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| Dolby Pro Logic https://forum.lddb.com/viewtopic.php?f=12&t=276 |
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| Author: | naiaru [ 31 Oct 2011, 07:52 ] |
| Post subject: | Dolby Pro Logic |
This may seem like a stupid question, but with Dolby Surround encoded tracks, is it better (or "purer") to leave Dolby Pro Logic on or off? And for that matter is it better to use Dolby Pro Logic, Dolby Pro Logic II, Dolby Pro Logic IIx, Dolby Pro Logic IIz or some other decoder? (I'm assuming the only difference between II, IIx and IIz is how many channels and/or where they go, but idk for sure) |
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| Author: | lons_vex [ 31 Oct 2011, 10:10 ] |
| Post subject: | Re: Dolby Pro Logic |
I always listened in Pro-Logic Mode to such discs. And I think you are free to decide which mode you select, i.e. the one you think makes the best sound in your opinion. |
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| Author: | bullruckle [ 31 Oct 2011, 13:59 ] |
| Post subject: | Re: Dolby Pro Logic |
Good question Naiaru. I have wondered the exact same thing. Is it better to set the Amp to Dolby ProLogic or Dolby ProLogic II when listening to a Dolby surround track or will they just give me the exact same result No Idea. You'd think because ProLogic II has the 2 after it, that it would be better, but I'd love to know the official answer. |
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| Author: | Guest [ 31 Oct 2011, 18:05 ] |
| Post subject: | Re: Dolby Pro Logic |
Pro Logic and Pro Logic II will not give you the same results. Pro Logic only separates stereo signals into four channels: FR, FL, C, Surround. Surround is mono with Pro Logic, meaning both rear speakers outputs the exact same thing. Additionally the surround channel is frequency limited. Pro Logic II separates stereo signals into 5 full range channels. It was meant to be and improvement over Pro Logic, and to replace Pro Logic. It is intended to be used with Dolby Surround sources, originally intended to be decoded with Pro Logic. PLII should sound better, and from what I read many people agree. In fact I have read a lot of people stating they feel that PLII decoding of the Stereo PCM tracks on an LD is superior not only to PL Decoding, but also superior to an AC3 on the same LD. However, I believe Receivers still support Pro Logic because of purists. I also believe that this Pro Logic decoding modern receivers engage in, isn't actually true Pro Logic, its Pro Logic Emulation. True Pro Logic decoding requires a separate Pro Logic Circuit, something that probably isn't worth the cost. PLII is able to emulate PL. Now is PL emulation any different from a PL circuit? Idk, I doubt it. But its something to think about. |
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| Author: | bullruckle [ 01 Nov 2011, 08:02 ] |
| Post subject: | Re: Dolby Pro Logic |
Thanks for the info Jami. So that's the difference between Prologic and Prologic II. The action in the back speakers. Nice to finally know. Thanks again. |
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| Author: | Guest [ 01 Nov 2011, 16:19 ] |
| Post subject: | Re: Dolby Pro Logic |
I also want to add that PLII does have uses unto its own in video games. |
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| Author: | Guest [ 12 Nov 2011, 22:26 ] |
| Post subject: | Re: Dolby Pro Logic |
bullruckle wrote: Thanks for the info Jami. So that's the difference between Prologic and Prologic II. The action in the back speakers. Nice to finally know. Thanks again. Is this the only difference? Does the original Pro Logic route all the dialog to the center channel? I use Prologic II and this definitely sends all the dialog to the center which is probably the main reason I prefer it over the Straight 2.0 PCM tracks. Also do any of these decode modes (DTS Neo, Matrix, etc.) extract a real .1 channel or is it just based on the crossover in my sub/receiver? |
