Does surround make sense for 2 channel material? - Page 2

I'd like to know more about your experiences here. Are there some particular CDs or tracks that you've found give poor results? Which surround mode are you using?


Is it the rendering of all vocals, or the main vocals, or the background vocals that you find most objectionable? As kiwi2 mentioned, the main vocals out to sound virtually identical when the surround mode is turned on vs off. However, background vocals are often spread in the mix, and when surround decoded, will appear in L/R and Ls/Rs. Is this what you object to?


Yes, as with the background vocals, the other music will also spread to the surrounds. I find that it simply widens the effect, rather than calling attention to itself as "instruments popping out the surrounds" as is too often the case in, say, Elliot Scheiner mixes. Now that's annoying!

Are your surrounds well matched to the L/R fronts, both in timbre and level?

PLIIX Music is the mode. The oddness usually results with tracks that are more the processed, studio-created pop or rock type recordings. The sound just gets way too spread around the room.

I just listened to Makin' Whoopee by Dr. John w/Rickie Lee Jones from In a Sentimental Mood. Instruments themselves are coming out of the surrounds and I can hear them (mainly piano notes). Actually, it's often piano ambiance that sounds too pronounced and includes actual notes in the surrounds.


It's the main vocals that seem somewhat pulled back in the soundstage. It's not that they sound different, and I have well-matched speakers across the front, it's just that they sound a bit recessed compared to two channel.


My levels are spot on. The L/C/R are timber matched (same drivers/same line), but the surrounds are not. It's a 7.1 setup with the surrounds at 90 degrees and about two-feet above seat level. Maybe it's the surrounds at the side that make the surround extraction too easy to localize?

Still listening to the disc, and a piano run just flew over my head from right to left. I'd prefer that piano stay up front.

BTW, I'm using default settings for DPLIIX Music on my Yamaha receiver, which are PANORAMA: OFF, CENTER WIDTH: 3, DIMENSION: STANDARD.

Since my setup is designed for multi-channel listening first, I'm interested in finding ways to make this work, but I don't want to interrupt my listening to tweak settings on a recording by recording basis.

John

The unmatched surrounds may be the cause of that.



I personally prefer Yamaha's own '7ch stereo' mode over PLIIx music or Nero:6 music mainly because it has a finer adjustment range. In PLIIx you can adjust how much extraction goes to the surrounds by -3 to +3. This is a 7 step range. In '7ch stereo' it's 0 to 100 in 1% steps.

And like I said earlier... adjustments in the time domain will make big differences to the soundfield as well. Changing the set distance to your front L/R speakers by even 0.1 meters can significantly change the focus of individual instruments and vocals. You don't have to go by exactly what the tape measure says or YPAO set.



And you shouldn't have to. I have my receiver set up now that the only messing around with the remote buttons I do in this regard is switching between 'straight' and '7ch stereo' when changing between a 2ch source and a multichannel source.

I've tried the 7 ch stereo, and while it delivers a very lively sound, I find that the soundstage up front loses its depth. I do find this mode useful while playing music in the background, but I don't like it for when I'm doing more critical listening.

I have not made any adjustments to the distances, but I'm not sure those changes would keep me from being distracted by instruments or by parts of an instrument's sound coming out of the surround speaker. I may play around with those to see what changes are produced. A nice thing about the Yamaha is the ability to save multiple configurations to memory for fast switching.

Thanks much for the details.


That's the same as my 7.1 setup. I have found that some folks check their speaker levels by sitting in the MLP and observing the SPL meter held in front. Seems reasonable, but the levels will be different compared to putting the meter at the head location and observing it from behind.


What, you don't like flying pianos?


Sounds correct.


I agree. Nor do I mess with it.

It might just be that it's not to your liking, and I perfectly understand and respect that. I was just wanting to confirm--and I see nothing odd going on.

@jpco. I had the exact same experience when I first started using PLIIx... Recessed somewhat hollow vocals, diminished bass, overly wide soundstage. Then I followed Sanjay's advice and adjusted my PLIIx settings the closest to stereo I could get and gradually moved away from that extreme till I was where I wanted to be.

I'm at work an don't have my specific receiver settings but i will look when I get home and post them for you to try.

I have set levels using a tripod and the receiver auto setup and by sitting with the SPL meter in front of me. Don't recall much of a difference, bit I'll double-check the levels.

