[ishmael]

I might be posting in the wrong spot, if so I'm sorry.

I'm looking for a DAC/amp that I can add in to my home theater for use with headphones. My new AVR does not seem to properly downmix 5.1 or 7.1 material into it's headphone out. So I end up with only the front right and left sound, which has no center channel dialog.... therefore useless. My headphone amps and DAC that I own don't have optical in, just USB, analog RCA, and 3.5".

I'm looking for a (hopefully cheap) device that I can connect to my source via optical, will downconvert the 5.1 (likely DD or DTS) bitstream, and give me 2 channel sound. I saw the JVC SU-DH1 but that is more for making virtual surround which I don't really need. It would work, but I'd be paying for something I don't want.

Quick test: if your DAC/amp unit has an optical in, what happens if you feed it a surround dolby digital or DTS signal?

Thanks in advance!

 

[ishmael]

anybody?

 

[linuxworks]

I have 1 (2 actually). neither one gets any use but their purpose was to be a 'movie dac' for 5.1 but to downmix to 2.0 for my stereo use

it was in the $120 range from ebay/china:

it has a not-so-great user interface (srolling, sigh!) but it does seem to decode dd5.1 and dts AND mix down to 2.0 if you want.

PM me if you want one of my spares. they came from ebay/china and while they do work, I ended up going a different route (using popcorn hour to downmix to 2.0 and from then on, its regular spdif to my stereo dacs)

(edit: I didn't mean I was offering free dacs. sorry if I gave that impression

)

 

[iriverdude]

All AV amps should downmix multi-channel to stereo, you said you don't get center speaker information, if that is correct you wouldn't hear ANY speech at all. Can you?

 

[linuxworks]

my yamaha av amp did a poor job on mapping the center channel out to phantom.

I think I have only 1 movie that is mono and ONLY just a single center channel of data; NOT even a courtesy l,r,c combo. in that case, I heard no sound. what a pita ;(

most movies have the center channel but ALSO make it quite usable to listen and ignore the center (redundant info is there, enough, in l+r). but some movies have ONLY that center channel (boggle).

I hate installing extra spkrs and my amp is 'just' a 2ch amp (beta22) so I have no choice but to downmix 5.1 to 2.0.

my longer term goal was to get a quality 5.1 dac, get all its output channels and do my own mixing down to 2.0, the way I want it done. have not gotton around to that since there are no good DIY 5.1 dacs or projects ;(

 

[Reticuli2]

Have your DVD player do the downmix, and also tell it to output PCM, not DTS or DD.

 

[linuxworks]

dvd player? what if the source isn't ON a dvd?

more and more, software is coming online and NOT on spinny plastic dinosaur discs

having the transport also be a dac is so, well, so 1980's!

(half kidding but only halfway)

 

[Reticuli2]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif dvd player? what if the source isn't ON a dvd? more and more, software is coming online and NOT on spinny plastic dinosaur discs having the transport also be a dac is so, well, so 1980's! (half kidding but only halfway)

Dvd player, software player...they should all have those options. Simply turn off output to DD/DTS and make sure 2ch mix down is on...including the sub. If this is a DVR, there should be a PCM option.

 

[iriverdude]

Quote:

my yamaha av amp did a poor job on mapping the center channel out to phantom.

The discrete audio systems with center speaker disabled is no longer "phantom" only in Pro-Logic era did phantom exist, and relied on your amp's ability.

If you watch movies I'd recommend you listen to them on a proper 5.1 system, it sounds so much better than listening to it just in stereo.

 

[linuxworks]

no thanks - adding more speakers is the LAST thing I want in my room.

I find that 2 sound sources (and a sub) is all I need. I never bought into the bose idea that 'more sound sources = better experience'. in fact, the more sources, the WORSE the annoying distractions are.

its 2.0 or 2.1 for me. that's all I care about. movies don't need 'tons of point sources' to be entertaining to me. the sound is ancillary to movies. too much fuss over what is usually NOT audiophile audio in the tracks, anyway.

in a LARGE theater, you need lots of sound sources just because of all the people there and the distance between you and the drivers. the same is not true in most listening rooms at home. its all marketing to sell you 'more speakers' and amps.

