Convert 5.1 etc to 4.0

[Guest DrSK]

8 minutes ago, al said:

I think where you are getting very confused is that 2.0 high quality stereo are designed to be fed 2.0 channel material and do a wonderfull job of it.

 

however this IS a very different situation to 5.1 which is designed very much with 5.1 speakers in mind for delivery. not fake speakers. not to say you cant use imagined fake created speakers and most come with modes for such. but it doesnt actually replace actually have those REAL speakers instead

 

I run a 2.0 bedroom system (actually augmented with a sub) and also have a separate  full 7.1.5 in the main setup (that incorporates a "high quality stereo")

 

I can tell you the 2.0 system in the bedroom or for that matter the 2.0 high quality setup (incorporated in the 7.1.4 setup) neither can replace the 7.1.4 setup....

 

 

No not confused at all. This stuff isn’t voodoo despite what marketing and brands want people to believe.

 

Here we are going in circles. People don’t want to get it or understand it. I came here looking for advice on a box which does what I wanted.

 

A few people answered my question, I demo’d an Anthem, Oppo and got the info I needed. Didn’t personally like the Anthem at all and the Oppo 205 with a few tweaks will be ok for now.

 

The path I’m going matches human perception in a plane which is good enough for me. I’m over trying to explain acoustics to everyone else.

[Satanica]

Centre and subwoofer are definitely the easiest to create with other speakers making them the least important. Try recreating a Left, Right, Surround Left, Surround Right with other speakers

[Guest DrSK]

8 minutes ago, davewantsmoore said:

The subwoofer was either poor, or it was setup poor.

 

A good subwoofer, setup well - only offers potential advantages over no subwoofer.

100%, compared to the mains. And if I want to put out more from 20Hz and lower I may go there once I tune the room. Mike does a nice isobaric with a roll off tuned to the ML2+Rs. I just don’t like the sound of everything else I have heard.

[cwt]

Dr S.K ; I would urge you to read this pdf treatise on multichannel sound by the Acoustical Engineering icon ; Floyd .E Toole '; although dated the principals he lays out still hold . We had 4ch reproduction eons ago with quadraphonics which was later emulated with dsp modes which even now cant emulate the true discrete we have now.. 

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Old habits die hard, and entrenched stereo music engineers find it  difficult to work with a center channel.  So several of them simply  don't use it, or use it very sparingly.  The sweet spot is back.  They invent "reasons" like:  the customer can turn off all of the other  channels and then can hear "the talent" naked, without the backing.  Another is that customers might buy small cheap center channel  speakers, thus degrading "the talent".  Since 80% or more of what we hear in a movie is from the center  channel, it seems to me that film people are the ones who should be  concerned.  In reality there is little to be concerned about.  This is a  regrettable practice that, I hope, will cease. 
 

http://www.mariobon.com/Articoli_storici_AES/Toole/Libro_bianco_Toole_123.pdf

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One of the most problematic nuisance variables is the position of the  loudspeaker and the position of the listener in the room.  To control  this variable at Harman, we have created a room with a "shuffler" that  physically moves speakers around, bringing them always to the same  locations when they are being auditioned.  It is pneumatically driven,  quiet, and computer controlled so that the positions are precise.  It  takes about three seconds to switch the positions of the active and  inactive loudspeakers. 

Easy to see why a Harman system is not so cheap 

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The first sound to arrive at a listener's ears is the "direct" sound.  If  the loudspeakers have been angled to face the listener, this will be the  on-axis sound, often the best possible sound from the loudspeaker. 
The Room - Early Reflections 
However, following only a few milliseconds behind, and only slightly  less loud, will be the early reflections: sounds that have been reflected  from only one surface in the room.
The Room - Reverberation 
Still later, come the multitudes of reflections that have been reflected  more than once, perhaps many times.  These are individually much  lower in amplitude, but collectively loud enough to be a powerful  factor in our impressions of sound quality, space and imaging.  In  small rooms, typically furnished, this sound field, although often  called 'reverberation' is not the directionally diffuse and temporally  complex reverberation that we hear in a concert hall, or many other  large, acoustically 'live' spaces.  

 

Edited April 15, 2018 by cwt

[Guest DrSK]

59 minutes ago, cwt said:

Dr S.K ; I would urge you to read this pdf treatise on multichannel sound by the Acoustical Engineering icon ; Floyd .E Toole '; although dated the principals he lays out still hold . We had 4ch reproduction eons ago with quadraphonics which was later emulated with dsp modes which even now cant emulate the true discrete we have now.. 

http://www.mariobon.com/Articoli_storici_AES/Toole/Libro_bianco_Toole_123.pdf

Easy to see why a Harman system is not so cheap 

 

Thanks but I’m an acoustics engineer and there was nothing in that paper I didn’t already know. It is an introduction to acoustics.

