have i figured this out right?

[nippyarosa]

i'm in the process of planning a bit of an ICE install for my arosa, at the moment i've only got a set of 300watt infinity 6x9's. next stage is a sub and amp but i'm a bit unsure of all the possible options.

firstly is it worth leaving the 6x9's connected directly to the headunit and simply get a two channel amp and bridge this for the sub?

OR

for similar money, would you reccomend i go for a three channel amp (like this http://www.allyourbass.co.uk/?menu=1&productid=2 )

If i've understood correctly i could bridge two of the channels into the sub leaving the remaining one for the 6x9's?? or do i need two seperate channels for the 6x9's?

also does that amp look ok in your opinion? price seems pretty low to me

this all gets pretty confusing but i'm getting there slowly :?

[LincolnLupo]

OK, I'm not really what you'd call an expert although I do have some idea on these things.

I'm not personally a fan of 6x9s but I know some people like them so I'm not going to go into that one...

to answer some of your questions...

the amp you've linked to is a 3 channel amp that is basically designed for running some fronts (or your 6x9s) and a sub on the seperate channel.

the amps are usually more powerful on the singular channel as it's needed for a sub which generally needs more power and also because most designs are really 4 channel amps with two channels permanently bridged into one to get three channels.

this would mean that the singular channel for the bass will almost centainly be about twice as powerful (approx) as the other 2 channels.

You could not bridge the two channels to get the sub and run the 6x9s off the other channel as you would need 2 channels to run them in order to get a stereo output, you wouldn't want to either (see above)

the price as you mentioned is very low but because of that I don't think I'd trust their specs too much (doesn't even list the outputs for each individual channel which is not a great sign), the cheaper amps never seem to get close to what they've claimed.

I'd look at spending a little more on an amp that other people have tried and tested, you can still get 3 channel amps for not that much though these days.

I'd ask tigz / loudlupo / tshirt2k - by the looks of it they've tried enough things to have an idea of what'll work well or not.

[Tigz™]

I am going to respond dude, but works all over the place atm so it'll be later..

one thing...

Dont buy that amp!

I'll go through it later....

[willh]

For simplicity and if you're not spending too much, just run the 6x9's off the headunit and amp up a sub in the boot.

It wont be the best SQ/SPL system but should stretch quite loud and clear once the EQ settings on the headunit have been set up right (low bass) so that the sub can deal with the low signals and leave your 6x9's and other speakers to tweet away!

[Tigz™]

Ok.

As sub frequencies aren't picked up by the ear so much, a sub needs 3x as much power as your componts.

As the amp only provides a combined power rateing this is just a estimate, but the 285wrms claimed should be broken down like this.

285w / 3

1 x 190wrms

2 x 47.5wrms

Now this is very optimistic.

It'll be rated at 14.4v so your not gonna get anyway near this, a Lupo elecctrical system gives are about 13.5v if everything is running right.

So Id say you can knock of 25% of the claimed power there.

The power supply is *****.

As the amp is gonna be having to work its tits off, your gonna lose lets say an estimated 25% through heat loss.

So I would say, (and this is VERY optimistic) you may get around:

1x 95wrms

2x 23wrms

So there you go, although they make it sound like your getting a desent amp for little money, Im afraid, its a little of a scam really.

Ok back to the questions.

First thing first, I am not a fan of rear speakers, to me if you are fitting a sub, fitting rear speakers doesnt improve the sound whats so ever, if anything you end up with a worse sounding system than if you stuck with the standard componts.

Saying that you have them now, so wont want to sell them to put towards the rest of the system.

A multi channel amp to power a sub and speakers never really works, unless your spending silly amounts of money.

You'd be better off with 2x seperate amps, one to power the components, (up front) and one for the sub.

The rears I would run off the headunit, but would disconnect the in built tweeters (I take it you bought 2/3 way one?)

Get your self a couple of large butter tubs, to fit under the shelf to try and help protect the inside of the cones from the air from the sub.

This should also give your mid range a little more of a kick.

If run without the tweeters, you shouldnt suffer from hearing all the music from behind you as much.

High pitched sounds are noticed alot more than mid range sounds.

Have you desided what sub you want?

How about how much space you can use?

How much you can spend on cableing?

Could you build your own box if someone worked the sizes out for you, or would you have to buy a silly `pre-built` one?

[nippyarosa]

oh dear, everything got complicated very quickly!

i didn't think that amp was gonna be any good, that price just had to be too good to be true

for simplicity's sake i've been looking at several "active" subs with built in amps

have heard good things about these

http://www.infinitysystems.com/caraudio/pr...Ser=BSL&Cat=PSU

[LincolnLupo]

OK, I can just about guarentee that eveyone will tell you that it's terrible or not value for money but if you pick one up cheap off ebay (about £100 or less) then they're great for adding a little more bass.

Don't expect it to shake your car or anything but I've heard them in action and they're not all that bad.

Certainly unless you substantially upgrade the amp and speakers for your front's / infinities this'll be of a good enough quality.

[LincolnLupo]

one more thing, if you're planning on pointing it sideways it doesn't fit.

A friend of mine had one and tried to convince me to buy it by showing me how small it would be in my boot before he sold it.

It fits in fine firing backwards though which most reviews said was the best position although it takes up the same room as my current sub box with amp on top when pointed that way (lose about half the boot).

The main market for it though is to get effective bass in your boot in no time with little experience, so sounds about right for you.

might want to read this...

http://www.crutchfieldadvisor.com/`ISE...ss_reviews.html

You'll have difficulties finding a black one though as they're no longer made and the clear ones look a bit cr@p if you ask me.

[nippyarosa]

so its lookin like a two channel amp and a sub is the way forward.

whatever i go for i'm gonna need to run a power cable to my battery, i've had quite a good look but i cant for the life of me work out how this should come through from the engine compartment to the cabin. on my mate's Ka there was a nice easy to find hole, does anyone know if the arosa's got one? or is drilling needed?

[Tigz™]

open your bonnet and take a look to the right hand side into the bulk head.

You will see where the wireing loom goes through.

Just pop a hole into the rubber grommet and feed the cable through into the passenger foot well.

Piece of cake style="vertical-align:middle" emoid=":D" border="0" alt="biggrin.gif" />

[nippyarosa]

actually put a hole through the rubber? i did see the point you're talkin about but i thought i'd actually have to remove the grommet