Can Rotel's receivers handle the new audio codecs?

[davewolfs]

Hey folks,

I am new to audio am looking at Rotel and am trying to understand if/how the current receivers (RSX-1067, RSX-1057) can handle any of the new codecs:

Dolby Digital Plus
Dolby TrueHD
DTS-HD High Resolution Audio
DTS-HD Master Audio.

It is my understanding that these are outputted from current HD players over LPCM.

With that said, can any of rotels players handle these audio formats? I saw some posts mentioning a Zektor product, but I am unsure where this product falls into the equation. A simple and thorough explanation would be GREATLY appreciated.

Thanks,

Dave

[hifiguymi]

The short answer is no, but there are a couple of things you touch on here.

1. Rotel does not have a product that will decode the new surround formats you listed. The RSX-1067 does not have HDMI on it at all and the RSX-1057 will only switch video with it's HDMI inputs. The RSX-1057 still requires a separate audio connection for any source using HDMI. Both receivers have multi-channel analog inputs so you can connect a source, using six analog cables (like a Blu-ray Disc or HD-DVD player) that has a decoder built in to it.

2. You are correct that current players (BD and HD-DVD) send audio out of the HDMI outputs in LPCM. To do that the players decode the DD+, dtsHD, etc internally and convert it to LPCM to send to a receiver. Since that is the case you don't need to have the decoding in the receiver. You just need a receiver that will support audio from the HDMI inputs like the upcoming RSX-1058. There are receivers that are just now becoming available that will decode DD+, dtsHD, etc, but there is not a player that will output those signals as of right now. I'm sure it will happen, but that is the current state of those players.

3. The Zektor piece you mention is a switcher that will allow someone with multiple sources with 5.1 channel analog outputs to be hooked up to a receiver or preamp with only one multi-channel input (which is most if not all of them). I believe it also switches HDMI as well. It does not decode any audio but I'm sure it switches it just like the video.

I hope this helps.

Eric

[davewolfs]

Thank you for the reply Eric.

So suppose I am using a Zektor device, or feed the receiver through analog audio inputs. What exactly is being sent from say a HD or BR player that has analog outs?

Is this information still LPCM, or is this analog audio information?

Whatever it is that is being sent from the analog outs, how will the receiver process it? And in turn, how will this sound quality compare to something that is capable of handling digital LPCM input?

Dave

[Blindamood]

When you use the analog outputs, the player itself does the processing, not the Rotel. So, whatever audio format you select (e.g., Uncompressed PCM, Dolby TrueHD, etc.) the player will decode and just send the resulting PCM (analog audio).

How this compares to a receiver or processor doing the decoding depends on many factors. For example, which one has the better DACs, bass management, etc. Many of the current HD players to not have comprehensive settings for bass management, speaker distance, etc. However, the sound quality can still be a substantial improvement over what you're used to hearing from standard Dolby Digital and DTS.

I am one of those who is currently using a Zektor switch from my Sony blu-ray player (and DVD-A/SACD player), sending the output to my Rotel RSP-1068. I'm very happy with what I'm hearing from my system, and see no reason to upgrade to a newer receiver/processor.

[hifiguymi]

Brad is spot on. If you use the analog outputs on the player the receiver does nothing to the signal except amplify it. All processing is bypassed when you use the multi-channel inputs.

Eric

[davewolfs]

I have heard that certain channels have to be amplified more then others depending on the type of PCM stream. Do you have control over this?

Also, what exactly is PCM? Sorry for my ignorance, but I am new to this and am trying to understand the basic principles of how this stuff works.

[Blindamood]

Also, what exactly is PCM?

More than you ever wanted to know...
Wiki - PCM

[hifiguymi]

I have heard that certain channels have to be amplified more then others depending on the type of PCM stream. Do you have control over this?

DD tracks are 6 dB softer than stereo PCM tracks. That maybe what you've heard reference to.

Also, what exactly is PCM? Sorry for my ignorance, but I am new to this and am trying to understand the basic principles of how this stuff works.

PCM stands for Pulse Code Modulation. It's the encode/decode that was developed by Denon for stereo audio signals. That is what digital recording and CD's have used all along.

Eric

[davewolfs]

So really it doesn't matter if PCM is sent over a analog or digital cord, as long as your receiver knows what to do with it you are good.

How much control do you have over the independent channels with the Rotel Receivers?

[PewterTA]

If you are using the multichannel input, then you really have very little control as those are more a 'bypass' than any real adjustments made. The only thing the pre/pro will control is the volume.

[davewolfs]

If you are using the multichannel input, then you really have very little control as those are more a 'bypass' than any real adjustments made. The only thing the pre/pro will control is the volume.

Got it!

So in terms of how things should sound, will this be any different from a receiver that takes an LPCM signal over HDMI, does its processing and outputs it vs the direct plugin audio route?

I am guessing yes.

[davewolfs]

Got it!

