# Sub facing question



## kid red (Jan 10, 2009)

I'm getting ready to work on a sub enclosure and amp rack for my trunk and wanted to get some feedback. I had thought originally that I'd aim it to the rear of the trunk as I recall an article stating rear aiming was a better option. 

However, in the log forum, I've seen just about everyone face the sub forward behind the back seats. Which would be the better option? I want to make sure what's best before I start fabbing.

This is what Im thinking.


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## t3sn4f2 (Jan 3, 2007)

You want to aim to the rear but only if you can bring the driver close the the end of the trunk, that way the bass that wraps around the sides of the box is more in phase with the one that immediately bounces of the trunk end.

The other way of mounting it with the sub facing forward behind the seat is only recommended if you can put a baffle that covers the whole face of the sub and doesn't let any bass wrap around and go in the trunk and com back out of phase, resulting in cancellations. In other words, make an IB wall even though you are using a box.


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## kid red (Jan 10, 2009)

I see. If I understand you, I had planned to have the entire backseat covered with a sheet of wood wrapped in carpet. So if I aimed forward, the speaker would be mounted in the center of this 'wall' like seat back. So I think I have it covered now, thanks.

I was just nervous that the forward facing sub would vibrate my kids around too much in the back seat


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## t3sn4f2 (Jan 3, 2007)

kid red said:


> I see. If I understand you, I had planned to have the entire backseat covered with a sheet of wood wrapped in carpet. So if I aimed forward, the speaker would be mounted in the center of this 'wall' like seat back. So I think I have it covered now, thanks.
> 
> I was just nervous that the forward facing sub would vibrate my kids around too much in the back seat


Yup, you got it. You can think of that wall (in this case) as being almost hornlike where it does not let the bass wrap around the box back into the trunk, and instead it forces it to radiate in a half sphere into the cabin, in front of the wall. 

Heres a good read on the other part about trunk position, which will relate to the principle behind the back seat wall.

Aiming a woofer box in a car trunk - bass cancelation -


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## kid red (Jan 10, 2009)

Awesome, thanks for clarifying that. I'll have to figure out how to mount and construct the sub facing into the seat now, but I'm glad I asked before hand.

Yea, that's the article I remember, the part 2 of it aiming it to the rear.


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## Fixtion (Aug 25, 2006)

i have my sub mounted the exact opposite of your configuration facing the back of the seat.
yes, seal off the back of the truck, as i am receiving bass out of phase, with a huge dip from 48-58.


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## Fixtion (Aug 25, 2006)

ps great sketch!


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## TXwrxWagon (Sep 26, 2008)

ok... Kid/Orlando... yes great sketch... props where props are due... let's get to the meat of the REAL issue...

what kind of vehicle? what speaker? what amps? what music? 

the concept that you have missed is the 1/4 wave principle. the idea is to find what frequency your VEHICLE can support THEN purchase a woofer &/or design a subwoofer "system" around what the VEHICLE can support.... if you are working on a Civic.. then you ahve under 12 ft front (windshield) to Back (taillight panel)... However an Escalade/Hummer is closer to 20ft... depending on how you measure...

this is the Fundamental error in the way we "sell" subwoofer systems. What can the vehicle support NOT what can we cram in the vehicle we have... 

So... what do you drive, what speaker(s) are you forcing to work, & what kind of enclosure (albiet totally wrong) are they in?

Rob


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## TXwrxWagon (Sep 26, 2008)

& just because I am a dick... I think EVERYONE should be required to fill out vehicle info & AGE on their profiles... but I digress...

the generic answer to your question is that the most of the sub frequency wve you can get in the vehicle, the more impact you will have INSIDE the vehicle... the 1/4 wave is the 1st fundamental & therefore the most critical to impact... after that.. you are trying to broadcast to the rest of the planet... So... if bass outside the car is your goal... make the distance from the cone face & the windshield as short as possible. If you want response INSIDE the car... then you need to look at getting as much of the initial frequencies inside the vehicle..

Rob


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## DaleCarter (Jan 3, 2008)

Speaker aiming should not affect the sound in an IB configuration. It is the physical location of the speaker that makes the biggest difference. 

The examples linked are for a speaker enclosure placed in different physical locations, not an IB. The linked article also has serious problems in it's methodolgy and conclusions.

Also, the "search" would have answered this question with numerous threads.


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## DaleCarter (Jan 3, 2008)

Oops. Boo on me for not reading the sketch, it ain't IB.


