Is DTS Headphone X a poor man's version of SVS Realiser? - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 12 Old 01-17-2013, 04:06 AM - Thread Starter
Member
 
valley_nomad's Avatar
 
Join Date: Dec 2006
Posts: 199
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
It looks like that DTS has found a generalized HRTF for everyone . Did anyone hear their demo at CES?
valley_nomad is offline  
Sponsored Links
Advertisement
 
post #2 of 12 Old 01-19-2013, 09:50 AM
Member
 
darinf's Avatar
 
Join Date: Jun 2004
Location: San Diego, CA
Posts: 58
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I did not see/hear the demo, but when I saw the press about the demo, I immediately thought that Smyth Research had licensed their technology to DTS.

The Smyth brothers used to work for DTS and were the original developers of DTS technology. In fact, all or most of the Smyth Research staff are ex DTS employees.

I don't know anything at all, I am just speculating, but I don't think Smyth research was involved in the development of Headphone X. I think SRS might have "copied" the Realiser.

In any case, Headphone X sure looks like the same thing as the Realiser, but in a more generic fashion rather than doing personalized ear/HRTF measurements.

I own a Realiser and I have found that the localization of the virtual speakers and the sound accuracy is still remarkably good even if the measurements were made with someone else's ears.

DTS could be using a binaural dummy head/ears to do their measurements to get a more generic HRTF, but even if you don't use a generalized head/ear shape, the effect works well, from my experience.

The biggest problem with Headphone X is having to re-encode all content AND implement new codecs in all the playback devices. I assume DTS does this so they can sell new licenses to all the movie studios, hardware manufacturers, etc. That's their business model, but how long will it take before anyone can actually buy a DVD with Headphone X encoding AND have a way to actually decode it and listen to it at home? It could be a long time...

Oh yes, and of course, Headphone X will never work with Dolby encoded audio.
darinf is offline  
post #3 of 12 Old 01-19-2013, 03:17 PM
AVS Addicted Member
 
sdurani's Avatar
 
Join Date: Oct 2001
Location: Monterey Park, CA
Posts: 18,732
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 471 Post(s)
Liked: 601
Having sat through the demonstration a couple of times (partly to get a second demo disc), it was quite good considering that my ears had not been individually convolved (like when I've gone through demos of the Smyth Realiser). The lady at the DTS booth first played the signal through each speaker individually to establish a baseline. Then told us to us to put on the headphones (no taking them off) as they repeated the exercise. Then surprised (some) people in the room by telling us that the second round was completely via headphones. They then repeated it a third time, letting us take the headphones off and put them on at will, just to prove to the doubters in the audience that none of the speakers were playing.

Like I said, the actual processing itself was quite good considering the limitation (no individual HTRF). I don't know (forgot to ask) whether the final version will use the HTRF that was demo'd or whether they will allow for a choice of different HTRFs (users pic the one that works best for them). It may end up being up to each manufacturer and how they choose to implement Headphone-X. Sounds at the left and right side were most clearly defined, with sounds up front being a bit more vague and sounds behind being a little swimmy. Still, the fact that I could easily tell front vs back vs side was impressive.

However, the most impressive part was the fact that they nailed the externalization effect. Headphone listening has always sounded to me like the soundstage was a hat I was wearing on my head. Centre image sounds seem to be in my forehead rather than outside of me. One of the holy grails of headphone processing is externalization, and DTS did an excellent job of that (not as good as Smyth, but still impressive). That alone made up for the less than pin-point directionality

Finally, one disadvantage was that there was no head tracker (like Smyth has). We humans make small involuntary head movements to constantly re-calibrate our surroundings. The moment the second round of signals started going though the speakers, I turned to my friend to tell him how great I thought it was... and the whole soundfield turned with me. OK, that blew the illusion. But for most headphone listening, I'd take this over an unprocessed signal any day.

Sanjay
sdurani is offline  
post #4 of 12 Old 01-25-2013, 06:01 PM
AVS Special Member
 
David Susilo's Avatar
 
Join Date: Aug 2002
Location: Markham, Canada
Posts: 9,402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 327
Quote:
Originally Posted by darinf View Post

I did not see/hear the demo, but when I saw the press about the demo, I immediately thought that Smyth Research had licensed their technology to DTS.

The Smyth brothers used to work for DTS and were the original developers of DTS technology. In fact, all or most of the Smyth Research staff are ex DTS employees.

I don't know anything at all, I am just speculating, but I don't think Smyth research was involved in the development of Headphone X. I think SRS might have "copied" the Realiser.

In any case, Headphone X sure looks like the same thing as the Realiser, but in a more generic fashion rather than doing personalized ear/HRTF measurements.

I own a Realiser and I have found that the localization of the virtual speakers and the sound accuracy is still remarkably good even if the measurements were made with someone else's ears.