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| Author: | publius [ 13 Nov 2011, 00:10 ] |
| Post subject: | Re: Dolby Pro Logic |
If by "real .1 channel" you mean LFE, there's no way to obtain such a thing from a stereo surround track. Modern matrix decoders perform "bass management", which allows you to obtain proper reproduction of the low frequencies in the soundtrack using a subwoofer or large speakers, as you prefer. |
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| Author: | Guest [ 15 Nov 2011, 21:12 ] |
| Post subject: | Re: Dolby Pro Logic |
I believe all they do is router lower sounds to the subwoofer, which isn't a substitute for having a true LFE track. The main reasons to use PLII isn't because it creates full range rear sounds. The rear sounds from PL isn't full range. This should give the sound more dynamic range, and less tinny sound. I do believe PL will route sounds in the vocal spectrum to the center. I will be honest, I have not experienced very much PL decoding in my life. I was too young to watch LD in its prime (plus my Parents had VHS anyway), so I've only watched them once PLII came out. I have watched some movies in PL Emulation as done by my receiver, and watched most of my LDs in PLII. I do find PLII to be better. However; PLII sounds the best when decoding Nintendo Gamecube and Wii games that have soundtracks designed to be decoded by PLII. Metroid: Other M for Wii I think is the best example of PLII decoding. |
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| Author: | tkmedia [ 24 Nov 2011, 05:42 ] |
| Post subject: | Re: Dolby Pro Logic |
I frequent use DTS Neo Music to decode for Dolby Surround of LaserDisc. |
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| Author: | sega3dmm [ 01 Dec 2011, 02:35 ] |
| Post subject: | Re: Dolby Pro Logic |
I use DTS Neo:6 Cinema Mode for viewing Dolby Surround-encoded LDs. However, I only use it when the PCM audio is being fed through an optical cable. For the standard 2xRCA jacks, I use Dolby Pro Logic IIx Movie Mode, though I haven't really tried DTS Neo:6 on analog signals. My receiver does not have classic Pro Logic I available, but while good for purists, not as good as PLII in general. I have also yet to do a comprehensive A/B comparison between PLIIx and Neo6. |
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| Author: | benmbe [ 01 Dec 2011, 09:08 ] |
| Post subject: | Re: Dolby Pro Logic |
Good day sega3dmm, Your comment; I have also yet to do a comprehensive A/B comparison between PLIIx and Neo6. I shall hopefully be doing exactly the same as yourself at some stage along with Logic 7, as I hear that this is excellent. Most of my equipment is still in boxes, and am currently in the process of trying to pay for my equipment support stands of which is proving to be a challenge. Tough times eh! Regards to all 
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| Author: | dgtwoodward [ 02 Dec 2011, 18:53 ] |
| Post subject: | Re: Dolby Pro Logic |
I was under the impression that all sound from any Dolby Surround track will only ever give matrixed - and NOT full range - channels of sound. All the information you can get is still only ever going to be matrixed out from the two stereo Left and Right channels, including the centre and rears. As far as DPL2 and others is concerned, they are performing technical jiggery-pokery with those sounds to produce a fake stereo effect from the rear speakers. I have heard both and the effect is not brilliant. My real question then becomes...why bother with all the fakey, jiggery-pokery, when your receivers are sophisticated devices with the dedicated digital inputs to give you full range separation? 