 

In summary I know the sweet spot will be smaller, I at least alluded to that many pages ago and I won’t be using the quad speaker positions.

Edited April 15, 2018 by DrSK

[Irek]

I watched Start Wars yesterday just to compare 2.0 vs 4.0 vs 5.1. In my opinion when watching Start Wars the 5.1 setup is far more superior over the 4.0 or 2.0. Basically in 4.0 setup the sound didn't follow the situation on the screen. Basically dialogues and sound effects were coming from the same point/speaker while the situation on screen was different, actors were standing in the centre of the screen and sound effects were far on the left hand side. 

[Guest DrSK]

41 minutes ago, Irek said:

I watched Start Wars yesterday just to compare 2.0 vs 4.0 vs 5.1. In my opinion when watching Start Wars the 5.1 setup is far more superior over the 4.0 or 2.0. Basically in 4.0 setup the sound didn't follow the situation on the screen. Basically dialogues and sound effects were coming from the same point/speaker while the situation on screen was different, actors were standing in the centre of the screen and sound effects were far on the left hand side. 

That may be true for your setup. I have never had issues with my system getting the locations of stuff wrong or muddy.

Mine could potentially be better in 5.1 if I could afford to match it throughout (which I can't). However for what I am currently after it would be unnecessary until I need to fit more people into the sweet spot or until I address some room issues.

Edited April 16, 2018 by DrSK

[Satanica]

50 minutes ago, Irek said:

I watched Start Wars yesterday just to compare 2.0 vs 4.0 vs 5.1. In my opinion when watching Start Wars the 5.1 setup is far more superior over the 4.0 or 2.0. Basically in 4.0 setup the sound didn't follow the situation on the screen. Basically dialogues and sound effects were coming from the same point/speaker while the situation on screen was different, actors were standing in the centre of the screen and sound effects were far on the left hand side. 

I now have a 4.0 setup as per this thread.

But I do redirect bass from small surrounds to L and R and my L and R speakers have two large sub-woofers to relieve them of work below 80Hz.

What I love about NOT having a centre and I've said this before is that dialog sounds like it's coming straight out of my screen, straight out of the actor's mouth's, not from below.

And I've had large and capable centre speakers before.

Edited April 16, 2018 by Satanica

[davewantsmoore]

14 hours ago, cwt said:

Dr S.K ; I would urge you to read this pdf treatise on multichannel sound by the Acoustical Engineering icon ; Floyd .E Toole '; although dated the principals he lays out still hold . We had 4ch reproduction eons ago with quadraphonics which was later emulated with dsp modes which even now cant emulate the true discrete we have now..

To be clear though, Toole is saying that content producers should use the centre channel  (as opposed to avoid it).

 

Not, that it is impossible to accurately present LCR content, using just L and R speaker.    (NB - A centre speaker does assist people not seated well for the L and R speaker, and does fix comb filtering inherent in stereo speakers - assuming the centre is very well setup)

 

[davewantsmoore]

18 minutes ago, Satanica said:

What I love about NOT having a centre and I've said this before is that dialog sounds like it's coming straight out of my screen, straight out of the actor's mouth's, not from below.

 

 

This is a typical symptom of a poorly implemented centre channel speaker.    No centre channel speaker is usually preferable over a poorly implemented one.

[cwt]

2 hours ago, davewantsmoore said:

To be clear though, Toole is saying that content producers should use the centre channel  (as opposed to avoid it).

 

Not, that it is impossible to accurately present LCR content, using just L and R speaker.    (NB - A centre speaker does assist people not seated well for the L and R speaker, and does fix comb filtering inherent in stereo speakers - assuming the centre is very well setup)

 

I can see your point Dave ; I just took it another way as explained under his heading  ;

Quote

 

Part 1 - How many loudspeakers?  What  kind? Where do we put them?  

Here we look at the basic theory of  multichannel audio systems, leading us to  understand why certain loudspeaker designs  and room arrangements work better than  others.

