In a 2002 X308, is the premium-amp model LNF4170AA and the regular-amp model LNC4170AA?

 

as in the alphabet - a,b,c,d,e, it's just a later version of the same thing. No such thing as a 'regular ' amp, it's either premium or no amp, as I understand it.

 

Thanks!

So the non-premium cars have all the speaker wires going directly to the head units instead of the trunk amp?

From an engineering perspective, that is a bizarre way to architect a car (many wires routed totally differently dependent on an customer-option.)

 

Certainly looks that way from the wiring diagram, see speakers are direct to head unit.

 

Cool, thanks dude!

 

Just to confirm, they all work the same right? Any LN*4170AA will fit my '02 VDP?

Please advise as I just ordered a replacement unit without knowing the exact model...

Ugg, they look different, the F model has an extra wire + plug...

 

you would have to confirm what wiring is already in place behind the boot carpet usually tucked up behind the cd player with bubble wrap. Maybe should have done this before ordering?

 

1. I have a VDP, so there is an amp that works fine, except no sound comes out of my subwoofer so I thought a new amp would fix the problem (?)

2. the ebay merchant kindly cancelled the order to my request and refunded, indeed the 98-99 units are visually quite different then 00-03 and no sense in adding yet more variables to getting this fixed

 

more likely the subwoofer, have you tested the wire connections for an output on a meter to confirm the sub channel is good? also test the woofer for ohm resistance?

 

No I have not, good suggestion, but how do you access the output wires without cutting the wire harness? Disconnect the harness from the amp and attach each tester lead directly to the two amp sub connections where the harness plugs in?

Also, I have a great TrueRMS tester but my EE education was a while back, so I need the dummied-down version; am I testing for voltage? Audio has inline capacitance, so it is AC right, not DC? What range of current is considered normal?

This is I think I can manage, unplug harness, stick each lead into the end of the harness sub-connections and set the tester to resistance, right What ohmage is considered normal? 4 or 8 or something else?

Thanks man, this is a big help!

Is there any possibility that the head-unit would not send the amp a subwoofer signal or is the crossover inside the amp?

After reading other people's experience removing the back seat to change the sub, the amp is definitely the easier part to fix...

 

to test the output of the sub channel of the amp it's Volts to 4V I think....? you do this by pulling the carpet and disconnect one side at a time (as the sub is dual voice coil) stick the meter probes into the connector + and -
The speaker is the same stick the probes on their connectors but set the meter to Ohms, there should be a resistance of some sort, I've a working one in a box somewhere I can tell you what it should read if I dig it out.
I didn't know you had an amp already - might have been something to do with your question about a standard system and how the speakers are wired to the head unit.
9 times out of 10, it's the speaker's rubber surround that's split, I think you're going to have to change or fix it.

 

Actually, all the speakers are wired from a junction under the back seat on the left side, which the loom from the head unit and/or amplifier plugs into.

--
Roy

 

Cool, is getting under the backseat easier access?

Sean, thanks, great info - and I hope you are wrong about the sub rubber, lol, but you clearly know your stuff...

 

The only real way of getting access to the subwoofer on the parcel shelf to test it, is by pulling the carpet that hides the petrol tank and then you'll be able to see what your after, here's a picture...it shows the bottom of the sub (a 6x9 dual voice coil) so it has two connectors from the amp.

Each connector has a + and - .....disconnect one at a time and see if you get anything from the amp while it's running, be very careful not to touch the meter probes on anything whist testing the amp or you might damage it.

Once you've confirmed wether you have output from the sub channels on the amp, you can test the speaker, as already mentioned - it can be a strain on the back as you'll have to reach up to connect the meter.

I upgraded my premium system recently, so it's still fresh as to what parts are where.

Hope this helps, and as far as taking the rear seat out to replace the sub, it's not difficult, don't worry about it.

 

Thanks!

How do you disconnect the connectors without doing any damage? Just pull each one off of the sub?

 

Jesus, they have a squeeze clip, squeeze ad gently pull - I'm now out of here, I've walked you through this.

 

Haha, thanks, I am away from my car at the moment and will have a limited amount of time to do the work when I return - so need to plan it like a military operation, lol.

 

This thread is long time dead but... if you don't have a premium system in your car (XKR01) is the wiring still all installed and can you retrofit the amp and the speakers?