When I first got my 950, Dolby Digital 2.0 broadcasts were processed as stereo--left and right sound only. Recently, all of my 2.0 signals have been processed with some form of pro logic steering (IE--sound mostly from center speaker with some sound from L,R and surrounds), even when the display clearly says "Dolby Digital" and not PLII or PL. This happens with the digital output from both my cable box and my DVD player. Neither a soft nor a hard reset changed the functioning.

Is this normal? Is the 950 supposed to default to pro logic in Dolby Digital mode if it encounters a 2.0 signal? If I switch to "stereo", the signal is processed as a true 2.0 signal. It's just when the display says "dolby digital" that it reverts to a center-channel playback.

I know this is different than when I got the unit, but I don't know why. Any ideas?

It's been a while since since I went through the initial setup on a 950, so I don't recall what the defaults tend to be for stereo processing on each input. This is normal if you tinkered with the surround processing settings at some point to enable some surround processing on a stereo broadcast. The 950 remembers what setting you used last for different signal formats on each input: I have Dolby 2.0 default to Pro Logic II with CES on the DVD input and I have any stereo signal (Dolby 2.0, PCM, or analog) default to Pro Logic II with CES on the cable box input. Keep in mind that there is not a digital audio format that is "Pro Logic" or "Pro Logic II" so you won't ever see them listed when the 950 is acquiring a digital signal. Pro Logic was a processing mode for stereo analog audio, and was most effective when that stereo signal had been set up with Pro Logic in mind. Pro Logic II is an improvement on it. It can be applied to any two channel signal, including Dolby Digital 2.0.

Right, that I understand. It's just confusing that it doesn't SAY what type of decoding it is using. Just "Dolby Digital".

I imagine from what you're saying that if I switch it to stereo during a DD 2.0 broadcast, then tune to a 5.1 station, then tune back to a 2.0 station, it will be broadcast in stereo. I'll try that out. Thanks!

Edit: Actually, that didn't work. Here's what happened. If I change the cable to a DD 2.0 channel, and switch to "stereo", it's 2 channel. Then when I switch back to a DD 5.1 channel, it still says "stereo"! It doesn't automatically go into DD mode, and just broadcasts left and right channels. But if I go to a DD 2.0 broadcast and choose PLII-C, then switch back to a DD 5.1 broadcast, the display says "dolby digital" and I get 5.1 sound. Then if I switch back to a 2.0 channel the display says "dolby digital", but despite there only being 2 channels of sound it's decoding it like a PLII-C (I imagine), broadcast.

That is, it does seem to be remembering, but only between PL and Dolby Digital, not between "stereo" and Dolby Digital. And it only just started doing this.

Seems odd.

poffypoffa,

>"Right, that I understand. It's just confusing >that it doesn't SAY what type of decoding it is >using. Just "Dolby Digital"."

When the 950 acquires the signal, it tells you if you're getting Dolby 2.0, or Dolby 3/2.1. Then if you change the volume, it tells you on the OSD what processing it's using.

>The Bigger Issue:

I'm assuming you're using the same digital audio input for all of these channels:

I was just playing with my system.
HBO was in DD 3/2.1
IFC was in DD 2.0
MTV(hits) was in DD 2.0

Here's my thought:
There are 2 different kinds of Dolby Digital 2.0:
Dolby® Digital 2.0 Surround and Dolby® Digital 2.0 Stereo.

If I set the input to "stereo", I get 2 channel (L and R) playback from all 3 channels.

If set it to to "plain" dolby digital
HBO: "standard" 5.1 dolby digital
IFC: what you were describing, sound mostly from center speaker with some sound from L,R and surrounds)
MTV: stereo L and R (what you used to get)

Most of the channels with 2.0 gave me the same bad results as IFC. Could this be your problem? Maybe more channels are now sending 2.0 surround, versus 2.0 stereo?

