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Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
Hi all,

I've got a project to connect my Apple TV to my Apple Cinema Display. So far, it's great; the Kanex XD converts the HDMI signal to MDP, but the ACD doesn't have volume controls, so the result is a static volume level.

I'd like to strip the audio from the HDMI signal before it gets to the Kanex XD, ideally outputting as SP/DIF. I've been looking at a lot of products, and they all say they can 'extract' or 'split' the audio, but it usually transpires they still transmit audio via HDMI, presumably assuming the output device can be muted or has no audio output.

Does anyone know any decent devices that take a regular HDMI signal, and output only HDMI video and SP/DIF audio?

Many thanks,
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
So, I thought I'd cracked this one this afternoon. I borrowed a HDMI to DVI-D cable, and a DVI-D to HDMI Apple adapter, but to my dismay, audio still played from the destination device :( I looked into if I could pull any pins from the DVI-D connector, but it looks like the way HDMI works the video/audio steams are all steamed across the same pins.

The Kanex XD standardises the input for the ACD, but I seemingly have no way of intercepting and redirecting the audio.
 

martinm0

macrumors 6502a
Feb 27, 2010
568
25
So, I thought I'd cracked this one this afternoon. I borrowed a HDMI to DVI-D cable, and a DVI-D to HDMI Apple adapter, but to my dismay, audio still played from the destination device :( I looked into if I could pull any pins from the DVI-D connector, but it looks like the way HDMI works the video/audio steams are all steamed across the same pins.

The Kanex XD standardises the input for the ACD, but I seemingly have no way of intercepting and redirecting the audio.

Can I play devil's advocate for a minute? Is there any specific reason you are trying to force the use of your Apple TV through your Cinema display? For the cost of the Kanex adapter you could have at least 3/4 the money for a 27" 1080p HDCP compliant monitor that would play the ATV perfectly. I know the ACD is pretty (I had one), but you are limited to only 720p from the Kanex device if I recall.

As for audio, you should be able to select a different audio output in the ATV menu. Do you have a receiver or anything that can take digital optical connection? That would be the best option if available.
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
As you said, I really like my ACD, had it a long time and would really like to keep it. The XD was only £70, a new monitor of similar quality would be much more than that.

I looked into this before I got the XD; the Apple TV doesn't have the ability to select a single audio output. I have a TOSLink cable and could run audio from the Apple TV to my Mac Pro and using that as a pass through, could play it from my speakers, but audio still came from the HDMI output to the test monitor I have. (admittedly, on that monitor you can actually turn the volume down/off, but it's a beat-up one I take to LANs, not really suitable to use day-to-day).
 

i-n

macrumors newbie
Mar 1, 2007
22
2
Hi all,

I've got a project to connect my Apple TV to my Apple Cinema Display. So far, it's great; the Kanex XD converts the HDMI signal to MDP, but the ACD doesn't have volume controls, so the result is a static volume level.

I read this today with interest as I'm planning on doing something very similar myself, albeit without the Kanex XD. My ACD is the 23" aluminum model so I'll be using a DVI to HDMI cable. As there are no speakers, I won't have the sound issue you're having. Great to see someone else with the same idea anyway.
 
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i-n

macrumors newbie
Mar 1, 2007
22
2
I read this today with interest as I'm planning on doing something very similar myself, albeit without the Kanex XD. My ACD is the 23" aluminum model so I'll be using a DVI to HDMI cable. As there are no speakers, I won't have the sound issue you're having. Great to see someone else with the same idea anyway.

Just an update on this, while the ATV displayed on my ACD, it was borderline unusable because it was so slow to respond to the remote.
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
So I revisited this, and realised I had the cable to do it. I bought a cable for my Wii ages ago that outputs as Component. It came with PS3 and XBox 360 connectors too, but since I already connected mine via HDMI, I ignored it.

I just need to convert Component to HDMI and run that into the Kanex XD. Since the audio is separate, I can just send that directly to my sound card so I can control the sound levels.
 

boston04and07

macrumors 68000
May 13, 2008
1,788
866
This is very interesting...I have an old Cinema Display (2008 LED edition I believe) that I haven't been using as much as I used to, and I've wondered if this is possible. Thanks for the instructions.
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
Brief update, I found a great cheap Component to HDMI converter and 720p/1080p upscaler on Amazon (made by Portta).

