connecting an ampilifer to the speaker wires

[mas123]

I have a X5 2003 and it doesn't have an amplifier. I have connected a amplifier to the speaker wires and the amplifier works fine, but when I switch off the car and leave it for about 20 mins and switch the car on there is no sound from the radio until I unplug the speaker wires from the amplifier. Does anyone know what the problem might be?

[clubba]

What happens when you leave the car off for only 5mins or overnight? Does the same thing happen, or is 20mins a magical time that this happens? Do you have any pics of your wiring? A pic would help to diagnose what might be causing your problem.

[mas123]

Hi,

If I leave the car for about 20mins or more then there is no sound from the radio. I don't have any pictures but basically the speaker wire: blue with a purple line is wired to the positive high input of the amplifier and the blue with grey strip to the amplifer negative high input.

If I switch the car off for about 5-15 minutes and back on again it works fine. Any longer and there is no sound from the MID radio.

Thanks.

[clubba]

How many channels is the amp? 5, 4, 2?

Also, let us know what else you have hooked up to the amplifier. Do you have a stock receiver (radio unit) or aftermarket? The things that should be running into the amp are power, remote amp turn on, and rcas (from aftermarket receiver) or speaker wires (from stock receiver, I believe). Running out of the amp should be ground, speaker wires running to each individual speaker. Hopefully it is a 4 or 5 channel amp you're using. If it's a 2 channel that is only 4ohm compatible and you wired 2 speakers out of each output channel then you would be dropping it to a 2ohm load which would (in the case of a 4ohm amp) be too much.

It's concerning that you can simply unhook the speaker wires from the amp and have the sound return. If wired properly, that shouldn't be the case. If your X doesn't have an external amplifier then it has one built into the receiver. Regardless of what type of receiver you have, you are getting amplification from one source or another (either internal or external) - otherwise, there would be no sound.

[clubba]

Crutchfield has a good wiring schematic, which is most likely overly-complex for your application. If your setup is as straight forward as I think it is, you can disregard the second mono-sub amp as well as all of the wires running to it, the capacitor, and the power block. A pic of your amp wiring would still be really helpful in diagnosing your problem.

Amplifier Wiring Diagram

[mas123]

Hi,

I have a MID radio and connected the speakers wires of the MID radio to a VIBE Liteair C8, which has a built amp with high power inputs. I have wired up direct feed from the battery for the postive and negative and for the remote I used a purple wire with a white strip which is near the CD changer. I used a volt meter to check it and it switches on with ignition.

The guidance I used for the speaker connections are:

http://www.xoutpost.com/bmw-sav-forums/ ... all-2.html


so the blue/purple stipe speaker to the positive highput on the amp and the blue/grey stripe wire to negative highinput on the amp.

The amp has 2 speaker high power inputs. When connected and working, the bass is very good and everthing sounds fine until you leave the car switch off for a while.

[clubba]

Originally Posted by mas123

The guidance I used for the speaker connections are:

http://www.xoutpost.com/bmw-sav-forums/ ... all-2.html


so the blue/purple stipe speaker to the positive highput on the amp and the blue/grey stripe wire to negative highinput on the amp.

That link takes me to the main forum page. Can you post the thread link?
Also, when you turn the car back on and you don't have sound from the speakers, do you still have sound coming from the sub - or is it just nothing from anywhere?

Does your amp have inputs for RCA cables in addition to just straight speaker cables? If it does, you should wire an RCA line out converter to the rear speaker wires so you can connect RCAs to the RCA inputs on your amplifier.

[clubba]

Here is a list of your wiring:

Radio Battery Constant 12v+ Wire: Red/Green
Radio Accessory Switched 12v+ Wire: Violet/White
Radio Ground Wire: Brown
Radio Illumination Wire: Yellow
Stereo Antenna Trigger Wire: White
Left Front Speaker Positive Wire (+): Yellow/Red
Left Front Speaker Negative Wire (-): Brown/Orange
Right Front Speaker Positive Wire (+): Black/Red
Right Front Speaker Negative Wire (-): Brown/Orange
Left Rear Speaker Positive Wire (+): Yellow/Black
Left Rear Speaker Negative Wire (-): Black/Orange
Right Rear Speaker Positive Wire (+): Blue/Black
Right Rear Speaker Negative Wire (-): Brown/Orange

[clubba]

I read through the manual for your sub/amp http://www.vibeaudio.co.uk/manuals/Compact8.pdf and it appears as though you do have RCA inputs (low input). I think the issue must be coming from the wiring you're using to run into the high level inputs. As I mentioned a couple of posts ago, I would buy an RCA line out converter and hook it to your rear speaker wires and run RCAs to your sub/amp. If you go this route, try not to run your RCAs parallel to your power cable as that can cause feedback - try to cross them at a 90* angle. I can't think of why 20mins would be a special time unless there is some kind of factory reset going on with the MID that someone else could speak to.

[mas123]

Hi, thanks for all your help and details. I have copied the post below where I used the instructions. The instresting point is that the colour of the wires I used do not match the speaker colour stated in your posts. As you sugguest I will use a RCA line out.

Thank you very much for taking the time to respond.


I have Fitted my Sub to a NON amp/DSP X5



To get a high level input you need to remove your B-Pillar
behind there at the bottem you will see all the wiring, you will see seperate wires wrapped in the black material.
remove a section of the black material from the smaller of the two bunches of wires and you should find 2 wires (in my case blue with violet strip and blue with grey strip, becasue i used the rear right speaker)

now you have you high level input for your amp, you need a remote on wire

Look in your boot/trunk and on the left where the amp is supposed to be you will see 3 connectors 1 will have a plug in in and the other 2 are left empty ( you may have more kit installed as factory option than me, but mine were empty)
the middle plug has a wire VIOLET with WHITE stripe -this is your remote on

the remote on wire only works on the ignition wire, and not when you just turn on the stereo when the igniton is off