Yamaha RX-V657 processing modes

[MichaelJHuman]

I have to admit I am confused by the various processing modes on this RX. They appear to be similar to other current Yamaha receivers, so if you have a similar one you might have insights.

My question is how the modes work for using the back surrounds with Dolby Digital sources.

First, it appears you must toggle the extended surround to EX which uses the Dolby EX decoder. This uses the back surround speakers even on 5.1.

You can also use select (on the remote) to select PLIIx movie, etc. What if anything does that do?

Futhermore, you can select a DSP mode such as Sci-Fi.

How do these work together? Thanks

 

[MDS]

- The Dolby Digital-EX decoder can be used to extract a 6th channel from a 5.1 DD track and it can be used to decode a disc that was mastered with DD-EX. If the disc is DD 5.1 then it will be recognized as DD 5.1 and the Dolby Digital decoder will be used, so you have to manually select EX if that is what you want. If the disc is DD-EX it may or may not be flagged correctly so it may be recognized as DD-EX or it may not and you would have to again manually select DD-EX. Many receivers have menu options to specify whether it should always use DD-EX, only use it if the flag is detected or never use it.

- PLIIx Movie/Music/Game are matrix decoders to extract rear surround info from 5.1 or 6.1 discs. They also work on 2 channel (analog or digital sources). There are likely others on the receiver as well, such as Neo:6. You would use one of them to turn a 2 channel or 5.1/6.1 into 7.1.

- Sci-Fi et al are digital signal processing effects and work on a variety of source formats. I believe Yamaha lets you layer them on top of straight DD or DTS decoding. They all alter the sound in some way that may or may not be pleasant to you. The manual probably describes how they work. 'Stadium' (not sure if available on the Yamaha) for example trys to mimic the sound you would get if you were in a large stadium.

You can try them all and develop your own preference. Once the novelty of the DSP effects wears off, I predict you will never ever use them again and will stick to the straight DD/DTS decoders and use the Dolby matrix decoders like PLIIx to convert 2.0 or 5.1 formats to 7.1.

 

[MichaelJHuman]

If I hit extended surround button on the remote repeatedly, I scroll through the options:
Off
Auto
Dolby EX

If I select EX, then I hear sound from the back surrounds even when I play a standard 5.1 source (This is confusing to me based on what I read about EX on Dolby's own site.)

Anyway, I can then immediately (while EX: Dolby EX is displayed) hit the < or > button and scroll through another set of choices:
EXolby EX (Displays Dolby D EX after a few seconds)
PLIIxMovie:ON (Displays D+PLIIxMovie after a few seconds)
PLIIxMusic:ON (Displays D+PLIIxMusic after a few seconds)
EX/ESolby EX (Displays Dolby D EX after a few seconds)

So it looks like it can somehow use the EX decoder to playback a 5.1 source on all 6.1 channels. And I can also use the PLIIx decoder in conjunction with the EX decoder. I am trying to understand how these decoders work together.

 

[MDS]

Yes, as I said you can use the DD-EX decoder to playback 5.1 over 6.1 channels. If that receiver were THX certified you could use the THX surround mode to do the same (DD-EX is the consumer equivalent of THX-EX). The off, on, and auto options are as I described before. Usually you can set these once in the setup menus but it sound like the Yamaha lets you set them on the fly as well and that is good as it adds flexibility.

PLII and PLIIx are not related to DD-EX. If you keep scrolling until you see PLIIx you would be using that decoder and not the DD-EX decoder. The receiver will only show you the modes that are applicable to the source so for example it will not show DTS:Neo6 if the source is DD 5.1 - it only shows PLIIx.

Honestly this is one of my pet peeves about modern receivers. There are so many surround modes and people invariably ask 'which should I use?'. The flip answer is try them all and see what you prefer. For what it's worth I use PLII Music (not PLIIx - I only have 5.1 speakers). If the source is DD 5.1, I use the straight DD decoder; if it is anything other than 5.1 (like DD 2.0), I use PLII Music. The reason I prefer PLII Music to PLII Movie is that it allows you to change certain parameters (Center Width, Dimension, and Panorama) whereas PLII Movie does not.

 

[Snap]

I find that for movies, I just set it to Surround Sound Standard. I also 99% of the time use 5.1 set ups. So the 6.1 extraction is not needed. Personally I find that anything other than the standard, adds to much effects to the tracks. I personally don't like the sound of the effects. But that is just me.

MDS, Great job on explaining the different modes.