[Greg Farris]

Anyone here have much experience with this?

I know, Dolby E is not meant to be a presentation format - it's a
transport format for post-production, the greatest interest being you can
transport a full 5.1 (or even 7.1) bitstream on a single AES-3 pair,
through one BNC connector.

But as HDCAM production increases, I am seeing more and more screening
rooms and auditoria presenting Dolby E from HDCAM cassettes, and I'm
wondering what is the best quality method to get the 5.1 sound to the 'B'
chain :

1) Decode the Dolby E bitstream with a DP572, then send the three AES
streams to a DP570, to use the analog monitoring output. Send the analog
signals to the External 6-track input of the Cinema processor CP500 or
CP650.

2) Decode with the DP572, then convert to a Dolby Digital bitstream, to
use the Dolby Digital input of the CP500 or CP650 (5.1 encoding may
induce delay).

3) Some are advocating decoding with a DP572, and sending the three AES
streams directly to digital inputs of a Yamaha DME 24 (or32/64) then
directly to the B chain

Anyone doing this type of decoding for presentation on a daily basis, or
have a clear opinion on which architectuire will provide the best quality
result for playback?

Thanks,
G Faris

[Scott Dorsey]

Greg Farris wrote:
But as HDCAM production increases, I am seeing more and more screening
rooms and auditoria presenting Dolby E from HDCAM cassettes, and I'm
wondering what is the best quality method to get the 5.1 sound to the 'B'
chain :

1) Decode the Dolby E bitstream with a DP572, then send the three AES
streams to a DP570, to use the analog monitoring output. Send the analog
signals to the External 6-track input of the Cinema processor CP500 or
CP650.

This would probably be my first choice. The limiting factor is the converter
in the DP570. I believe Dolby makes a box with Dolby E in and out and
analogue ins and outs on the other side as well.

2) Decode with the DP572, then convert to a Dolby Digital bitstream, to
use the Dolby Digital input of the CP500 or CP650 (5.1 encoding may
induce delay).

Delay, plus you're transcoding. Dolby E is generally designed for clean
transcoding to AC3, but why do it if you don't have to? This would seem
the worst of all the alternatives.

3) Some are advocating decoding with a DP572, and sending the three AES
streams directly to digital inputs of a Yamaha DME 24 (or32/64) then
directly to the B chain

This would be a good thing if the converters in the DME 24 (or what have you)
are better than the converters in the DP570. I can't say for sure so you
will probably need a listening test. But there are plenty of ADC boxes out
there with AES/EBU inputs that sound excellent.

Anyone doing this type of decoding for presentation on a daily basis, or
have a clear opinion on which architectuire will provide the best quality
result for playback?

I have experienced the problem once at a film festival that I work, and
the solution we came up with involved using a couple handy DAT machines
as converters and ignoring the surround channels entirely. We probably
could have come up with something better if we'd have been warned the day
before the showing....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."