Speaker Wiring Advice
- Thread starter Jimmi
- Start date
What loom did you fit, from where? Link or pic?
Some looms need the Amp inline to power the front speakers..... or is it a 4way hardwired speaker and preout for a sub?
Some looms need the Amp inline to power the front speakers..... or is it a 4way hardwired speaker and preout for a sub?
What sort of add on loom?
Most times the iso plugs that go into the back of the head unit has two plugs, one with the front and rear door speaker pairs so 8 separate wires to give four lots of live and neutral.The other plug will have an accessory live that is live when the ignition key is in and turned on to run or in the first accessory position as when sat playing the radio without the engine running and the dashlights blazing, then you'll have a permanent live for radio memory, a neutral and an auxiliary (solid blue) wire to provide a turn on live for external amplifiers or a powered antenna ie. built in pre amp or old school motorised up/down type. so they're powered when the head unit is turned on.
Generally add on iso looms won't provide high level RCA outputs though just the speaker level outputs at 4 Ohm impedance leaving you stuck with looking for amps that will take stereo inputs at 4 Ohm or getting a line driver to transform the impedance higher and reduce the signal voltage... the problem with speaker levels as inputs to external amplifiers is that the signal has already been amplified at the head unit leading to any distortion present on the signal that would power a 4 ohm speaker then being ramped up again by the next stage of external amplification, this is often the point where you can now hear your diesel injectors and alternator whine in the mix!
Quick answer to the original problem is to pull out the add on loom and go through the installation process again thinking of the signal path to the door speakers, on my van there is no rear speaker fader control on the head unit as there weren't any rear speakers originally when it was a panel van, good luck.
Most times the iso plugs that go into the back of the head unit has two plugs, one with the front and rear door speaker pairs so 8 separate wires to give four lots of live and neutral.The other plug will have an accessory live that is live when the ignition key is in and turned on to run or in the first accessory position as when sat playing the radio without the engine running and the dashlights blazing, then you'll have a permanent live for radio memory, a neutral and an auxiliary (solid blue) wire to provide a turn on live for external amplifiers or a powered antenna ie. built in pre amp or old school motorised up/down type. so they're powered when the head unit is turned on.
Generally add on iso looms won't provide high level RCA outputs though just the speaker level outputs at 4 Ohm impedance leaving you stuck with looking for amps that will take stereo inputs at 4 Ohm or getting a line driver to transform the impedance higher and reduce the signal voltage... the problem with speaker levels as inputs to external amplifiers is that the signal has already been amplified at the head unit leading to any distortion present on the signal that would power a 4 ohm speaker then being ramped up again by the next stage of external amplification, this is often the point where you can now hear your diesel injectors and alternator whine in the mix!
Quick answer to the original problem is to pull out the add on loom and go through the installation process again thinking of the signal path to the door speakers, on my van there is no rear speaker fader control on the head unit as there weren't any rear speakers originally when it was a panel van, good luck.
