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cabin gain in a ford explorer - Click HERE for Original Thread
Chris8sirhC
I was wondering if anybody knew what the cabin gain would look like in a normal ford explorer. ie. what frequency would it start and how much would there be per hz (like starts at 40, 6 db up at 30 etc)
ocool_15
there is no absolute cabin gain ie it changes per frequency per vechicle but it will have a general trend. To my understanding in a vehicle its 12db per octave. larger vehicle =lower freq for start of cabin gain. So i would guess the number you looking for would be say 12db/oct at guessing 35hz. I seen some good threads on forums, can remember where but try the
win isd company forum

Rockford
powered4sound-snail shell
sr20dem0n
It should be ~12dB/oct, but it will start much higher than 35hz. Sedans start around 60hz, regular cab trucks start closer to 75hz, and suvs start around 50-55hz normally. It would be pretty easy to figure out though, just take a sub/box, drive out to a field, set the sub/box on the ground and measure it's FR. Then stick it in the suv and measure again, subtract the two and you should have something reasonably close to the suv's transfer function.
ocool_15
cabin gain file with bass box pro as a default car is 12db/oct at 50hz. Its kind of surprising someone hasn't done measurements and posted on a site somewhere. Like test a Honda CRX, Ford Explorer, Ford Taurus wagon, Cavalier ect so that you could have a more accurate guess or model to start with. Has anyone found a accurate resource?
I have a 91 olds calais 2dr and would say its at a bit less then 50Hz
sr20dem0n
I've never tested my car (01 sentra 4dr), but it definitely starts higher than 50hz. One of the ways that I know is by my components. According to WinISD (not the greatest program I know, but it's alright) the maximum spl I can pull out of my mids IB before hitting their mechanical limits at 50hz is ~101-102dB, but I've personally measured them at 110dB in car with the doors and windows closed. As soon as I open the door though and let them play into the environment the output drops dramatically, so there has to be some significant cabin gain going on even at 50hz, which means the boost has to start somewhere above that. I really need to stop being lazy and actually measure it though.
Matt@Nearfield
Hi ya,

Cabin gain kicks in at the point where the longest internal dimension of the car/vehical is 1/2 wave length, so in most small cars, around 80hz, medium sized cars 70z etc.

The rate of cabing gain, given a completely sealed enclosure (read in a perfect world), would be 12db per octave. After many years of measuring about 8-9db is a more realistic figure.

^ is a 'quick and dirty' explaination, if anyone is interested I will explai the physics behind it :)

HTH,

Matt

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