terryg

Hi all

my 1st post so go easy please

Just purchased a 2008 IS250 (NON SAT NAV) and want to upgrade the audio as it sounds very average.

Option 1) I would like to install my own head unit and amps but I dont think thats an option given the standard radio is integrated into the dash.

Option 2) I would like to add a 4 channel amp to drive the 4 doors (with my own JL audio splits in all 4 doors) and add a Kicker monoblock amp to drive a sub box.

From what I have researched so far, I would need a converter of sorts to grab the speaker outputs from the amp and then convert them to RCA's. I have just however read that the factory amp has a built in crossover so I would not be able to grab a full range signal ? Therefore I guess my real question is...Can I bypass the factory amp totally and somehow end up with 3 x RCA outputs (Front,rear,sub) ?

Your help is much appreciated

jimnordon

1st, read through Is audio overview post. I use a audiocontrol Lc6, it has the ability to combine inputs into a full range signal. The Lc6 has three pair of inputs that can either be combined or set to pass through to the rca outputs, with a line level adjustment. I've got the front 6.5" feed to the "main" inputs and the tweet/mid feed to the ch2 input and then combined. The factory sub is a dvc so it has 2 channels feeding it. This works perfect, wire both channels into the 3rd input and leave it as a passthrough only. You will have plenty of low freq. going to your 6.5" without combining the sub signal. So, now you've got 2 full range rca outputs and 1 rca sub out. I run three full range amps and a sub amp off mine, works perfect. What about the rear feed? well, my system does fine without the ability to fade from front to back. You should be more concerned with a balanced front stage anyhow. The cleanest way to wire this is to get the metra plugs that fit the outputs of the factory amp. You can simply wire from the pigtails and leave the factory harness untouched. Google "metra 70-1761" ,there's a reverse plug to use the factory harness to feed the speakers also. The color codes will be meaningless in this application, so do your research for the correct positions.