DVD Recorder Encoding only 2 Channel Stereo?

[svoltmer]

I bought a Panasonic DMR-ES10 DVD Recorder and when I record from my satellite receiver box the recorded audio will not seperate artifically into 5.1 channels (ie; CS 5.1 or Dolby pro-logic) it only plays as a 2 channel stereo output. Why is this and are there any recorders that will record the audio signal correctly?

I am aware that you will only get the same analog signal that you put into it, but it's not even giving me that.

[trhouse]

The ES10 can only record Dolby Digital, 2 channel. It is in the specifications at the back of the manual. I do not know of a unit that can do 5.1.

[smearbrick1]

Does your satellite receiver even have 5.1 outputs? Does you DVD recorder have 5.1 inputs or a optical in? All good questions... without any of these (including a coaxial digital input) 5.1 is a no go... of course, it doesn't help that your dvd recorder doesn't support 5.1 recording.

[Epicurus8a]

I do not know of a unit that can do 5.1.

Agree with above.

[ntscuser]

The Panasonic records a 2-channel stereo signal without affecting it in any way except for varying the bitrate. A 2-channel stereo input encoded with Dolby surround or similar should be capable of being recorded by the Panasonic and played back on any surround receiver.

2-channel Dolby requires a minimum bitrate of 192 Kb/s in order to preserve the surround information. If the bitrate falls below 192 Kb/s for any reason - such as making too long a recording - the surround information will be lost. As a general rule, EP should never be used for making surround sound recordings.

This can also happen if the satellite channel uses too much signal compression or if the analogue outputs on the satellite receiver are set for front left+right instead of matrixed left+right which is possible with some 5.1 receivers.

[trhouse]

ntscuser is correct. The Panasonic manual says "Dolby Digital, 2 ch" but the Panasonic USA web site says

"Dolby Digital® (Dolby AC-3) 2ch Audio Recording Yes"

and Dolby Labs says,

"Dolby Digital (AC-3)
Surround sound technology that delivers high-quality digital audio for up to 5.1 discrete channels (Left/Center/Right/Left surround/Right surround/Low-Frequency Effects). The five speaker channels produce a directional and more realistic effect and the Low- Frequency Effects (LFE) channel (usually reproduced through a subwoofer) can often be felt as well as heard. Found in: DVDs; DVD players; broadcast programming in HDTV, digital cable, and (DBS, DTH) direct broadcast satellite (DirecTV/Dish/Sky TV); PCs; Microsoft Xbox game consoles; digital TVs; automotive DVD-Audio/Video players; automotive video, networking and home audio/video receivers; film soundtracks encoded in Dolby Digital."

It takes the right decoder to recreate the five channels from the two.

[smearbrick1]

It takes the right decoder to recreate the five channels from the two

The right decoder will not create 5.1 DD from a 2ch DD signal. The original signal is only 2 channels... 5.1 is 6 channels... it's not going to happen. The best that you can hope for is 2 channel DD (as is the input signal) or Dolby Pro-Logic Surround (which is basically 2ch audio that is left as 2ch audio only is also mixed into a mono signal for surround). Pro-logic does not make 6 discreet channels from 2.

You can make 2ch from 5.1 DD (through downmixing), but not the other way around.

[svoltmer]

When I watch TV from my Dish Box piped through my Kenwood Surround amplifier it has a kind of simulated surround similar to Dolby pro logic called SRS CS5.1. This produces a really full simulated 5.1 speaker surround sound. But if I record a program from the Dish receiver and play it back through that same Kenwood amplifier it will not allow the SRS CS5.1 sound as an option. This is really a deal breaker for me. So I think I will have to take it back. Is there a better recorder that will do what I want?

[Frobozz]

svoltmer,
How do you have the audio connected from the DVD recorder to the Kenwood? If it is via the digital audio conections then that may be the reason the Kenwood can't apply the SRS. The Kenwood may only be able to apply SRS to analog audio input. If that is the case, then I'd connect the audio from the recorder both ways. When I'm playing a commercial DVD with 5.1 audio I'd set the Kenwood for the digital input and when playing regular video from the recorder I'd use the analog input with SRS enhancement.

[trhouse]

svoltmer,

The reason for the problem is that SRS is not a Dolby product.

"CS5.1 stands for Circle Surround 5.1 and is licensed from SRS Labs. (You might recall SRS from their WOW Thing.) CS5.1 is another matrix system, which means that it derives six channels of sound from a two-channel source"

I doubt you can find a recorder for it, but the above quote came from a Kenwood review so some of their products can decode it like the one you seem to have.