I can use the XBox 360 / Wii / PS3 to Component cable I had lying around, connect only the RGB connectors to this, send the sound to my external soundcard and use LineIn to loop the audio back out (so I can control the volume). The upscaler is set to 720p, as that's all the Kanex XD can cope with for the 27" ACD (If you're using the older 24" from 2009, you can pass through 1080p sources), then this passes 720p through to the ACD with no audio :)

I've tested this out with the XBox 360. Initially it didn't work as the XBox defaulted to 480p on the Component connection, so make sure you have another screen or a TV handy to do this. Set it to 720p, reconnected to the Component to HDMI converter, and it all worked.

Haven't tested the Wii yet, but the idea is that the 480p connection out of the Wii is correctly upscaled to 720p, which the Kanex XD should accept, and hopefully it'll work too.

Next step is to get the Kanex SnapX and see if I can switch connections between my Mac Pro and my Kanex XD..
 

jamiestark

macrumors newbie
Jun 23, 2015
2
0
Chicago
I have the Kanex XD but my ACD is refusing to display. When I first connected it the screen responded, but it's now refusing to and I've rebooted, disconnected/reconnected a couple times. Is there a trick I need to know?

Thanks
Jamie
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
Wii works perfectly running an upscaled 480p image :)

@jamiestark which ACD do you have, and what are you connecting?

  • On the 24" ACD from 2009 it needs to be provided with a 1080p source
  • On the 27" ACD from 2010 it needs to be provided with a 720p source
  • The Kanex XD does NOT work with the Apple Thunderbolt Display.
 

jamiestark

macrumors newbie
Jun 23, 2015
2
0
Chicago
When connected to ATV display preferences is only giving me 720p; 1680x1050; and 1440x900 as options

If I plug the ACD in to a MacBookAir 2012 and pull preferences:

Apple LED Cinema Display: 24-inch (user manual has 2008 copyright date) so it should be the one you're referencing above.

Apple TV was purchased earlier this year, so rev2 - is that the issue? Do I need rev3?

I actually bought the Kanex XD to take the HDMI port out from a 13"MBPr to create 3 screens because my two TB are blocking adding a 3rd.

There are other instances of this being done, but everyone is lacking the two TB and I think that's really causing the !@#$blocking of adding the third. I've read thru the tech specs and understand that TB are capped at two in a chain or independently plugged in because there is only one bus on the computer (up to 6 TB capable with Mac Pro). So now i'm in creative "i'm going to win this battle" mode to prove it can be done.

examples of others:

http://apple.stackexchange.com/ques...15-late-2013-macbook-pro-retina/124479#124479


if stepping up to a ATV rev3 for 1080p is going to solve the problem, know that I have the Amazon and BB screens already open to buy it. I just decided to try and validate this would be my workaround before I purchased. In display preferences, while it won't show the screen, using ATV in extend desktop mode DOES give me the display preferences pane and I interlaced it to see if dragging the mouse crossed the black screen. It does. I can change the arrangement. So I think I've "beat the firmware system", but back to the original question....i'm only seeing 720p as an option with the current ATV I have plugged in.

Thanks
Jamie
 

boston04and07

macrumors 68000
May 13, 2008
1,788
866
Hi again. Does anyone know if this method would work with hooking up a 24" LED Cinema Display to an Apple TV 4? I have my old Cinema Display that doesn't get nearly as much use as it used to, but it still works perfectly fine so I would love to get some good use out of it. I was also just gifted a new Apple TV 4, and figure this combination could be perfect to use as a bedroom TV for me. The big issue is that you can't control audio volume, right? Well on the new Apple TV you can use Bluetooth external speakers (I think?) so if so, I would just use that as my audio source anyway, since I have a really nice pair already sitting in my bedroom. Would love to know what you guys think of this idea...
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
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280
The Kanex XD will run on the 24" LED ACD at 1080p :) Plus you can control audio from the remote, so that solution should work perfectly!
 

boston04and07

macrumors 68000
May 13, 2008
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The Kanex XD will run on the 24" LED ACD at 1080p :) Plus you can control audio from the remote, so that solution should work perfectly!

