SPL tricks- In progress from Shizzzons Build

[SPLScion 3]

there is one on each side and they vent directly to the outside of the vehicle, their big too dunno how I never noticed them before. Gotta love duct tape tho, if ya cant duc... you know the rest right.

[SPLScion 3]

I figured that with a wall they didnt affect you, but for me they were horrifying, considering my setup, subs up prts back, thats a major loading area for me, so it was killing me. What I want to know is why the buddies holding my hatch during spl runs never noticed the soundwaves slamming their feet and ankles. WTG guys <insert golf clap here>

[shizzzon 461]

yep. In the back of my car, i filled the whole passenger side up between the body and frame with expanding foam.

I didnt wanna do the driver side since the gas line is over there and my box was aiming at pasenger side anyways so it was a logical decision.

Have u ever tried messing with your ports any?

Slight cutting each back by an 1" and see if u gain?

If u have a DMM that can read in millivolt, go to ebay or somewhere and purchase the Hyperdynamics SPL meter.

It reads just as accurate as a Tlab and up to 186 so if u ever get that high, lol, WOW!

The meter is under $100 so it would be a great gift for yourself when testing.

It uses a dmm because it gives off voltage reading.

You then take the reading and type it into it's little basic program that comes with it and it tells u the db score.

Of course, when testing in real-time, the higher the mV, the higher the score.

[SPLScion 3]

its funny you say that cuz its what my buddy w/ the meter has, and every time he tells me what I am hitting and I roll through the TL it is exactly right, down to like a 10th! I will be filling that area I call my cavern with the foam too, thanks for the tip.

[shizzzon 461]

just got done doing Polyfill testing in my car.

Using a higher tuned port then dumping Acoustastuff in the box to attempt to lower tuning to peak at the proper frequency did NOT increase SPL at all, nor did it decrease either!

It did however increase pressure at very lower levels.

Port tuned to peak at 54hz yet 50hz is still the loudest... tested 36 hz before and after and 36hz did increase in pressure so it works at very lower levels but the increase is not substantial. It's better to tune to desired note than to "fix" the problem.

My last reading at the steering wheel was a 152.02 with the wrong port tuning.. this is when i stopped testing is when the score kept dropping as i was cutting the port off..

Well, i changed a few things-

Driver sun visor vertical, closed all vents, lifted middle console door open, glove box open, passenger seat must remain all the way back, forward in outlaw hurt me. Passenger sun visor down.

Acoustastuff stuffed in sunroof and closed. This does help VERY little but it does help, less than 0.1 db but it is readable.

I felt tons of air being shot out of the sunroof weatherstripping but when i sealed it off with duct tape, the pressure dropped! I am to assume that this may only help when everything is shut and rolled up only.

I put pressure on the sunroof and it increased pressure! I couldnt do it when i was metering myself but this is what i got just by opening, moving and stuffing sunroof-

I went from a 152.02(wrong port tuning) to a 153.41(wrong port tuning)

I now register higher at the metering position with the wrong port tuning than i did with the right port!

I backed the score up 3x within a 0.09 db difference!

[Lucky 76 5]

That is sick! Im gonna have to try that when mine is finished.

[slam 0]

some of these "tricks" dont work in all vehicles. The only way to ensure spl gain is to test ur own vehicle

[Lucky 76 5]

Ya I understand that but I am saying I will have to try it.

[SPLScion 3]

just got done doing Polyfill testing in my car.

Using a higher tuned port then dumping Acoustastuff in the box to attempt to lower tuning to peak at the proper frequency did NOT increase SPL at all, nor did it decrease either!

It did however increase pressure at very lower levels.

Port tuned to peak at 54hz yet 50hz is still the loudest... tested 36 hz before and after and 36hz did increase in pressure so it works at very lower levels but the increase is not substantial. It's better to tune to desired note than to "fix" the problem.

My last reading at the steering wheel was a 152.02 with the wrong port tuning.. this is when i stopped testing is when the score kept dropping as i was cutting the port off..

Well, i changed a few things-

Driver sun visor vertical, closed all vents, lifted middle console door open, glove box open, passenger seat must remain all the way back, forward in outlaw hurt me. Passenger sun visor down.

Acoustastuff stuffed in sunroof and closed. This does help VERY little but it does help, less than 0.1 db but it is readable.

I felt tons of air being shot out of the sunroof weatherstripping but when i sealed it off with duct tape, the pressure dropped! I am to assume that this may only help when everything is shut and rolled up only.

I put pressure on the sunroof and it increased pressure! I couldnt do it when i was metering myself but this is what i got just by opening, moving and stuffing sunroof-

I went from a 152.02(wrong port tuning) to a 153.41(wrong port tuning)

I now register higher at the metering position with the wrong port tuning than i did with the right port!

I backed the score up 3x within a 0.09 db difference!

wow thats a huge gain pushing on (and off) the sunroof! a bigger gain then I get when people do the same on my hatch wow. Did you test with only the center console open and then closed, also did you open just the top half of it or both sections of it open? for non-Tc pwners reading this our cars have 2 compartments for the center console.

I forgot that you run outlaw shizzzon :-) i think i am going to run the no wall class next season. that damn window line rule is kinda forcing me to, cuz i prefer at least 15" subs and multiples of 'em and large enclosures most of the time anyways.