I am trying to set up an Avid system. I am using Media Composer 7 and the new mac trash can. I need the audio to go out of the Avid and in to my speakers and video to my external TV monitor. I have been using the Black Magic Design and it has been so finicky. I was wondering what people were using today for a LOW BUDGET film/movie and what has been working most flawlessly

Also, what is the difference between having an external box vs a card? 

Avid Student 19:

I am trying to set up an Avid system. I am using Media Composer 7 and the new mac trash can. I need the audio to go out of the Avid and in to my speakers and video to my external TV monitor. I have been using the Black Magic Design and it has been so finicky. I was wondering what people were using today for a LOW BUDGET film/movie and what has been working most flawlessly

The cheapest solution is full screen playback. HDMI to your external TV, audio either via your TV RCA outputs or directly from the Audio Out of the Mac. You will have to set up system preferences/audio to make sure your audio is patched to the desired output.

Blackmagic's products are the cheapest dedicated I/O boxes (Intensity Extreme for Thunderbolt and Intensity Shuttle for USB3.0), but if you have one and are having problems with it, you may prefer to invest in a Aja Io XT (not cheap but very solid).

But before you buy new gear... have you installed the right Blackmagic Desktop Video version for your MacOS? That may be the cause of the "finickiness" you're experiencing. You may also be running the wrong firmware. I have a cheap Blackmagic Intensity Pro card in my second edit suite (MacPro2009) and it runs fine with MC v8.

Avid Student 19:

Also, what is the difference between having an external box vs a card? 

Using an external PCIe card on a MacPro2013 requires you to buy a PCIe/Thunderbolt2 adapter box (around €200). External boxes like the Aja and the Blackmagic listed above only need cables.