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## TXwrxWagon (Sep 26, 2008)

BACK UP!.... are you building a box/enclosure or using the trunk as an IB set up?

LET"S STOP THE INSANITY....


What kind of CAR?
What kind of install/enclosure/box?
What kind of Speakers?
What Amp?
What music?
What kind of Processors?

take it back to basics... you are ALLLLLLLL the F! over the place...

telll us about what you are doing.... then we can help...

<grrrrrrr>

Rob


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## zGhost (Oct 28, 2008)

Maybe I'm missing something here but if your building a baffle over the rear seat again why not just go IB. I have always gotten best response by facing the sub to the rear vs front in both trunk and SUV (inside cabin) installs. I fail to understand how the baffle and separate front facing design is beneficial. Someone please enlighten this old timer on this!


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## DaleCarter (Jan 3, 2008)

I think I am responsible for the IB confusion.


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## gijoe (Mar 25, 2008)

DaleCarter said:


> I think I am responsible for the IB confusion.


Haha, yeah i think so. 

So, backing up, the sketch you provided does not show an IB setup. In IB, the baffle that separates trunk from the cabin is the box. There is no additional box built around the speakers. Basically you turn the entire volume of the trunk into the box. Make sense? What you have is a sealed setup and you want to know how to aim the speaker. This is where you'll have to experiment but generally, facing the opening of the trunk and pulled all the way to the trunk lid works well. 

This all makes perfect sense in my head, but if it doesn't make sense to you, let me know. There are plenty of people who can probably explain this better.


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## t3sn4f2 (Jan 3, 2007)

zGhost said:


> Maybe I'm missing something here but if your building a baffle over the rear seat again why not just go IB. I have always gotten best response by facing the sub to the rear vs front in both trunk and SUV (inside cabin) installs. _I fail to understand how the baffle and separate front facing design is beneficial._ Someone please enlighten this old timer on this!


Sub bass radiates from the driver in all directions and is prone to cancellations.

By making a wall (even though you are not going IB) you focus and confine the omni directional waves into the cabin and keep it out of the trunk. As a result there are less cancellations and the listening space is reduced, increasing cabin gain.


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## TXwrxWagon (Sep 26, 2008)

I see an infiltration of CA.com members asking for advanced 411 they are not able to support...

OP... tell us about your set up....

Rob


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## kid red (Jan 10, 2009)

Wow, a lot of responses while I was at work  Sorry for the delay in responding.

Thanks for the compliments on my sketch (I'm a graphic designer/artist/web designer/etc)

So let's get some answers.
car-Audi A4 B7
sub- Mach5 IXL10
amp- Arc Audi 1000.1 (1ohm load)
enclosure- .6 cft sealed (as recommended by manufacturer)
music- all types, but heavy weighted towards hip hop, r&b, alternative, pop, 80s, etc
processor- none. I've read my RSN-E HU puts out a flat signal and I'm running 2 way non-active.

Correct, I do not intend to go IB, just want a clean, stealth install with minimal usage of my trunk. In my sketch, I have a sealed enclosure flanked by two frames that would hold my two arc amps. The wall in front would just be for looks and additional support. 

Thanks for all the input guys, totally unexpected coming from CA.com. Let me know if I need to provide any more info.


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## TXwrxWagon (Sep 26, 2008)

the best option is to try different positions see what sounds best...

My money is on rear(toward tail lights) or Down firing... with 2-3" spacers unde the enclosure....

Load the trunk area, block/cover the the rear speakers, & vent the trunk into the passenger compartment.

I question the 1ohm load on the Arc amp... where did that # come from?

Rob


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## kid red (Jan 10, 2009)

So you think facing rear from just behind the seats will prove better than facing the cabin? I'm confused now.

I'm running a DVC2 Mach5 sub on the Arc which, unless I'm missing something, is making the arc run at 1 ohm producing 1000w at some 54% efficiency. At least. that's what Arc's manual states.

<btw- sorry for not specifying my age (37) and vehicle info in my profile and not being able to respond until I got home from work>


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## t3sn4f2 (Jan 3, 2007)

kid red said:


> *So you think facing rear from just behind the seats will prove better than facing the cabin? I'm confused now.
> *
> I'm running a DVC2 Mach5 sub on the Arc which, unless I'm missing something, is making the arc run at 1 ohm producing 1000w at some 54% efficiency. At least. that's what Arc's manual states.
> 
> <btw- sorry for not specifying my age (37) and vehicle info in my profile and not being able to respond until I got home from work>


On the rear meaning nearly up against the end of the trunk firing toward the taillights. 

