I use this HU with stock Honda front speakers, some very basic Pioneers in the rear, and a Bazooka RS10hp sub. Overall I am pleased. The power of the amp is quite impressive, and I never need to turn it more than halfway up because it is more than loud enough. The sound quality is not the best. It does have an integrated EQ, so one can tailor the sound, but this is not audiophile quality. Without the DSO feature on, the sound is actually downright disappointing. With DSO on, it can be a little shrill, but adjusting the high pass filter helps. Working with the EQ and system wide treble control gives you the control to make it sound the way you want. The display is very cool and has a very clean look. This inside display is even cooler, but has a drawback-- I have found that if I have the display flipped down (CD slot exposed) the detachable face comes off if I hit a big bump, which shuts the system off. This means that I keep the face closed 95% of the time, forcing me to use the remote just to adjust the volume, this is a little annoying. Other than that it works well and has many great features. 3 sets of 5v preamp outputs, subwoofer level control, high pass filter, low pass filter, tunable EQ (factory setting are useless, but it will store your EQ maps). I don't use the radio too much but the tuner seems strong. The CD player works very well; it has read every CR-R I have tried so far, and rarely skips, even in my lowered/stiffly sprung car. Buy this HU if you want a powerfull, cool looking HU and you need compatibilty with a Sony changer. Don't buy if it you want the best sound quality money can buy. It has done what I need it to, but so would any HU for this price. I use a Sony MD changer so this forced me into a Sony HU, I would probably try a Nakamichi or Eclipse otherwise.
Sitting mid-way between the M600 and the M700, the M670 is the first of Sony's 'Active Black' car stereos to come with a detatchable face and it was for this reason that I bought it. The idea behind the 'M' series of Sony car stereo head-units seems to be that, when powered off, they look like a blank piece of plastic in the middle of the dashboard. The reasons for this are two-fold; firstly it looks pretty neat and secondly to disguise the fact that a car stereo is fitted. Unfortunately, only the first of these actually applies as any car stereo thief worth his salt should be able to recognise one of these shiny lumps of black plastic for what they truly are. I suppose I may have become too used to carrying round a plastic case with the front of my car stereo in it, but the 'PIN code via supplied remote control' security of the M600/700 didn't leave me feeling particularly comfortable. Instead, I opted for the good old detatchable face offered by the M670. Security wasn't the only thing that made up my mind, it is a superb looking stereo. Black and shiny when the power is off, simply displaying a clock and a back-lit SONY logo when the ignition is on. It's when you play a CD that it really comes to life... press the 'open' button and the face rotates through 100degrees to reveal the pristine silver control panel, lit in blue and red, with the CD loading slot just above the panel. Start to put a CD in the slot and it is sucked in by the loading mechanism and the unit starts to whir. Press the close button and the silver control panel is once more hidden away. As the CD is cued up, the display springs to life... If there is CD Text on the disc, the unit displays it briefly and then starts to play the first track, the bars of the graphic equaliser dancing up and down with the music. It looks almost like something out of Star Trek: The Next Generation! And if you think the dis
play is nice, wait until you hear the sound! There are 8 graphic equaliser presets, designed to enhance different types of music, from Jazz, to Classical, to Rock. Pick one that suits your taste and crank up the volume. There is also an option to 'elevate the sound' which is best used if your front speakers are mounted at ankle level, it fiddles with the sound and actually makes it seem like the speakers are up around shoulder height. With 4 x 50 watts of output it's plenty loud enough for me and certainly anything over half volume starts making the speakers rattle, but it's the quality of the sound that really impresses me. Aside from the display and playing CDs it is perfectly capable of controlling a CD changer, it has an RDS EON radio with automatic signal searching, Traffic program and the ability to select radio listening based on the type of broadcast (Pop Music, News, Classical etc). It comes with a remote control which, at first I have to admit, I laughed at. In practice however, the remote is a lot more convenient than having to open the front panel every time you want to adjust the volume. You can also get some strange joystick type affair that you strap to your steering wheel column for remote control, but I remain unconvinced about this and so haven't bothered. So, am I happy with it? Yes. Undoubtedly it's loads better than the standard cassette player that was shipped with my car, in both sounds and looks (it DOES look stunning, especially at night). I am glad that I bought it but there are a couple of minor niggles. First, every now and again it spits out CDs reporting an error. I just pull it out put them straight back in again and everything is fine. This could happen on any CD, I've not found one so far that it doesn't like on a regular basis. I would stress, it's very infrequent that this happens (maybe 4 times in 4 months) Second, when you want to take the
face off you have to hold down the 'open' button for 2 seconds... if you don't make the 2 seconds, all you manage to do is make the face revolve so you have to close it again and then hold the button down for another 2 seconds. Third (and this one isn't really a complaint about the unit), I am starting to think I should have bought a mini-disc player. CD cases don't fit in the glove compartment so I end up with them rattling around the door pockets. CDs end up in the wrong cases, etc, etc. mini-Discs would have been so much more convenient for the car. *Update* A fourth (and hopefully final) gripe. With the sudden change in climate we have experienced over the last week or two, my car stereo appears to have caught a cold. That is to say it simply WILL NOT accept any new CDs until it has warmed up a bit. Any CD that has been left in over-night plays fine, but if I want to change the disc before the unit has warmed up, it simply takes the disc in, rattles it around for 10 seconds and then spits it out. If I do this often enough, the LCD screen informs me that I should reset the unit... hardly user-friendly. I have puzzled long and hard over what could be causing this. All I can realistically come up with is condensation inside the unit. The people in Halfords agree and informed me that one other person has reported the same problem with an identical CD player. So I now have the air-con turned on every time I am in the car. It does seem to get the CD player working quicker so condensation is most likely the cause, but surely something this expensive which has been designed for installation in a car should tolerate the sort of environment it will be used in?! This problem has become such a nuisance that I've taken my rating down from 4 to 3 stars.