Dolby ProLogic II is very interesting

Anybody know how Dolby ProLogic II works? It is a HUGE improvement over the old ProLogic. Recently, I’ve been listening to my CD’s via ProLogic II. Very interesting results. Unlike the original ProLogic, ProLogic II maintains the original stereo soundstage but it also adds a nice spaciousness to the sound via the surround speakers. This effect varies from recording to recording. In fact, with some recordings, ProLogic II seems to extract certain voices or instruments from the original recording and place them in the rear speakers. ProLogic has a feature where you can adjust the width of the soundstage and the depth of the soundstage.

I know that some “stereo purists” may poo poo ProLogic II, but I think that it does a really good job of creating a spacious, 3d soundstage out of stereo recordings. The only thing that I don’t like about it is that it seems to diminish the level of bass.

 

Try Pink Floyd's "Meddle" or "Atoom Heart Mother" in PLII with center enabled. Strange, yet compelling.

There's a reason it's happening, but weather it's happening on purpose or not is another thing all together. That squishy fake surround!

 

Try Jimi Hendrix' 3 Experience albums

 

Yes, I have heard VERY good things about PL2, to the point that any new reciever I buy for DVD-A and SACD , I will make sure that it has PL2.

It does do an amazing job with audio Cds. Who wants to listen to the same old same old all the time?

 

You touched on the aspect of PLII that makes it compelling and that is leaving the stereo (R,L) essentially untouched. Before PLII there were other all-analog matrix decoding schemes that work in a similar fashion with the same basic philosiphy. Circle Surround (by RSP) and 6-axis (by Madrigal/Citation) are similar to PLII in many respects. I have had extensive experience with both of these for HT use. For older films recorded in stereo both work better than re-channeled, or 2-channel, Dolby Digital.

 

Actually isn't DPL2 taking "out of phase" information that is encoded in many recordings (as you say sometimes on purpose other times not) and using some fancy algorithm on it to redirect where the sound comes from within a 5.1 set-up.

I think that if a recording engineer purposely creates certain phasing effects in a recording they will work a certain "magic" with DPL2 more so than recordings that don't have that "weird" phasing.

 

How ProLogic II works according to Dolby

Okay folks, following is the technical information on how ProLogic II works, according to Dolby Labs.

http://www.dolby.com/tech/l.wh.0007.PLIIops.pdf

 

I don't have DPL2 on my own system but I've heard it in other people's homes, and I agree it's way better than the old DPL. My general problem with algorithms that take OOP info from a two-channel recording to generate surround signals is that, whether or not the resulting effect sounds pleasing or interesting, I can't forget that the artists and/or mixing engineers didn't intend for them to sound that way. My own rule of thumb is, if the original signal is two-channel, then listen to it on two speakers.

I don't think I'm being a "stereo purist" per se, as I have a 5.1 setup and I'm quite interested in seeing where hi-rez and surround-sound technologies will take the mass consumer market. I'm more like an "original intention purist" -- you know, the kind you bump into around here frequently.

 

I tend to agree with you on this point, but isn't it somewhat common knowledge that when Hendrix recorded and released his first 3 albums, that he purposely wanted some "out of phase" information inclusive on the recording to create a phantom surround type of effect (sort of like a Q-sound effect). I think that "Axis, Bold as Love" is notorious for some phasing that attempts to make you think that some guitar sounds/feedback are swirling around you instead of merely in front of you.

In this case, because only 2 channels were available to Hendrix, he could only present the music in 2 channels, yet with DPL2 those out of phase sounds would create somewhat interesting effects. I should probably try this myself since I have many versions of all early Hendrix albums on CD and vinyl, and my receiver has DPL2. (That is why earlier in this thread someone mentioned the 3 Hendrix albums.)

It would be interesting to see how Jimi would have approached surround sound if he were still alive with the advent of SACD and DVD-A.

 

Our family room has cathedral ceiling and it takes a lot to fill up the room.
A 5.1 speaker system became a necessity. So when it was time to build our audio system we purchased five identical speakers. When listening to Redbook CD's I prefer the sound coming from 5 speakers instead of two.

PROLOGIC II is nice but I think that Denon's 5 channel Stereo mode bests
it for Redbooks CD's. Denon's 5 channel stereo mode doesn't sound like a DSP mode at all.

 

Try Lexicon's Logic7 surround sound from 2ch sources. Much more natural that PLII IMO and you have a host of adjustment parameters to tailor the sound. A listen to "Money" with Logic7 and you'll be in awe.

 

You have a very valid point. But then again, Mikey has a valid point also. Depending on how you setup Prologic II, the effect can be very subtle or very dramatic. You can set it up so subtle that you are basically listening to the original stereo mix, except that it sounds more spacious.

Last night I was listening to some early Beach Boys recordings using ProLogic II. Brian's voice was solidly planted in the front speakers. When the other Beach Boys started singing their Oooooo, Ahaaaaa harmony stuff, I was completely engulfed by their voices. It wasn't like their voices came from the speakers behind me or in front of me, they were just everywhere. Every hair on my body stood up. I must have looked like a porcupine. It was almost like angels were signing. Just incredible.

