Car Audio Competition Tomorrow. Any Advice?

[Bobbytwonames 5,000+ posts]

I know. I'm $2,500 in just to hit a 148. I'm pretty much maxed out unless I do a blow through. And I don't want to cut my truck up. I met a guy with sixteen FI tens on 14K in a small Mazda Protege5 and he was only hitting 157's. I don't see how a novice is hitting 159's in an unaltered car. I'm guessing the rules aren't being fully enforced.

I asked USACi about the 159 and he said that it was a Toyota SUV with a full wall. I guess walls are allowed in the USACi novice classes. I'm going to check the Bass Wars organization and see where I would've placed with my cone area. They have a class that is 0-350 square inches of cone and port area. I'm sitting at about 243 sq. inches of cone area and port combined.

 

[Boominburban]

This is our Benefit show coming up. I'm going to post it up in the show thread.

 

[Boominburban]

Hey, kind of off topic, kind of not....
How do you guys find out about different shows from different organizers? Word of mouth? Is there a couple websites? Maybe some social media crap I need to follow?
Where I live in Northern California, even though the people are packed in like sardines (there are a lot of people that live here), there aren't too many shows/ competitions. Or at least any I know of. I'm just trying to get info on how to stay updated on dates and locations, if such a place exists.

In NC, you need to be checking out NSPL and Bass Outlaws. Bass Outlaws Finals are Dec 4th, in NC.

 

[hispls 5,000+ posts]

I hear ya there. Some of those scores just don't make sense. Stock 3K with a 157.5 seems a bit fishy to me.

What vehicle though? What if any are the power and cone area limitations on "stock 3"? Some "stock" class definitions just mean no modifications in front of the B pillar and/or nothing more than 2" above the rear window line. Explorer or similar body style with 4 18s in a decent box on say 8KW should get you around there if your vehicle does will with door open.

I guess walls are allowed in the USACi novice classes.

Damn. Ours used to have port area limitations even. I can't imagine a lot of first-timers just come right out the gate with a 159dB wall. Definitely seems contrary to the spirit of the thing IMO.

How do you figure out where your vehicle peaks?

Measure corner to corner in the cabin, divide by the speed of sound, then divide by 2, 4, and 8. That should generally get you in the ballpark of where you'll easily build up a good standing wave. From there just testing multiple boxes and looking at your frequency response and seeing where you always have a peak regardless of the box or tuning of the box. Peak will very probably change a little with door or window open or if you remove seats and may go up or down a cycle or two depending on the weather.

Two Arctic Wolf 9K's @ 2 ohms. 157's.

That's about the same cone are as 8 15s. Something went terribly wrong there.

 

[Bobbytwonames 5,000+ posts]

What vehicle though? What if any are the power and cone area limitations on "stock 3"? Some "stock" class definitions just mean no modifications in front of the B pillar and/or nothing more than 2" above the rear window line. Explorer or similar body style with 4 18s in a decent box on say 8KW should get you around there if your vehicle does will with door open.

Damn. Ours used to have port area limitations even. I can't imagine a lot of first-timers just come right out the gate with a 159dB wall. Definitely seems contrary to the spirit of the thing IMO.

Measure corner to corner in the cabin, divide by the speed of sound, then divide by 2, 4, and 8. That should generally get you in the ballpark of where you'll easily build up a good standing wave. From there just testing multiple boxes and looking at your frequency response and seeing where you always have a peak regardless of the box or tuning of the box. Peak will very probably change a little with door or window open or if you remove seats and may go up or down a cycle or two depending on the weather.

That's about the same cone are as 8 15s. Something went terribly wrong there.

What do you mean something went wrong? The subs aren't broken in yet in the Mazda. He told me that he is wired to two ohms and rising to 12 ohms. He's only getting about 14K out of the amps right now.

 

[Bobbytwonames 5,000+ posts]

What vehicle though? What if any are the power and cone area limitations on "stock 3"? Some "stock" class definitions just mean no modifications in front of the B pillar and/or nothing more than 2" above the rear window line. Explorer or similar body style with 4 18s in a decent box on say 8KW should get you around there if your vehicle does will with door open.

Damn. Ours used to have port area limitations even. I can't imagine a lot of first-timers just come right out the gate with a 159dB wall. Definitely seems contrary to the spirit of the thing IMO.

