alright, the other thread got dragged out wayyy to long, and was finally closed.. so im starting this thread with a question i had.

When you guys have your system's metered, what are the guidelines they make you follow??

i haven't had mine metered in over a year now... i went to an audio shop i always go to and had someone from in there meter my neon.. with my 2 old subs (jl 12w0's) and old amp (orion cobalt from god knows when), i hit a 134.7 dB.. which wasn't bad concidering how i had everything set up at the time.. when they audio guy tested it, he sat in the front passenger seat with the mic held just above the dash near the windshield, all doors closed, with the car at about 2000 rpm's.

now that i have basically all new equipment since then, i think it would be interesting to see what i'd hit now, but was just wondering what everyone has to go thru at competitions, etc... to have theirs recorded. i dont expect alot of people here on this forum to respond to this topic.. theres only 2 or 3 that i can think of that might have somethin to say, lol. all posts are welcome anyways tho, just try to stay remotely on topic!

 

haha the rules? There is a million rules, your just going to check out the web. Go to a search engine or something and go to Usaic or Usaci its something like that. They will have everything you wanna know. I got my old system ( 1 10") metered on termlab with windows up and hit 129.5. Mic's are not accurate and are becoming extinct

 

From what I have been told the mic goes on the dash near where the windshield meets the A-pillar. I'm not quite sure tho. My roomate and I couldn't even find a place around here that would meter his car and there aren't many compitions in the winter. He had two W7 12's in his Dakota with about 2200 watts RMS. It was mean. Now he sold one sub and has the same amps hitting on just one of the speakers. Itz still really mean. I would like to see what it meters.

 

ride n'low.. i know all about usaci and their competitions and records, etc.. and i know there's a million rules.. thats why i asked what i asked.. just wanted to see what the people here on the site go thru.. what they like, or dislike.. and what their methods are, etc.. not looking for anything national or anything like that.. just some input from personal experience i guess you could say..

shadyluke, that dakota must of sounded great! i love jl's!! a guy at the audio shop i go to had a 99 civic (lol, that was the car that had me sold on my speakers) with 4 10w7s in a fiberglass box he built for the trunk... sounded soooo nice.. that was the only civic i ever considered buying when he finally sold it to buy his new Z.. i love jl's subs.

 

It sounded great on the otherside of campus. If he turned it up while driving your ears wanted to bleed. No lie. Now hes got the 1100 watts on three 10W3v2 D6 in the trunk of his maxima. Thats pretty killer too. Hes excited for it to get warm to get metered too.

I'm intrested in where this thread is gonna go to find out how they do it if they don't use mics anymore.

 

yeah i'd like to hear about other ways of metering too.

why did he get rid of the other w7?? w3v2s are nice, especially 3 of them, lol.

 

He still has the one W7 in the truck. It is a quad cab Dakota and he lost two out of the three backseats for the box. Now he only loses one and it still sounds as good. Because he did the three W3s in his car he opted for the Dual 6 Ohm subs so he could wire it all down to 1 ohm. It really hits with 1100 watts.

 

ooohhhhh, alright i understand now.. i was thinkin he got rid of the 2nd w7 for the 3 w3v2's.

EDIT: just noticed you're from west grove.. thats like an hour away from me, i think.. where do you go to school?

 

Yep itz about an hour or less from Philly. I am an Engineering student at Penn State Erie campus. So unfortuneatly I am far from the action till the second week of May. I'm gonna try to make it to Centralia tho. Still trying to convice my co-pilot(girlfriend) to go.

 

Wow 2 12" w7s My one 10" w7 is pretty loud. There was a shop around by me that did it for a while but I they have since stoped. And the last show I was un able to make. I really want to get mine metered too since every chance I get I was unable. So this info could become useful

 

at all the shows ive been to, for legal itll always be on dash with windows and doors closed... u can rev 2000 and not go above it. if u do outlaw or renagade, which either goes on the kick panel or near the port, u can open doors windows play around and see what the meter reads. as for Crazy Port..i think theres no rules except the mic goes in the port 6 inches only. not sure about that...

Strider as for what u go thru..u jus pay money, say how many subs u have, or watts u have and what u drive and they put u into classes..so like 0-15 would be like one 12 or one 15, and then so on....u go up and the guy puts the thing where is goes, u sound off for about a min or however the judge desides and the highest score u hit on the meter gets recorded and then whoever is against u tries to beat that score..it ussually takes 10 bucks to redue it incase u messed up the first time. then at the end, highest score wins. my first time showing i was nervouse bcuz every one was watching and i was the only chick there competing...but im getn used to it now..i think its fun. u learn something new at every show and what song or sweep(tune) works better on the spl meter...and on the other post u said u saw a pic of my sub, what do u mean by prices?

