[rvruggiero]

Doesnt this limit the range of sound by tapping the sub outputs from the Logic 7 amp? I feel like the Logic 7 amp must be omitting a huge range of sound right if we're tapping the sub outputs...

Second question...having trouble identifying what the 4 wires should be in technics harness for sub ouptuts...anyone have the colors?

I am a bit confused...as in other cars, I've always just tapped into the rear speakers and used an LOC.

Also...its worth asking-I have the JL 500/1 amp + JLw3...do I absolutely have to use the LOC? JL 500/1 has speaker level inputs right?

Help would be appreciated...

[taibanl]

Originally Posted by rvruggiero

Doesnt this limit the range of sound by tapping the sub outputs from the Logic 7 amp? I feel like the Logic 7 amp must be omitting a huge range of sound right if we're tapping the sub outputs...

Second question...having trouble identifying what the 4 wires should be in technics harness for sub ouptuts...anyone have the colors?

I am a bit confused...as in other cars, I've always just tapped into the rear speakers and used an LOC.

Also...its worth asking-I have the JL 500/1 amp + JLw3...do I absolutely have to use the LOC? JL 500/1 has speaker level inputs right?

Help would be appreciated...

If you're seeking to power a sub, I would think you would want to tap the frequencies you are seeking to reproduce. Why would you tap a midrange speaker for a sub signal. That's utterly ridiculous :

I think you could likely omit the LOC, however, technic would be better to answer.

[bmw325i]

Sure you are missing out on frequencies by only tapping into the sub output. However those are frequencies you wouldn't want your sub playing anyways. The underseats play frequencies over 100 hz which is much higher than you need for a sub. Your best option is to pm technic for a harness.

[rvruggiero]

I already have a technic harness actually.

On my previous cars--a mazda 3 with bose and a g35...i was instructed first off to tap the INPUTS to the amp...not outputs as people had said that you wanted clear signals that were unaltered by the tuning of the amps. I'm not arguing...just curious.

Engineers of course designed the sound system to sound as good as possible...but not necessarily to sound best at all frequencies---the bose eq would mess with certain frequencies that it couldnt produce and it was tuned for the car to provide what it could for the price-hence we tapped the inputs before the amp screwed with those frequencies. I was just wondering if this isnt a similar case....and why it wouldnt be the same idea.

Also...any idea why the sub/amp and front subs under the seats wont start up with the car....they did work for the first week. Now...if i go flip one of the switches on the LOC--either the "wire" or "rca" switch...it will start working again-but only then. The remote turn on is going directly from the Headunit pin 13 to the amp...Ideas? Thanks guys!

[bmw325i]

Originally Posted by rvruggiero

I already have a technic harness actually.

On my previous cars--a mazda 3 with bose and a g35...i was instructed first off to tap the INPUTS to the amp...not outputs as people had said that you wanted clear signals that were unaltered by the tuning of the amps. I'm not arguing...just curious.

Engineers of course designed the sound system to sound as good as possible...but not necessarily to sound best at all frequencies---the bose eq would mess with certain frequencies that it couldnt produce and it was tuned for the car to provide what it could for the price-hence we tapped the inputs before the amp screwed with those frequencies. I was just wondering if this isnt a similar case....and why it wouldnt be the same idea.

Also...any idea why the sub/amp and front subs under the seats wont start up with the car....they did work for the first week. Now...if i go flip one of the switches on the LOC--either the "wire" or "rca" switch...it will start working again-but only then. The remote turn on is going directly from the Headunit pin 13 to the amp...Ideas? Thanks guys!

There's no way to tap into the inputs of the logic 7 amp, because the amp and head unit are connected with a fiber optic cable. If your just adding a sub I wouldn't worry about eq so much. If your wanting to upgrade further look into adding a sound processor.

Also why are you not using the remote wire from technics harness?

[Garticus]

As stated before......the amp input is an optical connector......can't "tap" into that.

I tapped into my sub output speaker wires with a LOC to get signal to my amp, it worked great and it's crossed over already. (Although I further attenuate the frequencies with my amps' crossover). Feeding your trunk sub amp with any other output should not work well as their output is processed and seems to be crossed over at some frequency above 100hz. (Not sure of what exact freq it is)

Not sure what you mean by the under seat subs won't start up with the car....they should work when you turn the radio on.......unless the sub speaker wire has been severed by the tapping technique. and the signal goes from your amps output straight to the LOC only.

[rvruggiero]

Originally Posted by bmw325i

There's no way to tap into the inputs of the logic 7 amp, because the amp and head unit are connected with a fiber optic cable. If your just adding a sub I wouldn't worry about eq so much. If your wanting to upgrade further look into adding a sound processor.

Also why are you not using the remote wire from technics harness?

Hmm. Thanks for all the help guys!
I'm not using the remote wire from his harness because after reading so many threads, I figured the headunit was the only way....and the best way.