DTS Neo 6 vs. Dolby Pro Logic II (CONSOLIDATED THREAD) (1 Viewer)

[Roger Dressler]

Cabreau wrote:

Do you get different options when you are in Music vs. Cinema modes?

Yes. In PLII, the Movie mode is the reference, preset mode just as Pro Logic was, for decoding Dolby Surround encoded content, but it also works for most stereo TV shows and the like, too. The Music mode is better suited to non-encoded stereo programs, particularly music, so there are some user adjustments that allow the effect to be altered. Center Width adjusts how the C signal is apportioned across the L/C/R speakers; Dimension shifts the spatial image either forward or backwards; Panorama emphasizes hard L/R cues in the mix, wrapping them further to the sides.

 

[Todd_Anisman]

Before this thread turned into a minor flame war, there was some really interesting discussion going on...Let's get back to that-

As for Listening to Stereo Music in DPLII, etc etc. Here's the catch guys-
It isn't mixed that way. PLII is essentially a way to deliver surround from a 2-track playback. Here's what happens:

A)All information that contains equal Phase and equal amplitude comes out the C channel.

B)All informatin that comes out equal Phase and unequal amplitude gets sent to the appropriate Left ot Right channel, according to relative difference in Amplitude.

C)All Out of phase Audio gets sent to the surrounds.

So, in a nutshell, the reason why you will often have muddy or indistinct audio is because of the separation of the elements within a mix. Mute your c. channel, and you will still hear the vocal "puuling" into the L and R channels of the front, perhaps even into the surrounds. this is because the phase relationships whcih provide space in a stereo mix decode in verry random ways in aPrologic environment. This could cause problems even in your overall frequency response- If there is out of phase audio, say at 1.2k, then suddenly your vocal can get "pulled" inot the rears, which can cause the smearing off audio that youall are hearing. when we are mixing for PLII, we are actually mixing through a Encoder->2track->Decoder (4-2-4) chain.

Hope tthis sheds some light. Bottom line is that YMMV on any particular title-You're gonna have to experiment to see which decoding process works best for each and every title.


-Todd A.

 

[Evan M.]

Great post Todd. I had an idea that is how DPLII worked but I didn't want to attempt an explanation as it may have turned into a "novel" LOL . Maybe this is why I think DPLII starts to sound a bit fake to me because no matter how good the chip, it is not going to get it right all of the time unless it is recorded and mixed that way, as is the case with stereo or SACD. Like what you and other posters said, for some things it sounds graet (DPLII) but but for other things it just doesn't cut it. Like I said earlier in this rollercoaster thread, after awhile I just get sick of trying to figure out "How is this song going to sound good" when I know it will sound good in stereo.
To everyone who has reviewed and posted on this thread: I apologize for my part of the small "flame war" that occurred earlier. I know it is a "no no" on this forum (and rightfully so). Normaly I never get like that but I felt as if I was getting put down for simply trying to come up with reasons why I thought a certain way. At any rate I am sorry for my part in almost turning a good read into a bi&ch fest . That was never my intention.

 

[Lewis Besze]

Todd,
your description of DPL II is sounds like the old DPL,I thought that Fosgate used a somewhat different approach,especially since the surrounds arent just "out of pahse" signals like DPL does it,but it's a "simulated stereo" surrounds,and full range at that .
Maybe Roger can explain this better then me.


Also DTS Neo-6 has gone through several "revision" on it's softawre, and the very early one had an annoying "popping" sound in the surrounds.It is impossible to know for the consumer which revision he has,but those of you with the Denon 3801 and 5800 has the first version.Subsequently each version was an "improvement",though it's unclear what was changed.

 

[Mark_J_H_Jr]

Not to toss fuel on the fire
But this thread had some information on the effects of comb filtering on 2 channel performance. Comparison of 2 channel versus PLII or Logic 7 or whatever your multi channel DSP of choice is, may provide some entertainment. It sure gave me something to listen for.
Like Evan, I did some open minded listening and found there might actually be something to what others say. Fortunately, we get to listen to what we like the way we like to hear it and it is really nice to have options like PLII, DTS and Logic 7.
Comb Filtering

 

[Todd_Anisman]

Lewis (and others)

You are partially correct. In a perfect world, yes, there are serious differences in how PLII decodes, however the principal of decoding is the same. I was going to post an article, but the system would let me create a link yet...But go to DolbyLabs and look under technical information and you'll be able to see an article that has a great explanation of the differences.

-Todd A.

