upcoming spl competition help

[Smanleyman 15]

after taking a moment to contemplate all the possible uses of duct tape... lol... what exactly should I try with it?

[BenHemp 1]

Sometimes people gain by putting duct tape around their subs to seal off leaks. Personally, I havent' gained from doing this. A better solution is to silicone the underside of the basket where it mounts to the box.

[odsound 0]

So last time I entered an spl I tied a guy with two 10" solo x's and a rockford fosgate t3000, and there's another in 2 weeks and im sure he will be there. I dont want to risk damaging my sub by upping the gains or voltage any more than i did last time, but perhaps i can adjust the box/ place it in my car differently?

The box is a little over 4^3 at 31, and it is about a foot back in my trunk facing into the car. Only ideas i have now are putting 45's in my corners to help flow and raise tuning, and face the sub towards the trunk. Are there any little tricks anyone knows about to give me just a .1 or .2 db gain?

here are some little tricks you should try out resin the inside of the box....try sitting someone on your windshield or lay someone on your roof....try making your passenger seat all the way forward and lean it all the way down with sun visors all the way down....try closing all your air vents this might not go on a official db drag event but will go in an outlaw match.... if you have a slot port make sure you round over the ends of the ports like this

.....threaded rod for bracing might work......thats about all i can think of now

[DeeCee 0]

corner load the sub ie move the box and aim it into the corner of the car opposite to the mic

whatever side the mic is on, move the seat as far forward as possible and fold forward

only press on the door side which the mic is located on

depending on how big your 45s are will impact the increase or decrease in result.

I generally use small 45s which don't impact much on the overall box volume to decrease deadspots at the wall intersections.

I also resin out my comp enclosures as well, though it seems that this won't be a viable option for this particular box

[DeeCee 0]

i have never heard of closing air vents to be a violation of dbdrag rules. Its a normal function of the car, so I def agree it should be done.

Pressing on the trunk lid or putting pressure on the roof has decreased SPL potential in all cars I have seen thus far and i've done some pretty extensive testing over the years.

[fritosaregood 0]

should i turn up every bass settin i have. or just make sure my gain is up to the right level

[Smanleyman 15]

Thanks a lot DeeCee that all sounds great... the best part of my box is I used mdf from a construction site my dad was on that was originally planned for shelving, so one side has a very smooth finish over it, so I used that side on the inside of my box, I guess thats kinda like resin, or at least the same principle...

About 2 years ago before I even had a system I went to an spl comp to watch my friend and we noticed pressing on the trunk lid lowered score... I dont think I can corner load the box is huge but I can have my port facing the trunk on drivers side, since the mic will be passenger dash.

Fritos the last comp I went to I had everything cranked bass knob, deck settings, and gain just past 3/4, I figure yea its probably distorting like crazy and is awful for the sub but for a few short burps my Q handled it...

[DeeCee 0]

ideally a system should be set up with an oscillioscope to ensure that you are not clipping the system into magic smoke.

So gains would ideally be at a specific level.

First things first though, you have to find your cars resonant frequency.

From there, testing with an o-scope is used to determine a) headunit clipping point, b) amp clipping point - both for the specific frequency

If you don't have the means to set up the gains with an o-scope, dependant on the system i'd set the gains around 1/2 first and then roll your volume up until you peak out.

That would be your system limit. You can slowly creep up the gain a little bit and a little bit more, but I tend not to push things past 2/3rds on an amp

If you guys can provide some pics of the boot area, then it would be helpful just to see how much room there is to move stuff around.

Oh and no bass boost or eq tricks to push it up. It doesnt' really have much of an effect if you are playing a single tone.

[fritosaregood 0]

i always here ppl say dont use bass boost. is that for the deck or the amp, i have my boost on my deck set to 0 but my bass boost from the amps is at 1/2, if i have the amp bass boost at 0, there is hardly anything playin.

[DeeCee 0]

Dependant on the amplifier or headdeck, a bass boost increases the volume at one particular frequency.

The problem with that is a) knowing what that frequency is and b) understanding what that boost does to the signal.

I've generally found that a bass boost doesn't provide a clean signal, so imagine if you input a dirty signal into your amplifier, you have more potential to distort the subwoofer making a situation where you can damage your sub.

[odsound 0]

i have never heard of closing air vents to be a violation of dbdrag rules. Its a normal function of the car, so I def agree it should be done.

Pressing on the trunk lid or putting pressure on the roof has decreased SPL potential in all cars I have seen thus far and i've done some pretty extensive testing over the years.

putting pressure on our roof gained us .4 of a db but it does not hurt to try it out it might help it might not.

[DeeCee 0]

except when the person who gets on teh roof has metal studs on their jeans or shoes or wearing any sort of metal lol

[KU40 173]

Don't just max out every setting. Honestly, just turn it up until it doesn't go any louder. It really isn't rocket science on getting the signal to it, that's the least of the worries of what will affect the score. What I mean by that is......once the sub is maxed out on how loud it can go, adding power won't do anything but increase the chance you'll blow it during the run. There is a power point where the sub reaches power compression, mechanical limits, etc., where it just won't get any louder. Maxing out all of your knobs just increases the chance that something will clip and overdrive either the amp or sub and send it into failure.

You won't get as loud as you can be on your first SPL run if you've never been on a meter before. nobody ever is. The best thing you can do is find a meter before the comp and just run test after test after test.

[DeeCee 0]

no its not rocket science but there is physics involved and understanding how everything works makes things more interesting

[Brian10962001 0]

You should flatten out all your bass boosts and set your crossover and gains from there. Not only will this sound better but it should give you a chance to find out where your car is loudest. I to often see people with cranked up bass boosts and the gain and crossovers nowhere near close to right. When I did my last SPL competition I had sweeps from 80 to 60hz playing, I did this because this was the "magic resonance" of my subs, box, etc. Later that day I got an SPL cd and ran sines from 50hz all the way up to 300hz and found that I had a VERY high resonance with my setup that I hadn't found before.