need help adding subwoofer - BMW 4-Series Forums
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post #1 of 6 Old 12-24-2013, 11:15 AM Thread Starter
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need help adding subwoofer

I just purchased the 435i w/M packaging with the Harmon Kardon stereo system.. the 2 little subs sound a bit weak and was curious if anyone has been successful in adding a sub/amp.. the BMW dealer told me I cant because the system is all fiberoptics and if i tried it would shut down the whole system.

any advice or help appreciated.
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post #2 of 6 Old 12-24-2013, 12:29 PM
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I know Pioneer has some really good subwoofers you can use, even some shallow mounted air free subs

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post #3 of 6 Old 12-24-2013, 12:58 PM Thread Starter
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yeah but is it even possible to do on this system?
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post #4 of 6 Old 12-31-2013, 05:17 PM
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Best to ask high-end audio shop...

I believe this would be possible depending on the ohm rating of the speakers you are going to use.

There may be some options of replacing the under seat speakers or even doing a larger sub in the trunk by using a high to low rca adaptor.

We plan on doing a 12" competition sub in the trunk once our 4 series arrives.

The best thing to do would be to visit a high-end stereo shop in your area to see what they recommend. They may be able to use prior 3 series options that they may have worked with in the past.

Good luck and keep us posted!
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post #5 of 6 Old 12-31-2013, 07:51 PM
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Worked at a high end shop while going to college
BMW's were easy to work on back them, added tons of subs (especially into 3 series)
The only issue with BMW's was having the special tool to get the stereos out of the dash (it was like a 5 sided allen wrench)
But a lot has changed since the the late 80's and early 90's and I have not kept up with the latest technology
But I agree with 4sure - check on the high end shops - if there is an interface that will allow you to turn your fiber optic signal to line level RCA then they will know about it
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post #6 of 6 Old 01-15-2014, 04:43 PM
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fiber optic cables? really

as long as you match the ohm rating I believe it should be fine

But I'm not entire sure because the system could be so complex that if it detects a different wattage draw from the new subwoofer it could throw an error up.

hard to say..

you can try it and if it doesnt work just sell the woofer.

its the installation that might be tricky

If you want to play it safe wait and see what other people say.

Or look to see if any F30 3 series have installed aftermarket subs with their harmon system.

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