AVS › AVS Forum › Audio › Receivers, Amps, and Processors › Need a relatively inexpensive solution for HDMI audio to optical out (DTS/DD--not 2ch stereo out SPDIF).
New Posts  All Forums:Forum Nav:

Need a relatively inexpensive solution for HDMI audio to optical out (DTS/DD--not 2ch stereo out...

post #1 of 10
11/20/12 at 11:16pm
Thread Starter 
I already have a pretty good Denon that decodes most of the standard HD audio formats for when I'm able to actually use my speakers--it does not have HDMI inputs. The problem is, I'm currently in a situation where I normally have to rely on headphones. This has not been too much of an issue for me due to having the Pioneer SE-DHP800 box (Dolby Headphone box that accepts DTS and DD formats). For any device that has an optical out, sound has not been an issue. Until now. The Wii U just arrived, and of course Nintendo skimped out on the options again as it only has HDMI out for HD sound. I ended up ordering the View HD 4x2 matrix that's supposed to take any audio source from HDMI and output those same audio sources over HDMI as well as "optical". The problem is that it doesn't actually work like that over the optical as it's SPDIF and only outputs in 2ch stereo.

I'm assuming there are receivers out there that have HDMI in/out that also have an optical out. But are there any that can output the HDMI video, while having the optical out used for the sound that won't break the bank? I was considering just getting a receiver that already has Dolby Headphone built in, but I really don't want one with a crummy headphone jack, and I already use a headphone amp as it is.

This is what I ordered, and unless I'm just completely retarded, the description is rather ambiguous and it does not say that the optical is limited to 2ch stereo (only that the headphone jack is): http://www.amazon.com/gp/product/B0031SWDKI/ref=oh_details_o06_s00_i00
Quote:
From ViewHD, this is the latest HDMI 4x2 matrix with SPDIF optical output to support SURROUND SOUND home theater or Hi-Fi stereo audio with 3.5mm headset output for powered headset application, flexible for advanced home theater setups.
Quote:
With EDID manipulation feature to support SPDIF digital audio format: DTS-HD / Dolby trueHD / LPCM7.1 / DTS / Dolby-AC3 / DSD or HiFi Stereo

Too bad the SPDIF does not work like that. Either that, or the EDID functionality is completely busted in the unit I ended up getting.
Edited by Plasmoidial - 11/20/12 at 11:24pm
Reply
Reply

AVS Top Picks

post #2 of 10
11/20/12 at 11:40pm
The only audio format the Wii U outputs over HDMI that's compatible with SPDIF is stereo PCM, it's not capable ouputing Dolby Digital or DTS. Multi-channel PCM isn't compatible with SPDIF and the switch you bought would have to actively convert the audio into Dolby Digital or DTS instead of just passing the audio as-is and no HDMI switch I know of is capable of this.

An AV receiver wouldn't solve your problem. No AV receiver I know of will convert HDMI audio in to SPDIF out regardless of the format.

I think getting a receiver with Dolby Headphone support may be your best option.
Reply
Reply
post #3 of 10
11/20/12 at 11:47pm
Thread Starter 
The description of this product makes it sound like it can actually output HD sound from the SPDIF and not just in 2ch. It can also output to multiple sources at the same time. The instruction manual even states that initially the audio from SPDIF will be the same audio that a tv would receive and produce, but to switch it to the actual audio format from the source, you hit the "audio" button on the remote, and it's supposed to switch over to the HD sound format. It's not just the Wii U that was problematic with this unit either. I tried it with the 360 and PS3 (which have no problems with optical out) and they did not work either. So is SPDIF simply not compatible with HD formats unless the software itself decodes the sound? Do the consoles and other units that have both HDMI as well as optical out simply have seperate audio processors for each? Why can the consoles do it, but not a standard audio box?

From the book verbatim (crappy English):
Quote:
It can control the optical audio output format by control the aduio key in the remote board. The default audio format for optical is the same as the TV audio output--Stereo Sound. When press the audio key for first time, the optical audio output is HIFI(including DTS-HD/Dolby-true HD/LPCM7.1/DTS/Dolby AC-3/DSD) while the tv sound is off. For the second time to press the audio key, optical audio output will go back normal as the default state. This operation can be done circulately.

So either the unit simply cannot do what it claims, or the switching functionality via the audio button on the remote is broken. And just so it's perfectly clear, all of the inputs are HDMI with this unit.
Edited by Plasmoidial - 11/21/12 at 12:25am
Reply
Reply
post #4 of 10
11/21/12 at 12:32am
Thread Starter 
Also, this looks like a more expensive version of what I bought and it claims to do exactly the same thing.

http://www.octavainc.com/HDMI%20switch%204x1%20ARC%20port_pro.html
Reply
Reply
post #5 of 10
11/21/12 at 3:10am
If you read some of the Amazon reviews for what you purchased, you'll note they say DD/DTS 5.1 is hit or miss, but possible with some devices.
Reply
Reply
post #6 of 10
11/21/12 at 10:49am
Quote:
Originally Posted by Plasmoidial View Post

The description of this product makes it sound like it can actually output HD sound from the SPDIF and not just in 2ch.

Of the formats the descrption listed only DTS, Dolby-AC3 (Dolby Digital) and HiFi Stereo (2.0 PCM) are compatible with SPDIF. All of the other formats would have to be actively converted into something SPDIF actually supported.
Quote:
I tried it with the 360 and PS3 (which have no problems with optical out) and they did not work either.

The Xbox 360 only supports SPDIF compatible audio formats over HDMI so it should work your HDMI switch. (However, one of the audio formats the 360 suppports, "Dolby Digital with WMA Pro", isn't compatible with your Pioneer headphone box.) For your PlayStation 3 to work you would need to disable all the audio formats that aren't compatible with SPDIF and your headphone box.
Quote:
Do the consoles and other units that have both HDMI as well as optical out simply have seperate audio processors for each? Why can the consoles do it, but not a standard audio box?

