Hello i have a question for you tech guys. my truck peaks at 48 hertz and my wall is tuned to 38 hertz. do i need to retune my wall to 48 hertz to match the trucks resonance for cabin gain to take effect? im currently doing 154.3 and i want to break the 155 mark. been reading for hous on multiple forums and read different things and just getting confused. can some one please help.

What are you running? What vehicle?

2 18" dual 2 ohm ufo btls on 2 bc3500s strapped at 2 ohms in 14cu wall tuned to 38 hertz in 05 dodge ram quadcab

If you are serious about wanting to get louder and don't own a meter that should be your first step.

thats what im saving up for. been going to comps just to get metered. started at 144 this year and my goal was to hit 155 by the end of this year. im so close just need that extra .7. added ho alt tons of 0 ga 5 group31 batts sound deadener tons of wood just had question about cabin gain

You could gain that 0.7 from silly things like seat position, vent visor position, people bracing the outside, making sure no wires are dangling in the box etc. Try rounding the port mouth, both inside and out, use 4" pvc pipe for that.

How long is the port ? You could keep the length, make the port area as big as needed to tune over 50Hz and start blocking the port until you match the peak frequency. Just you add a layer of MDF to the inner port wall, as long as the port wall and test each time.

Then you can make a port blocker to get your tuning back to daily.

Most of these changes can be tested in less than a day on a meter, as long as you have everything ready.

ive done the seat thing and visor ,closing my ac vents sanded the port mouth round added 45s inside people bracing my doors, dont have a meter to test until the next show. port is roughly 28 inchs deep and 40 inchs wide 5.5 inchs high would raising the tuning help with cabin gain

You could gain that 0.7 from silly things like seat position, vent visor position, people bracing the outside, making sure no wires are dangling in the box etc. Try rounding the port mouth, both inside and out, use 4" pvc pipe for that.

How long is the port ? You could keep the length, make the port area as big as needed to tune over 50Hz and start blocking the port until you match the peak frequency. Just you add a layer of MDF to the inner port wall, as long as the port wall and test each time.

Then you can make a port blocker to get your tuning back to daily.

Most of these changes can be tested in less than a day on a meter, as long as you have everything ready.

this ^^

Care to post some pics ? Maybe ideas will flow better.

In any case, you might lose with sun visors down and ac vents closed, so testing is mandatory. Same install, different port orientation and the seat position had to be changed completely to help.

Figure out if there is a test and tune day at some shop close to you or even rent a meter and test.

Any un-rounded corners of the box? Like where 2 boards meet? What about using ductape around the mounting area for the subs for more of a 'tight' seal?

hows the bracing in the vehicle? deadener?

J

Trying to upload pics now. Maybe someone can tell me if i can rewire from 2 ohms strapped down to .5 ohms strapped. subs are both dual 2 ohms wired to 2 crescendo 3500s at 2 ohms strapped. my electrical consists of 270a mechman alt yellow top g27 up front big 3 0ga 3 runs+ 3 runs - all 0ga to 5 g31 batts in back, i would think thats enough for a 3 second burp, what do you guys think can i hit that goal of 155, only .7 away

you seem to have enough batt.. but .5ohm strapped is your call, i highly do not recommend it.

Testing shows wired at 0.5ohm per amp, they pulled 596A rising to just a hair under 1ohm.

You are theoretically going to attempt to double that or in reality maybe increase current draw by 20-50%...

That's somewhere between 1440 - 1800A of draw in reality. Just be careful. The low voltage dip alone may cause problems if the protection circuit does not react fast enough.

Thats what i thought dont really wanna mess anything up. so then maybe my first idea was to raise my tuning up to where my truck peaks witch is 48 hertz. would trying this give me enough to reach my goal? I know i need a meter but cant afford one right now. all i can do is try different things to meter better. any other ideas i might not have thought of yet would be very helpful.

i will tell you this-

if your box is large enough for the 2 subs which it seems to be, your peak(not considering cabin gain) is usually only a couple Hz higher than your tuning...

