Pro Logic II--Help! (1 Viewer)

[MichaelM]

Hi there.

I have an Onkyo HT-R500 digital receiver. It works great and has great sound, EXCEPT when I'm watching Special Features on DVD or DVD's that are encoded with Dolby 2.0. Then it automatically switches from "Dolby D" to "Pro Logic II". Once this happens, almost always it sounds bad. Most of the sound comes out of the center channel. The sound coming out of the fronts and rears sounds choppy and sort of "blips" in and out, especially with dialogue. It's just not right. I first noticed it because I could hear some pops and clicks so I put my ear up to the speakers and it's all over the place. I have my DVD player hooked up with an optical cable. Again, with DTS and Dolby 5.1 all the speakers sound great.

The customer service guy at Onkyo thought it was because the sound was 2.0, not 5.1 so he said I should listen to in "stereo", any time the sound is not 5.1 (like most special features). But I thought that ProLogic receivers would decode the 2.0 and make the sound a "simulated" surround. In which case I shouldn't be hearing the bad sound.

Also, I've tried many DVDs and I've hooked up a different player with the same results. I have a PS2 hooked up to it also (with left/right audio cables) and with software labeled "Dolby Surround" it switches to ProLogic II and sounds great. So I hooked the DVD player up with analog cables and switched to that and it sounds good that way.

So, the problem is going from Dolby Digital 2.0 to ProLogic II. Shouldn't the receiver be able to do that? Do I have a defective receiver?Thanks for your help. The customer service people are pretty useless...

 

[Justin H]

I'm not sure if I'm understanding you correctly but:

Pro Logic II is indeed a simulated surround sound derived from a 2 channel source. Your receiver is correct in switching to Pro Logic II when it receives a 2 channel source, as it should sound "better" or at least use all 5 of your speakers. I'm sure you could turn this feature off and listen to 2 channel material in stereo, or a DSP mode if you wish to. But from what I've heard Pro Logic II is a big improvement over Pro Logic, which I don't care for too much. So I would imagine it can't be that unbearable to listen to.

As for the pops and clicks, I think that should be your point of concern. They certainly do not sound normal to me. My Pro Logic receiver has nothing that resembles pops or clicks so I would imagine this is out of the ordinary. Someone with more PLII experience may be able to help out more as I've not heard it first hand. HTH

 

[Vince Maskeeper]

Michael,

Are there specific DVDs with which you're having this problem?

The reality is that DPL 2 is just a dsp processing system- and it simulates surround from a 2 channel source. However- most DVD extras are mono in nature (lots of talking head interviews or unmixed temp audio from deleted scenes). Applying a DPL2 process to a mono source will result in the majority of the sound coming from the center channel (thats how PL and PL2 work).

As far as the blipping- that's where my concern would be. A lot of sound is produced in ways you don't notice until you have a hi-fi system (an example being gating, which causes a similar effect to what you describe). If you have some specific extras where you have expoerienced this- I'd be happy to pop them in and check them out and give you an idea of what is there on the source track...

But if you're saying that the problemed passages sound fine when running the analog off the dvd player, that might be another issue.

Does your receiver have another digital input? have you tried others to see if the same problem happens?

-vince

 

[MichaelM]

Hi Vince.
thanks for the reply.

I first noticed it when we were watching the second disc from the Snow White Platinum Edition. Before that I had watched some special features and not noticed it at all. But while watching this particular disc I kept hearing weird pops and things so I put my ear up to the speaker and it just sounded awful. The best way i can describe it is it sounds like the wires are being "jiggled" so that the speaker is losing connection and the sound is going in and out. In some cases there is very little sound at all. Other discs I've tried, with varying results, are Lord of the Rings special features, Gladiator special features, Tomb Raider Special features (which is on the same disc as the movie). It seems worse on the special features that are a separate disc rather than the ones that come on the disc with the movie.

BTW, last night, thinking the unit was defective, I exchanged the reciever for a new one at Circuit City (they have great Customer Service--I had already had it for 45 days but they exchanged it anyway) and hooked the new one up. It's doing the same thing. So it's not the receiver.