So in terms of how things should sound, will this be any different from a receiver that takes an LPCM signal over HDMI, does its processing and outputs it vs the direct plugin audio route?

I am guessing yes.

Anyone?

[hifiguymi]

Got it!

So in terms of how things should sound, will this be any different from a receiver that takes an LPCM signal over HDMI, does its processing and outputs it vs the direct plugin audio route?

I am guessing yes.

I depends on the quality of the DAC's in the player vs what would be in a receiver. Also how well the decoding is done in the player vs a receiver. The only way to know would be to try it with a receiver that had audio support for HDMI and compare it to the multi-channel output of the player. Since the only Rotel receiver that will do it is the RSX-1058, we don't know what performance will be like since they haven't shipped yet. :M :M :M

Eric

[davewolfs]

I depends on the quality of the DAC's in the player vs what would be in a receiver. Also how well the decoding is done in the player vs a receiver. The only way to know would be to try it with a receiver that had audio support for HDMI and compare it to the multi-channel output of the player. Since the only Rotel receiver that will do it is the RSX-1058, we don't know what performance will be like since they haven't shipped yet. :M :M :M

Eric

I don't think there is even a player right now that will send the raw stream. All players do the decoding.

I am still confused on the subject, with regards to timings etc...What part of the equation handles this?

[davewolfs]

I depends on the quality of the DAC's in the player vs what would be in a receiver. Also how well the decoding is done in the player vs a receiver. The only way to know would be to try it with a receiver that had audio support for HDMI and compare it to the multi-channel output of the player. Since the only Rotel receiver that will do it is the RSX-1058, we don't know what performance will be like since they haven't shipped yet. :M :M :M

Eric

Didn't they announce that receiver a while ago?!?

[hifiguymi]

Yes they announced the RSX-1058 a while ago. Rotel has them in the warehouse but there was a software update all of the receivers needed so they are finishing that process up right now. As soon as that it done, they will start shipping them.

Currently all players decode the DD+ and dtsHD internally and output the signal as uncompressed PCM tracks. All that is needed is a receiver, or preamp, that will decode PCM audio from the HDMI inputs. The RSX-1057 will not do that, but the RSX-1058 will from Rotel's lineup.

I'm not sure what you mean by timings. Could you clarify that?

Eric

[davewolfs]

Not sure what I mean either

It was based on another thread in another forum. But here is the quote:

BEGIN

Quote:
Originally Posted by pepar
what processing is left to do by the AVR/pre-pro if the player has decoded the codec?
Bass management, time alignment, surround processing, room correction, D/A conversion, etc. These are usually better done in a receiver or pre-pro (more crossover choices, finer distance settings). But decoding will be the same in both.

END

So what are they referring to by surround processing, time alignment, bass management etc...? Can the Rotel receiver do this with analog inputs from the player?

Another thing that I read is that there is supposed to be a +10 gain for the LFE /.1/ Sub channel. What does this mean? Can I control this?

[davewolfs]

Anyone?

[Blindamood]

So what are they referring to by surround processing, time alignment, bass management etc...? Can the Rotel receiver do this with analog inputs from the player?

Basically, no. As stated previously, the player is responsible for this when sending over the analog outputs. The only thing the Rotel can do is what they call 'LFE Redirect', where it sums the bass from all channels and sends to the sub, to provide additional bass reinforcement. The user manual (on the Rotel web site) can provide a more thorough explanation.

[hifiguymi]

When a digital signal is sent into a receiver or preamp, it does all of the time alignment (correcting for different speaker distances to the listening position), bass management (setting of speaker size, crossover frequency for the speakers and sub, subwoofer distance to the listening position, maximum sub output), post processing (lip sync, THX if applicable, etc), room correction - if applicable (eq for each speaker in the room), and digital to analog conversion. Most or all of these things are either done poorly in a player or not at all. If you have a multi-channel analog connection, all the receiver does is volume and nothing else.

Eric

[davewolfs]

When a digital signal is sent into a receiver or preamp, it does all of the time alignment (correcting for different speaker distances to the listening position), bass management (setting of speaker size, crossover frequency for the speakers and sub, subwoofer distance to the listening position, maximum sub output), post processing (lip sync, THX if applicable, etc), room correction - if applicable (eq for each speaker in the room), and digital to analog conversion. Most or all of these things are either done poorly in a player or not at all. If you have a multi-channel analog connection, all the receiver does is volume and nothing else.

Eric

Can you clarify on what you mean by digital signal.

Is this the actual raw and non-decoded data from a HD DVD that no player is currently outputting or is this the Decoded stream sent over a digital line i.e. HDMI using LPCM?

Assuming that it is LPCM over HDMI, when the RSX-1058 DOES come out, I am guessing it will be able to do what you state above.

[hifiguymi]

Yes. There are somethings like THX and room correction that are not features of the RSX-1058, but yes.

Eric