Best direction to place a sub ????

[COINERS]

So I originally faced my sub in towards the car because I had no other option because of the dodge boot floor in my VP and the shape of the sub box.
Any way I have recently re-built my boot now I have the option of flipping the sub around to face out towards the car.
Im not one of those yuppies that cruzers around with the music thumping so you can hear the bass from out side the car. All I want is a nice amount of bass to be herd inside the car.
Now my question is would it sound better with the sub facing in to the car or out towards the car. Id likes to get a rough idea on what to expect before I bolt the sub to the boot floor. Lol

This is my old boot lay out



And this is my new boot with a more leval floor


Thanks guys
Nick

[defyet]

Personal choice really,
No one can really say "yes it will sound better this way" and if they do they are basing it on there system or one they have heard like that.
The only way you will know is to experiment. Just onbolt it and face it backwards and see if it sounds any better.
I have heard some face back and others face forward and they sound equally the same it just depends on your setup.
Though take in mind you will get alot more boot rattles having it facing back rather then firing into the cabin.

Cheers,
Scott

[StoneX]

I can say that facing the box rearward has the same sound quality, but is louder than facing forwards. And not from just my install or one other. At least 10 other sedans, most Commodore models a Falcon and a Nissan Pulsar sedan. They all had cancellation when facing forwards, which was proven by opening the boot and the bass got louder inside the cabin. It is a very noticeable difference.

http://www.installer.com/tech/aiming.html

[VLDavo]

face it backwards to the rear of the car u get alot more loud off the subs

[defyet]

Hey StoneX,

Can you explain why you would get cancellation when facing it forward if its firing through the middle seat into the cabin ie. the sub is fully sealed off from the boot, so opening the boot would do jack shit. unless the sub was actually in the boot then opening it would make a difference.

Just a thought

[COINERS]

dam. for some reason i thorght my car had no rattles but im shore when i turn the sub around its all gonna change lol
stoneX that link u posted was very helpful. thanks mate
thanks for you input guys

[97 SEN]

Yeah, i'm also intrested in this, as i'm about to install into my new car and in my old i had it so it was sealed up against the middle seat with no gaps between the face of the sub and the boot area

[COINERS]

Also i was thinking about putting a piece of mdf along that back of the seats to mount the amps on to. Is that a bad idea. i just dont know where to place my amps now as i herd its bad to mount on the bottom of the parcel shelf :S

[defyet]

Hi,

Having them mounted to the back seats on MDF is fine and you wont have any troubles alot of people do this, infact most installs i have seen amps get installed on there side as it saves alot of room so mounting it to MDF on the back seats is no diff.

Mounting them upside down under the parcel shelf is a bad idea as you have heard as the top of the amp is Heatsink so if you mount it upside down the heatshrink is at the bottom (Heat rises) so the heatsink will be useless and the amp may get hotter and you could damage the amp this is the only problem with mounting it upside down. Otherwise connect fans to blow air through the amp to keep it cool but thats just a waste of time when you can mount it on the back of the seats.

Cheers,
Scott

[97 SEN]

I did exactley that and then had some hinged panels that came back from the seat at about 45 degrees that i could lift up and put stuff underneath. I also had the back panel of the amps and put a vent and a fan on them.... Damn i wish i had some photos of my old setup, never had overheating problem even running a sub bridge of one of my 4 chanel amps at 3 ohms instead of the 40hms the amp was rated to bridged.

[COINERS]

oh sweet thanks guys

[defyet]

Cool,
Some amps can get very hot, i know my Mono Blocks got red hot after playing it for 5min or so but never had a problem with burning them out, But your only running low amount of power so it shouldnt get to hot.

[StoneX]

Hey StoneX,

Can you explain why you would get cancellation when facing it forward if its firing through the middle seat into the cabin ie. the sub is fully sealed off from the boot, so opening the boot would do jack shit. unless the sub was actually in the boot then opening it would make a difference.

Just a thought

In theory, if the face of the sub is facing into the cabin and completely sealed from the boot, you shouldn't have any cancellation. But from my experience, that is near impossible to do. We tried with a EB Falcon... We jammed everything we could in the gaps venting from the boot into the cabin, yet the sub volume still changed increase when the boot lid was opened.

If you could mount the sub to a panel that is pressed air tightly up against the rear of the seats with no air gaps at all and all the holes in the parcel shelf were sealed, it MIGHT work, but that's alot of work when you can just face it rearwards and not have the problem at all.

[Brycestro]

a note on mounting the amps upside down to the parcel shelf underneath it: many will suggest not to mount an amplifier upside down for the reasons previously mentioned here. Heat rises, it'll rise back up into the amplifier and cook it.

HOWEVER: when mounting under the parcel shelf many will argue (ask 12voltking if your looking for a reliable source) that as the parcel shelf is metal the whole thing will act like one massive heatsink and cause the heat to dissipate away from the amplifier much better than it would even under normal circumstances. I've never done this personally but i think there's valid arguments either way.