Also, on my DVD player (Pioneer DVD525) there is a setting under Audio--that says Dolby Digital and you can select either "Dolby Digital" or "Digital--PCM". When I select PCM the sound is clear on most of the discs. For instance, The X-Files Season 5 box set is said to be "Dolby Surround" (when I push Audio on my DVD remote it says Dobly 2.0 on the screen)and if the "Dolby Digital" setting is selected it sounds like crap. But when I change it to "PCM" it sounds good. This doesn't seem to work for all of the discs because I tried it as soon as I noticed problems a few days ago and some sounded good, while others didn't.

Yes, I have tried other cables and other digital inputs with the same results. And last night I tried Analog again and it didn't seem to make a difference. There are so many variables but I think I've narrowed it down to this:

1. If it's Dolby Surround or 2.0, then the reciever switches to Pro Logic II. In this case, switching my DVD player's output to PCM seems to do the trick.

2. Maybe if it's Mono there's not much you can do but listen to it in stereo?

You are probably right about the mono vs. surround thing because you know how some menus are not 5.1 before the movie? Well, like in Gladiator those tend to sound good, even when the unit switches to ProLogic II. So maybe they put a little more work into those than they do into the interviews and such since it's front end to the movie.

Sorry to be so long winded. I'm surprised no one has had this problem before. Very strange. And I'm very anal so I gotta know!

Thanks,
Mike

 

[Michael Reuben]

If I recall correctly, there are various settings for DPL2. One of them instructs it to behave like plain old DPL. Have you tried playing with these settings?

M.

 

[Vince Maskeeper]

Possibly- certainly these usually are featuring recorded MUSIC Score, which by its very nature of recording process is very compatible with DPL/DPL2. This should give pretty pleasing channel decoding. However- again- if the issue is a gating process (like I mentioned above)- it's possible that these sound consistently good simply because the volume level of the material never really falls below the threshold of the gate.

If you have a specific time code and title/chapter number from the Snow White extras- let me know. I have this disc in my collection and would be happy to do some tests to see if I could find the problem in the source material (heck, I can pull the audio directly off the disc and run tests on the DD stream and a decoded PCM stream to make sure that the problem isn't part of the source material.)

-vince

 

[MichaelM]

The other night I watched an episode of The X-Files from the season 5 set. I set the DVD player to "Digital--PCM" and it sounded great. Likewise, on "Dolby Digital" setting, uh, not so great. So I'm happy with that. But it is a pain to have to switch back and forth. Also, playing Medal of Honor on PS2 sounded amazing in DPLII. I have that hooked up with the analog connections.

As for the Snow White disc, I noticed the bad sound during the special features section that is called "Disney Through the Decades".

It's too bad, really. Otherwise this unit sounds awesome for the price. In Digital 5.0 and DTS the sound is great. Also, as for switching the DPL off and listening to it direct, that's a weird thing on the Onkyo. It won't let me do this. You can switch to stereo but not direct. It says "unavailable". I thought that would be a logical thing to do as well. But no such luck.

BTW, my DVD player manual (that I've now read about 175 times) says about the Audio Menu. "When connecting the DVD player to a receiver with Dolby Digital, select "Dolby Digital". When connecting to a receiver with Dolby Pro Logic, select "PCM"." So this receiver has both, then what? So switching back and forth depending on the DSP seems to help. Weird and somewhat of a pain. How does it normally work? You select "Digital" and the receiver does the rest?

Thanks for all your advice and help.

 

[MichaelM]

If I recall correctly, there are various settings for DPL2. One of them instructs it to behave like plain old DPL. Have you tried playing with these settings?


I haven't found any settings like this on the Onkyo HT-R500. I have played around with every setting possible to no avail. Also, it won't let me bypass the PLII and just go "direct". I can set it to stereo, but what's the point of that? I'm surprised this hasn't come up before actually. It's very strange. But then again, I didn't notice it for a while. It's worse on some discs than others.

 

[Vince Maskeeper]

Direct and stereo are the same thing. Some receivers offer a "direct" mode in addition to stereo- which is the same thing as stereo just without passing through bass management.

