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Discussion Starter · #1 ·
My wife wanted some more thump in her 2008 Impala LS, so I bought her an Infinity Basslink for Christmas. It got good reviews and a powered sub in a box sounded like the easiest solution.

I'm ready to start with installation. I have an electrical background, so I don't think I'll have trouble wiring it (knock on wood), but the actual mechanical mounting of the subwoofer is where I have questions right now. I think the right rear of the Impala's trunk is a good spot since it fits quite nicely behind the wheel well and would corner load the bass as described in the manual for the sub. It would also provide easy access to the controls and make it easy to remove if extra trunk space is needed.

I just don't know how to go about mounting it in the trunk. My first thought is to screw the mounting brackets (provided) to the metal in the trunk of the car. I'd need to drill holes for the mounted tapping screws (provided) for the mounting brackets. I can't tell if anything is directly underneath the right rear area of the trunk that would make drilling small holes a dangerous / damaging thing to do. It's above the muffler, but it appears there is some space between the trunk bottom and the underneath of the car, so I can't tell what's between the two.

It's kinda late and maybe I babbled a bit. Suggestions for physical mounting of the sub are welcome.
 

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Discussion Starter · #2 ·
Anyone? Anyone? Bueller?

Here's another question / thought. As a EE, I'd prefer to run both power and ground wires in a twisted pair from the battery and not allow power to return through the chassis; simply put, it's just cleaner from an electrical perspective. Is there a reason not to do this for a sub / amp installation in a vehicle? My EE mind says it's better to do it this way than to return the current through the car's chassis, but since most people just connect ground to the chassis, I'll keep an open mind.
 

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Mr. Handy
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Anyone? Anyone? Bueller?

Here's another question / thought. As a EE, I'd prefer to run both power and ground wires in a twisted pair from the battery and not allow power to return through the chassis; simply put, it's just cleaner from an electrical perspective. Is there a reason not to do this for a sub / amp installation in a vehicle? My EE mind says it's better to do it this way than to return the current through the car's chassis, but since most people just connect ground to the chassis, I'll keep an open mind.
Yes, you can do this no problem. Just keep in mind the shorter the wire the better. Longer wires means more resistance and more resistance obv means less power. You will also be less susceptible to corrosion if you mount the ground in the trunk. I also recommend using some quality wire (copper not alum). As for the mounting IDK as I have any earlier model. But, I would mount it so the sub was firing forward for the most thump as it is a lower powered unit (no offense just advice).
 

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Discussion Starter · #4 ·
Thanks for the thoughts. The extra length wire would add a bit of resistance, but the large loop created by the current flowing through a wire then back through the chassis would create some hellish magnetic fields and be more susceptible to noise issues. However, if it's done this way across the automotive world, then I presume it's never been enough of a problem to merit running two wires to the battery along the same path as opposed to connecting the ground to the chassis.

As for position of the sub, I decided I will run my wiring first and play with positioning to see if an easy installation mounted to the back seat sounds as good as a corner load in the rear of the trunk like the installation guide suggests.

No offense taken regarding my "lower powered unit." I have a 250W sub in my living room and it practically shakes the whole house. I figured a 200W sub in a much smaller space will be more than we need; I'm not looking to shake grandma's bumper off as she idles next to us at a red light.
 

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Vader
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Car audio is way different from residential wiring. Ground it to the frame or you will get a loss of power and you will also get alternator whine more then likely. Ground to the sheet metal with a self tapping screw (SMALL ONE. YOU DONT WANT TO DRILL INTO SOMETHING). As far as which way it will fire: Fire it backwards. Sound will increase if it is bouncing off the trunk lid. Just my opinion. Been doing car audio for over 16 years off and on now.
 

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Mr. Handy
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Sound will increase if it is bouncing off the trunk lid. Just my opinion. Been doing car audio for over 16 years off and on now.
True but, if it's of low power then it doesn't matter. If I had that powered unit you know my ass would be mounting in the floor right behind my seat :giggle:
 

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Go Get It
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True but, if it's of low power then it doesn't matter.
Huh? Because it's a low powered unit, it matters MORE. You want the sub facing rear so that the trunk acts as a reverberation chamber. You want the sound waves to "ricochet" off the trunk lid if you will, and return to the cabin at a higher overall volume.
 

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Mr. Handy
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Huh? Because it's a low powered unit, it matters MORE. You want the sub facing rear so that the trunk acts as a reverberation chamber. You want the sound waves to "ricochet" off the trunk lid if you will, and return to the cabin at a higher overall volume.
The ricochet would be more effective with a dynamat or similar layer on the trunk lid. Without that, I believe the effect wouldn't be noticeable and you would be better off facing it forward. All it's going to do is vibrate your trunk and the trunk will absorb most of it. I do however have mine firing towards the rear but, I am also pushing alot more.
 

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Go Get It
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By facing the sub forward, you are essentially playing a speaker into a giant pillow, which will muffle the reverberations, unlike the trunk lid, which will amplify them, however unnoticeable it may be
 

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Mr. Handy
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By facing the sub forward, you are essentially playing a speaker into a giant pillow, which will muffle the reverberations, unlike the trunk lid, which will amplify them, however unnoticeable it may be
Yes which will amplify it right back into the box and into the "pillow" seat. Doesn't make sense if you ask me :eek:k3:
 

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Go Get It
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The seat does muffle those reverberations, you're right. But placing the seat directly in front of the speaker muffles the sound much more than if you let the sound reverberate from the trunk lid. Also, muffling the reverberated "amplified" waves will always provide more sound then non "amplified" waves.

Because we're talking about a subwoofer, which puts out frequencies that can easily pass through walls, this really is a minute difference and most people who aren't audiophiles won't notice.
 

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Mr. Handy
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The seat does muffle those reverberations, you're right. But placing the seat directly in front of the speaker muffles the sound much more than if you let the sound reverberate from the trunk lid. Also, muffling the reverberated "amplified" waves will always provide more sound then non "amplified" waves.

Because we're talking about a subwoofer, which puts out frequencies that can easily pass through walls, this really is a minute difference and most people who aren't audiophiles won't notice.
I understand what your saying now but, if there isn't much power to reverberate in the first place then firing it towards the rear will most likely decrease the power as your trunk will absorb it. Reposition your sub to fire forward and I guarantee you will feel the difference in your chest. Still a personal preference I guess. I have mine firing towards the rear as I have my amp mounted to the back of the seat and not the box (less vibrations to the amp). I also want to be able to take my box out when transporting large things without having to unhook the amp. I plan on eventually laying down some "rattle trap" Fat Mat in the trunk and doors which, will help with road noise and containing the interior sound. I cant wait for this day! I have been told it will be a night and day difference.
 

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i would do exactly what your doing. it would sound better facing the corner and have better sq. i keep my rear seats down all the time to show of my amp and how clean it looks but the box fills in the whole space any way. it does sound better with the seats down, its more loud and a little more clear. when i had 12's i would play with their positioning and they sounded beter facing the trunk. facing forward they sounded better outside the car.
 

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Vader
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The ricochet would be more effective with a dynamat or similar layer on the trunk lid. Without that, I believe the effect wouldn't be noticeable and you would be better off facing it forward. All it's going to do is vibrate your trunk and the trunk will absorb most of it. I do however have mine firing towards the rear but, I am also pushing alot more.
Always better to fire backwards. :eek:k3:

I cut out the bottom of the driver seat and mounted a 15 in it:biggrin:
:giggle::giggle::lol:
 
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