DTS could be using a binaural dummy head/ears to do their measurements to get a more generic HRTF, but even if you don't use a generalized head/ear shape, the effect works well, from my experience.

The biggest problem with Headphone X is having to re-encode all content AND implement new codecs in all the playback devices. I assume DTS does this so they can sell new licenses to all the movie studios, hardware manufacturers, etc. That's their business model, but how long will it take before anyone can actually buy a DVD with Headphone X encoding AND have a way to actually decode it and listen to it at home? It could be a long time...

Oh yes, and of course, Headphone X will never work with Dolby encoded audio.

1. DTS is not using binaural dummy, it uses room modelling
2. Headphone:X is NOT a new codec
3. Technically Headphone:X can work with ANY multichannel signal be it LPCM, Dolby or DTS because it is a post-processor and not an encoder just like Dolby Headphone works with LPCM, Dolby and DTS tracks.

follow my A/V tweets @davidsusilo

ISF, THX, CEDIA, Control4 & HAA certified
Reviewer for TED, QAV, AUVI & DownUnder Audio Magazine

my (yet to be completed) BD list
my home theatre

David Susilo is online now  
post #5 of 12 Old 01-25-2013, 06:13 PM
AVS Special Member
 
David Susilo's Avatar
 
Join Date: Aug 2002
Location: Markham, Canada
Posts: 9,402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 327
Quote:
Originally Posted by valley_nomad View Post

It looks like that DTS has found a generalized HRTF for everyone . Did anyone hear their demo at CES?

That article is filled with misinformation.

1. The headphones the used for the CES demo were the $99.99 Sennheiser, not $20 headphones

2. It does NOT require DTS-HD encoded bitstream

3. Although you can use any headphones, in order to get the best sound you'll need to use the headphones which the software have been calibrated to (there is a list of hundreds of headphones from the cheap to expensive headsets, one of them are of audiophile quality level -- yet?)

4. You can NOT tweak your sound to your liking as the article alluded to.

It's clear from reading the article that the writer only went to the DTS demo instead of spending any time with the DTS product development manager asking the necessary technical questions (I spent more than an hour talking to the product development manager and off-site listening more than just the demo)

follow my A/V tweets @davidsusilo

ISF, THX, CEDIA, Control4 & HAA certified
Reviewer for TED, QAV, AUVI & DownUnder Audio Magazine

my (yet to be completed) BD list
my home theatre

David Susilo is online now  
post #6 of 12 Old 01-25-2013, 06:35 PM
Member
 
darinf's Avatar
 
Join Date: Jun 2004
Location: San Diego, CA
Posts: 58
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by David Susilo View Post

1. DTS is not using binaural dummy, it uses room modelling
2. Headphone:X is NOT a new codec
3. Technically Headphone:X can work with ANY multichannel signal be it LPCM, Dolby or DTS because it is a post-processor and not an encoder just like Dolby Headphone works with LPCM, Dolby and DTS tracks.
]

1) I know it's modeling a room, but in order to model a room like the Realiser, the microphones are put in the listeners ears to account for the reflections/interactions with the pinna of the ear. I think having the microphones in the ear canal is the reason why the Realiser room modeling works so well. So rather than use an actual person's ears, I thought they might be using a dummy head's ears to get a more "average" pinna interaction.

2) On the DTS website when they say "requires surround content to be encoded as a DTS-HD bitstream, with the room information embedded in the stream" and then say "Finally, the reference data is decoded ". That may not be a codec, but it's the same idea. Or are you saying that HeadphoneX uses pre-existing codecs? Or are you saying there is no encoding or decoding? Is it just a signal processing algorithm? If so, then why do they mention encoding and decoding?

3) I am just going by what it says on their website, "requires surround content to be encoded as a DTS-HD bitstream, with the room information embedded in the stream". You may have more information than what's on their website. But to me the key word is "requires".

I am not trying to argue with you, I am just trying to figure it out based on what I read on their website. Hopefully your information is more reliable than what they say on their website.
darinf is offline  
post #7 of 12 Old 01-25-2013, 06:41 PM
Member
 
darinf's Avatar
 
Join Date: Jun 2004
Location: San Diego, CA
Posts: 58
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by David Susilo View Post


It's clear from reading the article that the writer only went to the DTS demo instead of spending any time with the DTS product development manager asking the necessary technical questions (I spent more than an hour talking to the product development manager and off-site listening more than just the demo)

Sorry David, I did not see your post about you spending so much time with the DTS product development manager.

I can assume that what you are saying is true and better information that the little bit they have on their website. Thanks for the clarification.

