X5 Audio Upgrade Advice..

[one_happy_canuck]

I just purchased an 03 X5 with Mk IV Nav and Alpine 6 CD changer, and while I'm happy with the X5 I'm completely unhappy with the sound system that came with it.

After perusing the discussions on this site I understand that I do not have the DSP or premium sound options, and I'm looking for advice about how to go about improving what I have.

I'd like to keep things basically stock, so my options in no particular order appear to be:

1. upgrading the speakers
2. upgrading to the DSP amp
3. adding a sub

The existing system has *some* bass but sounds very muddy and lacks detail, and I'd like to get this fixed first before going after monster bass, so I'm thinking that the speaker / DSP upgrade would be my best bet to start with.

I've looked at the BSW stage 1 upgrade for the speakers, but this looks like a lot of effort, and I'm wondering if it would be worthwhile without DSP?

Regarding the DSP upgrade I can pickup the amp on ebay and the installation looks pretty reasonable, but I'm wondering if the non-DSP option speaker configuration is compatible with the DSP amp, or if the DSP expects a different speaker configuration? I'm also wondering if after installing the DSP amp the DSP menus would simply show up in my Nav, or if there is some other configuration required there?

Alternatively is there another upgrade path that I should pursue?

Advice appreciated..