[adepaola]

Hey Everyone,

Grabbed a 335i xdrive with sport package, m exhaust and m performance tune recently. I want to move my polk subs from my s4 to the bmw. I have HiFi (Option 676). My setup is not crazy and my amp is a simple sony 1000w amp (http://www.amazon.com/Sony-Xplod-XM-.../dp/B00EPO5UC0). The amp has a hi level input which I utilized on the s4. Used wire taps to grab the + & - from one of the back speakers and the amp did the rest. Wire taps into the power to the stock amp to power the sony and I was done.

What are your thoughts of this working on the bmw? I found the wiring diagram for the amp so tapping in should be no issue, just over paranoid this may cause some sort of fault. Also I read the head unit sends low level inputs to the stock amp, should I tap in after the amp processes the input? Im CPO and under warranty and cant see how this would cause any issues with that.

Interested in your thoughts or if anyone as attempted a simple setup such as mine.

Thank you!

[almcbs]

Just buy the harness from technik. Makes things extra simple and easily reversible

[ctuna]

If you just do a sub the rest of the system won't
keep up.

The Hi Fi is the easiest system to upgrade and the process is well
documented.

http://www.e90post.com/forums/showthread.php?t=641323

[adepaola]

I understand I can upgrade the whole system however at the moment im paying for a wedding and just want to get the subs in the trunk. I know the Technic harness is convenient however if i already have the speaker level inputs why spend the money when i can get wire taps from radio shack for 3 bucks. I cant seem to determine if i should tap the speaker wires before they hit the stock amp or after, an thoughts?

[kaigoss69]

You can tap the wires going to the underseat woofers.