While we're in this conversation, I have another question regarding DPLIIx. Since I find the surrounds to be most distracting, how will DPLIIx Music function if I disable the surrounds and surround backs? Will it just process properly with the center and leave what would have been in the surrounds in the L/R speakers? If so, this may be a compromise that would provide some benefit in the front soundstage.

Thanks for your replies.

Thanks for the info. I'm interested in the progression you made from Sanjay's initial advice to the settings on which you've settled.

You should try disabling the backs and run it as a 5.1

More likely to give you a wide stereo experience rather than a surroundsound experience.

Too much center perhaps and losing some stereo effect. 7ch stereo defaults to everything at 100%.

My 7ch stereo setup is center - 48%, surrounds - 84%, and backs - 0% (off)

This sounds as though (the component recording of) the piano in the the LEFT track is slightly delayed behind the RIGHT track (what I once saw called an 'azimuthal' error). I've heard this sometimes on material 'badly' converted from analog tapes. As the audible artifact in (your) playback is a direct consequence of using the (available) steering process, the solutions would seem to be limited to using a surround mode which does not use/emphasize steering or to stick with (2 channel) stereo playback for the affected tracks.

I do not recommend that. It will not help the front stage to add the center speaker only. The soundstage magic actually comes comes from the surrounds. You could try adjusting the Dimension control to the front a click or maybe two (it should offer 3 clicks front and 3 clicks back, with the default in the middle). That will reduce the surrounds.

@jpco, My PLII settings on my Onkyo 706 are as follows:

Panorama: On
Dimension: -3 (as low as it will go)
Center Width 7 (as high as it will go)

The dimension being low seems to bring the vocals back to the front like they sound when played through 2 channels. Panorama seems to increase the recessed effect hence why the setting is negative and not at zero.

Hope this helps.

Setting the Center Width to max is equivalent to passing the stereo source to the front channels.

Panorama allows directional signals in the L or R channels to also come from the surrounds, so that will tend to compete with the vocals to some degree. Reducing the Dimension control biases the soundfield forward, as you noted, which in a way counteracts Panorama.

If Panorama is too strong, rather than offsetting it with Dimension, might be worth trying it turned off, and set Dimension back to 0 to see how that fares. Just for my curiosity--you can of course keep using whatever settings you like.

and the Dimension setting at 0 and it was a similar sound but I missed the extra oomph panorama gave the surrounds. Jpco should definitely try both settings though.

Thanks, minimalist1969 and Roger.

Center Channel
I've been playing around with some settings this morning. I started with the center channel on 7, moved it to 6, and thought the vocals held up as well as listening 2 channel. I could listen on 7 or 6 going forward.

How does the range of Center work from a technical standpoint? As I understand it, the center is composed of signals duplicated in L/R. If 7 is no center and 0 is full center, what's happening in between?

Dimension
While having the Center channel at 7 (nothing coming out of the center), I moved Dimension to -3 (lowest setting). A/B switching between DPLII music and STRAIGHT mode, I noticed a significant loss in output of overall signal, especially noticeable in the lower regions. With Center set to 7, I was expecting it to sound virtually identical with a little more spaciousness due to adding the surrounds. That was not the case. I could only get the output to match fairly well by returning Dimension to Standard.

I assumed moving Dimension to the negative settings would just return the signals to the fronts, but that is not what was happening. Is this how it's supposed to work, or is there something wrong with the implementation in my AVR (Yamaha RX-V1800)?

I also tried this with Panorama ON, but I didn't notice any difference.

After sampling a number of recordings, I found some that had enhanced soundstage and others that were distracting due to some instrument parts coming out of the surround and seeming to me to be placed unnaturally in the room. It seems for my purposes that there will not be a single surround setting for 2 channel music that will work (and now that I've started testing and thinking about this, I'm doomed to insane amounts of distraction and will probably never enjoy music again).

John

In between, the center signal is spread across all three outputs, L/C/R. The proportions are such that the total loudness level is kept constant, even though as the CW setting is changed from 0 to 7 the split is shifting from C to L/R.

