stephanscavi

iTrader: (1)

hey guys

i know u can get the highest spl at the resonant frequency. i know theres one of the box and one of the car. but my question is how do u find them. do u simply play a frequency at a certain volume and mesure the spl with one of the spl meter(one from radioshack would do?) and then change frequency and mesure spl at the same volume. and so on... to find the peak levels ( which will have two, the lower one for the box and the higher one for the car)??

i am correct or am i way off??

some help would be great.

thanks

Speakerman

I can explain a very simple version of testing.

You need a meter, a small sealed box, a lot of wire, and possibly a ladder or something similar.

put the box in the car and play a range of frequencies from 20 Hz - 100 Hz at the same volume (try and get around 120 dB @ 35 Hz). Document all of your findings.

Take the box out of the car and suspend it in mid air using the ladder or something similar. Play the same range of frequencies at the same volume. (go out in an open feild if possible...in the country where its quiet...Document all findings.

put the numbers side by side and find the difference of SPL in dB from inside car to outside car. The frequency with the highest increase of spl is usually what people refer to as the resonant frequency...

tune your box 4-8 Hz below that and burp at the res .freq.

TEST though. Its not always that easy.........