tuning fb: car vs truck

jmelton86 wrote: I've been advised by some to raise the tuning a good bit, to about 35-40Hz, and that I will still have the lows I crave. Was told that that low of tuning in a truck is pointless. What should I tune to? Thanks.

i own a ranger, it is extended cab. and trust me that guy is dead wrong. if you tune your port higher you will only decrease your subs low frequency efficiency. right now i have an 18 filling the entire rear cab, but i have had more than a few systems in my truck. all the way from single 8s to 3 12s, ported, sealed, even one bandpass box. one thing i noticed when i had the bandpass box was when i faced it to the back wall, my low end bass response improved. now granted it was a pretty garbage pawn shop setup, but thats just something i noticed. another setup i had was 2 old JL W6's in a JL HO box. normally this should have slammed, but in my truck you could barely hear it. however, if you walk down the street, it got louder and would make my neighbors angry. the box i have my 18 in right now is just the opposite, it is very loud in the cab but if you step a few feet away from my truck with the doors open you can barely hear it. i dont really know how to explain this in technical terms but what seems to be happening is a crazy relationship between the wave coming off of the sub and the wave coming out of the port. some boxes are louder when you are close to them and some are louder farther away. a ported box uses the rear wave reinforce the front wave, but depending on the design of the box this might not happen as soon as the waves exit the box. it may take a few feet of travel before the rear wave is in phase with the front wave, so until then the bass might seem weak because the port is acting like a second sub woofer that is just a little bit out of phase. if you design your box with this in mind you can make it to where the front and rear wave are in phase almost immediately out of the box within a certain frequency range. if i were you i would tune your box as low as you have space for to reinforce your low frequencies as much as possible and have it all down or rear firing. also use something like dynamat on your rear wall because it is very flimsy and your doors. long story short it really all depends on how you build the box. i hope i explained this well enough and if anyone sees anything wrong with it or has anything to add please point it out because this is just what i can gather from a few years of observation and trying to make sense of some technical writings