[ROBSCIX]

Just to clarify, I am not pro 5.1 can and trying to convince anybody to use them. I am asking other peoples opinions on these headphones as it relates to the technology of the design and implementation.
This is a discussion on theory and technology of these products.  This is not a discussion on the quality of this model over that model as it is irrelavent.  It is more a discussion of what is wrong with current designs, how they can be fixed or if the 5.1 idea can even be produced to produce correct and accruate surround sound sound.
 
So, all you sound experts what is wrong with them?

 

[David.M]

in b4 Graphicsm ^_^

 

[Ypoknons]

What do you mean by 5.1 headphones? The idea of 5 hardware drivers seems unnecessary to me; it seems unnecessarily expensive and difficult to design acoustically. My understanding is that we understand HRTF well enough to make it possible to reproduce the psycoacoustic cues for spatial awareness with two drivers; the mechanics and effectiveness of that is beyond my technical knowledge. Is part of the problem the limited amount of material available that makes use of those cues?

 

[ROBSCIX]

Quote:

What do you mean by 5.1 headphones? The idea of 5 hardware drivers seems unnecessary to me; it seems unnecessarily expensive and difficult to design acoustically. My understanding is that we understand HRTF well enough to make it possible to reproduce the psycoacoustic cues for spatial awareness with two drivers; the mechanics and effectiveness of that is beyond my technical knowledge. Is part of the problem the limited amount of material available that makes use of those cues?

 Yes, so called "5.1" surround sound cans with built in front and rear drivers..etc.
 

 

[earerror]

5.1 headphones its just a name...

 

[ROBSCIX]

Quote:

5.1 headphones its just a name...

Yes we understand that.... 
Any insight into the technology you wuld like to add?

 

[12thgear]

I haven't heard any 5.1 multi-driver headphones that sounded any good to me. I imagine for them to truly sound good, they'd have to require, at a minimum two excellent, full-range drivers per ear, and that they would be rather enormous. I got to listen to Tritton's flagship AX Pro headphones head-to-head with their AX 720. To my ears, the positioning cues from the Pro weren't very realistic, and I found the sound to be extremely unbalanced. The 720, on the other hand, while not audiophile headphones, did sound a lot more balanced, and the Dolby Headphone processing worked well. 
 
I think it's a genuine engineering challenge to develop multi-driver headphones that deliver balanced sound from each speaker, and mix the positional cues in a smooth, coherent manner. Dolby themselves did most of the work in making, essentially, a low cost HRTF encoder. And good headphones already exist. Combine the two, and you have a respectable surround sound experience. 

 

[maverickronin]

There is no technical reason why great sounding "5.1" headphones couldn't be made, but there are plenty of economic and practical reasons. 
 
First of all you'd need at least four quality drivers.  That's not just expensive, it would make the headphones pretty huge as well.  Second, it would need some special hardware to work properly.  Even if you made a set that could play straight form speaker outputs, it would need some kind of filtering and/or processing network to play the center evenly over the front left and front right drivers, and play the LFE channel over all 4.  You could probably do that with an analog circuit, but I'd bet you'd need a proper DSP to make it sound acceptable, and using a DSP necessitates using line level input (analog, TOSLINK, or S/PDIF) and a custom amp.
 
After that, they would need some kind of very open enclosure (MDR-F1 style) to make it sound right by keeping all the phases aligned and keeping the drivers from fighting each other or something, and which probably won't be very sturdy unless its either heavy or expensive.  If you want any kind of isolation, it will likely take some serious black magic to deal with the above issues.
 
None of this is impossible, but if a company spent the time and effort to create a truly good "5.1" headphone it would be monstrously expensive and only usable with its own DSP/amp combo.  I'm picturing something as expensive as the JH3A + JH16, but not sounding any better then my SE530s, except for the surround sound.
 
There still might be a market for this, if it weren't for the fact that HRTFs already work so well.  It's already a well developed field.   With prices ranging from free to if you even have to ask you can't afford it.  Software, or hardware, they work with all the amps and 'phones you already own, or may buy in the future, so they are much more versatile, and don't leave you locked in.  There's little room in the market for something that costs more and doesn't work as well.  That's why most of the ones now sold are just cheap gimmicks.

 

[Ypoknons]

The think the problem is really with content. DH does a so-so job with HTRF imo, SVS Realiser is still expensive and Yamaha dropped their Smyth licensed YSV-1; never tried the Beyer Headzone or Silent Cinema technologies. The Pearl Harbor headphone encoded track is supposed to be really good too. Plus there's no reason why games can't do a better job with their headphone encoding either. 