 

As for W7 those are mean subs very mean..loud and rumble everything...a guy in my club has a 12" W7 in his cogar..he got metered and hit 145. something ...did pretty good..but with the W7 u have to experiment with songs or sweeps..as for in a truck..i have no idea how it would meter...at the clash of titans show there was a ranger with 4 audiobauns in it and he hit like 150 or mayb it was 156, not sure, when i see him at the next show ill tell him bout this site....i ran against a yellow ranger who had 2 10"s and he only metered at 135..so it depends on a lot of things when being metered...just have fun with it...u can search online for metters...a good one thatll go up to 150 dp will run ya about $150..i ordered one for my truck so i can experiment more.

 

also another trick i saw at a car show was people would roll the windows up, but would open and shut the door, kinda "waveing" it, to increase and decrease the amount of pressure...it seemed to kick a few extra dB's in there....but is kinda ghetto..

 

My roomate just got in and said that they now use a pressure meter on the passengerside dash. It is placed with 4 inches of clearence between the meter and the windshield. Does that sound familiar Regina?

 

Your absolutly right Tippnover...when i went to go to Renagade my buddy told me to keep my windows shut and mess around with the driverside door...but since that was the first time i did renegade i kept everything up and closed..ill do something the next time tho to see what happens..but outlaw i hit 140 and this time in renagade i hit 143...so we will see april 9th at the next show what i do.

shadyluke they dont really messure it..i guess bcuz theve done it so long they kno where to place it...but im not sure if its a mic or pressure meter..it looked like a mic to me. id have to check into that. but ur right about where they place it for Legal. they have a suction cup lookn thingy that get placed on the windshield and holds it away from everything.

 

Well the guys above were talking about they no longer use a mic for legal. My roomie told me that they now use a pressure meter.

 

How do you measure sound pressure level without a microphone?

It'll be a microphone of some sort, whatever you choose to call it. It has to turn sound pressure waves into an electrical signal -- that's a microphone. Then that electrical signal is processed to determine the actual sound pressure level based on the calibration of the "microphone".

Not sure what you were getting at in that last sentence.

A microphone is a pressure meter, is what I'm saying. It's just a specific type.

A pressure transducer has to measure pressure RELATIVE to something. Most times, that is either a reference atmospheric pressure, or relative to vacuum. If you see a pressure on a typical pressure gauge, it's the pressure ABOVE atmospheric pressure.

Microphones measure pressure relative the the alternating pressure and vacuum (called "rarefaction") that makes up a sound wave.

A sound wave can have a maximum pressure of two times atmospheric pressure. This means that there is AN ABSOLUTE LIMIT TO SOUND PRESSURE LEVEL. The reason is that the air pressure has to come from somewhere. You can only compress the air by taking air out of another volume of space. Sound waves are alternating zones of compressed and "de-compressed" air. You can't end up with more than you started with, so that's why there's a limit.

I forget what it is, but it's well under 200db. I'll have to look it up I guess since I want to say it's something between 145 and 185 db -- but the number escapes me.

 

ya....they are prob right...but i dont kno too much about the meter,,but the one they had was about 1500 bucks...i kno one on ebay with a mic costs around 700..they are pretty expensive

 

^^^ neild could probably make a meter out of bubble gum wrapper, a band aid, a light bulb, and confetti...he's that damn good...haha

 

Ha ha! I posted more on sound and you guys posted twice while I was editing -- I'm getting too slow in my old age, lol!

 

heres a place for what rules and what not are.. http://www.clashoftitans.org/rules.html

at the last show a guy named virgil with a pos sound comp only honda civic hit 174 on the db meter

 

Thats why you need a 4.0 gotta at least be able to keep up on the street.

 

Yeah, but I need one in my BRAIN!

Okay, with regard to the 174, then the upper limit is probably about the 185 db number I posted. I still haven't looked it up. An engineer in a trade magazine calculated it out but I don't have the article handy.

By the way, every 10db is about 10 times louder, so to get from 174 to 185 takes quite a bit more "muscle".

 

And by then you gotta have the windows down or your gonna break em. And shaking your car apart like that isn't worth it to me. I need just enough to feel it. The neighbors don't need to feel it too.

 

No **** a mic measures sound! nothing gets past you. Check out how they do db drag racing