if he ever comes back, he should look into Digital Designs. back in the day i ran 3 JL 12W3s off of a MMATS D200, hit 150 area consistantly at dB shows. I switched out the 3 12s for one DD9515 (15) off of the same amp, and was not very far off (never got that measured officially). this was in the trunk of an Acura CL with sealed boxes. i used to hate hatchback guys, cause they do have the ability to hit higher numbers with the same setup. ahhh, the good old days.

 

We had a crew of crazed DD fans that would show up in WV and VA shows wearing baseball helmets with parts of blown DD subs glued on them. It was always fun.

 

PM sent.

 

sorry was busy geting drunk. yea i guess i deserve some knocking around, i expected that. anyway Im in process of picking out what I want since MLG ooked me up with one of hins custome boxes this week.

Thanks for all the coments I enjoyed it all.

Yea i wish i hade 20k to drop on audio.

ill read more when im sober.

 

yes you can definetly hit 150 in a Z with two squares...it key is in the box design...

i have seen 170 plus db LEGAL from a single 18, near 170 from a single 10 in a van no less...all legal DB drag scores...

so with enough interior removed, and a proper enclosure installed two squares can definetly hit 150 plus, the solo X is a monster of a sub lol

b

 

Big question .. at what frequency.

If you are talking about 74Hz (or any random high number) or some BS tone like that, who cares. There is no such trick to "designing" a SEALED box ... make it strong .. thats about it. If you are talking about a monifold ... somewhere you can place a mic where there is good compression ... I just don't get what you are talking about in "designing" something here.

 

maybe he meant air space / box size. i can design a .25cuft box for a 15, but it won't sound good, but with different air space you can tune.

 

I can see that ... but there is no "art" to designing a box. T/S params = box volume ... no hidden tricks to it.

 

Volume is the biggest part, correct, BUT there also is construction, not having leaks and having a box that stands up to the pressure/weight/vibration of the sub. Past that, box placement is very important. I have seen +/- 6b variances just from moving the box around in the trunk and the direction of the subs firing. On top of all of that there is always the ancilary problems of the vehicle, where the sheet metal is, how much there is and what kind of deadening it has.

The enclosure is almost as important as the Sub in a lot of ways.

 

Believe me ... I fully understand the effect of an enclosure ... I am just stating that there is no black art here (building one strong is about the only thing to do).

Just because a vehicle can measure loud (at a point - ie a mode) doesn't mean that it IS that loud all over. Box placement and mic placement are an "art", yes ... but that doesn't make the system any louder ... it just scores better

 

I gurantee though that a car that measures 150+ on the dash or kick panel will be LOUD to sit in. Most SPL Machines make their max base between 25 and 60 HZ (A Pretty broad range, but still low). 150db at lets say 35HZ feels pretty uncomfortable to be arround. The Upper 140s is about my max for tolorable listening, I prefer the lower 130s for "LOUD" bass in my SQ car, it also minimizes rattles.

For a guy that is used to less than 140db, 150 will make him feel like a super star.

 

My first DB-Drag event was a total let-down. Those high-SPL systems sound like a$$ when they are playing. Mine sounded very good, well-balanced with 138db. The Announcer made a comment that it may only be 138db, but that was between 25 and 35 Hz (with my selected material). This was with 2 Earthquake magma 12's with 400 WRMS from a PPI amp in the back of a 91 CRX. resonant freq of my box was around 30 Hz

I later learned about the resonant frequencies of the winning cars and that the mic was low-pass at 200 Hz. Some guy's systems were tuned to like 110Hz. Yuck! Also, mic placement is critical. The science just took alll the fun out of it. I was not willing to make my system sound like a$$ to get a high-SPL score so my first event was my last try.

 

I won a couple of first places up in Seattle for guys that worked for me this way in 1998-1999 dB drag races. They were all excited about entering the contests and were chatting about their speaker's and amplifiers. I asked them the procedures that the judges used. The car owner puts a CD of their choice in the player, the judge hangs a microphone inside, the doors and windows are closed and the measurement is taken. There were different race classes based on the number and diameter of sub-woofers.

I took a song and mixed it with a 1200 Hz 0 dB tone using Cool Edit Pro and gave it to the guys. One guy used the CD and took first place - that 1200 Hz tone fired his mid-ranges to insane volume lables ... and the song sounded like shoot to begin with. He said that from the outside you could hear the 1200 Hz tone somewhat but the bass notes of the song were what came out the loudest outside the car. These clowns used this same technique to win more than a couple of contests ... then someone got smarter.

Clearly if you're attempting to go hard core and drive yourself deaf in as quick as means as possible - and it's happening everyday to thousands of people - try one of these - this is what I call hard core:

 

M4gery with an Aimpoint, with Hogue Grip, YHM Rear sight(?) In CALI none the less???

 

the guys who are truly into the higher specturm of spL comps indeed makes box building an art.

at those levels, its no longer about sounding good, its about producing the highest pressure...

for example... how can someone armed with a single sub, produce higher SPL than someone armed wtih 12 or 15 or 20 or 32?

the ability of the sub of course counts for a little, but the rest all comes down to engineering and ingenuity...

say you have a SUV, and you have a single 12" sub, and you want to reach well over 160 db on the dash LEGAL, as for what freq, you obviously build itto the sensitivity of the SPL mike...usually in the 60hz range...

if you think this is simple, i invite you to try...but, if you are one of those truly gifted, you can come up with a 10 or 20 cub feet 6th or 8th or a millionth order bandpass enclosure with various little techniques built in, to get you there...

high 160 dbs have been achieved in this manner by a single 10 in a blazer...

 

you guys suggested a sealed box. I arguedthat there is no art to that. Now you come out and talk about bandpass boxes and stuff ... changin the game on me here.

Regardless ... I will again state that anyone with good woodcutting skills and the correct spreadsheet (with the correct T/S prams from their sub) can make ANY box with no special art or skill.

I don't want to try my hand at box building... I stick with building the woofers

 

I suggested a sealed box for Simplicity, you can get much more bass out of a ported type of enclosure.
Personally, I run an aperiodic enclosure for my single 10. Just getting the pressure release vent tuned was a nightmare, but had a satsifactory result.

So you build woofers for a living? (JBL?)

 

Cool ... I'm just arguing for the sake of arguing most of the time .. just passing time. I'm not sure what the OP here got out of all this .. but I hope he gets a good system

I used worked for Klipsch a while back .. then Pioneer .. but have since moved on to other things (I didn't build woofers .. ie - not a production line worker on here acting like I know a thing or two - I actually designed them)

 

I always liked Klipsch home audio, I have used/auditioned quite a few speakers of theirs and have always been inpressed with the range and clarity they got out of those horns.

I have been an audiphile for a while and competed in Sound Quality competitions in my car for a few years (even winning the World Championships in 2002). I wound up judging sound quality systems for a few seasons too. Lots of fun. I have probably sit in close to 1,000 cars with just about every make and model of speaker made.

Some of the best stuff is usually from the guys that didn't have a fortune to work with, but spent a LOT of time building perfect installs with the correct wiring, engineering and design. I have seen $3K systems completly beat down $40K systems in imaging, clarity and definition. Its really amazing what you can do with a little art and a lot of science.

 

in my ford escape i hit 135 with 1 12w7