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| Author: | sega3dmm [ 02 Dec 2011, 23:16 ] |
| Post subject: | Re: Dolby Pro Logic |
dgtwoodward wrote: As far as DPL2 and others is concerned, they are performing technical jiggery-pokery with those sounds to produce a fake stereo effect from the rear speakers. I have heard both and the effect is not brilliant. Sure it isn't "brilliant" by today's standards, but I have yet to find a sophisticated modern receiver that emulates old Dolby Pro-Logic, which is less "brilliant." I guess it's been outdated and outperformed by DPL2. And both DPL2 and Neo6 on my receiver receive the left, center, right, and surround channels correctly. I will tell you that my right surround channel gets oh-so little crosstalk from the center channel, but it shouldn't be something to cry about. We are discussing MATRIX technology after all. Quote: My real question then becomes...why bother with all the fakey, jiggery-pokery, when your receivers are sophisticated devices with the dedicated digital inputs to give you full range separation? When it comes to LD, most of the audio is delivered through two-channel stereo sound. An algorithm was made that can reproduce twice as many channels was implemented to films in the mid-70's with a little system called Dolby Stereo, and I think we all know the story from then on. If you are speaking about discrete surround on LD, we have a decent amount of DTS and AC3 titles on the database. Of the two formats, most of us here can only reproduce DTS from LD, because all you needed was an LD player with an optical/coaxial out, a receiver that supports DTS (which 99.8% do these days) and has optical/coaxial inputs, and an optical/coaxial cable. Presto! Five discrete, full-range channels and a subwoofer channel served on a silver platter. AC3 is much more complicated, making you hunt down a demodulator for a hundred bucks, more or less, and sometimes, requiring you to modify your LD player, just to watch movies in AC3! Most of us can't afford or are skilled enough to do all that so we rather sit down and watch our AC3-compatible films in the "fakey, jittery-pokery" matrixed surround track until we can have access to the demodulator and all that stuff. Heck, some can't watch LD in DTS because their LD player is analog-only. Makes it worse for them if the disc was in AC3, making the film monaural, or not at all. And unfortunately most people have their TV's built-in speakers as a sound system. |
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| Author: | Guest [ 02 Dec 2011, 23:29 ] |
| Post subject: | Re: Dolby Pro Logic |
I would like to update my account about the best PLII source. I believe The Legend of Zelda Skyward Sword's PLII soundtrack its much better than Metroid: Other M. Clearly a soundtrack designed to be decoded with PLII will sound better. I do believe that when Dolby designed PLII they intended it to be compatible with Dolby Surround sources. I have done A/B comparisons with PL emulation and PLII and I find PLII to be better on Dolby Surround sources. |
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| Author: | sega3dmm [ 04 Dec 2011, 23:47 ] |
| Post subject: | Re: Dolby Pro Logic |
I just finished an A/B comparison with PLII Movie and Neo6 Cinema. I've tested them with Akira, Stargate, and Saving Private Ryan. The LD player's audio was sent via 2x analog RCA cables (good ones at that). On the long run, Neo6 was the winner. It also appears that my pressing of Stargate has the PCM track out-of-phase, giving odd effects to both PLII and Neo6. It sounds kind of compressed, too, quite odd for a THX-certified Laserdisc. By this point I was fooling around with Neural Surround, giving worse effects. Neo6 gave me a duphonic stereo effect on the surrounds at one bit of Akira. It was dialogue that was placed in the surround channel of the mix. I haven't listened to this scene again in PLII or Neural Surround. Lastly, Saving Private Ryan. By this point it became a Neo6 vs. Neural competition. There was no shocking difference between the two, and I was kind of surprised because the arrival on Normady was a sound designer's wet dream! Maybe I was too engrossed by the film itself (first time seeing it) to notice a difference. I should look up Neural Surround more to affirm myself what I am looking for. Or maybe I am spoiled by discrete surround tracks. I'm pretty sure Dgtwoodward had a clear point that regardless of the content, you always will get a "fake" surround effect, despite his argument had snobbery of the "discrete" days. I'm going to get myself an AC3 demodulator and an LD player with an AC3 RF out. |
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| Author: | Guest [ 05 Dec 2011, 05:36 ] |
| Post subject: | Re: Dolby Pro Logic |
sega3dmm wrote: .....Lastly, Saving Private Ryan..... I'm going to get myself an AC3 demodulator and an LD player with an AC3 RF out. When you do get your demodulator all hooked up make sure to put Saving Private Ryan back in to test. A really great AC-3 track. |
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| Author: | publius [ 05 Dec 2011, 05:49 ] |
| Post subject: | Re: Dolby Pro Logic |
I find the discrete soundtracks very nice, although of course I only have relatively few. I'm going to be in a position to put one of my DDP-1s up for sale in a couple of months. I don't know how you feel about a decoder as opposed to a demodulator, though. (Link is to the manual as hosted on LDDb.) |
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| Author: | tkmedia [ 07 Dec 2011, 21:09 ] |
| Post subject: | Re: Dolby Pro Logic |
I just sold my fosgate Prologic II decoder recently. It has the most control over PL. 
