for resonant frequency? I think your frequency is a little low for SPL, if thats what you are going for, and I think it is. you really want to be closer to the 60s. I have a 10.5cf box with a 175 sq" port tuned at 50, playing 55 (you get a natural peak from the car about 5 hz above the tuning freq) but the big boys play in the mid 60 tuning slightly lower.
Posted: Sun Jan 02, 2005 12:09 pm
by William from NOLA
I have. I even have an Excel spreadsheet of the data. It's also how I found my transfer function.
http://megahurts4.servebeer.com/cac/van ... t_1995.xls
Test equipment: Termlab mic, JL Audio 10" in prefab sealed box given 300 watts rms. We tested it in the car, and then again out in free air.
Posted: Sun Jan 02, 2005 12:31 pm
by 71buickfreak
if you ant to get really sick you build a 1/4 wave enclosure, then you can get sick. my convertible used a 1/4 wave box.
Posted: Sun Jan 02, 2005 12:33 pm
by William from NOLA
I must look up 1/4 wave box. :)
Posted: Sun Jan 02, 2005 12:39 pm
by 71buickfreak
pretty cool stuff. do you like having seats in your van?????
Posted: Sun Jan 02, 2005 12:42 pm
by William from NOLA
haha, I'd like to keep my rear row (which I can't actually remove, stupid designers, it only slides) which is slid to the middle currently. Most of all, I'd like to not have a wall or use more than 600 watts RMS and break 150 dB (don't think 150 will be broken though with my power).
Posted: Sun Jan 02, 2005 12:43 pm
by GlassWolf
quarter-wave transmission line enclosure.
very large box.
TL enclosures have many advantages for SQ. better power handling, transient response, lower distortion, and a port that's in phase with the driver.
the drawbacks are design complexity, and enclosure size.
not any speaker will work in a TL enclosure either. the TS specs will determine which speakers are best suited to this type of box.
moe info on quarter wave TL enclosures:
http://www.diysubwoofers.org/tls/
TL and Aperiodic enclosures are probably two of the best enclosures you could choose for a pure SQ system. Neither is dieally suited to SPL events though, really.