[cossie123]

Hi I have a 2016 i30 and want to install a sub and amp but dont know where to start.  My brother told me I would have to upgrade the alternator first as it wouldn't handle a sub. Could anyone help with ideas on what I need to do to

[Dazzler]

Welcome cossie123.

I'm no expert,  but unless you go over the top I wouldn't have thought an upgrade of the alternator would be required!  Some other members will have a better idea though.

[cossie123]

Its a 400w amp,  plus I can't find info on how to wire a remote lead from the stock head unit to the amp

[CraigB]

If you've not tackled this type of install before I can only suggest you get an experienced car audio installer to do the task for you.

[cossie123]

ive installed amps before in older cars, the headunit wiring im not sure which are the speaker wires and the positive and remote wires. i dont have a diagram of which wire is which. im thinking of tapping into the rear speaker wires and connecting to high level input on the amp

[The Gonz]

Run your 12V feed straight off the battery to use it as a really good noise filter (it also lets you see whether the alternator is big enough gradually rather than as a nasty surprise). However, 400W can mean Peak Music Power Output (PMPO), a useless marketing ploy that sounds better than 18W Root Mean Square (RMS), so I'd be surprised you'd have a problem either way.

If you're brave and impatient and can't see whether the amp inputs are low or high impedance, start by assuming high impedance and feed the signal level lines to them. If no sound from the speakers (and you have re-checked that your head unit still works), try its speaker outputs on the amp inputs.

[Dazzler]

We have members with access to wiring info, so hang tight..

[GreyBanna]

I recently installed a subwoofer (400w, 10 inch) in my 2015 i30. I knew that installing a separate amplifier would create a lot of drama so I bought an all-in-one subwoofer, enclosure, amplifier and then installed that.
I ran the Positive wire directly from the battery and underneath the car, up through a grommet in the boot and to the sub.
I ran the ACC wire from the 12v accessory that located in the boot to the signal input on the sub.
I tapped into the rear speakers by taking both rear door panels off of each door and then locating what the colours of the wires that attached to each speaker were. Knowing what the colour of the positive and negative wires were I simply soldered my splice wires into these wires before they fed from the chassis of the car and into the door panelling and the wired them directly up to the sub (this sub accepts both low and high inputs)

Bam, its been working well for almost a year now.

[mickd]

Run your 12V feed straight off the battery to use it as a really good noise filter (it also lets you see whether the alternator is big enough gradually rather than as a nasty surprise). However, 400W can mean Peak Music Power Output (PMPO), a useless marketing ploy that sounds better than 18W Root Mean Square (RMS), so I'd be surprised you'd have a problem either way.

If you're brave and impatient and can't see whether the amp inputs are low or high impedance, start by assuming high impedance and feed the signal level lines to them. If no sound from the speakers (and you have re-checked that your head unit still works), try its speaker outputs on the amp inputs.

As Gonz said RMS is good , PMPO is gibberish.

RMS -Really Mean Sound - the only way to go, the real deal
Ask the  so called sound techs the RMS of anything and watch their faces. If they look stunned,  walk away.  Thi k I still got an old amp 40 watts RMS per channel in the shed 

[cossie123]

sorry i got my amp spec wrong this what the specs are
KX120.2 Kicker KX120.2 120 Watt 2 Channel Amplifier Stereo, bridged mono or Tri-Way output 30 watts RMS x 2 at 4 ohms 60 watts x 2 at 2 ohms 120 watts x 1 in bridged mode Speaker- and preamp-level inputs Preamp outputs (pass full-range signal to another amp) High-pass/low-pass crossover (variable 50-200 Hz, 12 dB per octave) Bass boost (0-18 dB at 40 Hz) Frequency response 20-20,000 Hz Requires 8-gauge power and ground leads — wiring and hardware not included with amplifier Unregulated Class A/B power supply offers a significant increase in power at 2 ohms 10-1/8"W x 3-1/2"H x 12-3/4"D Kicker

[cossie123]

also this is the same radio in my car