aiming subs at a hatchback window

I'm actually installing things right now-- I was just wondering: pros/cons of mounting a subwoofer so it's aimed at the window of a hatchback?

Specs/info for clarification:

Car: 1998 Eagle Talon
Interior: Back bench seat blocks bottom half of cabin, can be folded down for a single continuous cabin.
Enclosure: Q-Logic 1.25cf slot-ported/38hz-tuned/front is a very slight wedge/port runs top to bottom on the right side/thick-ass wood
Driver: Diamond Audio D610D4 - D6 Series 10" - 500wRMS/1000Peak - DVC 4ohm parallel wired to 2 ohms, pushed by:
Amp: Infinity Reference 611A Monoblock - 500wRMS@4Ohm, somewhere around 600-650wRMS@2Ohm
Deck: Pioneer Premier 690UB -- sometimes called 6900UB apparently

Pic:

Note: that's not my car. I live in Tucson, i.e. 'what's snow?'. And I sure as hell don't drive an automatic. Window is the same. I don't have the spoiler.



ANYWAYS, The back window is very large. It does not open, well except that it's part of the trunk. Probably anywhere between 10-13sqft of glass. It's got a convex-like shape. It does not have any heating elements on it. I was considering two options, both have the subwoofer facing rearward:

1) Aim the sub perpendicular to the glass, aimed at the middle of it. Basically, pound the window.

2) Aim it lower to change the angle of reflection so the sound (in theory) reflects off the window and heads directly forward through the cabin from there. Hopefully.

I dunno, some guy at a chain mobile-audio shop told me that was a good idea a long time ago.. but then again I made him think I was going to buy from his place (so I could pick up some free advice--you know, you're only worthwhile if they can smell the money) so I take his advice with a grain of salt.

Ideas?

Most will tell you to try it different ways and see what sounds best. Since its a Q-logic box and not one you'll be building, I'd say try it and see. I have my box in my Supra with the subs facing the glass and it sounds great that way.

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'85 Toy

It bumps! :)

I have always wondered if pointing woofers at the glass would yield more output than rear-facing...

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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

in a hatch back car, this is a great way to load a woofer

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So aiming a woofer at the glass is like up-firing? I always thought that facing a woofer towards a smooth, flat, sturdy (not flexible) surface like glass gives the air no 'restriction'. Meaning the air moves easier. More airflow = louder bass. I think this is why woofers sound so good faced to the rear; the inside of the trunk gives the air an area to 'flow' around.

Are these reasonable assumptions?

Is this why glass-faced-woofers sound so good, cause' they have a direction to flow? -lack of better words

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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

fire it upwards, yes. the increase in perceived output is called 'cabin gain'

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Up-firing in Hatchback will give you what they call a Horn Effect, check this link

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Shaking The Neighborhood

Man, I wish I drove a h/b! I now have inspiration to build a upfiring horn-type enclosure. I think this concept done with some rear facing bottom slot ports (with right math of course) could make some LOUD bass. Hmmm...

So this horn-effect is basically why Jeff is so loud, right?

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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

I find it extremely strange how well this car insulates low-frequency noise from reaching the outside when both windows and hatch are closed, and even to a good extent when the windows are open. It's not exactly what I would call a very 'solid' built car.. What's funny is that I actually had a bit of trouble equalizing the ridiculous bass coming from this box with the rest of the speakers (the downside of being spendy on my amp/sub and less so for the mains.) I bought some JL TR series 5.25" & 4" because this install was originally planned for another car. This car wants 6.5" in the back, 5.25" in the doors and some tweets up front, but I was out of money so I fabbed up some .220 plexiglass speaker adapters for the doors. Eventually I'll push the 5.25s up front and put some 6.5" XRs in the back, and it'll even out a bit better. But with a little work it's sounding very nice right now.

That sub is delicious. I just had a buddy with a newer Mitsu Eclipse w/ 2 12" ask me how many 12s I had in it. Then I told him to look behind him. He was quite surprised to find a single 10" sitting under the hatch glass. :P

I think I need to adjust the HP on the amp down a bit. I'm not sure why, but I feel like that might be the only base I haven't covered very well. Highly recommend Diamond Audio D6 Subs. Highly.