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| Author: | laserbite34 [ 18 Dec 2011, 21:12 ] |
| Post subject: | Re: Dolby Pro Logic |
I find Dolby Stereo pro-logic can be a good processor if the digital track failed as I have come across a few DVD in the past where the Motorola chip in my other AVR Kenwood KRF-X9050 won’t fully decode the signal rather its noisy pulsating signal that sounds like a machinegun. The Untouchables (1987) SE region 2 DVD won’t play in Dolby digital the analogue track is separate and played fine as a back-up. The same deal with Pearl Harbour (2001) region 2 DVD I later brought the first edition of The Untouchables and never bothered with Pearl Harbour I took it back. I then brought bluray player and Pearl Harbour again and was wondering if the same issue would happen? Nope it played fine. I then later got a new AVR to allow this, lossless to play, I use the PCM 5.1 track. As for Dolby Stereo Pro-logic II I find it creates more crosstalk into the surrounds from the fronts particularly the centre channel or speech/dialogue, so I always use Dolby Stereo pro-logic for Dolby 4:2:4 matrix films. Pro-logic II for Dolby digital with stereo surrounds gives a nice non distracting wrap-around to active the rear back surrounds, thou I have other tricks up my shelve to active them or make all the surrounds active depending on the type of film. Dts-neo6 matrix is not bad at creating 6 wrap-around channels but it does have bit of pumping effect on the sound it isolates some of the LCR common crosstalk say if sound is panned to left or right what you’d normally hear is mild crosstalk. The dts-neo6 reduces it with some type of extra anti-phase to eliminate these little fussy things sound details. There’s not much between the surrounds asides from cerate a centre back but its not true-centre-back. In the cinema the surrounds are arranged as horseshoe shape that warps the audience in surround same deal for 70mm Dolby, Todd-AO discrete and Dolby SR-D, dts and SDDS6/8 expect they use five-screen like the old Todd-AO 70mm. I’m just not keen on most AVR (yes there is no pleasing me):D they can only do what they have been designed to do. If they have RCA pre/outputs-inputs up 8channels or more then do some, experimentations with the surround channel. As for pro-logic its still a fancy way of creating extra like-channels at the press of button. To ether expand on the common three-screen to cerate a five-screen matrix that does wonders on The Sound of Music or West Side Story or any of the 70mm films that used five-screen spread across the screen. Half pans between left and centre or centre and right can be passed though a Dolby matrix or any good high quality matrix decoder to cerate two new channels. The results are best heard with matching x5 loudspeakers placed at the same height level and carefully spread part with equal distance between each one. 2001: A Space Odyssey (1968) the DVD region 1 or AC-3 laserdisc first pressing might have the original all-dialogue panning, I only have the matrix widescreen version and region 1 DVD, the bluray is fit for the dustbin! The Towering Inferno (1974) 70mm six-track mag, region-free bluray the panning can be also heard in matrix mix. The use of LFE.1 is pointless it sounds like its been beefed up along with other explosions or parts of the score with mild tiny extended frequency response. It would have been better if it was encoded in the same 70mm format, the two surrounds is waste when two of out of the six could be used for true-five screen! Logan’s Run (1976) Dolby Stereo 70mm Todd-AO has all the crazy wild dialogue and effects panning on the region 1 DVD I guess the AC-3 laserdisc, I have the region-Free, bluray and was pleased it was as close to the cinema version. In the early days the balance level between Dolby Lt-Rt had to be correct to reduce centre channel speech or from leaking into left or right front. Then came along, Auto-Azimuth that balances it automatically. There is one thing I like about and dislike about it. One if there is soft dialogue pan that is kinder half panned the decoder is trying to pull it back towards the centre, within a second or two. Least that was the headrace I was getting on one my AVR receivers in Dolby stereo pro-logic. If you get a really botched out-phase mix on common was VHS I have yet to come across one on laserdisc I have heard ones on DVD matrix only with I think, First Blood part 2 (1985). I later got the Dolby 5.1 and that sounded like it was mixed with Dolby stereo pro-logic II music mode it sounds dreadful! Same with First Blood (1982) expect for Rambo III (1988) which is true fully Dolby 5.1 discrete. |
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