Contour Enthusiasts Group Archives Forums Modifications Audio 148.7 Decibels at DB Drag ... on the quest for 150.0

Welps ... I went to the car toys first DB Drag of the season here in Washington today and I held it up for the tours baby. Yours truly turned in a DB Drag meet high 148.7 db and won first place. God, I never knew the 'tours could pound as hard as I did!

Next Mission - Next Sunday at 1:00pm in Everett CarToys for the sound-off there on my quest to break the 150 decibel barrier.

Jared
SVTweeter

hmmmmm 4 15 L7's with a rockford 800.2? hmm and only in the high 140s...something wrong there man...better get your car sealed more and i wanna say...well get so more power man..your under powering those subs by far..just had to put my 2 cents in...sorry i'm a car audio store owner...saw the post..

MHO, you should be close to 150 with 4 15's but remember it's in a trunk, if you had a hatchback you would gain alot. I dont think that you will gain the 1.3dB (unless the mic is a totally different mic that is not calibrated properly or the same as the other) 150 in a stock car is hard to acheive but not impossible ( 4 15's is a good place to start though too ) It will depend on a few parameters that were not mentioned in your post. I have bested a 152.4 (and backed it up with 151.9 and a 152.1) with just two 12's and about 2400 watts, no wall, in an Escort though. The car was stock, but had several extra batteries too.

Since it was a dB Drag event what were your other scores? Curious as to how you scored in the earlier and later rounds.

First Run - 147.1
Second Run - 148.0
Third Run - 148.7

After the competition was over I went with a different CD and actually hit a high 149, but of course I can't count that run. I'm thinking of getting 2 more Rockford power 800@2's however I kinda want to stay in the lower watt class. What do you guys think. Will the extra 2 amps, make it sound that much louder? If I get 2 more, then I would have 1 amp per speaker. I've already used like 72 sq feet of dynomat. Any ideas?

Well, Every doubling of total power should net you close to 3dB without considering the effects of power compression.

Dave

Well its good to se that you did get louder everytime. Most dB drager's stay around the same dB, unless they sandbag...LOL. So what it appears to me is that you were not sure of what note to play before you got the show. Once you figure out what the best frequency for your vehicle is starting off with that note on your first run should yeild you the loudest score of the day for you. On your way to the show did you play the subs? I recommend that you keep the subs completely off (you can turn them on before you have to compete JUST to make sure everythung is working, but not loud and for a few seconds only) Going up to the "tower" with your subs completely "cool" gives you a lower impedence for your very first burp. While playing your speakers on the way to a show the voice coils will heat up and raise you impedence of the coil, resulting in your amp producing less power.

I always got a good laugh out of the guys that roll into a dB drag event with there systems full blast, not only does it hurt them at the show, but never do they have anything worth showing off. Then they get spanked at the show and wonder why and ofcourse they leave before the show ends since they lost....LOL

One amp per woofer is a great thing, but will require proper tuning so that all the amps are producing the same power to each speaker, espcially if the woofers are in a common chamber. You may be able to acheive 150 if your amps are not tuned properly. Do you have two amps now? Has anyone matched the gains at the frequeny you plan on playing at the show? IF not then you should gain some dB's right there alone.

port the car!

Try to crack the front windows about 1 inch...it usually will give a db gain when coming from the trunk...keep in mind its not legal..

Does anybody else have any tricks they would use to get more db? I was windering if keeping the AC on full blast would make the air move more, that kind of thing. I got an extra battery for the subs, so power isn't a problem. I usually just do the runs with my car off. I kept my subs off the whole day until I got there and got setup to play. I think around 48 Hertz is when I hit the loudest, does that sound normal for 4 15's? I tried cracking the sunroof about a half an inch, but they caught me once again! Thatnks guys, keep the tips coming!

The freq that you hit your peak has less to do with the subs than it does with your installation. What size box are your subs in? Ported or sealed?

The box is supposed to be 11.5 sq ft. It is a sealed box that takes up the entire trunk. It's like 38'x38'x a foot deep or so, deeper in the middle (where the spare tire once was) than in other areas. Here are some pics to give you guys a better idea:

[img] http://svtitan.com/boxwithwires1.jpg [/img]

and the final product

[img] http://svtitan.com/speakersngrills.jpg [/img]

Thanks for your input guys! Keep the ideas coming.