My 950 remains in stereo if I switch it to stereo on any of the channels and then change channels. As for changing from Dolby PL to Dolby digital, I think that's driven by how you have set the Input Config in the 950's main menu. If I set mine to Dolby Digital, it does what you're saying. If I set it to PLII, and switch to a 5.1 channel, and go back to a 2.0 channel it returns to Dolby 2.0. But, if I set it to PLII-CR, I get DD+CR on the 5.1 channel, and PLII-CR on the 2.0 channel. I agree--a little odd.

And gonk,
"I have Dolby 2.0 default to Pro Logic II with CES on the DVD input and I have any stereo signal (Dolby 2.0, PCM, or analog) default to Pro Logic II with CES on the cable box input."

I was under the impression that you can only have one default processing mode for each input. How do you have a digial default for DVD and an analog default? (Unless you use a different input for each format, such as video1 and video2).

When the 950 locks on to the digital signal, it lists the format of the signal, not the processing that it is applying. In some cases, the two are identical (Dolby Digital 3/2.1 may be processed using Dolby 5.1 if you don't have surround back processing to add to the mix, for example).

Dolby 2.0 is just that - a digital audio signal containing only two channels of data. The source signal does not have any surround component, and Dolby Digital processing should yield only stereo. If Pro Logic II processing is applied, the results of that will vary. If the original recording that is being broadcast in Dolby 2.0 included some steering for Pro Logic processing, then you will likely get a surround experience ranging from fair to very good (depending on the nature of the steering data and of the program in general). If the signal lacked any steering, the old Pro Logic processing would tend to collapse everything to the center channel. Pro Logic II is a good bit "smarter" than Pro Logic, so it is much less prone to collapsing, but it will probably also have a much harder time generating surround data from such a source, making the results seem more like stereo.

For what it's worth, the way I've been using my 950 (which has worked out very nicely for me) is a process that I think of as "teaching" the 950. I don't recall what I've done as far as setting a default for each input in the menu - in fact, I think I've left those all on their defaults. Instead, as I come across each typical signal format, I select the surround mode that I prefer for that format. DVD's are generally the easiest, as you have Dolby 2.0, Dolby 5.1, and DTS as the big three. In every case, I apply some form of surround back processing, which is typically CES. When I first came across a Dolby 2.0 soundtrack, I set the 950 to PLIIC+CR. From that point on, unless I change something, the 950 always reverts to PLIIC+CR for Dolby 2.0. The cable box is potentially a bit more complicated: I have analog cables connected, which we use most of the time because the audio delay generated by the cable box and 950 in turn when channel surfing irritates my wife, but I also have a digital audio cable connected. The analog is simple to handle - it always uses PLIIC+CR (although I did also tinker with PLIIM+CR some). Digital, however, may use one of three different signal formats: PCM (for analog audio converted to digital by the cable box), Dolby 2.0, and Dolby 5.1. Dolby 5.1 of course uses Dolby Digital processing, plus CES. For both Dolby 2.0 and PCM, I selected PLIIC+CR the first time I came across them and have left them that way, so the 950 always reverts to them.

gonk,

I don't think that the 950 is fully "teachable". My 950 will operate as yours does: If I set my 950 PLIIC+CR (or PLIIM+CR), I get PLIIC+CR a dolby digital 2.0 signal or if I use the analog signal. When I switch to a 5.1 source, I get DD+CR-C get that format with a 2.0 source. This seems to be the most sensible way to leave the 950.

But lets say I'm watching an analog station CBS channel 2 and switch my 950 to 7-channel stereo.

Then I change channels to HBO and I switch the input to coax2. The 950 tells me it is getting a DD 2.0 signal, and if I change the volume, the 950 tells me it's processing in PLII-C.

Then I switch to Stars. The 950 tells me it is geting a DD3/2.1 signal. Change the volume, and it tells me it's processing in Dolby Digital.

