35 replies to this topic

[Dom]

What is the cubic feet under the seats?

[philster]

Not too sure i'll have to measure it and work it out when i get chance, i usually work in litres when building boxes etc.
I know there is enough room under there for most 8" subs but i plan on cutting the edge of the seat base away (like the do on racers) and then building the boxes so the subs aren't on an angle and look almost part of the seat.

[wobbit]

do ya recon one 8" sub would be ok as far as sound goes, im a little skint atm, lol cant afford 2 subs!!

[philster]

Well one is better than none! you could always buy another when you have the cash. Just make sure you get an amp which could power both, if the amp is 2ohm stable then you could wire them in 2ohm config, this means that the power from your amp will be greater (most are say 120watt rms @ 4ohm and 240rms @ 2ohm).

[wobbit]

Well one is better than none! you could always buy another when you have the cash. Just make sure you get an amp which could power both, if the amp is 2ohm stable then you could wire them in 2ohm config, this means that the power from your amp will be greater (most are say 120watt rms @ 4ohm and 240rms @ 2ohm).

yer thats the plan mate, cheers 4 ur help

[minimanshane]

Hey philster you mention the rockford sub but you will need a sealed box you can fit one in the below the seat but 2?
What about a cheap 8" freeair sub do you know of any?

[philster]

The rockford sub should be able to fit under the seat but you would have to have a sloped piece at the front, this is because the sub is 8 inches and the seat to floor about 7, it should be entirely possible but you'd have to measure the space that you've go to be able to do it.

Free-air isn't the best option in this space, the bass reproduction from a sub in a proper enclosure is far superior and as far as i'm aware no-body makes a dedicated 8" free-air sub, kicker make the comp VR which can be mounted free-air aswell as in an enclosure but it would be better in an enclosure.
If you do chose to mount the subs free air you need to stiffen any panels which will be acting as the enclosure. You also need to secure the baffle board as best you can and seal it, for what it would cost to mount it free-air and do a good job it would be as cheap and less time consuming to build a box for it (thats why i don't think its worth it)

Remember equipment only makes 5% of a decent install, but without the time and effort put into one it will never reach its full potential.

[minimanshane]

Yea but there is not enought cuft below the seat for non freeair subs.

[philster]

okay i'll get my tape measure out tomorrow and try and work out how many cuft there is under there.

I would think there'd be more than enough volume there for an 8" but like i said you'd have to angle the front part or the box so that it fits.

Will try and do it tomorrow and see whats what.

[AlexM]

Whats wrong with what they have done in MiniWorld?

[binge]

Right, looking good.

My dad bought me a set of Pioneer coaxs from an autojumble the other day for £2! :grin:

They are 5" coax, They look quite old, but they sound crisp, even through that sh1tty head unit ive got.

The crank up VERY loud too, and as far as SQ goes. I cant complain. They sound ace.

So A decent head unit, and a subtle sub. And I should have a phat system! :wink:


Bring on the TVs and PS2 again!

[philster]

Whats wrong with what they have done in MiniWorld?

Its quoted as a professional sound system which was supposed to have been installed by professionals.

Here's a few things thats wrong with it.

You can't effeciently put four subs in that space there simply isn't the volume.

They haven't even mounted the baffle board properly, they've just smeared a load of silkaflex on it (or bodged it simple as). For a baffle board to work effectively it needs to be mounted solidly (like fitting a frame or brackets for the mdf to mount on) and needs to be sealed as best you can.

The subs are not designed for free air

They have drilled holes in the doors (well i say drilled they look chewed) to let the speakers breathe? even though they would perform better if you didn't and as soon as it rains the water will pour down the backs of the doors and ruin your nice new speakers.

Its a real shame as he's spent a lot of time and money on the prep (ie dynamat sound deadening etc) but not really put any real thought into it.

Oh and he put wadding in to improve the 'bass reflex' but bass reflex is a term which refers to a ported box!

To most people it probably looks quite impressive but for them to refer to it as a professional install is stupid, all they've done is thrown a load of money and not much thought into it, if they just used 2 subs in sealed boxes it would sound better, less is more as they say!

[AlexM]

Excellent points there

What sort of brackets could you use? I plan on doing the same install or though as you have pointed out i wouldnt be cutting the doors for the same reason or fitting four 8inch subs as i also decided that they would not sound so good, so im going to stick to two.

I would much appreciate your ideas on how to go about this.

[philster]

Firstly use a piece of 3/4" mdf or ply as the baffle, you could do with painting this in some bitchumen based paint or sumat to stop it soaking up moisture from the carpets.

I'd use a piece of 1" or 3/4" angle iron bolted around the outside of where you want to mount the baffle, if you can don't leave any gaps and seal the the angle iron in place both on the mating face and at the back and front edge paying particular attention to the ribs in the floor.

To fix the baffle to the frame you could either drill holes in the angle iron and tap a thread into it (as long as the metal is a thick enough guage) or you could drill holes before you fit it and weld nuts on the back or you could drill through the baffle board and into the angle iron with a small drill bit and fix it in place with self tapping screws (if you chose this route re-drill the holes on the board so that the screw doesn't bite the mdf it only screws on the metal so that it draws the board tight against the angle iron)

When fixing the baffle in place put a decent bead of sealant all the way around the frame (enough so that when tightened it oozes out the sides).

Its also worth putting plenty of sound deadening on the seat base, floor and any other panels that would effectively form the box otherwise it'll sound poo. I would use self adhesive lino tiles for this on the floor, sides, back and stick a double layer on the seat base bit (top and bottom), if you want you can use dynamat but i doubt you'd be able to tell the difference and it would cost a lot less.

Once the sound deadening is done a good coat of underseal inside the enclosure will help deaden things furher and seal any little holes you might have missed. You can use brush or the rather messy spray.

Once done its just a case of trimming and mounting the subs, remember to put the wiring for the subs in first and this needs to be sealed also, i'd put the wires in through the side pocket through either a grommet (and then use a little sealant to seal it) or use a cable gland (they tighten up around the cable to create a water tight seal.)

With this done you will have a very well secured baffle and enough bass to rock your car! Its a good space to do this as its quite easy to get sealed properly (which is the key to a successful Free-air/Infinite baffle setup).

If you don't fuly understand what i've wrote i can always do a few pictures on the computer to show you what i mean.

Oh and if you decide to do it post some pics step by step if you can, i'm sure the mods would appreciate an faq.

[MINImiser]

Any pics of 2 X 8" subs mounted under the back seats?
Im thinking about doing this myself instead of fitting one in the boot.

Cheers


Ed