Remove the left side vertical trim panel in cargo area. Subwoofer is right behind it. Assuming you have the cd player, remove that by removing the screws on the left and right sides and unplug same. You can then remove the two nuts on the top of the subwoofer and now will have access to the bottom bolts securing the sub. Unplug the sub and remove. It's pretty easy once you get the cd changer out. The DSP amp is behind the panel that you will now see previously covered by the sub. Remove the top trim by popping out the plugs and then by the rear seat you will need to remove a screw or two and wiggle the large trim panel out. There are some clips that go into the pillar that are hidden. Play with it and you'll figure it out. Once off, the dsp amp is a plug and I think 3 nuts.
But I'm telling you from experience that if you have a DSP amp in your system, it is down in there behind that layer of insulation or whatever it is.
Here's a picture of the trim removed, the padding removed and the DSP amp removed. The DSP amp bolts to the black bracket you can see at the bottom of the picture.
Maybe instead of just popping a cover, having a quick look and saying it's impossible - actually take the bits of trim out fully and look properly? We're here trying to help - and most of the people here giving (free) advice have been in there and actually done it before..
It's even in the workshop manual... not that anybody seems to bother to read that anymore.
Are you sure you have a DSP system? On the non-DSP systems the sub amp is driven direct from the head unit (at least I think it is) on DSP systems the sub is driven by the DSP. So if you sub is still working then either you haven't got a DSP or you've got a mighty odd failure mode of the DSP. If you post the part number of the amp I (and others) can tell you what you've got. If there really is no amp behind the sub then take a door card off and see if you have separate door amps. Once we know what you've got we can help with the diagnosis, but be warned a failed DSP Amp is very expensive to replace - A whole new audio system is probably the best answer.
Perhaps we ought to get together as you have a '340 where only the sub works and I have a '340 where everything but the sub works!
I don't know how comfortable you are with circuit diagrams and whether you have a multi-meter but the place to start would be to measure he resistance of the 8 speaker circuits at the connector that plugs into the DSP (C0491) You need to look at Rave for the pin numbering as it's an oddly laid out connector but the speakers are as follows:
1&2 Rear Left Base
3&4 Front Left Base
22&23 Rear Right Base
24&25 Front Right Base
11&12 Front Right Mid
21&13 Rear Right Mid
31&32 Rear Left Mid
33&34 Front Left Mid
All these pairs should read around 4 Ohms. If they don't then you have a wiring / speaker fault.
If all these check out then check the power supply - both the permanent supply and the supply that switches on when turn the radio on. Actually might be worth doing this first.
Next would be to check that the radio is proving an input to the amp. This is a bit tricky. You should see something on a volts scale but a more useful test is to wire the radio output to another amplifier such as an external speaker for an Ipod or a computer. You can also try wiring the output of the radio into the subwoofer by jumpering the pins 9 to 6 and 17 to 14 on the DSP connector. Obviously you need to be comfortable with what I'm suggesting and please check my pin numbers because you can do damage if you get it wrong.
If you're getting an output from the radio at C0491, the power supplies check out, at least one speaker circuit is intact, but no sound then it looks as though your DSP is faulty.
If you were in the UK I'd offer to test it for you, but the postage / customs issues make that difficult. Maybe you can find someone nearer with a DSP, as your amp in their car and vice versa will tell you a lot.
Have you got the original stereo in still, or an after market ?
in your previous post you said front speakers were working with the other amp you purchased ! If nothing is working now I’d be checking the amp you bought is ok, they are quite hard to find in working condition, I got mine from USA as none over here at the time.
I buy a xqk100340 with navigation I buy a xqk100340 with out navigation no sound I bought a xqk100210 and that has sound coming from the subwoofers y don’t I have sound with the navigation xqk100340. Any ideas out there