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[sounds2k]

shouldn't need a converter. The bose system effectively has two "speaker" wiring looms. The head unit "speaker" wires from the head unit are driven at line voltage level, routed to the bose amp on the parcel shelf - which then outputs to the actual speakers (and bass drivers on the parcel shelf). In theory it should be possible to tap into the head-unit (ie, line level outputs) before they connect to the bose amp ...

[Jay w]

but the Alpine amp doesn't have speaker in connetors, only RCA's

[sounds2k]

but the Alpine amp doesn't have speaker in connetors, only RCA's

... a trip to maplin's and some soldering would be required ... just get a phono lead, cut it in the middle and solder onto the bose amp's wiring loom ... should be fairly straight forward?

[Jay w]

my stereo knowledge is a bit lacking so please excuse me if i sound like an muppet....

i understand the bit about splicing the wires and the phono leads, if i wanted to run the subs in adiidition to the current set up could i still do that in the way that was described?

Also the amp has a 'remote' connector, i know what it's for but does the bose amp have one as well i can splice from

And in addition i am going to need to run a power lead from the battery, does anyone know how much cable i am going to need and what ampage fuse to get,( i will be running 8 guage wire)

TIA

[sounds2k]

in the absence of someone with more knowledge -  haven't actually tried this yet!

hopefully the sub will have a gain control so you can adjust its' volume relative to the remaining speakers, in addition it'd also need to have a low-pass filter so that it only "hears" the bass part of the signal, but again I'd have thought this would be part of the sub's amplifier anyway. I'd expect the "remote" connector is a remote power switch-on signal which allows the amp to be switched on and off with the head unit. Basically although you connect big fat power cables to the amp, they should only be passing significant current when a voltage is present on the "remote" lead. Most after-market head units have this, not sure about the factory fit one though - there is a powered antenna output (see pics of the connector on my NCDC2013 here) - however I have a nasty feeling that on some radios this is only live when the radio is selected - so if you switch to the CD player the voltage on the antenna power lead disappears?

You'll need to check the instructions that came with the amp for the correct fuse rating, it may also give recommendations on the correct gauge wire to use too.

[Hillper]

The rating of the fuse depends on the cable thickness.  The fuse protects the cable.

The cable thickness is related to the power consumption of the amp.  8 Gauge will do nicely.  Use a 50 or 60 Amp fuse.

There are two routes you can take with the power cable.

From the battery, into the cabin filter 'void' via the loom grommet and through the bulkhead via the second loom grommet.  It will appear in the drivers footwell above the cardboard shelf thing.
It can then be run down the side of the car under the sill cover and up into the boot.
This will take about 5 metres.

The second route applies to auto facelifts.  From the battery, across the engine bay under the scuttle edge and through the blanking grommet where the throttle cable used to go.  Carefully threaded over the pedal mountings and down the car under the sill as before.
This will take about 6m, but it is much easier.

Tunnie was going to use this route until he discovered that despite having a facelift (the car I mean), his throttle cable hole was being used by a cable of some sort.  His is a manual.

You can run a sub independantly.

The amp should have a 'Low pass' filter, which should be selected.

The amp will have a gain control to allow you to balance the sub to the speakers.

I doubt if the Bose has an external 'remote' wire.  Any ignition switched feed will do.  (They'll be one feeding the radio), but put a small (1amp) fuse in line as close to the source as poss.

Mount the amp on some MDF and fix it securely to the car.

What model is it by the way?  If it's small enough, it may fit in the cubby hole.

[Jay w]

well if i can't follow that then i must be a muppet, simple and easy to follow, cheers chaps

its an MRV-F407, i doubt it will fit in the cubby hole, currently it is attached to the back of the sub box, it has a low and high pass filter as well as gain control

it is stood on its end currently, here are some pics

[Admin]

An Alpine MRV-F407 driving a pair of subs?  :-/

Wonderful wonderful amp, but not what I would use for a pair of subs.
I used to have one to drive the mids and tweeters and I loved it.

[Jay w]

hmmmm i take it the amp is not really ideal for the subs then?

