[JuicedboXed42]

like it say my right sub is not working i have a 2008 335i with a logic 7 system and for some reason its not working.

and before anyone says yes the eq setting for bal is correct.

[kaigoss69]

Sounds like you have answered your own question.

[JuicedboXed42]

^^ how do you figure i my right hand sub is still out ??

[kaigoss69]

That was my point... you ruled out user error, so what's left?

[JuicedboXed42]

im thinking its the amp would it be possible to get it repaired rather than replace the whole thing ?

[kaigoss69]

What makes you think it's the amp? My money is on the woofer.

[kaigoss69]

OK, do this:

1. Find the L7 amp under here:

http://i414.photobucket.com/albums/p...untitled-1.jpg

2. Disconnect the wiring harness (slide the connector locking mechanism sideways, towards you, takes some force and wiggling)

http://farm7.static.flickr.com/6112/...35927dd349.jpg

3. On the disconnected harness, find the speaker wire connection for the right side woofer. These are the thicker wires Red/Blue and Brown/White.

http://www.e90post.com/forums/attach...1&d=1209780605

4. Get a voltmeter, set to "ohm" and measure the resistance across the two wires. If you get zero/infinity, the voice coil is fried (this is the most likely scenario). If it is roughly 2 ohm, your amp channel for that woofer is bad (this is less likely because single amp channels do normally not go by themselves)

[JuicedboXed42]

so if the voice coil is fried how do i go about fixing it sounds like it is going to be one hell of a fix

[JuicedboXed42]

also i only think it is the amp cause i had some water get into where the amp sits i knew how to access the l7 amp but thank you for the info regardless. if it is the woofer do you think it woud just be better to just upgrade to the sws earthquakes ?

[kaigoss69]

Sorry, the reading should be 4 ohm for L 7 woofers.

Sure you can replace them with 4 ohm Earthquakes, but don't expect too much improvement without an external amp.

[JuicedboXed42]

yea right now im not looking for too much more but with those i figure i could always boost them with an external aftermarket amp. so just to clearify you putting your money that the sub went out ?

[JuicedboXed42]

also i check it and it was around 2.5-2.9 ohms

[taibanl]

Originally Posted by JuicedboXed42

also i check it and it was around 2.5-2.9 ohms

So u are correct. It's the amp

[JuicedboXed42]

Originally Posted by taibanl

So u are correct. It's the amp

those are the readings for the harness that plugs into the amp itself the amp was not connected during the test. how does that make it the amp that is bad?

[taibanl]

Originally Posted by JuicedboXed42

those are the readings for the harness that plugs into the amp itself the amp was not connected during the test. how does that make it the amp that is bad?

Bc speaker is good.

[JuicedboXed42]

but one speaker read 4.0 ohms which the one that works and the other one didnt tap 3 ohms. idkif you were aware but this is a logic 7 system that rates at 4 ohms

[kaigoss69]

Originally Posted by JuicedboXed42

but one speaker read 4.0 ohms which the one that works and the other one didnt tap 3 ohms. idkif you were aware but this is a logic 7 system that rates at 4 ohms

Could be a melted voice coil. You can put a couple of paper clips inside the connector and hold a 1.5V battery in between. The good speaker should make some crackling noises, the bad one should then be silent.

[bmw325i]

Set your multimeter to ac and check for voltage on that channel with the amp plugged in and a test tone or music playing.