Does anyone know what the transfer function frequency of a 4th gen maxima is???

 

Just get out a tape measure or a tone generator and figure it out. It can actually change depending on where and how you have items mounted in the trunk, if you seal the trunk, etc. Also consider that wavelength varies with temperature. But it is likely between 60 and 80 Hz, maybe higher.

 

Are you looking at this as a way to find out where to vent your sub? You should not vent at the tuning frequency of the car because you will end up with an amplified effect at a certain tone, which you definitely do not want unless you really are into 1 note wonders (like a pre-fab bandpass).

 

I have a box for music and normal listening, but I want to know it so that I can tune my vented box for an spl competition.

 

If you are serious about it, you will need to measure it. You need to make a "reference" box for this test. It should be sealed and easily portable.

1) take a measurement of the box in an open area, outside and not in your living room. Use a SPL meter an a test tone cd or audio signal generator. Plot the results. Or you can use a program like Speaker Workshop, Sould Easy, Etc.

2) Put the box in your trunk and run the exact same test.

3) Subtract #1 from #2 and that is the true transfer function of your vehicle.

Good luck and please post your results.

 

Thanks alot, i have a test tone cd, and an spl meter, so i guess ill be doing it this weekend, I will be sure to test results.

 

sorry for being ignorant, but what is a transfer function of a car? is it kinda like the resonant frequency?

 

The cabin of your car will have a different reaction to different frequencies. It can both add and subtract from your nominally flat SPL curve. If you can measure these additions and subtractions, plot them, and describe them mathematically you will have a function that the car is contributing to your overall sound.

You can guestimate the function by figuring out the dimensions of the vehicle. And, yes, the transfer function is kinda like a resonant frequency. The SPL will rise and or fall based on it.

 

I forgot to add, try and keep the box away from anything. It might be best to try and put the woofer on a stand to elevate it a few feet off the ground. You could have some floor bounce cancellations if you don't. You might try it on the ground first and if you have any dips in the SPL you might try putting it on a stand.

 

ah thanks for the explanation

 

I am going to go to an empty parking lot and do it so that there are no reflections anywhere. My sub is in a cylinder, it is 40 inches off of the ground when standing up straight, and I have really long speaker wire, so my car doesn't affect the measurments.