The Xbox 360 has essentially just two audio outputs, one for SPDIF and one for stereo analogue audio. The SPDIF output is useed for both the HDMI and optical outputs, this is why the Xbox 360 is limited to just SPDIF formats over HDMI. The PlayStation 3 has three, one each for HDMI, SPDIF and analogue so its HDMI output supports a much wider range of audio formats.

While both the 360 and PS3 both have CPUs powerful enough to encode dynamically generated 3D positional audio into Dolby Digital using only tiny fraction of their CPU power, only the Xbox 360 has a blanket licence to use the Dolby patented technolgy. With the PlayStation 3 games licence the technology on title by title basis, so not every game supports Dolby Digital. PS3 games can also support multichannel (5.1/7.1) PCM for surround sound over HDMI, and this doesn't need a licence. Other audio formats (eg. Dolby TrueHD, DTS, AAC) are only supported over HDMI or SPDIF (where compatible) if the original media being played (eg. Blu-Ray disc or a video file) uses ones of these formats. In that case the audio is bitstreamed without modification.

Nintendo went more the PS3 route with the Wii U, except they didn't implement any support for the now obsolete SPDIF formats. The only supported way to get surround sound is through multichannel (5.1) PCM over HDMI.

In order to connect your headphone box to your Wii U and get surround sound you need a device that's capable of converting the Wii U's 5.1 PCM HDMI output into Dolby Digital or DTS over SPDIF. In addition to the Dolby or DTS licence fee that would be required, such a device would need a powerful enough CPU to do the encoding. Add in the software development costs and you're adding at least $100 to the cost of the device, all for something with a very limited market. The Wii U might have created enough of a demand for such a device, but I wouldn't hold your breath waiting for one.
Reply
Reply
post #7 of 10
11/21/12 at 2:33pm
Thread Starter 
Quote:
Originally Posted by Ross Ridge View Post

For your PlayStation 3 to work you would need to disable all the audio formats that aren't compatible with SPDIF and your headphone box.

Trust me, everything that could have been tested was. That was actually the second thing that I tried, and I made sure to try out DVDs as well that I knew only had 5.1 Dolby Digital. I contacted Monoprice to see if their unit would do what I needed, and they are claiming that it will. But according to what you are saying about the Wii U's output, even their box would produce no results for my needs. It simply does not produce DTS or DD formats. I have also never had to disable anything for movies from the PS3 to output an audio format that the Pioneer box could handle. I have only ever run into an issue with it once, and that was with Darksiders. Dolby Digital would not play unless I disabled AAC.

I'm still a little confused about the SPDIF vs Optical out however. I thought that they were the exact same thing. What you are suggesting (as well as what I've read elsewhere) makes it seem like they might be different due to the limitations of the formats that can be sent through "SPDIF". I say this, because even on Blu-Rays that are something like DTS-HD 6.1/7.1 or Dolby Digital TrueHD (without just DD 5.1) the Pioneer box will downsample those to 5.1 formats no problem. While it's not a 1:1 lossless audio transfer obviously, it's still better than stereo, and it still produces a reasonable sound space for headphones. Unless I've just somehow been lucky and every non standard "DTS" and "Dolby Digital" formats on the games and Blu-Rays that I own were specifically designed to function through SPDIF. The matrix unit that I purchased is supposed to send the same information that the optical outs send to the Pioneer box, yet it never did anything but 2ch stereo.


So, it just looks like for the time being, I am stuck with generic Wii (2) audio again.
Reply
Reply
post #8 of 10
11/21/12 at 4:01pm
Quote:
Originally Posted by Plasmoidial View Post

I'm still a little confused about the SPDIF vs Optical out however. I thought that they were the exact same thing. What you are suggesting (as well as what I've read elsewhere) makes it seem like they might be different due to the limitations of the formats that can be sent through "SPDIF". I say this, because even on Blu-Rays that are something like DTS-HD 6.1/7.1 or Dolby Digital TrueHD (without just DD 5.1) the Pioneer box will downsample those to 5.1 formats no problem.

SPDIF is the same thing as optical. Both optical and coaxial digital audio outputs use the same SPDIF encoding and are limited to the same formats. Your Blu-Ray player (eg. your PS3) is either automatically converting these secondary soundtracks into an SPDIF compatible format (eg. TrueHD to DD, DTS-HD to DTS) or automatically choosing to use the primary soundtrack instead which is required by the Blu-Ray spec to be encoded in Dolby Digital, DTS or PCM.
Reply
Reply
post #9 of 10
11/21/12 at 4:08pm
Quote:
Originally Posted by Plasmoidial View Post

Also, this looks like a more expensive version of what I bought and it claims to do exactly the same thing.
http://www.octavainc.com/HDMI%20switch%204x1%20ARC%20port_pro.html

I confirmed with an Octava rep that the above switch will pass lossy DD/DTS 5.1 and PCM 2.0 from an HDMI input to the optical output.
Reply
Reply
post #10 of 10
11/21/12 at 4:11pm
Quote:
Originally Posted by Plasmoidial View Post

I say this, because even on Blu-Rays that are something like DTS-HD 6.1/7.1 or Dolby Digital TrueHD (without just DD 5.1) .....

AFAIK, all BDs must have a lossy DD/DTS track (not necessarily selectable) which is played when the receiving device cannot accept an HD audio track.
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Receivers, Amps, and Processors

AVS Top Picks

AVS › AVS Forum › Audio › Receivers, Amps, and Processors › Need a relatively inexpensive solution for HDMI audio to optical out (DTS/DD--not 2ch stereo out SPDIF).