Meter tuning?

[LosIsATool 5,000+ posts]

Need some advise from the CA.com community. I'm starting to think my car peaks to high to put up any kind of numbers with a daily box. I'm happy with the box I'm using now for daily but I need more then a 145 to win a real show, I do fine local in class. Normally take the win by more then 5 dbs which is sad. Gear is two XL m2 12s on a 5K. Right now the 145 is tuned at 31 hz peaking at 46, at 35 hz it peaked at 50hz hitting a 147. What do I need to tune to to break that 50 db mark or more, I dont have a problem swithing boxes since I cant to changable ports? I cant do a 8 inch areo so it will be a slot down the middle firing back, subs up. With no bends I can get a 46hz tune or higher. I'm not trying to do a complete one note wonder, just want to do a good number when I need to.

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[xSPLoder 10+ year member]

will this be for burping? running and aero would be the best choice if so IMHO with a hatch like yours. I would believe that either subs up port back or subs back port back would be the wiser choice so the subs can load off the hatch. Many guys in TNESPL run Tiburons with about 2-3 cubes per sub with aero. If I were you though, once the box is built, I would try a meter run with the port facing the hatch and another meter run with the aero port facing forward to see if you might gain or lose.

 

[LosIsATool 5,000+ posts]

will this be for burping? running and aero would be the best choice if so IMHO with a hatch like yours. I would believe that either subs up port back or subs back port back would be the wiser choice so the subs can load off the hatch. Many guys in TNESPL run Tiburons with about 2-3 cubes per sub with aero. If I were you though, once the box is built, I would try a meter run with the port facing the hatch and another meter run with the aero port facing forward to see if you might gain or lose.

It will be for burping but not 100% burping. I cant go subs back with the height I have to work with. Port forward wont work cause the amp rack is welded in behind the box.

 

[xSPLoder 10+ year member]

pretty much that just leaves you with subs up port back then or subs up port drivers side

 

[LosIsATool 5,000+ posts]

Tuning is my concern at this point. I'm not trying to break records just pop that 50 mark when I need to.

 

[pro-rabbit 5,000+ posts]

Sub up and port back typically works really well for these cars.

As for a "SPL" setup.. I would increase port area and raise tuning and then do some testing.

 

[xSPLoder 10+ year member]

Tuning is my concern at this point. I'm not trying to break records just pop that 50 mark when I need to.

example

 

[LosIsATool 5,000+ posts]

Sub up and port back typically works really well for these cars.
As for a "SPL" setup.. I would increase port area and raise tuning and then do some testing.

I'm a bit broke at the moment to be experimenting for the perfect setup. From most of the people that know DC subs, I'm hearing 54sq inches of port which I have used so far. 18 per cube has some good SQ and moves air. What do you suggest for my current goal? Like i said, I'm not trying to break records just put up when i need to

 

[xSPLoder 10+ year member]

I posted this from on another thread but this will help you with your tuning. "There is a guy on here named Bill Lolo a.k.a @psychoacoustics ; who makes custom 8" aero ports out of welded steel that slid in and out to make it fully adjustable without cutting or adding anything. http://www.caraudio.com/forums/subwoofers/550511-where-buy-aeroports.html#post8080998

http://s232.photobucket.com/albums/ee266/psychoacoustics/aeroports/ "

With these aero ports, you can change up the tuning just by moving it in and out without cutting or adding.

 

[LosIsATool 5,000+ posts]

[quote name='xSPLoder808']I posted this from on another thread but this will help you with your tuning. "There is a guy on here named Bill Lolo a.k.a @psychoacoustics ; who makes custom 8" aero ports out of welded steel that slid in and out to make it fully adjustable without cutting or adding anything. http://www.caraudio.com/forums/subwoofers/550511-where-buy-aeroports.html#post8080998

aeroports pictures by psychoacoustics - Photobucket "

With these aero ports, you can change up the tuning just by moving it in and out without cutting or adding.[/QUOTE]

8 inch wont fit. I dont have the width or depth to go external. The most i can get for the port is 6 inches wide and thats MAX. 10.75 high

 

[LosIsATool 5,000+ posts]

[quote name='xSPLoder808']I posted this from on another thread but this will help you with your tuning. "There is a guy on here named Bill Lolo a.k.a @psychoacoustics ; who makes custom 8" aero ports out of welded steel that slid in and out to make it fully adjustable without cutting or adding anything. http://www.caraudio.com/forums/subwoofers/550511-where-buy-aeroports.html#post8080998

aeroports pictures by psychoacoustics - Photobucket "

With these aero ports, you can change up the tuning just by moving it in and out without cutting or adding.[/QUOTE]

I found a loud tC using a 7.5 inch octo but he had level 3s. My motors are to wide to work with it. His was VERY close

 

[pro-rabbit 5,000+ posts]

Anyway,

I would suggest trying around 55-60 in2 with around a 45-48 tuning for starters.

While DC subs may like certain things, in your application it may be different. I have had builds for SPL were we almost doubled what I thought was the prefect port area...then some were it was nearly half... both set records haha.... so it's hard to say some times what will actually work and no amount of a math/physics will get you right the first time no matter how much we all crunch numbers.

Typically if you are just testing...I would say build some enclosures from some cheap wood that will hold up to a bit of abuse. then when you find something that is working...rebuild it from another material. Typically saves money that way. Down side is some times it's hard to know if you are going the right way when you alter the material because even that can affect the SPL level....even when it is the exact same enclosure.

 

[LosIsATool 5,000+ posts]

Anyway,
I would suggest trying around 55-60 in2 with around a 45-48 tuning for starters.

While DC subs may like certain things, in your application it may be different. I have had builds for SPL were we almost doubled what I thought was the prefect port area...then some were it was nearly half... both set records haha.... so it's hard to say some times what will actually work and no amount of a math/physics will get you right the first time no matter how much we all crunch numbers.

Typically if you are just testing...I would say build some enclosures from some cheap wood that will hold up to a bit of abuse. then when you find something that is working...rebuild it from another material. Typically saves money that way. Down side is some times it's hard to know if you are going the right way when you alter the material because even that can affect the SPL level....even when it is the exact same enclosure.

Thanks. Thats what i was thinking, just wanted to hear it from you before i went into it.

 

[Julian 10+ year member]

When making a burp box do not tune. What you do if you have access to a TL get some aeroports and meter yourself at a moderate to low level. Keep shortening/lengthening until you find the sweet spot in your car. Its extremely tedious but it makes for a better score. Burpers don't tune they do that.

 

[psychoacoustics 10+ year member]

thanks for the mention

actually i can make them any size 3-48" diameter lol

and yea they are adjustable in length if you choose to go that route

this is the ultimate spl testers dream port be sure to check the video out

aeroports pictures by psychoacoustics - Photobucket