Nah, i disagree about changing the speaker before the headunit. The original blaupunkt player in the facelift 156 (same as the 147 and gt, i guess?) is just rubbish. The soundquality is poor, low power output, and not so much settings for the sound.
It would be better sound to fit new speakers then the originalsound, but ofcourse, the best is to change both the speakers and the headunit.
I changed to a cheap 100£ alpine player in my dads 156, and it was a BIG difference in the sound right away, a lot tighter and more bass, and more detailed soundquality in the highter freq.
The problem to get very good soundquality in the 156 is the damping in the doors. Sound came very easily out, and ruins the soundacoustic.
Of course the other side of this is if you haven't tried changing the speakers first how do you know that they won't make a bigger difference??? Have you looked at the speaker specs? They are 40w Max (That's about 15w RMS) and the tweeters are 30w Max (That's about 12w RMS). If you get a decent Head Unit with 45w - 50w RMS per channel you'll blow the speakers at less than half output and then you'll be replacing the speakers as well as the head unit. That's OK if it's planned but if money ain't easy to come by - like it is for many of us at the moment - then do the speakers first, see what a difference it makes, then go for the head unit. Remember that it's important for you to be sure that the sound is how you like it to be - and the speakers will have more of an impact on that than the head unit because they reproduce
the sound. I do agree though though to get speakers that can handle at least 50w RMS - just in case you decide to go for a high power head unit later on or an amplifier.
I tried a new headunit after changing the speakers and ended up putting back to how it was because the marginal change in sound quality wasn't worth it for spoiling the look of the dash. I then tried an amp with the head unit through the exisitng cabling but I couldn't get rid of the interference so now I'm looking for one of the smaller integrated amp/subwoofer to go under the passenger seat to support the existing set up. Word on here is that that has a really positive effect on the existing setup for not much outlay.
One final tip don 't waste money on replacing the rear speakers - they are for rear seat passengers - concentrate on the front. That's where you are. You also prefer to hear sound from in front of you - that's natural - we tend to look at things we are listening to. So perhaps spend more money on one pair of components for the front and ignore the back. Good luck!!
146 1.6TS, 156 2.0TS, 156 1.8TS, 147 1.6TS, 147 2.0TS, 159 1.9JTS, 147 1.6TS, 159 1.9JTDm, Mito 1.4, GT, Giulietta 2.0JTDm, Giulietta 1.4tb, Giulietta 1.6JTDm........