Subwoofer location help

[tblt44]

I will be installing my JL JX360/2 amp and a single Polk 12 inch sub next weekend.
How to face the sub to get the best sound with the least vibrations.
I will be making the box.
options.
speaker facing trunk lid.(back of car)
box on drivers side speaker facing passenger side.
speaker at about a 30 deg. angle facing upward and towards the back seat.

I was also going to remover the sound material around the rear speakers and from the small holes in the rear deck to let some bass thru.

[MarcoZandrini]

I will be installing my JL JX360/2 amp and a single Polk 12 inch sub next weekend.
How to face the sub to get the best sound with the least vibrations.
I will be making the box.
options.
speaker facing trunk lid.(back of car)
box on drivers side speaker facing passenger side.
speaker at about a 30 deg. angle facing upward and towards the back seat.

I was also going to remover the sound material around the rear speakers and from the small holes in the rear deck to let some bass thru.

Towards the passenger compartment.

[ZeeZoo]

At a 30 degree angle towards the back seat or trunk door. Keep the sound waves symmetrical.

[tblt44]

Wow 3 different answers between this and another forum,have any of you actually tested different directions ? If I was going with a standard box I would just make it and test it myself but I'm not.I am making a box to fit with the back seat angle or fitting over the small hump on the drivers side and with a angle to bump against the back seat or a 30 to 45 degree angle facing rear deck and back seat.My last resort is to make a generic box and do tests.
Polk recomends a sealed box .88 in size,thats smaller than many other 12 speaker manufactures recommend.I want to keep as much trunk space as possible.

[nicco1117]

for me, the position of the sub doesn't really matter. what's important is how you make the sound cross towards the cabin. porting the skipass or parcel shelf is what you should do. unless you do that, you'll just get rattles all over your trunk without the bass you're looking for and the it'll just be muffled. 2nd thing is a good sub/amp combo.

[Hellrazor35]

I 2nd and 3rd and 4th the ski hole, I have build several sub boxes in e34 and e39's all mounted to the rear rear deck and firing through the ski hole. Either 1-12" or 2-12" RMS at 750 watt.

You still need to dynamat the trunk area. Make sure that you buy a head that allows you to control the sound timing! That way you can really focus the stage to the front. I'll look and see if I still have pics..

If you want more info let me know...

[tblt44]

More info is always good.I already have my amp and sub.amp is a IL jx360/2.how hard is that skipass to get out.I don't want to make a mess of the car getting it out.I do want good clean sounding bass in the cabin

[Addedatmosphere]

I always got the best results with the sub by the back seat, facing the rear. JL 10w6

[Hellrazor35]

First let make clear the a car is the worst place for sound, as apposed to a sqare room.

Now let talk about position of the sub....any speaker that produces sound has a front wave and back wave (inPhase/Out of Phase)that comes out and a cone and gets larger as it gets further away. If the the back-wave or front wave gets deflected and crosses the front wave/backwave you get distortion in the sound. So having said that any time that you face a sub to fire backwards it will sound like shit in most all setups. Sure the trunk will act to help with the base but it will be muddled and bad. So to resolve this you need to eliminate the back wave the best you can and allow the front wave to travel and expand in the cone shape. Why do you think all the damn rice burners vibrate.

The full wavelength does not have to completely develop to be OUT OF PHASE or IN PHASE with its own reflected sound. So again firing the sub through the ski hole allows the waves to be more closely in phase.

Rear firing sub WavePhase

In this picture, try to imagine the back of the trunk is the vertical black line at the left of the picture and the little square is the speaker box. This picture is an illustration of what happens when sound comes out of the right side (front side) of the little square speaker box. Sound actually goes forward into the car (incident wave (RED)) and also backwards to reflect off of the back of the trunk (reflected wave (YELLOW))... Both the incident wave and reflected wave get to the listener but they are way way out of phase causing mucho cancellation in the listening area. If you could open the trunk, the reflected wave would disappear and NOT reflect back into the car thus no cancellation...

Ski hole firing Sub WavePhase


Any time I build a sub box all MDF or MDF/Fibreglass I always line the back board with Dynamat to help cancel the back wave.

With the bimmers having the ski hole its a god send, punch the hole out fully line the trunk and rear cabin with dynamat, build a backing plate for the sub box to mount to and make sure you seal it (air tight) and now you have just a forward firing sub into the cabin.