P.S. CS has similarities to Dolby Prologic which is also a matrixed analog system. In theory, one could encode a Dolby Digital datastream with 5.1 channels and decode to a CS signal, just as Dolby's figure above shows Dolby Digital can be decoded to a Prologic signal.

In my second comment, I confused the matrixed Dolby Prologic with the new Dolby Digital. Dolby Digital is a single datastream which can be encoded with up to 5.1 channels of data but if the ES10 says two, then I would have to say the Dolby Digital datastream is only encoded with two channels.

[ntscuser]

If the Kenwood can decode 6-channel Circle Surround from a 2-channel source, it should be able to decode it from a recording made on the Panasonic. Try setting the Dolby Digital output from Bitstream to PCM as I read it can cause problems with some CS decoders.

[trhouse]

ntscuser,

The problem is that the two channel output of the ES10 must contain the matrixed six channel information, but the ES10 only records two channels to begin with so even if a decoder were available to create a matrixed six channel CS signal, there is still only data for two channels.

P.S. You are probably thinking that the recorder retains the matrixed six channel data, but I suspect that when the analog CS two channel signal goes into the ES10 and is converted to the Dolby Digital, two channel signal, that the four matrixed channel data is lost.

[ntscuser]

Circle Surround creates a quasi 6-channel effect from any 2-channel source. The satellite receiver outputs 2-channels. The Panasonic records and plays back 2-channels. The Kenwood converts the 2-channels to Circle Surround.

Latent surround information is only lost if the bitrate falls below 192Kb/s which ony happens on the longest record setting of the Panasonic.

[trhouse]

"The satellite receiver outputs 2-channels."

This is a two channel, matrixed analog signal

"The Panasonic records and plays back 2-channels."

It changes the two matrixed, analog channels to a single Dolby Digital datastream encoded with only two channels. Why would they ever encode 5.1 channels to the datastream if two could contain the same information?

"The Kenwood converts the 2-channels to Circle Surround. "

The two channels form the ES10 have no longer have the matrixed analog information.

[ntscuser]

The satellite channel also encodes matrixed surround to a single Dolby Digital bitstream. The Kenwood is able to decode this to a quasi 5.1 channel Circle Surround or 4.0 Dolby Surround. There is no reason why it should not also be able decode the same signal recorded and played back on the Panasonic.

Circle Surround and Dolby can extract surround information from almost any 2-channel source. It does not have to be encoded in any particular system. Some satellite channels enhance the signal for Dolby or Circle Surround playback but that does not change the essentially 2-channel nature of the signal.

Dolby Digital 5.1 uses 6-channels of discrete audio information which cannot be encoded on a bitstream of less than 384 Kb/s and is seldom used by any satellite channel.

If you read the original post you will see that the Kenwood is not even able to extract Dolby Surround from the output of the Panasonic which suggests it is reading the bitstream as front left + front right Dolby Digital stereo.

[trhouse]

If the satellite signal sent directly to the Kenwood is recognized as SRS CS5.1 how is Dolby involved?

P.S. Both CS and ProLogic are analog, matrixed systems. It is the conversion from analog to the datastream that cannot support the matrixed signals so they are lost. The only way it could be done is if the reccorder did like the Kenwood and decodes the CS signal into six channels, then the Dolby Digital encode could contain 5.1 channels. This is how the Dolby diagram above shows a down-mixed ProLogic signal being created. They could do that with CS too if the decoder were available. The Dolby Prologic matrixed signals are lost for the same reason. The Panasonic cannot encode a 5.1 channel signal however

[ntscuser]

"If the satellite signal sent directly to the Kenwood is recognized as SRS CS5.1 how is Dolby involved? "

The Kenwood can create a Circle Surround or Dolby Surround effect from almost any 2-channel source. It does not have to be specifically encoded that way.

The Panasonic encodes stereo signals with a nominal bitrate of 320Kb/s which is more than sufficient to preserve the latent surround information present in any 2-channel source whether specifically encoded for surround playback or not.

The only way surround information would be lost is if the stereo signal supplied to the Panasonic had already been decoded to front left + front right or if the Kenwood mistook a bitstream output from the Panasonic as being front left + front right.

[svoltmer]

I have both the Optical and the Analog inputs from the DVDR to the Kenwood because I suspected that information for the simulated 5.1 SRS was being lost in the bitstream conversion. It seems to work, but not as well as if the audio were run directly into the Kenwood, but for $190, I guess I should be good. Thanks for your help everyone! God Bless!