Of course this ability to maintain a constant level relies on the gains and frequency responses of all three channels/speakers being very well matched. If you hear the strength of the vocals increase as the CW is adjusted from 7 to 0, the C gain is too high. If vocals get weak, the C gain is too low. If the responses do not match, the tonal qualities will be affected. Finally, the tone quality can also be affected (mainly when the CW is set for 3-4, not 0-1 or 6-7) by small timing differences of the C speaker vs the L/R. If you add 1' to the C speaker distance, it will reduce the timing about 1 ms, and you can hear the difference in vocal tone quality as all three speakers blend together.


The Dimension control uses summing/differencing of the input signals, and that means when signals are mixed, the overall gain of the path has to be attenuated in order to ensure headroom is maintained. You are hearing that gain shift, and if you want to do a direct compare with 2-ch, then you would need to reduce the volume control a few dB when in bypass until the loudnesses match.

In the Yamaha, the control works like this: –3 (towards the rear) to +3 (towards the front). That means the vocals will be suppressed not only by the level protection I mentioned, but also by biasing the soundfield to the rear. Since you are averse to strong surround effects, I would not recommend setting Dimension to anywhere between -1 to -3. If anything, maybe +1.


Based on your descriptions, I'd recommend turning off Panorama, and trying Dimension at 0 and see how the surround effect feels. Did you confirm your channel balances are correct with the SPL meter located at ear position?

If so, and you still feel the surrounds are too strong, then try Dimension at +1, and maybe even +2.

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Hey JPCO, I think you have cut through much of the mumbo jumbo of too much theory, with not enough listening.

Yes, it´s an interesting topic, but comments like "If you think about it, you have four real choices with a spectrum joining all of them. You can use two speakers and allow the room to do all of the surround processing (by bouncing sound here there and everywhere), you can use multiple speakers with room treatment and allow a surround processor to do surround processing, you can use two speakers with room treatments aimed at removing reflections entirely, or use multiple speakers with a surround processor and NO room treatments such that both room and processor are doing processing." really end up confusing the issue, as they do not help us move forward in the real world!

^^As Bill Miller would say^^

There are cogent and defensible arguments for both approaches to music reproduction as discussed here, plus an almost limitless number of other possibilities. Ultimately, I refuse to have to make a choice. Perhaps someday I will, but as long as I can forestall that day, I'll be happier doing it both ways.

With a multichannel music system, the key to excellence begins with identical speakers, supplemented with multiple subs. Yes, you want good electronics as well, but without a closely matching speaker set up, electronics can't do their best. Even in a well-treated or moderately-treated room, without matching speakers, it's an uphill battle. The good news is this works well even with modestly priced speakers, as long as they match well and are supported by well-implemented subs. Whether running 5.1 or 7.1 channels, current PLIIx, L7, and other systems can do an exceptional job of enhancing the listening experience.

However, one cannot assemble a hodge-podge of different speakers, even from the same brand and expect to get the best results.

For stereo listening, which I do a lot and enjoy immensely, I think the real benefit is that it's more practical from a budgetary standpoint to buy two very nice, even exceptional speakers than to buy five or seven pretty good ones. Plus, if there's any resistance in the household, getting two big speakers in the house is easier than five big speakers, not to mention getting five big speakers all in the right places.

The power and fidelity of two big, well-designed speakers is hard to deny, and the sheer joy of listening to them is a treat. Nonetheless, they are harder to set up right; in fact that can be an endless task of tweaking, moving, switching equipment, that is joy to some and bane to others. (I'm sure someone is thinking "I just stuck mine in the corners and they sound fine." Well, good for you. )

Despite my enjoyment of stereo, I listen to more music in surround as a matter of preference. It is simply better. The set up is more predictable, the control over the listening environment is greater, the sound is more immersive and multi-dimensional, and the imaging is wider and deeper. When all the speakers are identical or closely-matched from the same line and supported by multiple subs, it is unbeatable for music, even "reprocessed" stereo.

Can we get one system that does it all? Maybe, but that's asking a lot. The normal hybrid system is better speakers up front and smaller satellites around the room, plus a sub somewhere. This seems fine for HT, but we're talking music here, so it's not as fine. For music, this system will probably sound better to more people in stereo than in multichannel.

For one thing, it's automatically biased toward the front with better speakers. That's a simple truth. Those speakers also are likely to get slightly better placement by necessity. In addition, in the switch between surround and two channel, there's likely to be a level-matching problem in that the fronts sound immediately louder and clearer. It must be better then, right? Even knowing this is a false comparison, I'm still influenced by it for a few seconds before I remember to match the levels before and after.