On my install this is how I have done I have ZERO rattle and can crank the system and ouot side you can't event tell that I have 2-12@750RWS firing in the car. But crack a window or moon roof and all hell breaks loose...

[iwannabeam3]

I have a rear seat delete with my sub in the middle. Best sound ever.

[Currie846]

interesting thread！ [IMG]http://www.**********.info/7.jpg[/IMG]

[jessezipper]

I had a 99 crown vic with 2 12" rockford fosgate p2s in a sealed box, i had the subs facing upward , still had lots of bass with less rattle that with it facing forward or towards the rear bumper

[Hellrazor35]

I had a 99 crown vic with 2 12" rockford fosgate p2s in a sealed box, i had the subs facing upward , still had lots of bass with less rattle that with it facing forward or towards the rear bumper

Your missing the point...it is better not to restrict the wave, you want the wave to be able to expand.

Here is the original that the guy wanted replaced because it rattle to all hell. mounted in the trunkl floor.....Nice looking but...


Here are some shots of 2-12" sub that it did and a couple of kicks







Kicks




So anyway trust me you will be very happy and have no rattles. You can even open the trunk and the volume will not increase...open the doors or moon roof and Oh YA!!!!

[vicky007]

I will be installing my JL JX360/2 amp and a single Polk 12 inch sub next weekend.
How to face the sub to get the best sound with the least vibrations.
I will be making the box.
options.
speaker facing trunk lid.(back of car)
box on drivers side speaker facing passenger side.
speaker at about a 30 deg. angle facing upward and towards the back seat.

I was also going to remover the sound material around the rear speakers and from the small holes in the rear deck to let some bass thru.

on the back door at 35 degree angle will be perfect with perfect sound output.
for trance it is more sutible

[burnitttt]

I have a 10" Boston Audio sub and a 550w MTX amp and was thinking of mounting it to and firing it through the ski hole. I am just looking for clean base, will this work or do I need to look into another sub? I would also like the option to beat down the block if I wanted..

[tblt44]

I would love to fire it right at the skihole but I dont have a fold down armrest.
I will be punching the metel plate out and removing the sound deadener around the few holes in the rear deck.
I still want my rear speakers.
I'm building a box and going to play around with the location.If I have to build another one than I will.This one will work for all directions,just not the best for sideway's.

I will post pics starting next week.Monday I will start my project.

[Hellrazor35]

Yes you would have to punch the ski hole out and trim the foam.

Here is a quick video I shot so you can see and hear the difference..
[ame]http://youtu.be/lJVqyAk6PPg[/ame]

[tblt44]

will the center piece romove from a solid bench back seat???????

would I be better off with a 6 foot ground or a 6 foot power wire ? 4 gauge.Install starts tomorrow after work.

[Hellrazor35]

will the center piece romove from a solid bench back seat???????

would I be better off with a 6 foot ground or a 6 foot power wire ? 4 gauge.Install starts tomorrow after work.

Yes it is made to be punched out. Both are fine, but the shorter the ground the better and try and ground everything at the same place. I ran my OEM battery ground then the 0g the ground block and then to the amps. Only ground I have is the factory off the battery. System has almost Zero noise at all. Only noise you can hear is on the AM channels.

I did 0G PWR and GND to the distro blocks and then ran 4g to the amp and 8g to the subs. 12g to the x-overs and 12g throughout the car. Ran an ANL fuse off the batter and maxi fuse block for pwr..

[tblt44]

Ok if i mount the amp on the pasenger side i will have a short ground and a short power wire.if i mount on the drivers side i will have about a 6 ft power wire but can ground to the factoryground for the amp.either will probley be ok i have a 4 g

auge amp kit.

[tblt44]

OOk took all carpet out exposed the factory amp.now not sure where i want to mount the amp so i made my box yesterday instead.today i might splice into the white wire and speaker wires at the factory amp.

[Hellrazor35]

Toss the factory amp out. Why in gods name would you want to use it???

[tblt44]

Well the amp and sub are in.sounds great with the trunk open.not a lot off bass gets thru with the trunk closed. I punched the ski pass not much different also the amp gets pretty hot is it ok to bolt it to the carpet.Well maybe It does hit ok inside with the right cd.

[Guam135i]

Nice

[aparisi59]

how exactly do u punch out the ski hole????