[sparkymarky]

Is there a downside to using channels 1 and 2 for front speakers
and channels 3 and 4 for underseat speakers?

I'm thinking in terms of head unit "fade" setting between what the head unit says 'front and rear fade' but what now will in effect be fade between the fronts and underseats; obviously a mid setting will give a balanced sound volume between the fronts and underseats but will wiring this way that also yield a reduction in power/volume for either fronts or underseats even when at a mid setting?

At the moment i have things wired differently to this, hence the question. I dont want to be upping gains because i'm losing volume/power due to the fade setting.

Thanks in advance.

[Go Horns!]

Depends on what channels you use as inputs for the amp. What system do you have and how were you planing on connecting the amp?

I have the HiFi system and an aftermarket amp. I use my front channel input for the fronts and underseat, and I use my rear channel for my subwoofer.

[sparkymarky]

Present = hifi pro head unit. Fl and fr channels into a y splitter into 1) jl audio amp for front speakers high passed @ 200hz and splitter 2) imto audiocontrol digital crossover @hp of 80hz and then into same jl audio amp and low passed @200hz for underseats (so that underseats are bandpassed 80-200hz).
Rear left and rights as per original hifi amp in order to keep rear pdcs (no real music volume on rears, faded to front).

Now, am replacing head unit with xtrons latest android 6.0. Has 4 channel rcas out. So thinking of doing as per the original post , rather than splitting the front left and right as i am doing at present. Then in order to preserve rear parking sensors, use not the rcas but the xtrons rear speaker outs to the original e90 rear speaker wires..........thoughts?

[sparkymarky]

I do have a sub amp as well but the new xtrons has a dedicated sub rca out so its not a wiring concern here.

[jimgandhi]

I had that setup in my old car and it worked great for me. I just didn't have any rear fill which I could care less about since no one ever wants to ride in the cramped up back seats I had. This nice thing is, using the fader, you can adjust how much mid range vs mid bass which worked great for me since I listen to a wide range of music.

[sparkymarky]

Originally Posted by jimgandhi

I had that setup in my old car and it worked great for me. I just didn't have any rear fill which I could care less about since no one ever wants to ride in the cramped up back seats I had. This nice thing is, using the fader, you can adjust how much mid range vs mid bass which worked great for me since I listen to a wide range of music.

Thanks for that, think i'll do it this way then!

[cooperdj]

I'm a new owner... just picked up my 2009 E92 325i last week and loving it so far. However I'm a bit confused about the amp setup.

It has a Focal 4100 amp in the boot (pictured) and the sound is great if you're sitting in the back (which noone does)

Seems to have the front speakers completely disconnected though, is this normal? I'm guessing it's a lazy way of putting a 4 channel amp in? Anyway, I need the front speakers to work so I'm after some suggestions of the best way to do this please!

[BMW3DK]

hi,

This + your subamp can & will work.

Rear speakers can run off the headunit (should mainly be used for PDC anyway..).

depending on installation it can work good or great :-)

:-)

// Chris

Originally Posted by sparkymarky

Present = hifi pro head unit. Fl and fr channels into a y splitter into 1) jl audio amp for front speakers high passed @ 200hz and splitter 2) imto audiocontrol digital crossover @hp of 80hz and then into same jl audio amp and low passed @200hz for underseats (so that underseats are bandpassed 80-200hz).
Rear left and rights as per original hifi amp in order to keep rear pdcs (no real music volume on rears, faded to front).

Now, am replacing head unit with xtrons latest android 6.0. Has 4 channel rcas out. So thinking of doing as per the original post , rather than splitting the front left and right as i am doing at present. Then in order to preserve rear parking sensors, use not the rcas but the xtrons rear speaker outs to the original e90 rear speaker wires..........thoughts?

[BMW3DK]

Hi,

sonds like someone with his ears reversed installed this.

Either you pull it out and start over or you go to an expirienced installer.

Music comes from the front - you are only having the back to the stage when you are in the bar...

:-)

// Chris

Originally Posted by cooperdj

I'm a new owner... just picked up my 2009 E92 325i last week and loving it so far. However I'm a bit confused about the amp setup.

It has a Focal 4100 amp in the boot (pictured) and the sound is great if you're sitting in the back (which noone does)

Seems to have the front speakers completely disconnected though, is this normal? I'm guessing it's a lazy way of putting a 4 channel amp in? Anyway, I need the front speakers to work so I'm after some suggestions of the best way to do this please!

