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magictooth
04-03-2004, 01:00 AM
I've been wondering if there is any difference in PL II decoders by the various manufacturers. I have an Onkyo Integra DTR 8.3 and I really dislike playing anything in PL II. I find that too much information comes out of the center channel at the expense of the fronts. When I use the "direct" function for watching satellite, I seem to get a wider soundfield because only the L/R are working. I guess it is nice to hear some crowd noise from the surrounds when watching a sporting event, but other than that I haven't found PL II to be a very good decoding scheme.

markw
04-03-2004, 04:23 AM
I find the problem with DPL II and other similar functions it's that when applied to any source originally recorded (and there for intended to be played back in) two channels is that it makes too many "assumptions" as to what sounds go where resulting in, let's say, "unpredictable" results.

As far as that center channel bit, I'd venture to guess that many two channel sources with a lot of center fill will probably cause a lot of activity in the center channel. A lot of these work off of phase differences between channels and, lacking that, treat a lot of sounds a mono source which, in DPL, defaults to the center channel.

IOW, two channel music sounds best in two channel mode. Very, very few two channel music benefits from artifically induced ingredients. YMMV.

Movies recorded in surround sound (VHS Hi-FI) are another story. IMNSHO, these most definitely benefit from DPL and even moreso from DPL II

Lexmark3200
04-05-2004, 11:49 AM
Interesting topic; I too find that PLII "Movie" mode (as my Onkyo calls it) just plain sucks for the most part when playing back Hi Fi VHS tapes....I recently gave my Sony Hi FI VCR a workout and watched Goodfellas and later on that week, Independence Day, both Hi Fi Stereo VHS tapes (originals, not recorded from cable or anything like that), and Goodfellas was pretty dissapointing. No directional surround ambience at all, really, but Independence Day fared a bit better because it is, after all, an action flick...there were effects of ships flying over and blowing up, etc, but nothing like Dolby Digital's 5.1 discrete effects....nothing. I even notice some crackling and static from VHS tapes when watching them in PLII mode; the fidelity compared to DVDs is terrible.

Playing music back in PLII "Music" mode I stay away from because, like Mark, I feel two channel stereo CDs should be played back in standard stereo mode. The only time I play back CDs in PLII Music is when it is a live recording, such as Metallica's S&M....that sounded waaaaaay cool in PLII Music....the crowd was in the surround speakers.

TV shows just plain suck in surround modes, too (if you dont have your cable hooked up directly and digitally to a receiver)...I tried watching the Sopranos through my Onkyo receiver and played with different DSP modes, and they all sucked....dialogue was creeping through all channels and the volume was ridiculously low. Sopranos are broadcast in DD 5.1 in my state, so I would eventually like to connect the cable box's digital out to one of my receiver's digital in's.

Worf101
04-05-2004, 01:06 PM
I'd been avoiding it for all the reasons you mention. When watching TV via cable I use "All Channel Stereo" on my Onkyo 898. Recently though I tried DPLII Movie when watching HBO broadcast in stereo. I actually got some amazing separation in the Mains while watching "Deadwood" last night. Some actually tracked left to right. It was scary. I didn't expect it at all.

Still playing around with it.

Da Worfster :cool:

Lexmark3200
04-05-2004, 01:17 PM
I'd been avoiding it for all the reasons you mention. When watching TV via cable I use "All Channel Stereo" on my Onkyo 898. Recently though I tried DPLII Movie when watching HBO broadcast in stereo. I actually got some amazing separation in the Mains while watching "Deadwood" last night. Some actually tracked left to right. It was scary. I didn't expect it at all.

Still playing around with it.

Da Worfster :cool:

Wofster,

Yeah, I have played with All Channel Stereo on my TX SR600, too, but this mode just sucks dude....dialogue shouldnt come from every speaker in a system. I hate that. For some reason, because my VCR is running in a loop with my cable box, when I watch cable, the channels dont come through in stereo, so watching cable shows in PLII Movie wont work----all information comes from the center channel only.

JSE
04-05-2004, 01:33 PM
I'd been avoiding it for all the reasons you mention. When watching TV via cable I use "All Channel Stereo" on my Onkyo 898. Recently though I tried DPLII Movie when watching HBO broadcast in stereo. I actually got some amazing separation in the Mains while watching "Deadwood" last night. Some actually tracked left to right. It was scary. I didn't expect it at all.

Still playing around with it.

Da Worfster :cool:


Deadwood sounds pretty good with my PLII Movie but I tend to prefer to watch it in DTS Cinema.

By the way, that's one Kickarss show.