Anyway, I look forward to being able to buy a product with Headphone X someday. Then we'll know for sure what it can do.
darinf is offline  
post #8 of 12 Old 01-25-2013, 07:31 PM
AVS Special Member
 
David Susilo's Avatar
 
Join Date: Aug 2002
Location: Markham, Canada
Posts: 9,402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 327
The website is, admittedly, misleading and confuses people. From what I've been told, the technology itself is a post processing of multi-channel sound. So be it DTS or Dolby will have to be decoded first into multi-ch PCM, then processed using HeadphoneX. Whether the implementation will stricly for DTS soundtrack only, only time will tell. Most probably, and this 100% speculation on my part, due to the processing power required, for handheld devices it may just be DTS only whereas the home application may be using its full technological potential.

Regardless, I'm extremely looking forward to this technology for both the home and on the road.

follow my A/V tweets @davidsusilo

ISF, THX, CEDIA, Control4 & HAA certified
Reviewer for TED, QAV, AUVI & DownUnder Audio Magazine

my (yet to be completed) BD list
my home theatre

David Susilo is online now  
post #9 of 12 Old 01-26-2013, 01:45 AM
AVS Special Member
 
Roger Dressler's Avatar
 
Join Date: Jul 2000
Location: Oregon
Posts: 8,218
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 124 Post(s)
Liked: 165
Quote:
Originally Posted by darinf View Post

In any case, Headphone X sure looks like the same thing as the Realiser, but in a more generic fashion rather than doing personalized ear/HRTF measurements.
A key difference is that if you want to hear your recordings as if played in the Concertgebouw with Realiser, you have to take your ears to the Concertgebouw to get them measured there. With Headphone:X that room model comes with the recording.

Quote:
DTS could be using a binaural dummy head/ears to do their measurements to get a more generic HRTF, but even if you don't use a generalized head/ear shape, the effect works well, from my experience.
Whether it is a dummy head or based on real humans (dummy heads are derived from humans, too), it is still an approximation to any given listener’s personal HRTF. The trick is to find a good one, but moreover, to render it effectively. Typical headphone processors, to reduce computations, generalize what may have been a great HRTF into a "low res" version that degrades spatial/timbral accuracy. Realiser works not only because it starts with your own HRTFs, it preserves their details. That's not easy when computation capacity is limited.

Quote:
The biggest problem with Headphone X is having to re-encode all content AND implement new codecs in all the playback devices.

Oh yes, and of course, Headphone X will never work with Dolby encoded audio.
Yes, the optimal solution to hearing the experience as in the original venue is to use soundtracks which carry the embedded room information. But the headphone rendering, with respect to HRTFs and room modeling, will work just as well with any existing content. I suspect they will offer a set of generic room models from which the user may choose. I may end up listening to a movie in a different dubbing stage, but do I really care?

Quote:
Originally Posted by David Susilo View Post

1. DTS is not using binaural dummy, it uses room modelling
These are two different things. Room modeling is not a substitute for HRTFs, it is in addition.

Quote:
Originally Posted by darinf View Post

2) On the DTS website when they say "requires surround content to be encoded as a DTS-HD bitstream, with the room information embedded in the stream" and then say "Finally, the reference data is decoded ". That may not be a codec, but it's the same idea. Or are you saying that HeadphoneX uses pre-existing codecs? Or are you saying there is no encoding or decoding? Is it just a signal processing algorithm? If so, then why do they mention encoding and decoding?
The room information is “decoded” from the bitstream and applied to the post-processor. The audio codec itself is not changed.

Quote:
3) I am just going by what it says on their website, "requires surround content to be encoded as a DTS-HD bitstream, with the room information embedded in the stream". You may have more information than what's on their website. But to me the key word is "requires".
Yes, if you want to hear the audio within the venue where it was produced, you need the room information for that recording. Otherwise, you will be in some alternative (but presumably good sounding) room.
Roger Dressler is offline  
post #10 of 12 Old 01-26-2013, 04:34 AM
AVS Special Member
 
David Susilo's Avatar
 
Join Date: Aug 2002
Location: Markham, Canada
Posts: 9,402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked: 327
^^^^^^ correct on all accounts. Ecept for the binaural head part, which I don't know.

follow my A/V tweets @davidsusilo

ISF, THX, CEDIA, Control4 & HAA certified
Reviewer for TED, QAV, AUVI & DownUnder Audio Magazine

my (yet to be completed) BD list
my home theatre

David Susilo is online now  
post #11 of 12 Old 01-26-2013, 01:43 PM
AVS Special Member
 
Roger Dressler's Avatar
 
Join Date: Jul 2000
Location: Oregon
Posts: 8,218
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 124 Post(s)
Liked: 165
Quote:
Originally Posted by David Susilo View Post

^^^^^^ correct on all accounts. Ecept for the binaural head part, which I don't know.
I do, which is I why I posted. wink.gif
Roger Dressler is offline  
post #12 of 12 Old 01-26-2013, 01:59 PM
AVS Special Member
 
William's Avatar
 
Join Date: Apr 2000
Location: Atlanta
Posts: 8,373
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 35
How much processing power does this take and are inexpensive chips available already?
William is offline  
Reply Audio theory, Setup and Chat

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off