[david in germany]

Originally Posted by cooperdj

I'm a new owner... just picked up my 2009 E92 325i last week and loving it so far. However I'm a bit confused about the amp setup.

It has a Focal 4100 amp in the boot (pictured) and the sound is great if you're sitting in the back (which noone does)

Seems to have the front speakers completely disconnected though, is this normal? I'm guessing it's a lazy way of putting a 4 channel amp in? Anyway, I need the front speakers to work so I'm after some suggestions of the best way to do this please!

I would be willing to bet that the previous owner didn't want to leave the front speakers they installed in the car and took them out. I personally would start at the amp and disconnect the RCA connectors one at a time and see if any of them do nothing. If you have two channels that when you disconnect them do nothing, they should be your front channels. Trace the speaker wires for those channels and see where they end.

[BMW3DK]

Also an option!!

Disconnect the speaker wires at the amp and test with a 1.5v battery if and where it pop's in the car.

:-)
Chris

Originally Posted by david in germany

I would be willing to bet that the previous owner didn't want to leave the front speakers they installed in the car and took them out. I personally would start at the amp and disconnect the RCA connectors one at a time and see if any of them do nothing. If you have two channels that when you disconnect them do nothing, they should be your front channels. Trace the speaker wires for those channels and see where they end.

[ctuna]

cooperdj

You might want to figure out what type of sound system it
came with . There are three common systems.
You could do a Vin check with one of the free
BMW online vin checker. If you do not have tweeters in the front
doors chances are it came with the base system.
You will need to figure out how the wiring got rerouted.
You could measure for speaker resistance at the amp connector. There should be some in the 2 to 8
ohm range if there is a speaker present.

It would have been better if you started your own thread.

[cooperdj]

Originally Posted by ctuna

cooperdj

You might want to figure out what type of sound system it
came with . There are three common systems.
You could do a Vin check with one of the free
BMW online vin checker. If you do not have tweeters in the front
doors chances are it came with the base system.
You will need to figure out how the wiring got rerouted.
You could measure for speaker resistance at the amp connector. There should be some in the 2 to 8
ohm range if there is a speaker present.

It would have been better if you started your own thread.

Thanks! Yeah I would have started my own thread but as a new member it wouldn't let me so I figured I had to post on someone else's first.

No tweeters on mine, and no centre speaker so as far as I can tell it's the base model stereo.

[cooperdj]

Originally Posted by david in germany

I would be willing to bet that the previous owner didn't want to leave the front speakers they installed in the car and took them out. I personally would start at the amp and disconnect the RCA connectors one at a time and see if any of them do nothing. If you have two channels that when you disconnect them do nothing, they should be your front channels. Trace the speaker wires for those channels and see where they end.

Funny as my mate said exactly the same thing - said the rears are hard to change so probably couldn't be bothered but took the fronts.

The RCA connectors both have splitters on, seems to me that they're both just pointing to the rears. Do I need to be checking the blue cables on the left to see where they go? Managed to find the wiring specs for the amp and said they were the speakers - apologies for the noobish questions but wasn't expecting to have to do immediate audio work on it!

[david in germany]

Originally Posted by cooperdj

Funny as my mate said exactly the same thing - said the rears are hard to change so probably couldn't be bothered but took the fronts.

The RCA connectors both have splitters on, seems to me that they're both just pointing to the rears. Do I need to be checking the blue cables on the left to see where they go? Managed to find the wiring specs for the amp and said they were the speakers - apologies for the noobish questions but wasn't expecting to have to do immediate audio work on it!

The RCA connectors are signal in so they can't only point to front or back. They took two signals and split them to four channels. Do like I mentioned.

It should be labeled at the RCA connectors to the corresponding speaker wires. the RCA would be the easiest to unplug and plug back in instead of needing a allen key or screwdriver to disconnect the speaker wire.

[cooperdj]

Originally Posted by david in germany

The RCA connectors are signal in so they can't only point to front or back. They took two signals and split them to four channels. Do like I mentioned.

It should be labeled at the RCA connectors to the corresponding speaker wires. the RCA would be the easiest to unplug and plug back in instead of needing a allen key or screwdriver to disconnect the speaker wire.

ok thanks for the advice. Issue I had was that the amp is sitting under the lining of the boot so can't easily access the back. Will just have to dig it out and see what's going on in there!

[david in germany]

Originally Posted by cooperdj

ok thanks for the advice. Issue I had was that the amp is sitting under the lining of the boot so can't easily access the back. Will just have to dig it out and see what's going on in there!

You only need to access what is right there on the front.