You, sir, are a gentleman and a scholar! :D Thank you very much for clarifying this - I totally forgot that the new Siri remorse does volume as well! *duh* Can't wait to get this hooked up. I also had no idea that the Kanex would run 1080p...I was expecting much less so this will be very nice!!

If I recall correctly, the new Apple TV can also put the display to sleep when the Apple TV itself goes to sleep - any idea if that works too? If not no biggie, just curious!!
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
The ACD turns on when it receives a signal, and turns off when it doesn't so this should be fine too :)
 

boston04and07

macrumors 68000
May 13, 2008
1,788
866
The ACD turns on when it receives a signal, and turns off when it doesn't so this should be fine too :)

Ahh this is fantastic! Now I'm excited to get this hooked up. I probably won't be able to for a couple months or so, but I'll be sure to post back with my results whenever I do. This definitely will be a great way to bring some new life into my old display!
 
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boston04and07

macrumors 68000
May 13, 2008
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Hello again! Just finally got around to purchasing a Kanex converter and it should be here in a few days. I'll post again once I've gotten it all hooked up and will let you guys know how it goes. I'm looking forward to it - it'll be fantastic to see my old display get some regular use again!

Before I do, I just have one more question! I mentioned up thread that I'll mostly be using nearby Bluetooth speakers as my main audio output, but I'm just wondering - if they get disconnected or can't be used for whatever reason, will audio be able to come out of my Cinema Display's built in speakers? Basically I guess I'm just wondering if the Mini DisplayPort/Kanex/HDMI setup handles audio as well as video. I think it does from what I can tell from my research, but haven't found anyone else doing this with my particular model of Cinema Display (LED 24"), so just wanted to see what you guys thought! Thanks in advance :)
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
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280
If you're using the LED 24" ACD, you'll get a 1080p image, and any audio will be passed through to the internal speakers at line level. Unfortunately, because of the simplistic approach Apple took to making the ACDs, there's no way to change this volume up or down. You also can't strip audio from the HDMI stream, (though using dubious cheap adapters or a proper AV receiver you can copy the audio and output this elsewhere).

However, since you're connecting a new Apple TV model, that has built-in volume controls, so you should be able to cope with this. What I'm not sure of is how a Bluetooth speaker system would behave. I'm assuming it's a little like an iPhone speaker / bluetooth headset style setup; it'll either output audio across HDMI or via Bluetooth. But I don't have anything like that, or a newer Apple TV, so I'm not sure how this would behave. Do let me know though, interested to find out :)
 
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boston04and07

macrumors 68000
May 13, 2008
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866
If you're using the LED 24" ACD, you'll get a 1080p image, and any audio will be passed through to the internal speakers at line level. Unfortunately, because of the simplistic approach Apple took to making the ACDs, there's no way to change this volume up or down. You also can't strip audio from the HDMI stream, (though using dubious cheap adapters or a proper AV receiver you can copy the audio and output this elsewhere).

However, since you're connecting a new Apple TV model, that has built-in volume controls, so you should be able to cope with this. What I'm not sure of is how a Bluetooth speaker system would behave. I'm assuming it's a little like an iPhone speaker / bluetooth headset style setup; it'll either output audio across HDMI or via Bluetooth. But I don't have anything like that, or a newer Apple TV, so I'm not sure how this would behave. Do let me know though, interested to find out :)

Awesome @Draeconis, you've been a fantastic help through this! Thank you! I will surely let you know and post pictures when it's all done, hopefully next week or so. I now have another Apple TV 4 hooked up to a television, and it controls volume just fine. Apple did a great job at making that aspect of it totally seamless; I can control volume and turn on/off the TV all using the Siri Remote, which is a big improvement over the last Apple remote. I also just hooked up my MBP to my Cinema Display and the Cinema Display's volume was controlled perfectly well by just the Mini DisplayPort connector. So, I'm hoping the connection to the display is no different and that controlling the output volume on the Apple TV itself controls the volume coming out of the display. I don't see why it wouldn't after fiddling around with this stuff, but you never know! I think that was my main concern - it had been a while since I'd hooked up the display, and couldn't remember if Mini DisplayPort handled volume or not and whether the volume has been controlled by the display's USB connection to the laptop, but it doesn't seem like it was.

