Audio through Mini Displayport (HDMI Adapter)

I'd like to connect my MBP to my amp using a HDMI adapter. Will any audio pass through this? Enabling a 5.1 output?

Cheers

MacBook Pro 2.66GHz Unibody, Mac OS X (10.6.1)

Posted on Oct 2, 2009 3:28 AM

Reply
8 replies

Oct 2, 2009 3:57 AM in response to Agent-Trig

No. Apple's implementation of DisplayPort +does not+ include audio (even though the standards for both DisplayPort and HDMI do).

So, you'll need to get your audio from the headphone port. That's a combined analog/optical out, so if you connect a mini-Toslink to Toslink cable (assuming your TV/receiver has optical audio in) you'll get 5.1 surround/DTS.

If you're willing to sacrifice the 5.1 surround, there's also a mini-DP to HDMI adapter +with audio+ coming out soon (was supposed to be out already, but has been delayed). The audio output comes from USB (it's analog only), and is 'merged' with the mini-DP video into the HDMI cable.

Oct 2, 2009 7:15 AM in response to neuroanatomist

Very interesting. The Kanex adapter apparently uses USB only for power, and a mini-TOSLink plug for the 5.1 audio, which is then converted inside the adapter to a signal that travels through the wires in an HDMI cable. The Monoprice adapter uses USB for the audio signal, which may mean it can't handle 5.1 audio (the blurb about it doesn't say). So they are distinctly different products, and at distinctly different prices. I had at first suspected that they might be the same product marketed under different names, but that's not so.

Oct 2, 2009 8:20 AM in response to eww

Thanks, that explains my earlier confusion - this is a different/newer product than what was pre-announced!

http://www.kanexlive.com/

They have a version with digital audio, and a different (slightly less expensive) version with USB audio. The USB audio version of the Kanex product is equivalent to the Monoprice product, is analog audio only, and can't output 5.1 audio. The digital audio version takes the optical audio from the headphone port.

Oct 22, 2009 8:17 AM in response to neuroanatomist

Okay, now I'm confused. I always understood the digital audio limitation on the mini display output to be the result of stepping it down to DVI before bumping it back up to HDMI with an adaptor. Unless there's a mini display-to-HDMI option AND the mini display port is wired for audio, I don't expect anyone will be making a single-port, single-cable solution anytime soon.

In any case, that's not what caught my attention on this thread... I'm still trying to get dolby 5.1 (i.e. AC3 passthrough) to work +at all+ on my audio output with a Toslink adaptor and Quicktime/iTunes. I've noticed that Plex passes AC3 bitstreams over the Toslink without any issues, so I know it's not an Apple hardware limitation. I just don't want to use Plex to watch my movies in 5.1

I've messed around with the output settings nine ways to Sunday, but it's obvious the downconversion to digital stereo is happening in QT long before it ever gets to the hardware. Has anyone heard a good reason yet why AC3 passthrough was disabled in Quicktime and iTunes? It used to work.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Audio through Mini Displayport (HDMI Adapter)

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.