Antti Salonen

If the rear speakers in the Berline are anything like the ones I removed from the rear shelf of my Coupe, they are 6.5" paper "full-range" speakers. They sound as bad as they look, with barely any low or high range. I suggest you adjust the balance all the way forward, or disconnect the rear speakers, and be done with it. For good sound all you need is a pair of good speakers with separate tweeters in the front and a sub in the back.

Sorry for a late reply, but I guess this could be useful to others as well. To remove the rear speakers you only need to remove the part covering the speaker. To do this remove the Torx T20 screw on the side, close to the top. Then pull up firmly on the cover and it should come off. The rear seat belt goes throught it so you can take it off completely, so throw it to the backseat. Then remove the speaker screws, pull out the speaker and unplug the cable. All other screws there mount the lower part (where the speaker is mounted) to the body, so don't touch any of those. Of course if you don't plan to install anything else there, there's no need to remove the speakers. Just set the balance all the way forward.

I finally installed the Infinity BassLink today. It was reasonably straight forward, and I ended up doing it a lot like it was done in wozza's example. I took the power from the fuse box next to the battery, attached the fuse holder on the battery and took the cable to the passenger footwell (the right side of the car). From there I just run the cable under the removable floor mats (option) and the seats, nicely out of sight, all the way to the trunk. The BassLink takes speaker level signal, so I removed the rear speakers (this is a coupé) and extended their wires a bit and connected them to the subwoofer. The front speakers were replaced earlier with Pioneer TS-Q171C. I'm sure there are a lot better component speakers available, as these don't have separate crossovers (just a highpass filter in the tweeters), but then these were only 130 euro. The sound is quite nice with the stock Blaupunkt RD4. The BassLink is definitely the strongest link here and it doesn't take a lot of space in the trunk. I also added some dampening in the front doors and around the trunk, ant the whole upgrade cost just 500 euros. It's pretty easy to do and I believe a good way to upgrade the stock audio system. With a bigger budget the Blaupunkt RD4 would definitely be the next one to go, although I would definitely like to keep the steering wheel controls.

That's pretty much it, I believe. I haven't driven on anything lower than 55 profile before.

Another question while I'm at it... I'm in the process of upgrading the standard speakers my Coupé, and I already replaced the front door speakers and the tweeters on the dash board with a new set, and added some sound proofing on the inside of the door panels. With the (absolutely awful) rear speakers unplugged the sound is now reasonably good even with the standard RD4 head unit, but the low end is obviously lacking. I guess I'll eventually end up replacing the head unit as well, but that'll wait for a while. I picked up an Infinity BassLink active subwoofer at a very reasonable price, and once I get it it'll be installed on the side of the trunk. It has speaker level inputs so connecting it to the rear speaker wires won't be a problem. I'm not sure if there's 12V available somewhere from the trunk, but in any case I think it'll be necessary to run a good thick cable straight from the battery with a fuse near the battery. So can any of you give any pointers regarding how to route the power cable? From the passenger footwell I can run it under the floor mat and then under the seat but what's a good (and possibly easy) way to get it from the engine compartment to the passenger footwell?

I guess it's more about tyre size and road surface than anything else. I'm now running the tyres at 2.4 bar all around and the noise is not so bad. On smooth roads it's very reasonable.

They are Nokian Z, which are not cheap and based on the reviews I could find, they should be pretty quiet. I guess a big part of the problem here (Helsinki area, Finland) is that the roads here just aren't that smooth. While there are no pot holes the road surface is typically pretty rough because of the winters and the fact that everybody uses studded tyres for 4 to 5 months a year. Anyway, I dropped the tyre pressure to 35 psi all around and it definitely helped, but I'm wondering how low can you go without throwing off the handling or having uneven tyre wear? Based on some Googling many run this size around 30 psi, and for Skoda Octavia for example the manufacturer's recommendation for 205/50R17 seems to be 32 front and 31 rear.

So, I got this new C4 Coupé (photo) a week ago and I have about 900 km on it now. Apart from a few minor complaints (creaking back end, clunky gearbox) the main annoyance I have with it is the tyre noise. The tyres are 205/50R17, same size that comes with the VTS. So, what can be done about it? This is my first car and I don't really know what to expect, but at least my sister's Focus is a lot quieter, but then the tyre size is something like 185/65R15. Tyre pressure is currently 2.6 bar (38 psi) all around. Does that seem reasonable or is lower fine? What about sound proofing? When I removed the front door panels to replace the speakers I noticed that there was absolutely nothing under the panels, so I added some proofing there which made some difference. How easy is it to improve the sound proofing so that it makes a real difference? Basically I'm looking to upgrade the audio system further by changing the head unit and adding a subwoofer in the trunk, but I'm not sure if it's good investment if the tyre noise is as bad as it is now.

Yeah, I guess we're consulting the same calculator (link), because that's the number I've seen too. Considering that on most cars the speedometer shows higher than the real speed, I think increasing the tyre diameter a bit should actually get you closer to the truth.

Thanks for the input, everyone. I don't intend to go any wider with the tyres. I think I'm getting 205/50R17, which should have almost exactly the same width and diameter as the stock 205/55R16 tyres. The law here (Finland) requires different tyres for winter use, so I need to get a second set of wheels anyway, and I'm looking at 17" for purely aesthetic reasons.

I'm getting my brand new C4 Coupé in July, a silver 1.6-litre with the glass roof. The first thing I intend to do with it is to replace the stock 16" wheels with some nice-looking 17" alloy wheels. The stock wheels appear to be size 6.5x16 ET26. So the question is - If I get wheels of size 7x17 or 7.5x17, what's the acceptable range for rim inset (the ET number)? One wheel which I'm considering is 7x17 ET25, which I guess should be a near-perfect fit. One, however, is 7.5x17 ET18, so the centerline of the rim would be 8 mm outer than with the stock wheels. Would this cause problems with bodywork clearance or handling?