Either way, it's just a good-to-know aspect of all this, as the Apple TV 4 does in fact output audio to Bluetooth and AirPlay speakers nicely, so I'll mostly just be doing that. That would send the audio to the speakers from the Apple TV device itself, I think, bypassing the display entirely - at least that's how it works with my TV.

All in all I've really been liking the Apple TV 4 a lot. It handles AirPlay very well so I'm also looking forward to using my Cinema Display as a second display again from time to time, only wirelessly. It's great finding ways to repurpose old devices like this. :D
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
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You're welcome :)

Weirdly, I think if you have a Mac connected, it only sees the internal speakers if you attach it via USB, and doesn't send audio out of the MDP connection. But it's a regular MDP port, so miniaturised DP, which is similar to HDMI, which transports Audio/Video across 3 streams (iirc), so regular HDMI sources connected to the ACD via the Kanex HD send it audio at line level because they can.

You're lucky you have an ATV4, I only owned an AVT2 (at the time) and couldn't change the volume. Eventually sold it and focused on getting the Xbox 360 / Wii to work. Still does, although the Component to HDMI converter/upscaler does mangle the green channel a little.
 
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LiveM

macrumors 65816
Oct 30, 2015
1,268
614
Are you guys saying you can't connect your ATVs directly to your ACDs? I haven't had any problems using the Apple HDMI to DVI adaptor beyond resolution.
 

boston04and07

macrumors 68000
May 13, 2008
1,788
866
Are you guys saying you can't connect your ATVs directly to your ACDs? I haven't had any problems using the Apple HDMI to DVI adaptor beyond resolution.

Yes. We're talking about the LED Cinema Displays that have Mini DisplayPort instead of DVI.
 

boston04and07

macrumors 68000
May 13, 2008
1,788
866
Hello again!

So it's a rainy day where I am, and I finally got the chance to get my Cinema Display out of storage and try this all out, since my Kanex came a few weeks ago. So, I'm not getting this to work yet, but I'm thinking I may have been shipped a faulty Kanex. They only had them available from third-party sellers on Amazon and when I got it, it was pretty clear that it had been opened up and then repackaged. Basically what's happening is this: I plug in the Kanex's power supply, plug in the Cinema Display's Mini Displayport cable into the Kanex, and then connect the Kanex to my Apple TV 4 via HDMI, and the screen will flash on for a second, and I'll see a yellowish-tinted Apple TV home screen for another second, and then the picture just completely cuts out and the display goes back to sleep. I've tried hooking the Apple TV back up to my living room TV and changing it to display various resolutions, and the same exact thing happens. The Apple TV works perfectly with my two HDTVs and the Cinema Display works flawlessly plugged into my rMBP 15, so I'm thinking that the Kanex is just failing to deliver the feed for some reason, since everything else works great. I've even tried the cables I use to connect the Apple TV to the Kanex on other screens and they work fine too.

So, I'm going to exchange the Kanex for a different one and hope for the best. I've read reviews about their hardware being kind of flakey anyway, so hopefully it's just a matter of getting a unit that will work. Plus, the way it was packaged when I got it really leads me to believe I may have gotten a unit that someone else had returned for not working properly. At this point I just want to get this to work for the sake of getting it to work, since figuring out things like this is fun for me. Plus, it'd be awesome to be able to get more use out of my display - now that I have it hooked up to my MBP again, I forgot just how nice it is to use. It'd been months since I've used this and I'm all about getting as much use out of devices like this as possible. It'd be sweet if I could hook up an ATV to it and use it as a wireless secondary Airplay display for my MBP and as a casual streaming device when I'm not. :)

So, I'll let you guys know how it goes once I get the replacement Kanex!
[doublepost=1468182341][/doublepost]Edit: Sorry for the double post, but I just thought of something. On the Kanex box it says that the "supported resolution" for the 24" Cinema Display is 1920x1200 @60hz. Does that mean that the Apple TV 4, having the maximum resolution of 1080p at 60hz, can't output the necessary resolution? The Kanex was definitely packaged sketchily, but perhaps that's why this isn't working...
 

Draeconis

macrumors 6502a
Original poster
May 6, 2008
985
280
Hmm, sorry it's not been so simple for you. Why not see what happens when you plug something else in on the HDMI connection of the Kanex running at 1080p?
 
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