So that's a quick and general response for my part. I think both two-channel and surround systems have a place in the house if possible. I won't choose one if I don't have to, and I think it's very hard to have one system that does both two-channel and surround well, though certainly not impossible. I'm also writing only about music systems, not HT.

There are some excellent arguments for three-channel systems (L-C-R) as Sanjay mentions, as well as mono systems (whether single full-range driver, two-way, three-way, coaxial, etc.), four channel systems, and more. As always, I appreciate Roger's comments, since he spent his professional life dedicated to understanding and developing ways to make the listening experience better for all of us.

This thread is of great interest to me since I have been synthesizing surround channels from 2-channel stereo sources for more than 25 years. As others have said to do this convincingly isn't easy.

I prefer classical orchestral and pipe organ music. Music of these genres is normally performed in large spaces. As preposterous as it might seem I attempt to convey the illusion of a concert hall or large church in my home listening room. Having said that I don't think there is any substitute for discrete multi-channel recordings made in a natural environment. In other words, not studio processed multi-channel.

The key component in my ambience simulation is a Lexicon 224 Digital Reverberator. It hasn't been manufactured for years but for my purpose it is ideal. Its successors are among the most popular in studio use today. It synthesizes four channels from a two channel input. It has vast control over pre-delay time, decay time for both bass and mid range frequencies, cross-over, and depth.

My listening room is not acoustically treated but it is of irregular shape with multiple floor levels and ceiling vaults some as high as 18 feet. My side channel speakers are JBL 4311's placed 13 feet above floor level and just a little bit forward of front channel speakers which are at floor level. Perhaps I should call them height speakers since they do give an impression of the soaring heights of a large church or concert hall. Rear channel speakers are JBL 4315's about 6 feet off the floor. My listening position is about 9 feet from the front speakers and 11 feet from the rears and 16 feet from the height/side speakers. The front speakers are my own design utilizing mostly JBL drivers and are quad amp'd.

It's taken lots of time and trials getting the optimal tonal and volume balance between all channels. Each channel employs UREI 527A and 537 equalizers, and multiple Crown and McIntosh amplifiers. I have an Audio Precision System One with instrumentation mics and an Ivie IE-30 spectrum analyzer to keep everything calibrated.

I am completely satisfied when comparing my synthesized ambience with that embedded in good 5.1 SACD recordings of classical or organ music. There is little difference. The synthesized channels can't be identified as such but you sure know it when they are off. If they could be individually identified my charade would be exposed as a carnival gimic.

However when it comes to music recorded in a more intimate setting like a jazz club or studio I find it is better to leave the ambience channels off unless listening to 5.1 SACD's and bypassing the Lexicon 224 altogether.

As the poster of that quoted statement, I'm curious what problem you have specifically with it, why it confuses the issue and in what way, and what you propose we do to "move forward in the real world."

This isn't an easy topic to wrap your head around for the typical enthusiast, as evidenced by the many posts, diversity of opinions, and continued discussion in this thread, even among persons with much experience and knowledge in the field. Recognizing that there is a spectrum (2 orthogonal ones, actually), describing the cases that define the extremes, and reminding people that all real systems lie somewhere within the area defined by those extreme cases (ignoring Kal's case of only discrete multichannel source material) is the best way I can think of to help someone on the journey to understanding their choices in music playback.

Do you disagree with the content, or just think it confuses the average reader?

Personally, I found the explanation quite concise. There are four basic approaches: 2 channel with and without room treatments, and multichannel with and without room treatments. In descending order of quality I would put multichannel sound with room treatments at the top and 2 channel sound with no room treatments at the bottom. The positions of the other two scenarios are debatable.

So, I've checked my levels and tried the different settings, and my perception of extracting surround from two-channel music is pretty much the same. I like it for some tracks, but find the distraction of sound sources placed noticeably in the surrounds takes me out of the listening experience.

I've tried PLIIx Music, Neo 6 Music, and Neural Surround. It's surprising how very different all three of these sound. Neural seems the least "discrete" of the three, but it still sends some instruments to the surrounds in ways that seem artificial to me.

Thanks for the suggestions. I always find this to be an interesting area to explore.

