# Direction Subs Face in a Trunk



## remeolb (Nov 6, 2009)

I've heard a hundred opinions and never any real concrete evidence. I also searched and can't find results. Does it matter what direction your sub faces in a trunk? Right now I have my subs firing toward the back seat (into the car) from the trunk. I did this to minimize vibrations in my trunk which seems to have worked. I am definitely looking for an SQ setup with great low frequency extension. Does it matter whether they point toward the back of the car? What if I went from two 10's to a single 12 mounted in the side of the trunk firing sideways? How does how the subs are placed affect their sound? If it matters I guess my question would refer to sealed sub enclosures.


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## MarkZ (Dec 5, 2005)

Yes, it matters. Do a search for subwoofer aiming. There have been plenty of discussions on it.

In short, sub placement matters. When you turn a box around (aiming it differently), you're actually changing the placement of the cone. So aiming is really all about placement. In general (and this really IS a generalization), you'll get less cancellation the further back the cone is (ie. towards the rear of the vehicle). Alternatively, you can let the sub continue to fire directly into the cabin, but seal off the front wave from the rear wave with a false wall, etc. I usually liked installing sealed boxes behind the rear fender wells, because that's the furthest back you can usually go without it being intrusive.


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## kyheng (Jan 31, 2007)

Basicly almost anything comes ito play. Woofer's specs, enclosure's concept(sealed, ported, IB....). And your listening preference.


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## remeolb (Nov 6, 2009)

MarkZ said:


> Yes, it matters. Do a search for subwoofer aiming. There have been plenty of discussions on it.
> 
> In short, sub placement matters. When you turn a box around (aiming it differently), you're actually changing the placement of the cone. So aiming is really all about placement. In general (and this really IS a generalization), you'll get less cancellation the further back the cone is (ie. towards the rear of the vehicle). Alternatively, you can let the sub continue to fire directly into the cabin, but seal off the front wave from the rear wave with a false wall, etc. I usually liked installing sealed boxes behind the rear fender wells, because that's the furthest back you can usually go without it being intrusive.


Thanks for the tip on searching "subwoofer aiming." I had tried "direction subs face", "direction to fire subs", "pointing subs" but never tried "subwoofer aiming." I found one thread that was quite helpful...

http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/16382-2-questions-i-have-trouble-subbass-direction-pathlelengths.html

and this link which was also very helpful...

Aiming your subwoofer box

The goal of minimizing the cancellation from the reflected wave makes great sense. I'm guessing that most people don't mount their subs that close to the back wall of their car. So how do the folks that know what they are doing combat the wave cancellation issue? 

Since a sub wave propagates spherically, does that mean that placing a sub in a fiberglass enclosure in the rear corner of the trunk would have the desired effect? So long as the driver was close to the rear wall of the trunk.


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## MarkZ (Dec 5, 2005)

remeolb said:


> Thanks for the tip on searching "subwoofer aiming." I had tried "direction subs face", "direction to fire subs", "pointing subs" but never tried "subwoofer aiming." I found one thread that was quite helpful...
> 
> http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/16382-2-questions-i-have-trouble-subbass-direction-pathlelengths.html
> 
> ...


Eddie writes like a 5 year old, but he knows his ****.



> The goal of minimizing the cancellation from the reflected wave makes great sense. I'm guessing that most people don't mount their subs that close to the back wall of their car. So how do the folks that know what they are doing combat the wave cancellation issue?
> 
> Since a sub wave propagates spherically, does that mean that placing a sub in a fiberglass enclosure in the rear corner of the trunk would have the desired effect? So long as the driver was close to the rear wall of the trunk.


Yep. That's what I meant by in the fender well. Or you could go the partition route or the IB route.


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## remeolb (Nov 6, 2009)

MarkZ said:


> Yep. That's what I meant by in the fender well. Or you could go the partition route or the IB route.


Recommendation? I'm going to be using a Morel Ultimo 12. My preference would be to glass it into the corner but I'd be willing to consider the partition route. What are the pros and cons?


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## strong*I*bumpin (Oct 3, 2005)

good reading here as well...Car Audio Subwoofer Enclosures Second Order, Infinite Baffle, Free Air


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## t3sn4f2 (Jan 3, 2007)

remeolb said:


> Recommendation? I'm going to be using a Morel Ultimo 12. My preference would be to glass it into the corner but I'd be willing to consider the partition route. What are the pros and cons?


This might be of interest. The only downside I think being trunk rattle.

http://www.diymobileaudio.com/forum/889288-post266.html

You don't have to install it under the deck by the way. The instal is down IB style just with a small AP box behind the driver. On the rear deck, on the partition wall, it doesn't matter.


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