pioneer headunit problem

[AnDReII]

hey guys.
i have a pioneer avh-p4250 double din h/u in my car and i seem to have a problem
when i play music off my iphone through usb it makes a crackling sound that is quite annoying when listening to music loud or soft-.- any ideas on what the problem could be?

I know that when i got jb-hifi to install the head unit about 5 months ago there was a black usb that came with the package that they put in the back of the head unit and its got a connection at the other end to plug the iphone usb in.. so basically its 2 cables, could this be the problem?

http://www.pioneer.com.sg/data/sg/pr...H-P4250DVD.jpg <----


and another problem..

i got kicker comps with a 2000w alpine vpower amp and it cuts out from the voltage dropping, whats a good way to fix this? i dont want a capacitor.. so any other ideas would be good

http://stereogirl76.com/mrpm2000.jpg <--- amp

http://forums.justcommodores.com.au/...ercompsubs.jpg <--- sub

thanks in advance

[Red_Vs_Ute_18"]

Hey lewis here

with the head unit have u just tried checkn the cable to see if its broken/frayed anywhere along the line or jst make sure the connections still tight?
and just to verify.. does the crackling happen when u have a cd or the radio on or is it just when playing through ur phone?

[AnDReII]

ummm i didnt really check the cable but it looks cheap and nasty..

and yeh im pretty sure its just on iphone/ipod :S because i just made a cd and it didnt do the crackling, radio didnt seem to do it either.

[StoneX]

Do you have a USB stick you can put a couple of songs on? Then plug that into the USB socket to see if it's actually the USB or the iPod.

[AnDReII]

good idea with the usb ill try that tonight.

any ideas on the second problem i have?

[wrx884]

got any specs on the amp and subs? Ur alternator should b keeping up so check wat ur voltage is on idle and again at the point where the amp cuts out and find out how much voltage drop ur getting. if its goin under 12V usually amps go into protection mode and do cut out 4 that reason., so u may just need ur regulator changed but that depends also on the awaiting specs.

[AnDReII]

what exactly do i use to check the voltage lol?

Alpine MRP-M2000 Mono subwoofer amplifier — 2,000 watts RMS x 1 at 2 ohms - Features & Specs at Crutchfield.com <--- thats the specs for the amp...

the subs are only 300w rms so they say at jb hifi... so i cant be even close to pushing the amp to the limit.. could it be that im using a 4 gauge cable instead of a zero gauge to power the amp for the subs?