Measure corner to corner in the cabin, divide by the speed of sound, then divide by 2, 4, and 8. That should generally get you in the ballpark of where you'll easily build up a good standing wave. From there just testing multiple boxes and looking at your frequency response and seeing where you always have a peak regardless of the box or tuning of the box. Peak will very probably change a little with door or window open or if you remove seats and may go up or down a cycle or two depending on the weather.

That's about the same cone are as 8 15s. Something went terribly wrong there.

16-10's is closer to 7-15's.

 

[Bobbytwonames 5,000+ posts]

What vehicle though? What if any are the power and cone area limitations on "stock 3"? Some "stock" class definitions just mean no modifications in front of the B pillar and/or nothing more than 2" above the rear window line. Explorer or similar body style with 4 18s in a decent box on say 8KW should get you around there if your vehicle does will with door open.

Damn. Ours used to have port area limitations even. I can't imagine a lot of first-timers just come right out the gate with a 159dB wall. Definitely seems contrary to the spirit of the thing IMO.

Measure corner to corner in the cabin, divide by the speed of sound, then divide by 2, 4, and 8. That should generally get you in the ballpark of where you'll easily build up a good standing wave. From there just testing multiple boxes and looking at your frequency response and seeing where you always have a peak regardless of the box or tuning of the box. Peak will very probably change a little with door or window open or if you remove seats and may go up or down a cycle or two depending on the weather.

That's about the same cone are as 8 15s. Something went terribly wrong there.

These are the Street Beat rules.

 

[Boominburban]

What do you mean something went wrong? The subs aren't broken in yet in the Mazda. He told me that he is wired to two ohms and rising to 12 ohms. He's only getting about 14K out of the amps right now.

If he's truly rising to 12 ohms, there is no way in heck he is anywhere near 14K. He's lucky if he's seeing 500w per sub with even 3x rise. He is most likely rising to about 6-8 ohms, and seeing around 3-4k out of each amp. Now if he's strapped at 2 ohms final impendence, the amps would be seeing 1 ohm each, and with great electrical and very little rise, he could be clamping around 14k total, possibly. But not likely. more like 10-11k.

 

[Bobbytwonames 5,000+ posts]

If he's truly rising to 12 ohms, there is no way in heck he is anywhere near 14K. He's lucky if he's seeing 500w per sub with even 3x rise. He is most likely rising to about 6-8 ohms, and seeing around 3-4k out of each amp. Now if he's strapped at 2 ohms final impendence, the amps would be seeing 1 ohm each, and with great electrical and very little rise, he could be clamping around 14k total, possibly. But not likely. more like 10-11k.

He's very experienced in Car Audio. He's in his 50's (like me) and I believe what he told me. He said the subs aren't broken in yet and that's why he is rising so high. He has three alternators and a lot of lithium in his little Mazda. He actually had to remove the power steering to make room for the alternators. 157's is a very respectable score being wired to two ohms with brand new subs.

 

[Bobbytwonames 5,000+ posts]

I would've won my class in the Bass Wars organization this past weekend. The "Savage" division. It's a cone area plus port area division. A lot of big scores in the other classes though.

 

[hispls 5,000+ posts]

The subs aren't broken in yet

Which will surely gain him the other 3-4dB he ought to be getting out of that cone are and power.

These are the Street Beat rules.

I thought you said "stock" before. Still though 3rd rank of that is b-pillar wall and 6 15s or thereabouts and modifications up to 12" from the roof allows quite a bit of wiggle room to reinforce and for box/cone/port area.

Definitely an imposing looking leaderboard there though. Are all those dudes from around town or are people driving out from Los Angeles or other metro areas?

 

[Bobbytwonames 5,000+ posts]

Which will surely gain him the other 3-4dB he ought to be getting out of that cone are and power.

I thought you said "stock" before. Still though 3rd rank of that is b-pillar wall and 6 15s or thereabouts and modifications up to 12" from the roof allows quite a bit of wiggle room to reinforce and for box/cone/port area.

Definitely an imposing looking leaderboard there though. Are all those dudes from around town or are people driving out from Los Angeles or other metro areas?

SEMA was in town so there was quite a few people from out of town. The 182 and 179 scores are from local guys. There's a lot of guys in Vegas in the 160's though.