I have fitted radios into Rover Metro's, Vauxhall Nova's, Ford Escorts/Orions, Uno Turbo's, Peugeots, 306's being where I gained most experience, and also a Nissan Sunny GTI-R which needed slowing down with a little extra weight!!
At the time the Sunny was a bit of an experiment with it's owner trying home cabinet speakers which unlike dedicated car speakers which have a 4ohm voice coil, the cabinet speakers use a voice coil that gives an 8ohm resistance.
Now the ohmage of any speaker plays a big part in how it works and also how the amplifier powering it works. The higher the ohmage value the harder it is for the amplifier to drive it this in turn stops the Amplifier supplying it's true power output and in our 8ohm speaker case as apposed to 4ohms this effectively halfs the power available.
To allow the Amp. to see a true 4ohm load we are going
to connect the seperate Tweeters in Parallel so the Amp see's a Mid Bass
speaker and a Tweeter on one stereo channel.
There is a calculation that makes this setup produce the desired effect. 8ohm + 8ohm = 16, but because the speakers are connected in Parallel this resistance is halved = 8ohms. Then this 8ohm's connected to a single stereo channel of an Amp. then halves this figure again, making the final load that the Amp. see's = 4ohm's. If you have already read about my car the Sub Woofers I use are connected in a similar manner.
This is the same sort of route that the sound off boys
take in order to use a relatively small output Amp. to produce big power
and drive multiple speakers. Classes are decided by the total amount of
power in the car, thus in order to compete in the novice classes the maximum
power of the entire system is limited to say about 300Watts. But wired
correctly a 2x30watt Amp. could be made to produce double that, this has
to be done carefully and the Amp. has to be up to the job.
If it can't take the massive increase in power flowing through it will go bang! Trust me I know.
The first Amp. I had to power my own Subb's just couldn't
take the way it was wired even though it was carefully planned and deemed
to be capable. I think that during some music tracks, namely Bass Tracks
the load on the Amp. changed allowing to much power to flow through the
outputs. Various things were added in order to help such as bigger power
cable, the Capacitor and a Pro-line Driver in an effort to reduce the amount
of work the Amp. had to do, all to no avail.
The Amp. tackling the job now is much stronger and capable of being run harder, as they say you pay for what you get.
If your multi-changer doesn't put the disks back in the
cartridge right, this is what you have to do!
In my case the CD tray, which the CD sits in inside the magazine, was clipped back inside by the changer ok. However the CD itself did want to stay on the tray and hence got stuck. The only way then of removing the magazine to reset the disks was to literally take it apart, a decision that wasn't made to lightly as the electronics board on top needed removing first.
The changer I'm happy to report works exactly the same now, and hopefully(!) won't have a problem again.
My Celine Dion CD(?!!) though died (ok, you can stop laughing
now!! We all like a little punishment sometimes!!).