 

[Marty Neudel]

>As for Listening to Stereo Music in DPLII, etc etc. Here's the catch guys-
It isn't mixed that way. PLII is essentially a way to deliver surround from a 2-track playback.<

Todd,

this is a minor point but, actually, Dolby sells mixers for DPLII, and they are used, albeit I've been unable to discover which recordings are made using it.

Marty

 

[David Judah]

The DPL II encoders were released last April, so hopefully we'll see them being used more and more where appropriate.

DJ

 

[Gary Kellerman]

I have not had the opportunity to play with a receiver with the features of DPL-2 and DTS-NEO. In reading many of the responses on this thread, Mr. Dressler I believe gave important advice as to how to look at the movie and music mode of DPL-2. Use the movie mode on Dolby Encoded sources. Use the music mode for Non-Dolby sources. Suppose you have a music CD that was Dolby Encoded. It would probably be best to try DPL-2 movie and then try DPL-2 music and see if in fact that cd plays better in movie mode. This would certainly support Mr. Dressler's statement particulaly if you have more than one Dolby Encoded music CD.

I do not know how many HTF members have ever played with some forms of passive surround decoders. Since 1987, I have one system that is a 5-channel dynaquad concoction. The so called stereo recordings on LPS and CDs were far from stereo when played on this system. Many recordings(but not all) had marvelous multi-channel reproduction. I had 5 channel reproduction from Dolby Surround movies on tape or from HBO as well. I believe I sent a letter to Mr. Dressler at Dolby Labs on this some years back.

My brother just bought a Marantz 5400 for his home theater. If this unit satisfies him, it will replace his Yamaha 2095. I will have that opportunity after he has fooled with his system to see how well DPL-2, DTS-Neo and CS-2 sounds on 2 channel movies and music. My experience all these years with the above Dynaquad system has given me the knowledge I feel I need to evaluate these new formats fairly. In addition, there is one additional test that I will perform. I have homemade vhs videos with stereo sound tracks made with a video camera and portable vcrs in the field with that camera equipped with a stereo microphone. The supposed stereo soundtracks decoded out into 5 channel surround sound that was quite accurate. Since these are true two channel soundtracks from a unidirectional microphone, I am curious to see what these three formats in his Marantz 5400 will reproduce from my recordings.

 

[Todd_Anisman]

Marty, David-

The unit is called a DP563. However, i doubt it will find it's way into the music field very often, except for the SACD/DVD-A world. It's like 4K!!!

-Todd A.

 

[LiorM]

Hi
Since most aduio cd's are mixed while using only 2 speakers
I assume they intend to be played on a stereo system...
Any dsp, no matter how good or sophisticated it is,
will change ! the original intention of the artiste or the sound engineer.

As far to the DPLII or NEO6,
Theoretically , since DPL is encoded with Dolby technology ...
I assume that they ( Dolby ) will do the decode better then
the competitor ...
But hey ... there is more then theory in sound so ...
Do an A/B test, try to figure out what fits you and your system and then decide.
Even after you decide try to change your listening preference, there are surprises sometimes ...

 

[JasenJ]

As a newbie who just installed my surround speakers yesterday, I've found this thread very interesting. One of the first things I noticed upon listening to DD, DTS, or using any of the surround modes for TV was that all the "life" has been sucked out of my front speakers. This "life" being the out of phase sound that my receiver was creating (or was there in stereo material) using a virtual surround mode (I'm assuming). All that out of phase info really created a nice deep, expansive, spacious soundstage - now that's all gone and I guess the surrounds are supposed to take over that job.

Hopefully as I calibrate my system, listen more closely to well encoded material, and generally get more used to the new surround sound, I'll be more pleased. But initially I was like "What the ...?! What happened to my space?" In well encoded true 5.1 material is there usually very much out of phase sound in the fronts, so you get "spaciousness" from the fronts and surround speakers?

- Jasen.

 

[David Judah]

However, i doubt it will find it's way into the music field very often, except for the SACD/DVD-A world. It's like 4K!!!

I agree--it will probably be used for TV and games for the most part. While it would be interesting for music, there are plenty of other options for DVD-V and Hi-rez.

Kind of related to the topic, I re-arranged my speakers last night(I'm constantly doing it thinking I will find that perfect placement for my room--I'm going on two years for this particular space)and while my previous placements have yielded good results, this new placement definitely improved things for both stereo and multi-channel. So, if some aren't getting satisfactory results with PL II/DTS Neo, don't automatically assume it's all the DSP's fault. Try moving things around a bit and experimenting with the digital delays. It's easy to get into a HT rut and take even the simple things of system set-up for granted.

DJ

 

[Evan M.]