So, since you know where you peak at in the vehicle.... This is something that will interest you-

The impedance curve will spike at tuning, it always will.

What i would do is tune to 46-48hz. Keep it wired at 2ohms and do testing to MAKE SURE you are tuned right!

Then, you should safely be able to strap at 0.5ohm for a burp without failure.

if u really intend on competing for a while u really need to save & invest in a termlab meter

spl is a very funny thing since the slightest adjustments , tuning or settings can make either a gain or actually a loss in output , this is why u need a meter to check it right away

what may sound like a good idea in theory may or may not give higher numbers in your vehicle & what works for others may not work out in your case , been there done that

if u have friends that compete too maybe u all can chip in together to buy the meter

Then that is what im gonna do. hopfully i'll hit the mark at the next comp and i can start on new box aiming for small ground pounder. Thank you for your advise

You do not need a ton of money to invest in an SPL meter.

www.spllabusa.com

You have been talking to the National Director of Sales.

Edited July 31, 201213 yr by shizzzon

You do not need a ton of money to invest in an SPL meter.

www.spllabusa.com

You have been talking to the National Director of Sales.

He is dah mann !

Trying to upload pics now. Maybe someone can tell me if i can rewire from 2 ohms strapped down to .5 ohms strapped. subs are both dual 2 ohms wired to 2 crescendo 3500s at 2 ohms strapped. my electrical consists of 270a mechman alt yellow top g27 up front big 3 0ga 3 runs+ 3 runs - all 0ga to 5 g31 batts in back, i would think thats enough for a 3 second burp, what do you guys think can i hit that goal of 155, only .7 away

We run 2 AQ3500s strapped at .25each and .5ohm total. 200 amp alt and 5 Dekka 34 batteries. I still see high 12s in voltage.

good thing you posted! I thought he was running 5500s, then yes, your battery bank will suffice. the amps themselves will perform more stable if you burp at or very close to tuning as i mentioned earlier.

So then i would be ok to wire down with the electrical that i have. Thats great kinda new at spl and just want to be safe. So after i retune my wall i would be safe wiring down to .5 and do a 2-3 second burp? I dont really demo like some hard core bass heads, but would like to some day. Side note i have a few other g31 batts sitting in garage, if i added some of those would there be a cushion to help with the extra voltage with out straining alt? Just checked out the site and like those prices, Dumb question comming how does it compare to term lab, not that i have any experiance with the tl either, but every one uses tl.

So then i would be ok to wire down with the electrical that i have. Thats great kinda new at spl and just want to be safe. So after i retune my wall i would be safe wiring down to .5 and do a 2-3 second burp? I dont really demo like some hard core bass heads, but would like to some day. Side note i have a few other g31 batts sitting in garage, if i added some of those would there be a cushion to help with the extra voltage with out straining alt? Just checked out the site and like those prices, Dumb question comming how does it compare to term lab, not that i have any experiance with the tl either, but every one uses tl.

The more batts the better, just make sure they are all good. The spl labs meter is very accurate and a bit cheaper than the TL.

Like i tell other new customers-

We wouldn't exist if the Termlab didn't.

We are the competition to that meter. Our SPL based meters are calibrated to be within 0.1db of the Termlab measuring sine waves.

Think of it like this-

Take 100 Termlabs and 100 SPL-Lab meters....

Go out and burp all day long. What is the result? the same.. You wouldn't be able to tell which company's product you were using in terms of resulting score.

I would also not add more G31s if they are not same makemodel as current ones being used.

Ok so then what i have in the truck currently will be ok to burp at .5 ohms after i retune wall? what about doing a 30 second run on music (street beat) at the same comp. Been averiging 153.4 on music at 2 ohms.

I noticed a lot of fluctuations in score with my Spl lab mater. Good for beginners getting an idea of what they are running but if your a serious competitor, I would suggest a termlab. What good is testing different things if your meter is never the same...

Not bashing the Spl labs meter, it was just time for me to step up to a termlab for a few bucks more.