# Sub Positioning in an SUV



## Pseudonym (Apr 17, 2006)

ive decided to reincorporate my spare tire into my Jeep Cherokee (2001) and totally redo my system layout. the backseat is essentially useless in my jeep so its out and thats where the sub box/amp rack is going. my plan was to build a box 40w x 22L x 12H to fit in that area. the subs will be in a box within this box that will be 22x12x20 firing up. my question is before i dive into this project, i want to know what position the subs should face to achieve the best spl. i figured since theyre right behind the front seats that having them fire straight up wouldnt make them any less loud than having them fire forward or back. as it sits with no backseat, the jeep is just one big open interior area.


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## Pseudonym (Apr 17, 2006)

anyone with some insight?


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## SteveLPfreak (Sep 26, 2005)

Having just experimented with different drivers in different enclosures and positions, I can tell each is a little different. I would suggest trying a few different locations and seeing what you like best. Output and frequency response will change depending on location.


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## edwelly (Mar 29, 2006)

I have a Honda Pilot - in which I was running a RE SE12 for a while. With the sub up, the sub sounded more detailed, but w/ the sub firing back, the sound was a lot louder but not as detailed. 
In the end, I went back to a single 10 firing up as the RE sub was too much for my taste.


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## bobditts (Jul 19, 2006)

id say if you fire it off the rear glass it will be a lot louder than firing up.


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## demon2091tb (May 30, 2005)

What about side firing, i'm planning this, but i've always done a rear firing substage, any problems assocaited with this?


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## mvw2 (Oct 2, 2005)

Well, you have two things working against each other when considering where and which direction a sub fires. First, loudness does come from proximity. The close it is, the louder it will sound. 

Then you have phasing. When the sub emits a sound, it radiates in all directions. It will bounce off any hard surface and radiate back at you. The problem arises when these radiating waves mix with the original waves and start amplifying/canceling sounds. This is frequency depending as the length of the wave varies by frequency. In a particular position, you may find that 63Hz is very boosted but 37Hz is basically non-existant. I'm just picking random numbers for example, but realize that they do interact and can influence the original sound to nearly double the amplitude or nearly eliminate the amplitued completely.

For the issue of phasing, the common "best" approach is to have the subs as far back as possilbe near the rear wall. Also realize, that you can face the subs toward the rear wall, up, toward you, or even sideways. It's just that the closer it is to the rear wall, the more in-line and less devistating the reflections are. Rear firing, up againts the rear wall. One problem associated with this is that the box can get in the way of the sound.

These are generalities. In reality, you just want to try different positions and see what works best. I've moved mine around in my car a bit. It sound the cleanest up against the rear hatch, but it's also in the way at that spot. For convenience, it's slid up against the rear seat, a few feet away from the rear hatch. It doesn't sound as clean, but I can actually make easier use of my trunk area. Just try different methods and see what sounds best.


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## niceguy (Mar 12, 2006)

This is what I was told over at CAF in the SPL subforum: For vans/suvs, subs up or facing front, no wall.

However, though I haven't tried the front firing method, I found rear firing to be better than firing up. Perhaps w/the large rear hatch/glass, I dunno. I built the second ported box in a tower style- about 33" high versus ~16" high for the other ported box in the van (both identical tuning/subs).

TO ME, it seems that the 16" high enclosure actually sounds a little louder than the taller box (after testing individually), though it may have been a placebo effect...

Jeremy


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## BodegaBay (Dec 16, 2005)

I found that I prefer having my sub face sidways tucked way in the rear right-side corner vs. facing backwards against the rear seats. I thought it sounded better SQ wise. Curiously, my OEM sub was mounted the in the same position in my SUV. On a plus side (and almost required for me), the side firing position saves me a bunch of valuable space.


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## demon2091tb (May 30, 2005)

I have a scion tC, and i'm hoping that the side firing rear right corner close to taillight would be a good spot, and allow me enough room to get it out of the way in the area provided, how to get a nice shape on the front though i'm concerned with.


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