With continued listening to 2-channel music in 7.1 surround modes, I have the following observations:

• Neural Surround - stable surround image, main vocal not too recessed, soundstage collapsed toward the center a bit much, some artifacts where it seems that complete sounds don't locate in the same place at times (sounds odd when this happens).
  
  
• Prologic IIx Music - wide soundstage, very enveloping surround effect, main vocal recessed in the mix, sounds somewhat brighter, almost as if the main channels are artificially processed.
  
  
• Prologic IIx Movie - wider soundstage than Neural but narrower than Music, main vocal not as recessed as Music, surround envelopment less than Music
  
  

After much listening, I prefer the stability of the real center image over the phantom center stereo image. However, I don't like it when the vocal recedes into the mix or becomes diffuse across the front speakers.

With that in mind, I changed the Music Center Width to zero. I expected this to give me a similar center sound to the Movie mode, but it did not. The vocals are still somewhat recessed and spread more across the three front speakers when compared to Movie.

A few questions:

1. Is there a way to get the center channel in Music mode to sound similar to the Movie mode? I know this is contrary to what most prefer, but I do like the stable center image, and I'm getting a good blend L/C/R.
   
   
2. With PLIIx Music, the fronts clearly sound brighter in my system, somewhat artificially. Is Music doing any processing of L/R that is not happening with PLIIx Movie?
   
   
3. With my preferences, I'm leaning toward PLIIx Movie for listening to music. The center is stable and not recessed, and the surrounds do not seem too prominent to me. However, in reading Dolby Surround Pro Logic II Decoder Principles of Operation, I see that something called Autobalance mode is on. How much will this affect imaging for the front soundstage when listening to music?

Thanks in advance for any insight regarding these questions.

I can assure you there is nothing in PLIIx that can change frequency response in the front channels. In the Music mode, PLII applies a gentle shelf filter in the surrounds to take the HF edge off. That filter is disabled when Panorama mode is turned on. So make sure Panorama is off.


Based on what you report, I trust your ears!


Did you check the timbre match of the center to the L/R speakers? Using the internal noise test signal, does it sound the same as it steps from L-C-R, bot tonally and loudness? I have found that careful EQ and gain trims can make a difference.


If you have Center Width set to minimum, and it sounds different in the L/C/R than Movie, something is broken. They are identical at the point. Yes, the surrounds are still treated differently, so maybe kill those speakers when comparing just to make sure it's not affecting the test.


See earlier reply.


Autobapance has a very long time constant. Really slow, so that only the long term gain imbalance is affected. And with modern, high quality digital sources like CDs, there are essentially no balance errors anyway.

Instead of doing on your own the first time around, I would think that it would be preferable to actually experience someone else's multi-channel setup and then decide how far you are willing to go. Setting up a home theater multi-channel system cold, is a lot harder than what you might think because there are so many details that you cannot know or be aware of. So consider that before spending anything.

Thank you for the reply, Roger.

I turned off surrounds and moved Center Width from 0 to 7 and back again. I'm glad to find that there is not much change in the timbre of the vocal at all. I listened to the AVR noise through each of the three front channels, and all sounds good.

I then tested PLIIx Music and Movie with the surrounds turned off. Switching back and forth, I could hear a wider soundstage in Music, but I no longer perceived the vocals as being recessed. It seems that either the recessed vocals were an illusion that had to do with the surrounds being engaged or that processing is different in the center when there are no surrounds. Either way, my concerns about vocals in Music mode with center at 0 were allayed.

Going back to a previous post of yours in this thread, I made adjustments to Dimension, moving from Standard to positive values after re-engaging the surrounds. Here is where there is a noticeable difference in the vocals to my ears. The issue I've described as recessed vocals is no longer apparent when moving Dimension toward the positive.

I'm not sure how much of this was in my head and how much was reality, but I thank you very much for your help. The surrounds and their processing were having a great affect on how I was hearing the front soundstage. I'll listen a while on Dimension settings 1-3 to see which are most enjoyable.

That's exactly right. And somewhat counterintuitive, which is what makes all this experimentation a bit of fun. Glad to hear of your progress. The Music mode was intended to exploit the spatial properties, whereas the Movie mode was aimed at the directional properties--like panned surround effects for surround movies/TV programs.