Upgrade the B&O amplifier and subwoofer.

[Talentrews]

Greetings everyone, I hope you are all doing well. Thumbs up!

I am seeking knowledge and assistance, and I am certain that there are those here who can provide it.

Our model b8.5 is equipped with the B&O sound system, which delivers excellent audio quality. However, it is worth noting that the bass performance is not as strong as some may want.

I have a few inquiries about the upgrading of my subwoofer and the amplifier that drives it.

I have acquired a high-quality RD500/1 amplifier, which I expect to function flawlessly by using the current sub wires and connecting a pair of RCA leads to them.

I have some inquiries:

1. The wiring in my sub contains blue and yellow stripes, as well as white and yellow stripes. Do we have knowledge of the polarity, distinguishing between the positive and negative?

2. This amplifier is compatible with both high level and low level input signals. Do we have information on whether we should use the high or low output from the audio sub amplifier cables that power the original subwoofer? Can this be verified with a metre to ensure accuracy? The amplifier has a low range of 200 millivolts to 2 volts and a high range of 800 millivolts to 8 volts, among other specifications.

Assistance from anyone who have experience in this matter would be much appreciated.

[Talentrews]

I have received advice from others who have performed this modification on the B8.5 Audi, suggesting that I connect the cables from the factory subwoofer directly to the amplifier using the High setting. However, I would appreciate some clarification on this matter.

[Kenjibb]

via tapping into the signal from the sub wires, you will get a processed signal that has undergone digital signal processing (DSP) via the B&O amplifier. To provide a clear signal with a wide frequency range, I recommend using either the high voltage front speaker output or obtaining a device with low voltage RCA output.

[Talentrews]

Greetings, I appreciate your prompt reply.

I believe your statement is accurate, as I have conducted some research and have come across reports from others stating that the subwoofer becomes much louder when the radio volume is down and gradually decreases when the volume is increased. I presume this phenomenon occurs due to a regulated connection from the original subwoofer wire.

If this is really the situation, can we be absolutely certain which signal is a whole range signal by using the wires on the B&O amplifier located in the trunk (assuming I have navigation)?

If the front door woofers are the ones in question, can I just connect directly to them by tapping?

[Kenjibb]

If you want to ensure certainty, get a multi-line adaptor. I am uncertain if the front speakers get an unaltered signal covering the whole frequency range or whether there is a limit set below 100 Hz.

[Talentrews]

How does this function by accessing the fibre optic network?

Do you have any suggestions?

I would want to access a whole range signal if available, but I am not how to determine whether the front speakers are capable of producing a full range of frequencies.

Should I connect an LC2i Pro between the subwoofer pre-out and my new amplifier to prevent roll-off?

[Kenjibb]

https://mobridge.us/product/da-g2-standard-most150-vag/

[Talentrews]

Alright, I am considering accepting your suggestion if we are certain that the fronts have more control.

To clarify, if I understand correctly:

1. I need access to the Front Door Lower Woofers. Connect the positive and negative terminals of the left woofer to the corresponding inputs on the left side of the amplifier. Connect the right woofer's positive (+) and negative (-) terminals to the corresponding right input terminals of the amplifier.

2. In order to get the desired outcome, should I set the amplifier voltage input to a high level rather than a low one?

3. Since this amplifier is compatible with high input, there is no need for additional equipment such as a lci2lro. I would just connect to the front doors via the amplifier in the trunk and establish a direct connection to the amplifier.

4. Are we aware of the specific colour of the cables that are being used by the factory B&O amplifier for the front door woofers?

I really value the assistance you have provided so far.

[Kenjibb]

1 affirmative 2 affirmative 3 affirmative, your amplifier is compatible with high level input, eliminating the need for an extra converter.
Four Please go to the forum thread in the above link and search for "a5oc". You will find several topics discussing the wiring schematics of the audio system. In my prior installation, I used a quadlock adapter to extract the speaker output directly from the MMI unit, rather than from the amplifier. Uncertain about the availability of such products for B&O.

[Talentrews]

Appreciation is extended.

Did you get the signal from the MMI rather than the amplifier? Is that technique distinct from the act of connecting to the front woofer cables on the amplifier in my car's trunk, considering that the B&O system is MOST and hence I assumed there were no speaker wires at the MMI?

Therefore, I am able to accurately locate the speaker wires that connect to my front woofers, remove the rubber insulation from the wires, and then connect additional wires that will be connected to my rd500/1 amplifier by soldering. So, the plan is to operate the subwoofer while using the standard amplifier to power the front door speakers, correct?