How to find out what my truck cab is tuned to.

[55437Audio]

I'm terriibley sorry if you guys have answered this a few times but how do I find out what the physical tune freq of my cab is. It's a ext cab f350.

Thanks, Austin.

[Red-navi-916]

im gonna go ahead and say 46hz... other then that ill wait on bill or hank

[Boon]

im gonna go ahead and say 46hz... other then that ill wait on bill or hank

Wat.

I'm not entirely sure if you're being serious or not ;o

It depends on like a million things - have you deadened it, how big is the box, do you have seat covers, what position is the box in, what position are the seats in, how do you have the sun visors placed, is the glovebox open...

You have to chuck everything in there and sweep it with a termlab, with the box's port sealed off. That way it should give you a representation of the cabin gain. That's the only way to know your true resonant frequency for any given setup.

Some guys I know could change their peak by 10hz just from moving their box around.

[55437Audio]

Wow. So pretty much a term lab would have a setting to check what the cab freq is at? I could get all the info too.. But a tl would do it too?

[55437Audio]

Double post. Sorry!

[Boon]

Wow. So pretty much a term lab would have a setting to check what the cab freq is at? I could get all the info too.. But a tl would do it too?

Yes. You put it on peak hold, run a 30-80hz sweep through your system then open the numeric data window and it shows you the Peak Frequency.

[Lynbo]

Like Boon says to run a sweep, just wanted to add a few more things somewhere don’t remember so some of the numbers maybe off. Ready here we go use a 10” sealed sub in a sealed enclosure built to manf. specs, you do not need to over power this sub rms or under is fine. Run the first of two test in an open space with the speaker supported above the ground at least 2 feet and sub facing the mike which is 3 feet away but facing the speaker and run the frequency sweep. This will give you or show you a baseline reading of any peak frequencies that the speaker may have on its own. Now run the second test in your vehicle in your example F350 ext. cab you will place the sub on your rear seat with the sub facing up. Run the sweep again then compare the two sweeps and you should see a difference or peak(s) that is from your vehicle. If I remember right the test should be at same volume for both test to have as close a comparison as possible. This should get you close to your cab frequency but remember that any changes be it damper material applied, removing seats and installing sub-enclosures would change the cab frequency. The changes you make to the interior will change the cab air space or the sheet-metal vibrations, you will have to retest again but you should be close. Depends upon what your goals are with your truck.

[55437Audio]

I understand fully. Thanks guys.