Dolby Headphone progress?  

Your jack will work like any jack--i.e., a 2-channel analog downconversion of the material you're listening to. Now, there are external DSP products that will reconstruct a pseudo-Pro-Logic effect from that, but Dolby Headphone has nothing to do with any of that.

Dolby Headphone must be incorporated in the player at a stage before the headphone jack. There are currently no Dolby Headphone-equipped players on the market to my knowledge.

Hope this helps,
Philip Brandes

John,

When you mentioned the jack on your "Philips" (without identifying which Philips product you were talking about) I assumed you were talking about a Philips DVD player with a typical headphone output. In any case, the jack on your RPTV is not a headphone jack, it is designed for passing a broadcast signal in digital PCM form to a pre/pro for Pro-Logic decoding. This still has nothing to with Dolby Headphone, which only operates on a 5.1 Dolby Digital bitstream, not the Dolby Surround PCM signal output from your RPTV.

Thank you for the reference to your previous thread. I am quite familiar with the technology, having reported on it as part of SMR Forums' coverage of CES 2000 and the more recent AES Convention. As I mentioned before, Dolby Headphone is not currently being positioned or marketed for external decoder box applications. It is being implemented in DVD players, to process the digital audio signal as it is read from the disc. Whether or not it may be theoretically possible to use it in combination with other digital sources isn't clear, but it is irrelevant as there are no plans that I know of to bring that capability to market. That isn't to say that might not change, but I wouldn't hold my breath. And in any case, there will never be a way to get Dolby Headphone to work with your RPTV's digital out unless it carries a Dolby Digital bitstream.

Cheers,
Philip Brandes

[This message has been edited by Philip Brandes (edited 01-14-2001).]

If you use one of the digital outs on a dvd player, I think it would be very easy to implement an external DH decoder.

I have played around with the DH functionality in windvd and powerdvd on my computer. The produced 2 (DH decoded) channel audio was sent trough a high end audio delta 1010 sound card with external DA converters, into a class A headphone amp matched with my sennheiser electrostatic headphones.

I think the perception of the sound is very individual. I can't say that I'm impressed at all with DH!
However, I had the same experience with a Sennheiser Lucas prologic decoder a couple of years back. My friend (who bought it from me) though it was fantastic, and I could hardly hear any surround at all.




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Dolby Headphone uses a 5.1 digital source, so it must be implemented directly in the player, and this is the implementation strategy Dolby is pursuing (especially in applications like portable DVD players and airline systems). There will never be an external "adaptor" for it.

Cheers,
Philip Brandes

You're right it can be done if you're sufficiently technically minded...my comments were about commercial products.


That's a whole other issue--whether it's worth the trouble! My own experience with DH has been decidedly mixed. I have been able to get a convincing sense of the rear channels set farther back. However, I have never heard a completely satisfying front soundstage--it's more like the usual headphone effect of sounds directly from the sides and from the center of the head. At AES, the Lake T. guys told me that it takes a little getting used to and you need to just relax and not force it. This seemed to work a little--I eventually got the fronts to extend up about 1/2 way, but never fully to the front.

Other folks claim better success with it, so I think you're right about there being a lot of individual variance.

Cheers,
Philip Brandes

It takes a good deal of procesing to to Dolby Headphone properly, and as observed, the results will vary person to person. It works quite well for me, but then I am especially interested in spatiallity. Contrary to popular belief, Buzz does not have to do with space shots (Buzz Aldrin nor drugs) and Goddard in this case is not a Space Flight Center. It's all about spatiality, my specialty.
Seriously, I actually can get a nice front image and quite a bit of height. But it does take some learning. And relaxing does indeeed help...

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Buzz Goddard
TAG Mclaren Audio

I've only heard Dolby Headphone on Singapore Airlines, and with that environment and those headphones I honestly cannot see why they bother.

Peter M

P.S. DH was developed by a small Aussie company which licensed the technology to Dolby.

Actually, that isn't quite right. Dolby Labs has already determined that Dolby Headphone technology is compatible with Pro Logic 2, in addition to 5.1 of course, so the possibility exists of future external adaptors finding their way to the market place or the technology being implemented in low-cost CD and 'Walkman' types of source equipment.

Charles Wood
Fosgate Audionics
Rockford Corporation

Interesting info about PLII compatibility, Charles. But the only implementations of DH so far have been for DVD playback, in the context previously discusses. is Dolby actively promoting development of products along the lines you suggest, or is this just a future possibility? Even if they're starting to plug it now, it will take some time to get it into the market. I just wouldn't expect to see products anytime soon.

Cheers,
Philip Brandes

I've heard the word 'possibilities' expressed as regarding the use of Dolby headphone technology in conjunction with PL2. You are correct in that it won't happen soon...certainly until full DSP solutions exist to reduce hardware/circuit board real estate and costs. Like you, I would imagine any potential products are some a year to two away from reality.

Charles Wood
Fosgate Audionics

John,

The only good use of a 486 these days are as firewalls.
- I can't belive how much I paid for my old 486 http://www.avsforum.com/ubb/frown.gif



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