Prevent auto-pairing for certain devices (Bluetooth) I have a Early 2011 Macbook Pro 13" running OS X 10.10.1 (Yosemite). 

At work, I have a Apple Magic Trackpad and an Apple Wireless Keyboard, both which use Bluetooth. When I get to work, my Mac automatically connects to both of them (if Bluetooth is on).

At home, I have a Belkin F8Z492-P Bluetooth Audio Adapter hooked up to my stereo (sorry, no product page available). If Bluetooth is on, my audio will automatically be routed to the Bluetooth adapter (which is something I rarely want). 

How can I make OS X automatically connect to my trackpad and keyboard at work but not automatically connect to the bluetooth audio adapter at home? 

Currently, I shut Bluetooth off when I get home, but I'd like to avoid toggling Bluetooth when I get home/when I get to work, since it is quite annoying to start typing on the wireless keyboard and have nothing happen, or not have audio when I get home.

If this is not possible, can I prevent OS X from switching my audio automatically when connecting to the Bluetooth audio adapter?
I had the same problem and FINALLY found a workable solution. Run this in your terminal. After this you just need to manually connect to your bluetooth audio system.

sudo defaults write /Library/Preferences/com.apple.Bluetooth.plist DontPageAudioDevices 1