JSE

Sir Terrence the Terrible
04-05-2004, 02:09 PM
This whole DPL II stuff is really comical to me. There is no DPL II encoded stuff anywhere at this moment, however this is being marketed as a format just because Dolby put it out there. It doesn't matter if we are talking about 2 channel music, or 2 channel movie, if it is decoded by DPL II it is a DPL II artistic creation MADE BY THE DECODER, and not by a certified audio engineer. It's artificial, fake, and decided arbitrarily what is directed into the stereo surrounds since there are no stereo surrounds in the format to which two channel movies are encoded in(DPL)

Whether movies actually benefit from DPL II highly depends on if you are looking for geez whiz bang, or trying to accurately decode the movie in its properly encoded format

Magictooth, the answer to your question is no. DPL is a chip based for anyone who chooses to include it within the pre-amp or receiver. The only difference would be the degree of control over DPL II. Some manufacturers include all processing modes for DPL II, and some just offer the decoding only.

Lexmark3200
04-05-2004, 02:14 PM
This whole DPL II stuff is really comical to me. There is no DPL II encoded stuff anywhere at this moment, however this is being marketed as a format just because Dolby put it out there. It doesn't matter if we are talking about 2 channel music, or 2 channel movie, if it is decoded by DPL II it is a DPL II artistic creation MADE BY THE DECODER, and not by a certified audio engineer. It's artificial, fake, and decided arbitrarily what is directed into the stereo surrounds since there are no stereo surrounds in the format to which two channel movies are encoded in(DPL)

Whether movies actually benefit from DPL II highly depends on if you are looking for geez whiz bang, or trying to accurately decode the movie in its properly encoded format

Magictooth, the answer to your question is no. DPL is a chip based for anyone who chooses to include it within the pre-amp or receiver. The only difference would be the degree of control over DPL II. Some manufacturers include all processing modes for DPL II, and some just offer the decoding only.

Yeah Terrence, but isnt it true that store-bought VHS tapes have "Stereo Surround" material encoded onto them even though they simply read "HI FI STEREO"? Underneath these Hi Fi labels, the tape usually reads "DOLBY SURROUND"....so arent surround directions there on the stereo tracks already, ready to be decoded?

magictooth
04-06-2004, 07:30 AM
Magictooth, the answer to your question is no. DPL is a chip based for anyone who chooses to include it within the pre-amp or receiver. The only difference would be the degree of control over DPL II. Some manufacturers include all processing modes for DPL II, and some just offer the decoding only.
Sir TT, thanks for the reply. Sometimes I flip through the various DSPs and I wonder how much I paid for them. I've got 2 or 3 DPL II modes, but they all sound basically the same with a 2 ch. signal like satellite.

As for watching VHS, my VHS machine serves mostly as a clock in my HT room. I don't want to sound too elitist, but I don't think that I've watched a VHS movie for a long, long, LLLLLOOOOOOOONNNGGGG, time. And I don't think that I'm going to start.

Sir Terrence the Terrible
04-06-2004, 08:54 AM
Yeah Terrence, but isnt it true that store-bought VHS tapes have "Stereo Surround" material encoded onto them even though they simply read "HI FI STEREO"? Underneath these Hi Fi labels, the tape usually reads "DOLBY SURROUND"....so arent surround directions there on the stereo tracks already, ready to be decoded?

Dolby Surround is a 4:2:4 decoding. That means the 2 channels decode a Left,Center,Right, and mono Surround. DPL II takes the mono surround and splits it to faux stereo surround. The directional information that DPL II generates comes exclusively from the decoder, and is not found on the tape or broadcast(or any 2 channel source run through a DPL II decoder)

Dolby Stereo surround is just a name that dolby gave the home version of the Dolby Stereo theatrical decoder to distinguish the different technologies. The theatrical version uses Dolby A noise reduction, the home version uses a Dolby B noise reduction variant hence the two different names.

VHS recorders use the moniker "Hifi" instead of Dolby Surround to describe the better quality stereo audio, to avoid paying royalities to Dolby for every player made. This keeps the price down, and leaves the door open for other 2 channel formats to appear on tape.

joel2762
04-11-2004, 04:15 PM
in the world that can precisley (mighta spelled that wrong) re-create the real sounds on it's own, it needs to be mixed by people...Nothing can create perfect surround sound on it's own without it being previously mixed..I think some people like the Pro Logic just to show off their system..Look I have all these speakers and they're all making sound! Cool eh!?...I leave my PL on, I just like the sounds from the rears, it might not be accurate but I don't really care for buying a surround system and using two speakers. That's my opinion. I like all the speakers on. But actually, I always leave the center channel in OFF mode unless i'm watching a movie recorded in DD or DTS, I can't stand listening to music with the center, it sucks. You can't expect Pro Logic to be entirely accurate but it does what it's supposed to. Some people like it, some don't! It's all opinion.