Tonight I will have to listen to Mr Hendrix's Electric Ladyland in ProLogic II. I read in the liner notes that the beginning of Voodoo Chile was intentionally mixed out of phase.

John

 

Not just Hendrix . . . I'm sure all the prog- and art-rock bands would have gone nuts! And what about the Beatles?

I'm sure you're right, and I've had some similar hair-raising surprises with plain ol' DPL in the past. Oh well, I'm sure I'll be playing around with DPL2 next time I upgrade my setup . . . which won't be anytime soon since I just got an HDTV and my wallet is really hurting.

Speaking of "synthetic" surround sound, Bose has something they call Videostage 5 that they claim "gives you a five-channel surround sound experience from everything you listen to – VHS tapes, stereo CDs, even mono TV programs." I wonder if the process they use to create surround from a mono signal is anything like the mix on the recent AHDN DVD.

 

I wonder if they will be using a lot of reverb and time delay. Maybe they will do something like the "Reprocessed stereo" that was used on the early Dave Clark 5 LP's. Think about it, "Reprocessed Surround". They would divide the mono audio into 5 different frequency ranges. Each speaker would play one of the 5 ranges. Yikes!!!!

 

If surround were to be available to Hendrix, Bold As Love would have been a much wilder album.

 

Waddaya got?

 

A Philips 34PW9817. It's a discontinued model that I got cheap, although it still cost more than I really should be spending right now. I wouldn't have gone for it if I hadn't been afraid of missing out on a great deal. Anyway, at least I'm single and there's no one to bug me about my spending.

 

In the ol' days of Quad, Crawdaddy magazine ran an article headlined "Why Quad should reunite the Beatles".

The point was that the Beatles would had made music that had to be listened in Quad.

Imagine DarkSOTM being released then ONLY in Quad, with a sticker saying "It is the opinion of the artist and producer that this album must be listened in a Quadraphonic setup, ideally through a Tate II decoder, in order to obtain the intended results. While it will offer adequate stereo playback with no loss of any musical content, a splendid time is only guaranteed for all with Quadraphonic systems".

 

If anyone wants to try Pro Logic II on the cheap, Circuit City has a Sherwood receiver on sale this week for $129 that has Pro Logic II, DTS, the works, etc.

 

Even Ringo said :

"If 5.1 had been around when we did The Beatles we would have used it"

 

The absolute minimum I'd spend on a PL-II receiver is whatever the Onkyo models are going for at Circuit City. The Sony, Panasonic, Kenwood models all sound puny next to the Onkyo. In fact, my speakers are not an 8 ohm load, they are more like a 5.5 ohm and as a result, everytime I turned the receiver up to a realistic volume, the amp overload circuit would just shut the whole thing off!!!

Imagine, just as you are getting into the record or movie and -pow- DEAD SILENCE.

Stay away from the el cheapos unless you are unemployed.

My 65w Onkyo cost all of $299.

PL-II does sound pretty good.
I have to cut the treble slightly on some material and kick up the bass,
the matrix-ing tends to dry out the sound.

 

Q-Sound recording of Madonna's Immaculate Collection

I have Madonna’s “Immaculate Collection” that was remastered in “Q-Sound”. Q-Sound is supposed to give stereo recordings a three dimensional sound. In my opinion. when Immaculate Collection is played in stereo mode it still sounds like a stereo recording. However, when it is played in ProLogic II, it sounds like a multi channel recording. In fact, some really interesting things happen such as voices moving from speaker to speaker and from front to back. In the song “Like a Prayer”, Madonna says the word “God” at the very beginning of the song. The word begins in the front speakers and quickly fly’s over your head into the rear speakers. In other songs her voice moves in a circular sequence from front to rear speakers. Now, you may say that this type of sound processing is bizarre, but keep in mind that Madonna is very bizarre and IMHO, these effects perfectly fit her style of music.

If you do not have the Q-Sound version of this CD, keep in mind that the songs on the Q-Sound version of Immaculate Collection have been altered. Some are played at a faster speed than their original version and the fade-outs have been changed on a few songs. Some songs are segued together.

 

I think it could be a good thing in the car. When you have your tweeters on the front console and the woofers in the door, you sit rather close to one speaker and far away from the other. With ProLogic II one could create a center channel and feed a speaker in the middle of the console with it. I think the center speaker would help a great deal in making a more realistic soundstage, especially in this rather difficult listening situation. As far as I know ProLogic is good at extracting the center information from stereo.

As far as I know there is at least one manufacturer that makes a ProLogic II decoder for the car.

 

All of this talk sounds just like what my Aiwa stereo has. Basically a button named QSurround. I'm already in love with it. For those who have The Beatles "Revolver" and a ProLogic II or other "fake surround" (though it's hard to call it that because it is so real) aplliances and listen to Tomorrow Never Knows. I won't give details, because I'd like to compare what all of you hear with my list of details I put down. But the song is so freakin' cool and for those Beatles fans claming 5.1 is sacrilage, well The Beatles were so ahead of their time after all.

BTW, how do I tell if a disc is made in QSound?

 

On the Madonna disc, Q-Sound is noted on the Jewel case.