 

[maverickronin]

Quote:

The think the problem is really with content. DH does a so-so job with HTRF imo, SVS Realiser is still expensive and Yamaha dropped their Smyth licensed YSV-1; never tried the Beyer Headzone or Silent Cinema technologies. The Pearl Harbor headphone encoded track is supposed to be really good too. Plus there's no reason why games can't do a better job with their headphone encoding either. 

That's only the hardware side of it though.  There are lots of cheaper software DSP options if you use a HTPC.  Creatives CMSS3D (I thinks that's what its called anyway) is supposed to be a lot better than the Dolby.  Too bad their drivers are a crapshoot.

 

[Edwood]

All those fad headphone companies trying to create "5.1" headphones with multiple drivers at different locations in the headphones are completely absurd.  A difference of 2-3 inches in placement does not make for convincing virtual speakers outside your head. 
 
Best free solution for music, would be Graphicism's Foobar plug in based on Dolby Headphone.
 
Best budget hardware solution which has DTS decoding, would be the JVC / Victor SU-DH1, which is also based on Dolby Headphone.
 
Best solution period is the Smyth Research SVS Realiser system.  Combined with a an excellent PRIR personlization captured at a top end studio set up, it is THE best I've ever heard.  Really wish the Realiser had existed before I dropped several thousand $$$$ into a speaker based home theater over the years.
 
-Ed

 

[12thgear]

 
Quote:

That's only the hardware side of it though.  There are lots of cheaper software DSP options if you use a HTPC.  Creatives CMSS3D (I thinks that's what its called anyway) is supposed to be a lot better than the Dolby.  Too bad their drivers are a crapshoot.

CMSS3D is pretty good, but in my limited experience I wouldn't say it's a lot better than Dolby Headphone. I'd love to hear a Realiser or Headzone though. I'm sure it'll make my Mixamp come across as the consumer junk it really is. That sounds a bit harsh. For the money I'm amazed the technology works as well as it does. 

 

[Edwood]

I also have the Astro A40 MixAmp.  It's implementation of Dolby Headphone is not as good as the JVC.Victor SU-DH1.  I found that using the SU-DH1 and outputting it to the analog input in the A40 MixAmp (with the MixAmp's Dolby Heapdhone Off) sounded better.  So you get better virtual surround sound with the headset mixing capabilities of the MixAmp with games.
 
It's a shame about the Yamaha YSV-1.  I would've bought one of those as well, even though I have Realiser, I'd like YSV-1 as a back up and travel system.
 
-Ed

 

[haloxt]

The different ultrasones I have all sound like surround sound speakers with different placement quirkiness, they don't use multiple speakers per channel but poke holes in the bufferboard and let sound come from different directions to different parts of the ear, so much of the same shortcomings of ultrasones are relevant for 5.1 headphones. And the headphones move with your head, which I think is counter to the perception of spatial data, and why SVS has a head movement tracker. The problem with ultrasone's surround sound attempt is that it is pretty crude, I think because of small headphone size and the need for a generalized HRTF, when individualized DSP like SVS would be preferable. And of course different recordings have different soundstages, so there's the need for DSP, multiple channel data on audio cd's, or some recording standard. The lead engineer at Ultrasone said speakers placed on the ceiling with surround sound DSP makes a very accurate soundstage, and I imagine any headphone with SVS software would do a better job than real 5.1 headphones or any iterations of ultrasone's single driver surround sound.
 
Lol I know the pfr-v1 isn't 5.1 or even surround sound, but they are really like stereo speakers. I can switch between speakers and headphone out with a button on my dac/headphone amp and the angle of sound is extremely similar. The company I'd trust to make non-software-based 5.1 headphones properly would be Sony. Not sure I'd buy though, I like sound coming from in front of me unless I'm playing a computer game where people can sneak up behind you.

 

[Ypoknons]

Quote:

That's only the hardware side of it though.  There are lots of cheaper software DSP options if you use a HTPC.  Creatives CMSS3D (I thinks that's what its called anyway) is supposed to be a lot better than the Dolby.  Too bad their drivers are a crapshoot.

Sorry, my post kind of wandered, it was late for me. What I meant is that there seems to be a dearth of headphone specific material out there mixed specifically to take advantage of HRTF and headphones, and this seems to me to be the biggest problem with headphone 'surround sound' today. If more music, movies tracks and games took advantage of these psycoacoustic cues, we wouldn't have to worry about all these solutions that downmix 5.1 ... but how good are these solutions anyways? How much room is there for improvement?