Lior & Jasen, these are a lot of issues that I was bringing up in the beginning of this thread but I got bashed by some for thinking the way I did. Jasen, I feel the same way you do about the front speakers being sucked away when using a DSP. I said that good fronts will create a soundstage and enveloping sound if set up and used correctly and that if people heard a big diffrerence from stereo to DPLII that might be because their speakers may be defficient in the area of recreating stereo. That created a snowball effect to the almost downfall of this thread.
I then tried to use an open mind and give DPLII and other DSP's a second chance (with music, I always like them for t.v.). After setting up my surrounds and playing with the phase of all of the speakers I found that it can be a very enjoyabable experience. Roger (who posted on this thread) really knows his stuff about setting up everything and the theory behind DPLII. One of his posts is particular is a good read. Like I said earlier, I still certainly enjoy stereo more then DSP's but after messing around a bit I do understand how they can have a real positive effect on music listening.

 

[Roger Dressler]

Lewis wrote:

Todd, your description of DPL II is sounds like the old DPL,I thought that Fosgate used a somewhat different approach, especially since the surrounds arent just "out of phase" signals like DPL does it, but it's a "simulated stereo" surrounds, and full range at that.

As Todd pointed out, the core principles decoders use to determine where sounds belong are indeed the same in Pro Logic and PLII, and Neo:6, CSII and Logic 7 for that matter--gain/phase relationships of the two input signals. But as we know, they are all different in their sonic details. The technical descriptions we provide are simplified and only intended to illustrate the basic operation, and this is most clear when we talk about one specific channel condition in isolation.

In music, the decoder spends very little of it's time steered only to one channel, so myriad decoder-specific design choices affect the end result, as Lewis correctly observed.

 

[Jonathan Dagmar]

I was under the impression that Pro Logic 2 and Neo 6 did not qualify as DSPs, as they do not actually modifty the sounds, they only redirect it.

For what it's worth, I enjoy the sound of my CDs in pure stereo, especially the well recorded ones. However I prefer the effect that Pro Logic 2 produces. I find it opens up the soundstage, and makes me feel like I'm really "there". Neo 6 I am not as fond of for music, it sounds simialr to DPL2, but with a little more agressive separation. I really enjoy both modes for tv and video games, and could never go back to anything else.

On the other hand, true DSP modes, (HALL, THEATER, CLUB, etc) produce horrible effects that I can't stand to listen to. They muddy up the sound, alter the tone, occasionally make lyrics harder to hear, and so on. For this reason I do not feel that it is fair to Lump PL2 and Neo into this category. They really aren't the same.

 

[Lewis Besze]

I was under the impression that Pro Logic 2 and Neo 6 did not qualify as DSPs, as they do not actually modifty the sounds, they only redirect it.

That alone qualifies as DSP just like Bass Managment does.It is true that in most common use DSP reffers to one of those "enviromental/venue surround" modes.
Roger thanks for the clarification!
Evan,
just "move on" as I did!

 

[Roger Dressler]

Johnathan, you are right, it is sensible to divide the field of signal processing algorithms between those that add new sounds like reverb or echo, and those that do not like matrix surround decoders. I'm sure other categories are also useful to define, such as filter/EQ, upsamplers, etc. The term DSP gets confusing because DSP sometimes means Digital Soundfield Processing, or more generally it refers to the ICs that perform the math to do any of the types of processes mentioned above, Digital Signal Processors, which come from the many chip makers.

I'd also like to comment that some folks have referred to "5-ch stereo" as a DSP mode, and while the DSP chip performs the splitting of the signals and the L+R summing for the C output, it's not a DSP sound mode by the definitions we're using here.

 

[Evan M.]

Lewis, I assume that by the little guy winking at me that you are saying "move on" in jest. I have moved on from our little spat, as I have learned much from it believe it or not . In posts after the "spat" I was warning people who were bringing up things that sounded similar to my viewpoint that it was already spoken about and could result in another "debate". Sorry if you took that as me not putting it to rest. Now that I re-read my last few posts I could see how you could read it that way, it was not my intention (although I did feel "bashed" and the "novel" comment was uncalledfor, but that is neither here nor there). Glad to see I have been taken off of your "ignore list"

 

[FeisalK]

Lior,

Any dsp, no matter how good or sophisticated it is,
will change ! the original intention of the artiste or the sound engineer.

IMO the original intent of the artiste / engineer is an enveloping soundstage - they are currently hampered by only having 2 channel playback systems in place, and therefore try their best when recording in stereo. After all, stereo was always compromise from the beginning - the minimum number of channels needed to simulate a 3-dimensional sound environment.