And making venting through the ski hole to allow the bass to come into the cabin even more then what passes through the rear seat.


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## kid red (Jan 10, 2009)

t3sn4f2 said:


> On the rear meaning nearly up against the end of the trunk firing toward the taillights.
> 
> And making venting through the ski hole to allow the bass to come into the cabin even more then what passes through the rear seat.


Ahh, I see. Yea, I want to keep trunk space, so having it near the lid wouldn't work and I don't have a ski hole to fire through, it's 60/40.

So then facing forwards right behind the rear seats is my best bet then?


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## t3sn4f2 (Jan 3, 2007)

kid red said:


> Ahh, I see. Yea, I want to keep trunk space, so having it near the lid wouldn't work and I don't have a ski hole to fire through, it's 60/40.
> 
> So then facing forwards right behind the rear seats is my best bet then?


Yes if you want to go with an enclosure.


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## kid red (Jan 10, 2009)

Awesome, thanks. Is there any desired distance from the back of the seat that the woofer should be at? Other than excursion clearance of course.


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## t3sn4f2 (Jan 3, 2007)

kid red said:


> Awesome, thanks. Is there any desired distance from the back of the seat that the woofer should be at? Other than excursion clearance of course.


Maybe some extra clearance in case someone pushes on the seat back really hard when sitting down.


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## TXwrxWagon (Sep 26, 2008)

interesting read:

Aiming a woofer box in a car trunk - bass cancelation -

Rob


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## trunks9_us (Oct 25, 2007)

TXwrxWagon said:


> interesting read:
> 
> Aiming a woofer box in a car trunk - bass cancelation -
> 
> Rob


I agree I am reading it now it is going to help me with as few questions I had myself.


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## MCarmer (Apr 6, 2009)

the article doesnt say anything about aiming the sub when its ported and the sub facing forward sealed off from the cab. Few inches from the back of the rear seats.

Anyone got experience with that?

I was thinking port on the driver side with the sub being centered down the middle of the car, or at least as close to center as possible. The box being sealed off from the face of it from the trunk.


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## talibmohamid (Dec 5, 2008)

man that is a awsome drawing man.....did you do that


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## blamus (Mar 9, 2009)

what about putting the sub in the corner? Most people I see place the sub on the far back passenger side corner and have it facing the opposite side (driver). How does that compare to putting it rear facing as far back as possible? (generally speaking of course)

At least that article didn't mention this very popular configuration.


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## Badmunky (Mar 9, 2009)

I'm about to do that my self. I have my sub firing threw the sky hole in my back seat and don't like the sound. In defense of the option I don't think I sealed the sub from the trunk well enough. But I'm not willing to rework every thing for a sub that I think is to small any way. 
I went with a 10" sub for the first time in my life and am going back to a 12" sub as that seams to play what I like better.

Link to my install.
Click me!

Later.


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## pimp-150 (Apr 9, 2009)

I've always kept my enclosure pointing towards the rear with the seats down. You tend to not hear as much port noise (ported enclosure) that way.


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## Badmunky (Mar 9, 2009)

I will be running a sealed box. Made of fiberglass if I put it where I was planing.
But I could build a wood box if I pointed it at the back of the rear seats firing forward threw the pass threw.

Trunk space is #1 on my list. Sub is #2. 
Sorry but I use my trunk almost every time I drive my car.

Later.


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## maybebigfootisblurr (Nov 4, 2011)

I have an '02 Passat, and have gotten the best response with my subs facing the rear of the trunk, with the back of the enclosure roughly 8" away from the back seats. I do not have a "pass-through" in the back seat, so I cut one out through the open arm rest and made a trim panel covered with grill cloth. My rear deck was removed, sealed all openings, and used adhesive to firmly install the deck. This is a similar body/cabin, and I only have to adjust the sub's phase to my liking.


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## m3clubracer (Feb 5, 2016)

What happens if you fire the sub through the blank speaker hole (left by the old sub) in the rear shelf? G37 with 1000.1 amp, Type X, ported box to 34hz.


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## gregerst22 (Dec 18, 2012)

m3clubracer said:


> What happens if you fire the sub through the blank speaker hole (left by the old sub) in the rear shelf? G37 with 1000.1 amp, Type X, ported box to 34hz.


is the sub the same size or smaller than the hole and is it directly attached or in front of it? If not the hole won't do much.


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