Setup menu options for receiver

Balfa

I have a mouldy-cheap Amphion Mediaworks T352 DVD player/surround receiver, and there are a couple of menu options on it that confuse me. Needless to say, the manual that came with it is truly awful so I'm wondering if anyone here can cast light on these options, what they do, and how they should be set? I'm aware that changing any of them will probably result in less than optimum performance, but i'm more curious than anthing else.

I will give the menu item and the available options to set it to.

Speaker Setup menu
-Downmix [Lt/Rt, Stereo, V Surr, Off]
-Post Drc [On, Off, Auto]

Dolby Digital Setup menu
-Dual Mono (1 + 1) Setup [Stereo, L-Mono, R-Mono, Mix-Mono]
-Dynamic Range Compression [sliding scale from "off" to "full"]

Pro Logic II Config menu
-Pro Logic II [On, Off, Auto] (i know what this is. just wondering why there's an "auto")
-Mode [Music, Movie, Pro Logic, Auto] (again, i know that DPLII offers a music and movie mode, but what are the other two options about??)


Thanks in advance. By the way, this is the cruddiest piece of crud ever built. Don't ever consider buying one. I'm just trying to make the best of what I've got, and it was only $70 including 6 speakers

robbie1876

Ok, I'll have a go at some of these.

-Downmix [Lt/Rt, Stereo, V Surr, Off]
Downmix is for the analog RCA outputs. DVDs are recorded in 5.1 digital audio, but the analog outputs are just stereo. So this option asks you what you want to do with the 5.1 channels of digital audio. Lt/Rt will output just the left and right channels of the 5.1 mix through the audio output. Stereo probably mixes all channels including the centre and sub into a stereo feed. This is what the option should be set to imo.

-Post Drc [On, Off, Auto]
I have no idea what this is. Does changing the setting have any effect on the sound?

-Dual Mono (1 + 1) Setup [Stereo, L-Mono, R-Mono, Mix-Mono]
Not sure on this one either. I would guess its to with how the amp should handle mono sources, so I wouldnt worry about it

-Dynamic Range Compression [sliding scale from "off" to "full"]
This is a handy one. Have you noticed that the dynamics of a DVD can vary considerably? For example, you could be watching a movie and there is a very quiet scene with little or no dialogue, and the next scene could be something exploding, which can be very loud. Dynamic Range Compression reduces the volume differences in movies. Quiet scenes are louder and louder scenes are quieter. This is very useful if you are watching a movie late at night and have to keeep the volume low. Without the compression on, you'd set the volume so you can hear the dialogue, but then when the loud bits come along you wake everyone up. Compression smooths the volume out for you. Don't use any compression when you are normally watching movies and don't have to worry about volume.

-Pro Logic II [On, Off, Auto] (i know what this is. just wondering why there's an "auto")
I wouldn't trust the amp to decide when to use PLII or not, so I'd leave this on 'On'

-Mode [Music, Movie, Pro Logic, Auto] (again, i know that DPLII offers a music and movie mode, but what are the other two options about??)
Pro Logic must be the old Pro Logic I, which is crap, I wouldn't use it. Again, I wouldn't trust the amp to pick between Music and Movie for you, so do it yourself when required.

Hope some of that helps.

Robbie

Balfa

Thanks. That's been really helpful. The manual says post drc "is selected to adjust post dynamic range compression to obtain different compression results", so i guess i'll try it tonight when i'm watching something quietly with DRC turned up full


Also, is there any way to know for sure when DPLII is in use? Because i have stereo RCA connectors from PS2 to DVD/receiver, and I tested some games, some of which are supposed to support DPLII and some of which aren't, and in all games, there was sound coming out of the rear speakers :O


edit: this is just an amateurish guess, but was there sound coming out of the rear speakers because the DPLII decoder will do its matrixing maths on the stereo channels, and come up with some probably weird results for what the rear speakers should output, regardless of whether the source is intended to be DPLII or not? So I have to manually turn off DPLII when i'm playing a non DPLII source, or else leave it on auto and hope the receiver can figure it out?

2nd edit: Similarly, i would have to choose "Pro Logic" when i'm watching a (urgh) Pro Logic I source or else the results will be pretty weird?

lensman

as you said you have the 6 speaker kit connected to this amp you should
only change one of the settings you mentioned and that's the first one,..
set "downmix" to OFF, this allows the correct sounds to go to each of the six
speakers giving the proper surround effect when your playing a dvd.

robbie1876

lensman wrote:

as you said you have the 6 speaker kit connected to this amp you should
only change one of the settings you mentioned and that's the first one,..
set "downmix" to OFF, this allows the correct sounds to go to each of the six
speakers giving the proper surround effect when your playing a dvd.

No, the downmix doesn't affect what gets sent to the speakers, only to the stereo line level outputs. Setting it to 'OFF' shouldn't make any difference to the speaker sound, if it does I'll eat my hat!

Balfa wrote:

edit: this is just an amateurish guess, but was there sound coming out of the rear speakers because the DPLII decoder will do its matrixing maths on the stereo channels, and come up with some probably weird results for what the rear speakers should output, regardless of whether the source is intended to be DPLII or not? So I have to manually turn off DPLII when i'm playing a non DPLII source, or else leave it on auto and hope the receiver can figure it out?

You are absolutely correct, DPLII is just an algorithm and works on any source, be it pro logic encoded or not. On stereo CDs it tends to pick out the vocals for the centre channels, and things like strings and ambient guitars get sent to the rear channels. Quite clever really. And yes, I'd leave it on auto and let it do its magic, but it's whatever your preference is I guess.

Balfa wrote:

2nd edit: Similarly, i would have to choose "Pro Logic" when i'm watching a (urgh) Pro Logic I source or else the results will be pretty weird?

AFAIK, the DPLII algorithm will happily decode the old pro logic signal and then put its cherry on top of that, enhancing the original signal and creating '5.1' type effects.

My (admittedly limited) understanding of the old pro logic is that within the audio spectrum of 20Hz to 20KHz, the rear channels were hidden in a very specific frequency range. This is why there was never much action going on through the rear channels with the old pro logic system, because there wasn't much sound there in the first place. The centre channel was created by analysing the left and right channels and whatever was common got sent to the centre.

In a DPLII system, the entire frequency range is analysed by the algorithm and it picks out what it thinks should be sent to each speaker, usually with amazingly good results. Thus the rear channels aren't limited to the odd blip and squeak now and then, but tend to be sent quite full range signals from the DPLII processor.

That's my understanding of it, but I haven't researched the way it works as such, so am open to correction here.

Robbie

lensman

I was assumning that the unit was a dvd/amp combination ? 1 box with 6 spkrs
hanging off it,
I have used 3 dvd playrers over the years which I connected by phone plugs to a seperate amp and 6 speakers, every dvd player I had was setup with "downmix" off ....if not I did'nt get the full 6 channel effect from a dvd movie,
I also had dvd conected via scart to my TV which did not have sound when the audio output from the dvd was setup in this way, in order to have sound to the TV I had to set the audio up as "downmix" on and "L+R" on or "stereo" on, but
this setup disabled AC3/dolby digital 6 channel sound.
My amp is a seprate unit, 6 channel amp ( not a reciever/decoder) I always leave the sound decoding to the dvd player.