 

Under that heading he goes on to describe the failings of the quadrophonic system [ or systems ] at the time ;

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 In the seventies, there was an attempt to do better.  It failed because  of industry disagreements over which of several competing systems  should become the standard.  Frankly, I am glad it failed, because it  was the wrong arrangement of channels.  With no center channel, the  annoying stereo sweet spot remained.  Most of the systems had a lot  of crosstalk, or leakage among the channels, so that even the front-  back impressions depended on the listener being half way between  the front and back speakers.  With no side channels, the sense of  amb ience and spaciousness was less than it could be.  A lot of paraphernalia for another antisocial system.

Ive always followed that dictum ;right or wrong ; the center channel is there for panning and anchoring dialogue  ; a sweet spot is fine for 2ch music 

I should admit ; Ime glad we have left this channel based system and are starting to embrace object audio as it is a more precise way of steering sound elements more precisely rather than via a channel , If your room can accommodate it of course 

[davewantsmoore]

4 hours ago, cwt said:

Under that heading he goes on to describe the failings of the quadrophonic system [ or systems ] at the time ;

Yes, LCR an accomodate a larger listening area  (which is why I mentioned LR being setup well for the listening position).

 

4 hours ago, cwt said:

the center channel is there for panning and anchoring dialogue

The point is, that this can be done with LCR down-mixed to just L and R speakers ..... assuming you are siting in the right place.

 

[Guest DrSK]

On 16/04/2018 at 12:24 AM, cwt said:

Dr S.K ; I would urge you to read this pdf treatise on multichannel sound by the Acoustical Engineering icon ; Floyd .E Toole '; although dated the principals he lays out still hold . We had 4ch reproduction eons ago with quadraphonics which was later emulated with dsp modes which even now cant emulate the true discrete we have now.. 

http://www.mariobon.com/Articoli_storici_AES/Toole/Libro_bianco_Toole_123.pdf

Easy to see why a Harman system is not so cheap 

 

Thanks but I’m an acoustics engineer and there was nothing in that paper I didn’t already know. It is an introduction to acoustics.

[Guest DrSK]

Hi all

 

A quick update. Thanks to everyone.

 

Ended up with the following system and very happy in terms of performance and budget. Basically dual stereo systems which I use independently for different music content or a HT.

 

Oppo 205 ($2k) down mix to 4.0 with LFE to L/R via analogue out and option of downmix stereo PCM and rears via 205 analogue.

 

The PCM runs to a Gieseler Audio Konverter as does the L/R analogue out to the HT bypass. The Konverter Pre outputs to an early Metaxas Soliloquy power amp via Lenehan FoilFlex interconnects, the amp runs to Lenehan ML2+R speakers via Lenehan Ribbontek cables.

 

The rears run from the Oppo 205 via Lenehan interconnects to an ancient Inkel integrated which has surprisingly good clarity and head room. The rear speakers are Lenehan ML1 Reference. The integrated is easy to set levels as the volume dial is indexed by feel. I just remember the dial position for the F/R calibration.

 

For simplicity I may run the analogue out and HT bypass through the Konverter and control volume from the Oppo. However the analogue out on the 205, while good, is no where near as good as the DAC in the Konverter. It only took 3s of music for the Konverter to blow me away over the 205 (some reviews of the Konverter put it close to a PS Audio Directstream). I get far better sound using the PCM stereo downmix to the front and the analog to the rear for the 4.0 which is not too surprising. The Oppo has plenty of options for delays and trim and worked just fine.

 

All speakers are set at full range. Adjusting front rear balance once learnt is fine but not user friendly when not using HT bypass with the analogue. I’m however never more than 8m away from a range of NATA calibrated acoustic gear if I need to check levels.

 

I’ve also connected the second output of the Konverter to the Inkel. The rears don’t have the same low end below 50Hz which for some of the more pop mixed music with blown base for mass market iPods etc actually works better than the front system and the Inkel being a tad less punchy in attack can be a bit kinder to some music content and older recordings where the lower end is missing a bit anyway.

 

Very happy having a dual stereo hifi setup and a 4.0 system that in my opinion sounds much better than most 5.1+ systems (give or take the smaller sweet spot for the centre).

 

I’m currently doing some measurements and modelling of my room to gain more experience and comfort in the modelling of studios and performance spaces. So far getting good agreement and it seems the next step is diffusion. RTs are surprisingly good with a couple of couches, a mat even with tiles and gyrock elsewhere.

 

I think when trying to achieve a hifi music system and HT with the same gear less speakers is a plus, far less complexity in sorting out the room acoustics when you add more sources and the sound stage of good stereo is fine in the sweet spot (full 210 degrees of wrapped sound plus the rears to do the rest).

 

 

Edited January 8, 2020 by DrSK