P.S. if your looking for another option for amp mounting consider making a false floor out of some MDF and chucking it under there. I've done that in my car and it's nice and safe away from being bumped and knocked up. Cheers, Bryce.

[defyet]

This MAY sound stupid but just because it is mounted to a metal panel does not mean its going to act as a large heatsink area.
Heat is rising back into the circuit board and components inside the amp and on the bottom of the amp before it even uses the underside of the parcel shelf as a heatsink. Think about it, when the amp is mounted normally heat is rising off the components into the heatsink, when its mounted upside down the heat cant go anywhere and will heat up. So it has to travel through the circuit board, and use the bottom of the amp and parcel shelf as a heat sink?
I Doubt It!
I work with metal all day long, If i have two plates together and heat the top one up you need to give it a fair bit of heat before the one under it will get warm, and in saying that metal doesnt always spread heat very well it normally sits in one area. I could heat a 50mmx50mm area up so it is melting but i could touch the metal 2 inches away and it would still be cool. Heat tends to only sit in one area with metal.

When an amp heats up the air circulates inside the amp like it would in a box, the heat inside the amp could be enough to damage the amp before heat would even transfer through the ass of the amp and into the parcel shelf, It takes a fair bit of heat to transfer heat through two plates of metal!!!!

Just my 2 cents, Not looking for an arguement i just find it odd how you can say a parcel shelf would be better then a heatsink when they are designed to keeps things cool?

PS - I dont think he will get much heat of hes 4channel amp by the sounds of it anyway so he wont have a big problem with heat.

[COINERS]

i have one 4 chanel amp and purchasing another 4 chanel on tuesday. ill keep you guys all up dated with photos late next week.
thanks guys

[StoneX]

Wait... Why do you need 8 channels?

[COINERS]

I got 1 amp in use at the moment
Now as you know Stonex from my other tread I needed to get another amp to power the sub. I Went to Jb the other day and spoke to the guy and his got some 4 channel kickers they are trying to get rid off for like 200 bucks cheaper then what I saw last week.
So I asked him if it would run with my sub and it check out fine.
May even put speakers in my boot at a later date.

[StoneX]

Oh ok, so you're just going to bridge 2 channels of the amp and have 2 spare for future upgrade?

What Kicker amp is it?

[COINERS]

not 100% but i looked around the net and i think its the 04kx350 4X90 watts. ill doble check it 2nite or tomoz for ya

[lieos]

the reason the subs sounds louder when facin out is because the subs sound wave is increased bacause before it enters the cabin it uses the boot the increase the sound wave. where as facin straight into the car the bass wave is what the sub puts out

[defyet]

In other words the sub is louder in smaller area's. Eg. Hatchback cars, boots etc.
Having it facing into the cabin of a sedan is a much larger area and will not be as loud, facing it into the boot it is projecting into a smaller area and will be louder, as its only qaurter of the size of the cabin in a sedan. You just have to eliminate all those annoying rattles liek the number plate and boot lid hehe.

Sorry but the post above was abit mumble jumble but you were on the right track!

[Tasmaniak]

talk about a subject done to death.

You need to factor in standing waves.
Expansion waves
Half wavelengths
Full wavelengths
quarter..yadda yadda yadda.

I have given trying to explain to people the logic behind how it works. It got to the point where I now say this...

Coiners. Put the sub in one way and drive around for a week. Th next week turn it around and listen to it for a week. Which one sounds better? Good! Now put it the way you want it and screw the bitch down and leave it there.

[garfa]

oh come on 12volt and stone! lets read another couple of pages of them trying to cinvince each other that the boot lead increases the bass volume magically and that its better to mount the amps on a nice weak shit mdf board so the thief can just grab the thing and run!
:b: :b: :b: :b: :b:

[defyet]

talk about a subject done to death.

You need to factor in standing waves.
Expansion waves
Half wavelengths
Full wavelengths
quarter..yadda yadda yadda.

I have given trying to explain to people the logic behind how it works. It got to the point where I now say this...

Coiners. Put the sub in one way and drive around for a week. The next week turn it around and listen to it for a week. Which one sounds better? Good! Now put it the way you want it and screw the bitch down and leave it there.

Didnt someone already say that above? Oh it was me, thats right.

oh come on 12volt and stone! lets read another couple of pages of them trying to cinvince each other that the boot lead increases the bass volume magically and that its better to mount the amps on a nice weak shit mdf board so the thief can just grab the thing and run!

Whats the difference between mounting it on MDF then on metal? Its just as easy to unscrew it no matter where it is mounted in the boot, Unless you can think of a magic device that is going to stop thieves from stealing it?
Who said he was going to mount it on a "weak shit mdf board"?

More people post bullshit around here and repeating what other people say then posting something useful.
Not hear to start an arguement just a discussion.