Right I have tonight finished for good, chopping and changing the ICE components in the ZED....................and I have to say that i am very impressed with the final resultant sound, now you may laugh, but i set a goal that the system must make a good re-production of Ultra Nate - Free. If I could do that, then all other songs would sound good too.................my opinion, the other consideration was that when i hade my Volvo V50 last year I went for the top of the range sound system which with a gazillion speakers, amps, sub woofer and professional sound tuning by bods at Volvo sounds mighty impressive and that is playing Ultra Nate - Free, my favourite Spanish Guitar tracks, Bon Jovi, Queen and a little bit of Dino on the side, all are impressive in the Volvo - Bench Mark set! Now the Zed was not built for sound, other than listening to the fruity exhaust and the purring engine (Its a four pot, so it purrs). the previous owner had chucked the business head unit and inserted an Alpine EUB-100 HU, now that in its self at time was considered a decent HU, however if you dont buy the correct harness, dont have a clue about the BMW audio set up, you end up with a disaster that is part re-cabled speakers part crossed over tweeters, part BMW system and amps. Mix it all up with the lovely BMW paper cones and you have the equivalent of a symbol in a steel drum..................not good. Where do you start.............well, change the foot well speakers (pioneer 5.25 3 way coaxial) and rear speakers (pioneer 4" 2 way coaxial), yep it got louder, but it was a louder steel drum, also the drivers tweeter did not appear to be working??? Checking the wiring the left hand foot weel was spliced into the right hand tweeter, re-route new cables, by passed BMW amps, sound is now decent but no base, and driver tweeter is blown, and driving above 50, switch off and listen to exhaust, which is nice because new SS system fitted. Step forward Pyle Slim Active Sub (also known by other names), fitted in line with phono cables, power from ignition, now have bass, but can't play loud as speakers on driver side start clipping. back to drawing board. Problem current HU has pre out but uses rear channel, four speakers on from two channel requires more power and HU has no LPF or HPF, decision made New HU, AMP and another set of speakers required including tweeters required (Must be a component set up with passive cross overs) Shopping List: Alpine IDA-X311RR Digital Media Receiver £110 (Controls and charges IPOD from HU) Alpine KTP-445 Head Unit AMP 4 Channel Amplifier £75 (Inline Amp plug and play into HU) Pyle 8-Inch Super-Slim 600-Watt Active High-Power Subwoofer Enclosure FLI - Integrator 5.5" 225W Component Speakers (2 sets 4 speakers plus cross overs) £120 MB Quart RTC 19 Tweeters and crossovers £40 3.5" Hard drive (old laptop) and caddy £7 I have been installing this gear since October 2011, finishing over christmas with the rear 5.25" speakers and cross overs when fitting my new heated M Seats. So first set up of the system produced a nice sound but again as the volume got to half way the speakers began clipping, problem?, power has been sorted by routing the sub lead direct to the battery, new HU has four channels plus pre-outs. I left this problem alone for a few weeks as i had a more fundamental problem, the HU would not recognise my hard drive or a USB stick? Turns out my hard drive was formatted in NTFS and not FAT32, no problem i thought , quick re-format on windows computer to FAT partitions, wrong, turns out the FAT Configuration on windows PC's XP and above is not FAT32, you need a special program to do do this......................or an Imac................so formatted to FAT32 on the IMac, copied all my music 200GB to the HD and hey presto the HU can now read the hard drive......lesson learned here i think. Now, after thinking i would never have Volvo-esque quality, i decided to research the HU and discuss with an ICE builder in Cannock, it turns out that the HU has a number of sub woofer settings and also the ability to set both LPF and HPF, after discussion we agreed that the best setting would be setting the LPF to 80 - 100hz and the HPF to 100Hz or above, at the same time selecting Sub Woofer system 2 and setting the LPF on the subwoofer to 120hz. The clipping was caused by the LPF and HPF not being set and consequently the Bass signals were also being sent to the main speakers, causing a power overload and hence the clipping (popping sound, like a blown speaker) The transformation is incredible, I have no clipping, crystal clear highs mids and lows (BASS), and if i needed can now have full volume. I am very pleased with the re-production on Ultra Nate and as guessed all other genres sound pretty good also. it is now very close to the quality of the Volvo, and close enough not to want to spend any more money.