I switch back to HBO. The 950 tells me it's getting a DD 2.0 signal. But now when I change the volume, it's reporting that it's processing Dolby Digital.

Back to channel 2, back to analog. And now it's procesing PCII-C.

Meanwhile, the Pro-Logic handles different feeds very differently. Many of the sources totally collapse almost totally into the center channel. But some are handled much better. And although PLII is better, it's still so variable as to be annoying. While watching the football game today on CBS's analog feed, the 7-channel stereo is just a fuller clearer presentation. PLIIC+CR is a bit more muffled and it's harder to hear the announcers.

A little more testing, and right now my best guess is something that ScottH hinted at. For some reason, I think my cable company is now broadcasting in Dolby Digital 2.0 Surround across the board instead of Dolby Digital 2.0 Stereo. I have to find a Dolby Digital 2.0 stereo signal on DVD to test that theory, but right now that's all I can think of.

EDIT: But it doesn't work. I used a specifically Dolby Digital 2.0 Stereo signal coming from a DVD (the Spanish audio soundtrack on Basic Instinct), and it steers the audio to all 3 front speakers. That has to be wrong. I cycled through all the surround modes, and back to Dolby Digital, and it still processes it as a pro logic signal.

BUMP.

I am now having this exact same problem as the original post. For channels that are broadcast in Digital Dolby 2.0, the Outlaw 950 used to send the signals to the mains only (my desired behavior). I am 100% positive that this was the case because I would often manually switch into PLII mode when I thought it sounded better using the center speaker.

Today I noticed that 2.0 broadcasts are coming almost entirely from the center speaker. The display says "Digital D", not "Dolby P" or "PLII"

I can put the 950 into stereo mode, but as poffypoffa says, when you change channels to a station with a 5.1 signal, it stays in stereo mode and I need to switch it off manually.

UGH! Any ideas?

my god. i think i need a smoke.

scott - can you give a general explanation that an engineer can understand to set the defaults for digital coax input cable and dvd? i thought proligic was an analog thing of the past and prefer not to use it - but all the other stuff you and gonk are talking aout is making mky head spin...

sorry if my stupidity is pulling this thread off topic. we can start another thread if this is to far off poffypoffa's topic.

The original Pro Logic was generally done in the analog domain, but it's long gone - and Pro Logic II is a significant step up in the world. Don't be afraid to use Pro Logic II on your 950. In addition to be handled in the digital domain these days, it is much more intelligent: Pro Logic's tendency to collapse to the center channel has been largely eliminated, and instead of the mono surround signal produced by Pro Logic you get separate left and right surround channels. You might want to take a look at my terms and tech page for even more info on the different surround modes...

excellent tutorial gonk. well done. i'm pretty famiar wit hthe formats. but it still eludes me as to what the most effect 950 setup/defaults should be for the cable box and dvd player. i have a note paper taped to my entertainement that wife/kids complain about - to comple. i kind of miss my previous acurus act-3 because it allways seemed to know what processing mode to use automatically. can the 950 be programmed to operate more automatically?

i apolologize to poffypoffa once again for hijacking this thread with stupid questions...

The best arrangement is going to depend on personal taste. I'll offer an example, though - the arrangement that I used when I had a 950 (which happened to be an arrangement that worked well with the 950's surround mode memory). The cable box used Pro Logic II-Cinema processing with Cirrus Extra Surround (since I have surround back speakers) when using analog, PCM stereo, and Dolby Digital 2.0 signals. This gave me effective surround, with the exception of sources that were too flat for anything except 5/7 Stereo to do anything with. DVD's (including the DVD recorder) applied Pro Logic II and CES to Dolby Digital 2.0 soundtracks, CES to Dolby Digital 5.1, and CES to DTS 5.1 while DTS-ES and flagged Dolby EX got their respective processing modes. CD's went with pure stereo. The 950 can "learn" your patterns because it has a memory for each input that remembers the processing mode you selected the last time you had that signal type.