best sub firing direction

I tried to search for this but couldn't find any information.  I was wondering what the best direction would be to fire a subwoofer.  Would it be upfire, downfire, or just regular sideways?  Is there going to be any difference in sound between these?  Also, I know that you need to find the sag for downfiring, do you have to do the same for upfiring?

I'm guessing it doesn't matter much in direction because bass is non-directional but I would like confirmation.  I am wondering for a box for a pickup truck.  The box will be under a seat.

Well, it the box is going to be UNDER a seat, then you really don't have much choice, do you? Seems to me you are going to have to make it either up or down-firing, and it would also seem to me that "sag" would be the same for either direction.

But regarding direction in general; despite the fact that subbass frequecies are supposedly non-directional, I am here to tell you for a fact that it WILL make you a difference which way you fire the subs - cancellation will play it's part. While this fact may be more evident in a "trunk" vehicle than in a truck like you have, IMHO it will always play a part and the best way to figure out the best way to aim is trial-and-error.

In a trunk car, that has the subs contained entirely in the trunk(i.e. - no vents into cabin), rear-firing seems to be the best bet in my experience. As far as a pickup-truck, you're on your own for testing

-Matt

I wouldn't say that; upfiring you are probably going to hear more sub noise, but down firing you would probably have to make the box bigger to keep the cone from hitting the floor.

But like I said, it is going to be heavily install-dependant. Where are you thinking of putting the box/sub? What kind of truck?

-Matt

I have absolutely no useful links or really anything authoritative here - I'm really just trying to get closer to 1,000 posts - but the one guy I ever met that messed around with underseat subs would point them up - maybe 2-1/2, at most 3 inches between the bottom of the seat and the surround- with a real small PVC port - like 1-1/4 inch PVC pipe @ ~6inches or so - venting toward the rear of the cab.  Can't tell ya I remember the dimentions of the enclosure...

The truck sounded really good.  And the seat "massage" was great.  Lotsa 'feelin' - real warm sound - but part of that I think was the smaller diameter woofers - he was using some old JBL 8's, cheap ones at that -  Real interesting sounding system - never heard anything quite like it - I'm still toying with the idea of imitating it. . .

If it's an extened cab, I'd try to make the subs work either behind or under the rear seat (this may be what you'retalking about, I really don't know yet...). There's no way you are going to have enough room under the front seats to make them work. But honestly, they are probably going to have to be in a sealed box, as IMHO there's not enough room for a properly designed ported enclosure for anything more than 8"s...

-Matt