Do the errors you hear also occur in "Stereo" mode? Does the behavior in stereo mode stay the same as it does in DPL2 when trying the different DVD player modes?

-Vince

 

[Michael Reuben]

I'm surprised this hasn't come up before actually.

That should tell you something.

M.

 

[Vince Maskeeper]

As Michael's somewhat blunt post above alludes, I think the answer here is that this doesn't come up often because it is not normal- and is almost certainly caused by error in configuration or equipment. This is probably not a case of a problem that exists in every configuration and you were the only one able to notice it- rather it's likely that you're the only one experiencing this particular set of errors due to your specific config or hardware problem.

I think at this point, the fact that you have switched out the receiver and the fact that problem doesn't happen with the PS2 as the DVD player seems to point a serious eye in the direction of your DVD player's digital bitstream as the prime suspect in this case.

Again- the process to determining the problem is a very simple and methodical approach (and essentially what I've suggested above):

1) Determine if/when this problems happens using the DVD player in the various connection modes (Digital Bitstream, Digital PCM, Analog) with DPL2 turned ON.

2) Determine if/when this problems happens using the DVD player in the various connection modes (Digital Bitstream, Digital PCM, Analog) with DPL2 turned OFF (STEREO MODE).

3) Determine if/when this problems happens using the PS2 in its various connection modes (Digital Bitstream, Digital PCM, Analog) with DPL2 turned on.

4) Determine if/when this problems happens using the PS2 in its various connection modes (Digital Bitstream, Digital PCM, Analog) with DPL2 turned OFF (STEREO MODE).

By checking all 12 of these configurations, I assume you'll find that the problem happens when using Dolby Bitstream from the DVD player- with or without DPL2 turned on... meaning a problem with how the player is passing the stream or in an incompatibility btwn the player and the receiver.

But, even if I'm wrong- the answers to these 12 options will almost certainly give a clearer picture of exactly what is happening and where the problem likely exists.

-Vince

 

[Ralph Bru]

it should still show up digital, just not DD. also it will use prologic II

I own a onkyo tx-494 and thats what it does when using the 2.0 track.

clicks and pops are not good. I had that happen with my JVC and got rid of it, was obviously a problem and annoying.

 

[MichaelM]

Vince:
Here's what I know so far. I'll try the rest when I get home.

1. DVD (with PLII): Digital: sounds awful. PCM: sounds good in MOST cases (I have to play with this some more). Analog: sounds the same as Digital (at least it did the last time I tried it).
2. DVD (Stereo mode): All sound good in stereo.
3. PS2 (with PLII): Only have connected to receiver with Analog inputs. In this case, it sounds great (Medal of Honor sounds like Saving Private Ryan). I have to hook it up digitally and try that.
4. PS2 (Stereo mode): I haven't tried this since the DPLII sounds so good with the PS2.

I will try these other modes see what happens. But so far it does seems like it's the DVD player set to "Digital" instead of "PCM" while playing a Dolby Surround or 2-channel disc. Also, the player I have connected to the receiver is a Pioneer 525 (it's about 3 years old); I also have a Phillips Progressive Scan (only about 6 months old) on my big screen in another room so I hooked that up to see if it was the player. I got the same results.

Thanks.

 

[MichaelM]

Oh yeah, one thing I forgot. Regarding your last statement (problem happens when using Dolby Bitstream from the DVD player) does this still apply even though with Dolby 5.1 and DTS the sound is great?

 

[Vince Maskeeper]

Well- since I'm still not 100% clear on what exactly you're hearing in either case- I'd still leave the option open... Although now it sounds more like it's an interaction of DPL2 and dolby 2.0 material (although it sounds like the analog output is also messing up, which should be essentially identical to the PCM output).

I really wish i could get an hour with this unit first hand- It's quite intriguing!

-Vince

 

[MichaelM]

I wish you could get your hands on it too. It's frustrating for me.

Here's the thing with the analog. At one time I tried it and it seemed fine. But I tried it again and got similar results to the ditital issue.