The problem i an see is mounting something like that amp without losing a lot of boot space, it's a classic case of want good sound but use the boot a lot.

Friend suggested bolting it to the parcel shelf, but then the heat is sinking right back into the amp and will in time damage the PCB.
Plus running all the cabling to the doors would be a nightmare.....

does the Bose amp deal with all the speakers or just the back ones?

[Hillper]

The amp's fine for the subs.  I think Laidback just meant it's a shame to use it for going thump, thump, thump!  He had a soft spot for his!

The amp can't be mounted upside down as you say.  It will probably overheat.

The Bose speakers are all driven.  I believe the earlier Philips system just drove the rear 'subs'.

[sounds2k]

... does the Bose amp deal with all the speakers or just the back ones?

all of 'em ... it had been ripped out on my old miggy, I traced the wiring to where the amp should have been and there were feeds and returns for front and rear speakers - each feed connected to its' respective return.

[Jay w]

ok that's really cool, got some ideas now....

I have been given a suitable amp for the subs by a friend, so the alpine will replace the bose amp and the other amp drive the subs.

I am going to put the alpine amp where the bose was, now i know that the shelf is a bit smaller than the amp, the plan is to cut the side that is facing the seats, that way when you are looking in the boot it won't look too apparent, will there be enough of a gap there to keep the amp cool?

From there the speakers will be looked at, i can see this being a long process that has lots of questions

[Hillper]

The normal way to mount an amp is either horizontally with the fins upwards or vertical with the direction of the fins vertical.  The second method is supposed to be more efficient.

How hot the amp gets will depend on how hard you drive it.  So the size of the air gap around it will depend on this.  But no less than about 1" if possible.

It's not the simplest of plans, so take it step by step and plan carefully and you won't go wrong.  Just prepare for some hassle and a few cuts and bruises!

What's the other amp?  

Remember, you're running 8 gauge cable.  That'll allow about 450Wrms total amp power over 5 metres.

Edit.  And keep asking questions!  

[Jay w]

The normal way to mount an amp is either horizontally with the fins upwards or vertical with the direction of the fins vertical.  The second method is supposed to be more efficient.

How hot the amp gets will depend on how hard you drive it.  So the size of the air gap around it will depend on this.  But no less than about 1" if possible.

It's not the simplest of plans, so take it step by step and plan carefully and you won't go wrong.  Just prepare for some hassle and a few cuts and bruises!

What's the other amp?  

Remember, you're running 8 gauge cable.  That'll allow about 450Wrms total amp power over 5 metres.

Edit.  And keep asking questions!  

Cheers for the advice there.

Looking at the propsed mounting place and the size of the amp, i doubt i am going to be able to get away with putting the Alpine where the bose amp sat, although i don't run a lot of volume, i may have another look at the cubby hole where you mounted yours, all i would have to do then is re reoute the speaker cables.
the Bose amp does look like it has a remote lead, looking at the loom that goes to the amp i have found 4 black sleeved wires (each one with two wires in) 8 wires (coloured in pairs with the second wire having a tracer) a red, brown and a red/white cable, the red/white being of a smaller guage that the rest of them.
I am going to test the red/white to see if it is powers up only when the stereo powers up, if so i could be in business.

The other amp hasn't arrived yet, i will have to have a look at it, the plan was to run both of the amps from the 8 guage cable, i doubt collectively i am running anywhere near 450W and the puprose of this to make a start on improving the quality of sound not to have big volume.

The main fuse is placed in the fusebox next to the battery, i like to keep things subtle and simple, i have been taking pics so i will post them up once finished

[Hillper]

Saw the guides.

Very good Jay!  I particularly liked the tip about removing the passenger air vent to get at the bulkhead. Great tip.

Now when you have the other amp in, you'll need to set the filters on the door speaker amp to 'Hi pass' so they only get mid and high frequencies and the filters on the sub speaker amp to 'Lo pass' so they only get bass and sub bass.
This way, the doors will rattle a lot less, the door speakers will survive and you can get more output from them if they're just handling the mid and high frequencies.  The subs will have more than enough output to fill the car.

Keep up the good work.