How do you figure out what to tune your box to for a specific subwoofer? For example: if you are tuning for spl how do you know what frequency will hit the loudest? I think sq tuning frequencies are usually listed in the manual but I want to be able to make a box specificly for spl (no specific subwoofer in mind). I heard that winisd isn't the greatest but how do the spl nuts do it ? Their boxes are always gigantic with huge ports and I want to know why they chose the port size and how they came up with the perfect box desing.

Thanx much guys.

__________________
Vehicle: 2004 Chevy Aveo Hatchback
Battery: Stinger
Wire: W.S. 0 Guage (ground/power strait to battery)
Head Unit: Eclipse CD3000
Speaker Amp: Infinity Reference 7521a
Subwoofer Amplifier: Infinity Reference 1211a
Speakers: Kicker Titanium 5.25"
Subwoofer: Image Dynamics IDQ 15"

I am definately no expert but I believe most SPLer's tune the box to the car's resonant frequency. This is the frequency when played in the car will exibit a gain in SPL. The only way to find out your cars resonant frequency is with a meter. Once you have this frequency you tune your box a few hertz below and then burp at the resonant frequency.

I think I read on the DD site that you should have at least 16" of vent area for each cubic foot of volume.Also bigger is not always better for internal volumes.

I am sure there are more educated members that will correct any incorrect assumptions I have made...

Best of Luck!

Hey thanx dude, I was readin that on the DD site also. I have never heard of the resonant frequency of a car. That is crazy but it makes sense.

__________________
Vehicle: 2004 Chevy Aveo Hatchback
Battery: Stinger
Wire: W.S. 0 Guage (ground/power strait to battery)
Head Unit: Eclipse CD3000
Speaker Amp: Infinity Reference 7521a
Subwoofer Amplifier: Infinity Reference 1211a
Speakers: Kicker Titanium 5.25"
Subwoofer: Image Dynamics IDQ 15"

Everything has a resonant frequency! A fork, a table, your car. If you strike a glass the tone you hear is it's resonant frequency. If you recreated that frequency at high volumes it would shatter the glass. (I only know this cause I watched them do it on Mythbusters... haha). Each car will have a different resonant frequency even if they are the same model and year because it is such a complex structure, this is why only by testing it can you find the resonant frequency.

P.S. I was reading on another forum that in the new season of Mythbusters they attempt to destroy a car using subwoofers. Being an American citizen you might have already seen this, but I heard the did like 160db at 16hz and blew out some windows and stuff. Not bad. Us Canucks have to wait for good t.v. and it drives me crazy. What I wouldn't give to have ESPN, HBO, or ComedyCentral. I am starting to get depressed. Anyway, enough of me ranting.....

Check out the episode here...

http://www.realmofexcursion.com/vide...hbusters.1.wmv

Nice thanx for the post!

GREAT POST DUDE! That was an awesome vid.

__________________
Vehicle: 2004 Chevy Aveo Hatchback
Battery: Stinger
Wire: W.S. 0 Guage (ground/power strait to battery)
Head Unit: Eclipse CD3000
Speaker Amp: Infinity Reference 7521a
Subwoofer Amplifier: Infinity Reference 1211a
Speakers: Kicker Titanium 5.25"
Subwoofer: Image Dynamics IDQ 15"

I wonder what they could have done if they put more effort into the cone of the woofer... that thing fell apart pretty fast. Cool idea though, mechanicaly powered sub...

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