Discussion in 'MacBook Air' started by Boe11, Feb 28, 2012.

  1. Boe11 macrumors 6502a

    Sep 12, 2010
    Hi there,

    I've got an older DLP projector (optoma h30) that I'd like to get hooked up for watching downloaded movies and streamed content. The problem is, its inputs are analog only, VGA-A/V-Svideo My question is sort of multifaceted.

    1. I'm currently using an 11" MBA and TBD as my primary PC. If I were to purchase a mini Displayport to VGA adapter and hook it up to the thunderbolt display's TB port, is there a way that I can toggle between external monitors within OSX? So if I were going to watch a movie, could I just go into system preferences and switch my exterbal monitor over to the projector, or would I need to physically switch cables each time with the MBA?

    2. Am I better off getting an apple TV and trying to use digital to analog adapters down to the projector? I've heard that's not a great way to go.

    3. Any other ideas?

    I'd rather have a more modern digital option, but I already have this gear and hate to see it go to waste. Once it's setup, it's actually pretty fantastic to watch movies on.

    Thanks for any insight you can provide!

    Edit: Here's some info on the projector.
  2. kolax macrumors G3

    Mar 20, 2007
    You can't daisy chain MiniDisplay Port with Thunderbolt (i.e. plugging in a Mini DisplayPort device into your Thunderbolt display won't work, the device you plug in has to be Thunderbolt too).

    You're best off just getting a Mini DisplayPort to VGA adapter, and unplugging the Thunderbolt Display and plugging in the projector each time you want to watch a movie.

    Don't buy an Apple TV and hook it up to your non-HD projector. You'd be better off investing in a new projector that's HD. Not the cheapest option though.
  3. Boe11 thread starter macrumors 6502a

    Sep 12, 2010
    That's what I was afraid of. I can't imagine I'd get much for the projector if I tried to sell it. I see there are some pretty reasonably priced HD options out there now, but I just shelled out 115 for a new bulb :(.

    I might snag the MDP-VGA adapter and see how it works with the air. If it sucks, I'll probably try dump it on CL for a couple hundred and get an HD projector.

    TVs are cheap now, too, but there's nothing quite like watching a movie on a 10 foot screen :D

    Thanks for the quick and concise response.
  4. jamesr19 macrumors 6502

    Nov 7, 2009
    on a big screen with an old projector the quality would be dreadful!

    the only way to get dual monitors with different resolutions on a macbook air is by using a USB to DVI you can't hook up any kind of monitor via daisy chain. This would run perfectly on 1024x768 or 1280x1024 (I've tried it)
  5. LordVic macrumors 601

    Sep 7, 2011
    You can "daisy chain" with Thunderbolt and Display port

    Display port is carried along the Thunderbolt channel so that you can use Display port devices over the connection channel

    however with 2 caveats:
    the Macbook Air can only power 1 external display. So thats either a monitor or your projector. not both.

    The Minidisplay port must be at the end of the chain of devices. Therefore it must be the last device connected through the Thunderbolt port.

    So if you were to connect 1 cable from your MBA to your Thunderbolt display, then plugged the Mini Display port into the outbound Thunderbolt on the Thunderbolt display, in thoery, if you disabled the Thunderbolt display, you could output through to the projector. Whether this can be switched software wise to not output to the TBD and to the Minidisplayport instead, I don not know. I guess playing around might be able to tell you (if you have all the parts already)
  6. kolax macrumors G3

    Mar 20, 2007
  7. jsolares macrumors 6502a

    Aug 8, 2011
    Land of eternal Spring
    I read that there are issues if the TBD is where you connect the minidisplay port adapter, but it'll work if you have a lacie or pegasus box in the middle :S

    Bottom line you can daisy chain minidisplay port to thunderbolt but not if the thunderbolt device is the Thunderbolt Display :(
  8. LordVic macrumors 601

    Sep 7, 2011
  9. Boe11 thread starter macrumors 6502a

    Sep 12, 2010
    Well, I ordered the mdp adapter, so I'll test things out once it arrives. I don't mind the act of swapping cables when I want to watch a movie, but the biggest pain is that I've got my peripherals and external HD hooked up to the TBD.

    I guess I'll see how it works and figure it out.

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