what i need to ask is that i think its only 2 channel amp but on the back of my head unit i fitted there are 4 rca outputs , ie 1 audio front left, 1 audio front right , 1 audio rear left and 1 audio rear right , and at the moment i have only the fronts going to the sub/amp in the boot..and
what i want to no is that if i get some audio rca splitters will it be ok to connect the rca lead to both front and rear outputs from the head unit?
just wish my sub/amp in the boot had 4 outputs instead of only 2 , please let me no if ok to do the above..
no, don't do it. from what you describe, the headunit has 2 sets/pairs of RCA preoutputs. exactly what model headunit is it (brand, model nummber)?
also, are you running any rear speakers?
the amp only requires 2 inputs (L+R). there is NO benefit in trying to feed it a summed signal from 4 outputs. and it will only SHORT out the preouts from the headunit which is not good.
btw, what benefit were you thinking you would achieve? i ask, cos it may help explain why it won't help.
in the end, you can connect the amp inputs to either of the front or rear preouts. depending upon the brand headunit, you can have 3 different scenarios:
1. connect to 'front' preout: this way, the front speakers and sub volumes are fixed, relative to each other (ie: you can't separately adjust the volume of the sub compared with the fronts); but you retain 'fading' between front and rear speakers
2. connect to 'rear' preout: this way, if you use the 'fader', you can adjust the volume of the sub compared with the front speakers, BUT, the rear speakers will also change volume
3. connect to 'rear' preout and if the headunit has this feature, change the mode of this preout from 'rear' to 'sub/non-fading' (eg: pioneer headunit): this turns the rear preout into a sub preout, making it independent; this means you can adjust the fader without affecting the sub volume, and you also activate a separate sub volume control
option 3 is best if the headunit has this feature. next best is option 1 (which is how you currently have it), then option 2.
Also how do i stop the number plate rattling from the base? ive tried tightening but still no luck, could there be anything else thats rattling from anybody elses experience?
best method is to add some self-adhesive 'sound deadener'. this is special matting that adds weight to stop audible rattles/resonance. for example 'Dynamat Xtreme', which is an excellent quality product, and available from car audio stores.
a cheaper method you may wish to first try is using some cheap self-adhesive closed-cell foam rubber stripping (ie: household doorway draft-stopper stripping). most hardware stores will stock this. apply to back of the number plate, and it softens/cushions any rattles, and if thick enough, will help hold the number plate in position by pushing gently against the car.