Rear speakers crackling then fail.

Ok, so i have an F, didnt have reaqr speakers when purchased so bought the rear speaker cover and was donated the t-bar complete with one working speaker. Bought 2 new 6x4 200w speakers and installed them My wiring loom didnt have any connections for rear spears, only front ones so i cut the iso lead from the stereo for the rear speakers and wired them directly. Started off fine and all working, but after a couple of days the rear speakers just begin to crackle very badly and stop working. The only way to get them to work is to set the sony head unit to mostly front fade with such a tiny bit coming from the rear you can barely hear it at all. Ive tried swapping the wiring around but all to no avail. The speakers output should be powerfull enough to handle more coming out then it does. Even the head unit comes up saying "failure". Ive installed new FLI speakers and tweeters in the front without a problem and they work fine. Any suggestions on why this might be happening? Here are the speakers i have installed in the rear...

4" x 6" 2-way speakers
Peak Power 200W (each Speaker)
Impedence: 4-ohm
Frequency Response: 100Hz-18kHz
Sensitivity: 90dB/W/m
Magnet Structure: 20-Oz
Cone Material: POLY INJECTION
Voice Coil: 1” ALUMINUM
Tweeter: 1” POLYIMIDE DOME
Grills included

Thinking back ive connected both rear speakers using only one wire coming from the head unit, could it be that im overloading the wire and should run a separate one for each speaker?

Sorry mate, you're outside my sphere of knowledge with this one.

I know, its out of mine also. installed loads of sound systems in cars but never had an issue like this before. I might try running an independent speaker wire to each rear speaker and see what that does,

Hi, Each rear speaker should have a separate pair of wires, Mine are 200w units but happily run on some four core alarm cable. The crackling/fading out may be your head unit :nonod:
Have you tried swapping the front and rear outputs, ie: connect the front speakers to the rear outputs, it may be that if you have not used the rear amp it may be cream crackered :bat:

Sounds to me as if the speaker impedence is wrong. You say they are 4 Ohms? If thats the case, you will probably find that the amp output is rated at 8 Ohms per speaker.
If you have wired them using one two core cable off one output, then they are probably also wired in parallel. This means that you are splitting the signal over the two speakers (4#2= 2 Ohms). This will overload the amp.
The way around this is to wire the speakers in series (4+4= 8 Ohms), giving you the correct impedence and matching the output to the speakers.

Series:- + wire from amp to + term speaker 1, - wire from speaker 1 to + term on spkr 2, - wire spkr 2 back to - term on amp.

By the way, shouldn't this be in the Pitstop subforum with it being tech related?

Ok thanks, i'll try that on monday, have a fiddle around and see if i get any joy. The whole idea of this car was to have the music loud and the roof down, so at the moment only 50% of this is possible.

Sounds to me as though you have burnt out the head units internal amp.
Your head unit has 4 speaker outputs why didn't you use them??
Most standard head units are anything from 4 x 45 watts to 4 x 60 watts but that's usually max output and not rms.
Are your speakers 200 watts each?? Is that 200 watts max output or rms??
Has all speakers stopped working or just the rears that you have wired in??

All these questions are relevant , if no music is heard you have more than likely popped the internal amp completely and your head unit is scrap , if it's not workin on the new speakers only then you have probably damaged that channel of the internal amp and even if you wire it correctly you will still either have no sound from the rear at all or only 1 speaker will work on the other rear channel that currently is not wired up.

So basically by wiring it incorrectly you have scrapped your head unit

Possibly expensive mistake my old fruit

Head unit was £20 on ebay, i am now getting sound from the rear speakers again, its just too much volume going through them and it fails the rear speakers. The front ones work fine. I've faded the head unit to front only and will re-wire everything tomorrow while other bits are being done on the car and see what joy i get then. Will keep it updated as to progress.

You may be in luck if thats the case
Does the head unit cut power to all speakers or just the rear ??
Basically your overloading the amp for that channel and the unit is cutting the signal to the overloaded channel to protrct itself , so if you rewire it correctly you may avoid having to replace the unit

Usually when you lose sound in this way if you turn the head unit on and off it "resets" and you get sound again until it overloads again . . . I obviously wouldnt recomend doin this as it could cause the unit to fail as in the way i mentioned in my first post
Personally is keep the volume down or disconect 1 speaker until you get the time to sort it just to be on the safe side mate

It just cuts the rear ones off. I'll re-wire it all tomorrow and see what happens, hopefully i can find the mistake ive made somewhere along the line and finally get some decent music on the go. Until then, its just faded fully front.