I think overall I need to sit down with it and like you said use the same passage from the same DVD and try all the different modes like you suggested. Part of the problem is that when I first noticed the problem I would get an idea and run home after work and try that. Then when that didn't work, I'd try something with another disc, etc. So, I was all over the place, trying this, hooking up that. I guess the best way to try to eliminate options is to go down the list you made with the same disc and try everything. I'll do that tonight if I get home in time and report everything back here. They're definitely some things I want to try. But I do know that the last time I tried DVD with analog connections, it didn't sound good. But, since I was changing this and that maybe I left the DVD Audio Menu to "Digital" and not "PCM". The manual with the DVD Player says to switch it to PCM for receivers with PL and Digital for DD receivers. Well, this receiver has both...

 

[MichaelM]

Oh yeah, geez, I keep forgetting things. I really have reread my messages before I hit "submit". Sorry...

No, I haven't tried playing a DVD on the PS2. In fact, I've never used it for that. I'll try that tonight also.

Yes, Stereo mode seems to sound good with everything I've tried it with. Although that's not much yet. But yes, the DVD I noticed this problem with first is the Special Features disc of Snow White. I switched to Stereo and yes it was fine where it sounded horrible with DPLII.

 

[Vince Maskeeper]

That is of interest- but then I'd also check it out in analog mode with DPL2 on and then off. We need to determine if DPL2 interaction with direct digital dolby formatted sources are the problem, or if it is the DPL2 processing on this receiver that is the issue (ie is DPL2 mucking up every source- or just dolby formatted digital sources).

 

[MichaelM]

Ok, the results are in. I tried the 12 variables you suggested, Vince. And here's what I found:

1. DVD Player--PLII on
a. Bitstream: bad sound
b. PCM: good
c. Analog: good

2. DVD Player--Stereo Mode
a. Bitstream: good
b. PCM: good
c. Analog: good

3. PS2 (hooked up via digital cable)--PLII on
a. Bitstream: Seemed better than the DVD Player on this, but not by much. Still didn't sound really clean.
b. PCM: good
c. Analog: good

4. PS2--Stereo
a. Bitstream: good
b. PCM: good
c. Analog: good

Also, for the first time since getting this unit, I put in a CD. I use my DVD player as a CD player. The CD sounded great in PL2 mode and with the several available DSP options. The receiver showed "PCM" on the display when the CD started.

But, most interesting was the discovery that ProLogic2 MUSIC mode sounds GREAT when listening to a movie. In fact, I thought the problem was solved until I realized that I left it in "Music" mode as opposed to "Movie" mode and put in an episode from Season 5 X-Files. It sounded great.

The best way to describe the differences are:
1. In Movie Mode the dialog is mostly coming from the center channel (as it should) but then you also hear little "blips" of it coming from the front speakers and some from the rears. It's not clean and very "choppy".
2. In Music Mode the dialog sounds more "stereo" but it's very clear, and smooth, as are all the sounds.

Mostly, I notice the problem with PL2 in Movie Mode during dialog and some surround sounds. That's when I hear the "blips", and sounds as if someone is jiggling the speaker wire and dislodging the connection. Some of the sounds come through, but it's like there are "layered sounds" that are quite making it. But again, Music Mode sounds great.

Any thoughts?

 

[Matthew David]

Hi.

I just purchased the Onkyo S650 HTiB as my very first foray into the wonderful world of surround sound and I have been having similar problems. Obviously, I had a very limited budget. That being the case, I'm currently using my Xbox to play DVDs (expect questions from me about DVD players soon :p ). I have NOT noticed a problem while playing any DD 5.1 game. Also, the GameCube only plays DPLII and I've not had any problems with it.

I've noticed this to be the case on numerous X-Files seasons and "24". Of course both of these are DD 2.0. But I've also had the same problem with the "Insomnia" DVD. "Insomnia" was the first time I heard this and was also the first thing I watched in 5.1 so I assumed it was just something that happened or perhaps the cables were loose. They weren't.

I plan on investigating further today with "Speed" DTS and DD as well as "Episode I" and I'll tell you what I find.

Perhaps someone can tell me why the receiver tells me that its playing both DD and DPLII when using a DD 2.0 DVD? I assume that its because it is DD and being decoded into DPLII, but I just want to make sure.