A little bit about my system from previous post here.
http://www.clubknowledge.com/cgi-bin/car_audio_faq/faq.cgi?g4910
Went to summer showoff 2007 in ohio this weekend and showed the car off, was a great time. They had a audio comp. with bass race and db drag. I hit 136.8. with 2/12 inch jl audio w3's with punchpower 800 a2 old shool amp. and a 1 farad RF capacitor. thought i was doing ok, untill i see a mustang with one mtx 12 inch and a hi fonics amp hitting 139.0. was it because he had a hatchback?
I was 10 seconds away from winning the bass race (which you couldnt hit above 129.9 but had to stay as close as that number as you could for 30 seconds, I was holding it right at 129.0 with the other guy olny staying around 120 db. when part of the song hit a bit lower and made me go to 130.1 which is DQ.
It was my first comp ever, just to see what i was even hitting db wise. The guy who put on the stereo comp in ohio had a memphis audio yellow van set up with a bunch of subs that was hitting 150 + it was for sale . show was alot of fun. now where should i start in gaining more db before the next show. I need some dynomat put in trunk i know that, how much should that gain me?
at the present time i still have the sealed box. should the w3's be replaced. I want to hit in the 140's..
Replies (11)
30Hertz on 06/10/2007 19:28:39
I'm not familiar with the Bass Race class however some people I know do compete in it on the east coast. However, the Bass Race that I've heard of, your NOT limited on the dB output. That doesnt make any sense. The Bass Race is suppose to be the highest average dB over a given amount of time using any available MUSIC cd on the consumer market.
SPL encompasses to many things to list, but 3 big ones are, surface area, power and enclosure design.
I'd think you should be able to hit in the 140s no problems with a pair of 12s, however you wont be hitting close to that with a sealed enclosure. You need to redesign your enclosure and go ported for sure. A buddy of mine hit 150dB on the Term Lab with a single Sony Xpode ported just to prove a point. Grantid he loaded about 3kw of power to the sucker and the box was a one note wonder but it worked.
Power is another! You can get loud with low power but it takes a LOT of time and knowledge in the craft of SPL. No one just outa the gate is going to bust out with high dB without some serious time and effort put into the design, testing and more rebuilding till you have found what works with your vehicle and the power given to it.
Surface area plays a big role in the SPL capabilities but isnt always a must. The more surface area (the larger the sub) the more air it can potentially move to create pressure. The Xmax of a sub plays a part but generally you dont have to have high Xmax. Xmax gives a higher potential to be louder and the lower frequencies due to the wave length being longer. Generally speaking, most SPL is done within the 40-60hz range and doesnt require a huge range of motion on the part of the woofer due the shorter wavelength.
Theres to much information to really go over in a single post for you to grasp and understand.
Main thing for now,,,,redesign and build a ported enclosure. Test and redesign. If you have the cash, and are serious about getting indo dB, IASCA, MECA or any other Sound associate let me know and I can give you some solid proven performers for subwoofers, amplifiers, alternators, batteries and pretty much everything else that are common in the lanes.
Now I'm back to work,,,,
-30 Out
COFFEE
Pontiac_gp_dude on 06/10/2007 21:15:36
before i bought the fosgate punch power 800a2, i had a coustic amp 1200s 2 channel amp which im not using, ( i believe this amp is 250w per channel) my question is can i hook up that amp also and use both channels of it to one sub, and then use my fosgate for the other sub, would this work or not so much? i imagine it would make one sub louder than the other, but i just need to know if i should sell it, or use it for now.
2nd question is , if i bought a JL audion 1000/1 amp. can that 1 channel be used for 2 subs, untill i can afford a second JL 1000/1?
Pontiac_gp_dude on 06/10/2007 21:19:39
is there a big ported box online somewhere thatwould be sufficient for my to jlw3's for the bass im looking for, as im not very good at building , i could build something but it wouldnt be perfect. thanks for all your help
Pontiac_gp_dude on 06/10/2007 21:23:38
The reason i was limited to 129.9 in bass race is because in qulifying the promoter told me to stay under 130.0 to stay in that class as it would be better for what i had, as im wasnt hitting close to a 139.9 for the next class. you can see the rules here shows under qualifying, i was trying to stay in the 129.9 class.
http://www.termpro.com/dbdrag/rules/index.asp?Page=3
30Hertz on 06/10/2007 21:50:26
I do not suggest using two different amplifiers to power a setup.
You need to run either 1 amp per sub, or two subs per amplifier. If you run one amp per sub, it needs to be the same make and model as the one being used for the other subwoofer.
Also keep in mind, if you run more than one amplifier it might place you in another class. Read up on the class rules before making any decisions on whether your going to run two amplifiers or one.
You can run a single 1000/1 for two subs. Just make sure the impendance given to the amplifier is correct. (Two JL subs wired in paralell should be fine for the 1000/1.
Your not going to get the best results from a prefab box. Not only that but larger doesnt always equal a higher SPL. It depends on the frequency being burped and the subs parameters. Generally for CRX boxs and higher tuned ''fart boxes'' we have a smaller enclosure. Lower tuned we generally go bigger. Also if were running two subs or more we go bigger just because of the airspace needs from the subs being used.
-30
Pontiac_gp_dude on 06/20/2007 17:35:59
Would this box do anything better for me?
http://www.hifisoundconnection.com/Shop/Control/Product/fp/SFV/30046/vpid/1632950/vpcsid/0/rid/118099
kirchatndftbl on 06/21/2007 00:32:25
thats still a prefab box a custoom box that you know what its tuned too will probably do more justice
i thought you had 2 12's this box is for two 15's
Pontiac_gp_dude on 06/21/2007 12:07:40
yea i meant to post the box with 12's in it, does say it is meant for jl w3 subs. I need someone around here that can build me one.
kirchatndftbl on 06/21/2007 20:34:03
if newb is paying attention to this he might be able to make one and ship it for a reasonable price but thats up to him if he sees this post
sounds of peoria can make boxes but i wouldnt trust them to install anything
swez on 06/21/2007 21:04:55
Hum, I take it you meant to link this one:
http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/1632940/vpcsid/0/SFV/30046
That's not a bad price for a semi-custom, dual 12 ported sub enclosure. Question is... how much would shipping costs be to your location?
Yes, a good box maker can use these dimensions and tune the ports to your desired needs too. However, finding a guy who knows what he is doing and can meet your budget needs locally may be a bit more challenging. This is time consuming and materials costs are about $60-75.00 alone.
The other issue here, if you don't have flip down rear seats in this car, to get more bass SPL into the cabin, making a pass through vent from the trunk to the cabin is pretty much a must. In most sedans and coupes, this means making a large vent in the rear deck and make it look good and large enough to pass bass waves into the cabin. That often takes some good planning and can be very labor intensive too.
However, just doing the vent is sure to net a solid +6 to +10dB more bass SPL inside the cabin. That would improve your numbers in competition and can still use the sealed box you have now. This give us the best SQ and a good uptick in SPL w/o buying a new box.
Comments?
Swez
kirchatndftbl on 07/11/2007 21:44:16
any luck yet??? hows everything goin
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