I just don't agree, sorry. not for typical home movie watching. movies just aren't THAT important (lol) that I have to bulk-up on big heavy speakers and wires all over my room

 

[linuxworks]

Quote:

Originally Posted by Reticuli2 /img/forum/go_quote.gif Dvd player, software player...they should all have those options. Simply turn off output to DD/DTS and make sure 2ch mix down is on...including the sub. If this is a DVR, there should be a PCM option.

some don't pay licensing for dts downmixing (its a for-fee thing) ;(

my popcorn hour will never (ever) have dts decoding. 'they' don't like that (the industry).

so unless your dac can decode dts, you are out of luck with that protocol.

dd5.1 is decodable in software and has no licensing issues, per se. so some hardware streamer boxes (like my pch) WILL map dd5.1 to 2.0.

still, it does it very poorly. there is a 3 or even 10db loss in gain when they map it (using a sigma chip; but using 'old libraries' it seems).

I abandoned my yahama receiver since I did not trust its analog or digital conversions (even in 'pure direct' mode).

if you are happy with an avr box, that's your solution. I was not, though. and I don't use dvd players anymore (many of us don't).

having a dac that does the mapping IS useful!

but there are damned few ;(

 

[iriverdude]

Did you listen to all your stereo music in mono? No. That's what you're doing with multi-channel soundtracks, they're designed for multi-channel and you're downmixing it.

I far prefer listening to the home theatre in 5.1 with Logic 7, than using 2 channel mode, if the film has a decent multi-channel soundtrack. It just adds so much atmosphere. I recently added a pair of THX dipoles to brothers system and he's said improved it.

 

[ishmael]

I didn't mean to start an argument. I actually do have a pretty decent 5.1 setup, but I have a 3 year old and a new baby on the way, so I don't really get to watch loud movies anymore. Hence the need for headphone downmix.

Let me clarify: my AVR actually does a wonderful job of downconverting DD/DTS into stereo. I can even employ the (sometimes) convincing Dolby Virtual Headphone feature. My problem is with high res PCM material from HD DVD and Blu-Ray players.

My AVR handles PCM over HDMI, but does not support bitstreaming of TrueHD, DTS-Master Audio, or DD+. My HD DVD and Blu-Ray players can decode those and send them as multi channel PCM, so I get the full benefit.....

....EXCEPT when I want to use headphones. My AVR doesn't know how to downmix multi channel PCM, so I only get the main L + R channels. No dialog except what bleeds over. It is not good for watching most films.

I can switch from HDMI audio to standard optical or coaxial digital output, and then the headphone problem is solved. But at that point my players would be sending lower quality downmixes of the high res stream (toslink/coaxial can't support the high res codecs). Lossless TrueHD ends up as 640k DD. Lossless DTS-MA ends up as a core file at 1.5mb. Not sure if I could reliably ABX the difference, but I want to keep the lossless when using my speakers.

The answer to all this is of course what my first post suggests: Keep everything the same in my setup, but add another unit that can decode the standard lossy DD/DTS signal from the optical out on my players. Set up my harmony remote to mute the main AVR volume, and instead use the new device (or do it manually if no remote) to control headphone volume.

Thanks for the help, Linuxworks I'll PM you.

 

[linuxworks]

Quote:

Originally Posted by iriverdude /img/forum/go_quote.gif Did you listen to all your stereo music in mono? No. That's what you're doing with multi-channel soundtracks, they're designed for multi-channel and you're downmixing it.

for some people, they appreciate multichannel sound.

I'm not one of those people. not everyone is.

at least I get to save all the bother of the spkrs, amp sections and so on

my movie-watching needs are *way* less than my audio needs. perhaps its a blessing

 

[Fedderman]

Ishmael - I have a very similar challenge, want to keep the 5.1 multichannel for my sound system but also down mix to stereo for headphones. Did you find a solution, and if so, can you share it? Thanks!