My Uncle is a technophobe who has become addicted to his iPad and iTunes. I thought, great, I'll hook up a mac mini to the AUX jack of the Beosound 9000 and give him his entire music collection.

Oh lawdy what a trek. I won't go into details but here's where I'm at:

This part is important. In the AUX jack on the 9000, there is a B&O cable connector that connects has 4 female RCA jacks.

The B&O is hooked up to two Beolab speakers downstairs via Left and Right Speaker out, and two speakers upstairs, plus an IR eye upstairs, via a Masterlink cable (I think that's what it's called). In addition, two of those four cables coming out of the AUX jack go to an amplifier which powers in-wall and in-celing speakers throughout the house.

I put his iTunes collection on a Mac mini. The headphone out of the mac goes in to the other two of those female jacks. I had no idea this jack can do such a thing-- two cables sending audio out, two cables sending audio in.

PROBLEM 1: But here's one catch. If I play a CD on the 9000, it will go to the B&O speakers upstairs, downstairs, and the ampllfier powering all those inwall/inceiling speakers. But if I play A.AUX, the upstairs Beolab speakers won't play the music, even though all the other speakersdo :(

PROBLEM 2: Upstairs there is also one of those IR eyelink things. If I point the upstairs remote at it, it will play CD's on the 9000 downstairs, but it will not do anything if I press A.AUX; just keeps playing CDs and if I press stop, then the BEO9000 is kind of jammed up and won't play A.AUX until I play with the CD's downstairs a little bit.

Can you guys help me? It's taken me weeks just to get this far, only to discover two Beolab speakers still won't play nice.

Sorry for the long post. Didn't know how to say this any shorter! 

It depends a little on which BS9000 you have, but assuming it can handle N.Music, you need a device called a Beoport. This will attach to the Mac and Masterlink and you will be able to control all the music via remote. There is some software to install on the Mac, but that should allow all you want. I must confess to not completely understanding your set up. The Aux out is at standard line out level so I don't really see how that is powering the speakers.

I have experimented further and discovered something:

When I use that remote eye upstairs and press the A.AUX command, or if I press stop, this is what screws up the Mac mini playing to it.

I realize my post is confusing, but when you say "powering the speakers" do you mean the non-beolab speakers? I tried to point out that the AUX out goes to an amplifier which then powers the in-wall and in-ceiling speakers.

Thanks for taking the time to reply.

Desmond, what happens if you get the Mac mini to play downstairs, go upstairs and press the mute or volume up button on the IR sensor?  

The overwhelming majority of BeoLink active and passive kits (the thing the round sensor eye is hooked up to) have a software bug whereby they won't allow you to select A.AUX from the link room.  It literally took years to resolve it, and there is a new software version that fixes the issue.  Only problem is, you have to open up the link controller and replace the computer can to get it.

But with the BeoSound 9000, there's an easy workaround -- simply press "A.TAPE" or "A.MEM" (depending on which version of the Beo4 you have) to access the aux input, it does the exact thing as LIST/A.AUX, has its own dedicated key, and works in a linkroom just fine.