Resonance

[stan 0]

What resonant frequency of this car(honda civic 4d 2007)? Your recommendations for construction of the ideal box(spl), for Solox 12!

Edited May 16, 2008 by stanley

[SUNDOWN/FI BEATIN 0]

im pretty sure no one will know that off the top of their head... considerign you can take two identical cars and get two different resonant freques... the only way to find out really is with a meter.. build an enclosure to you liking.. size and what now.. install it in the car, cover the ports with some wood. then run a sweep.. where ever it peaks thats were you tune your enclusure for SPL that is..

[audio-neon 34]

Resonant frequencies are also install dependent. Don't expect to take your sub, toss it in a 1 ft. cubic box, run a sweep etc... And than put it in a 4 cu. foot ported box.

Honestly, I would build your ported box (start a little on the larger side (~ 10% more than your design goal. I would also use aero-ports as it makes re-tuning easier.)

Many will see my methods as overkill but they have worked in the past.

Remember to have your seating in the position it would be in for metering (IE drivers seat all of the way forward or as far as you can with you in it, passenger seat all of the way forward with the seat tilted forwards or tilted all of the way back, back seats down etc...

Also instead of playing a sweep, play 4 second burps Allow the car to recharge the batteries in between burps and find your 4 hz range. Now wait a full day to test out the 4 frequencies with as quick as possible burps from the resting voltage of your vehicle so that the sub is as close to the same temperature between burps.

At least that is how I would do it.

Now for the box, after you found your resonant frequency. (you will need an extra set of aero-ports to trash) I would take bricks and load them into your enclosure one by one (also recutting the aero-ports you will be trashing to keep the frequency the same.) This will help you to find your subs ideal enclosure volume with the power you have available (it also accounts for the affects the vehicle will have.

[helotaxi 46]

And what you're looking for is the peak of the cabin gain, not the resonant frequency. Each piece of the car has a resonannt frequency and that's the freq at which it normally vibrates based on mass and rigidity. Find the resonant frequency of a pice of the car and play that freq and watch that piece jump all over the place.