HT acoustics and the Benefits of better speakers in stereo and multichannel audio

[Kvalsvoll]

You can assert this but it, in my daily experience, is simply not true.

If so, it says that the multichannel system setup is flawed.

If the multich front speakers are similar, position same, room acoustics the same, then of course they will sound the same. But different practical considerations leads to differences, at least for movie/home-th vs 2-ch rooms.

If you simply add surround speakers to a 2-ch room system, the that will of course not destroy anything at all, and gives the opportunity to experiment with upmix or using a dsp to add delayed sound and increase ambience.

But my experience is that 2-ch can give a good impression of the recording space, and it gets better with better speakers and better room acoustics. Reducing early reflection level significantly, while retaining some of the later decay, increases sense of room and space that is present in the recording.

 

[Blumlein 88]

@Thomas savage I can't give you a a direct answer, but I can give you the next best thing from Francis Rumsey, one of the leading researchers in spatial audio:

• (2014) Francis Rumsey - Spatial Audio: Reconstructing Reality or Creating Illusion?

snip....

That is a worthwhile video to watch, and like often the case opens more questions than it answers, but it does eliminate some avenues to pursue.

 

[tuga]

I am primarily interested in classical music and in most instances classical music is performed in front of the listener.
And in my experience as listener of both live and reproduced classical music a "real" stereo recording (2-mic, or 2-main+2-ambience to 2-channel to L&R speakers) produces the most realistic soundscape.

source: Linkwitz' "The Challenge..." paper


Not having listened to a decent multi-channel system I cannot comment on its performance but I can understand both the appeal and the potential effectiveness of adding surround ambience cues again as long as it's in "real" stereo (1-mic to 1-channel to 1-surround speaker); personally I don't feel the need for them, I am quite happy with having the soundstage recreated between my two speakers and perfectly capable of the level abstraction required for listening to 2-channel stereo.

Height information is in my view a superfluous gimmick. More so if achieved by "extracting" information from a conventional stereo recording, as is extracting ambience from a stereo recording .

The reason I value sharp stereo phantom images is because I perceive this as to impact instrument separation which is paramount for the reproduction of the timbral nuances of classical music and acoustic instruments and of the intrinsic complexity of large orchestral and choral pieces.

 

[Jon AA]

However, this speaker seems complex for 100º horizontal coverage. If that's the approximate desired coverage, designs such as Revel M16 (and presumably the identical-in-relevant-part S16 on wall variation) or the better small pro monitors get us there with smoothness to boot. CBT also looks more promising in this role.

That's pretty much in line with Toole's recommendation of 90 degrees horizontal dispersion being required for surrounds (room size, etc, dependent of course).

 

[Jon AA]

Height information is in my view a superfluous gimmick. More so if achieved by "extracting" information from a conventional stereo recording, as is extracting ambience from a stereo recording .

Complete nonsense. In a large number of venues, when you listen to something like an orchestra, a large percentage of the sound you hear (some of the strongest first reflections) are coming from above the orchestra.

When you point microphones in those directions, and front height speakers play back what they record, the original soundstage of the orchestra is much more realistically presented to the listener than two speakers at ear level can try to convey.

I don't know why you think you need to have such a strong opinion on subjects like this when you have never heard a multichannel recording played on a multichannel system, much less an "immersive" recording played on a system capable of it.

It's not something that requires rocket science. Just a listen. With many of these recordings, there is not just an "immersive" track, but also a 5.1 track...and also the stereo track on the same blueray. When listened to on a complete system you can switch between them instantly and compare them in real time to hear the difference.

I strongly suggest you try doing so...and then form an opinion.

 

[pozz]

I am primarily interested in classical music and in most instances classical music is performed in front of the listener.
And in my experience as listener of both live and reproduced classical music a "real" stereo recording (2-mic, or 2-main+2-ambience to 2-channel to L&R speakers) produces the most realistic soundscape.

source: Linkwitz' "The Challenge..." paper


Not having listened to a decent multi-channel system I cannot comment on its performance but I can understand both the appeal and the potential effectiveness of adding surround ambience cues again as long as it's in "real" stereo (1-mic to 1-channel to 1-surround speaker); personally I don't feel the need for them, I am quite happy with having the soundstage recreated between my two speakers and perfectly capable of the level abstraction required for listening to 2-channel stereo.

Height information is in my view a superfluous gimmick. More so if achieved by "extracting" information from a conventional stereo recording, as is extracting ambience from a stereo recording .

The reason I value sharp stereo phantom images is because I perceive this as to impact instrument separation which is paramount for the reproduction of the timbral nuances of classical music and acoustic instruments and of the intrinsic complexity of large orchestral and choral pieces.

Can you name a few halls that you've visited before? Maybe ones you were most/least impressed by.

 

[tuga]

Can you name a few halls that you've visited before? Maybe ones you were most/least impressed by.

The lecture hall which host the local orchestra is quite bad for music: https://www.sheldonian.ox.ac.uk/

Complete nonsense. In a large number of venues, when you listen to something like an orchestra, a large percentage of the sound you hear (some of the strongest first reflections) are coming from above the orchestra.

...

When you point microphones in those directions, and front height speakers play back what they record, the original soundstage of the orchestra is much more realistically presented to the listener than two speakers at ear level can try to convey.

I don't know why you think you need to have such a strong opinion on subjects like this when you have never heard a multichannel recording played on a multichannel system, much less an "immersive" recording played on a system capable of it.

It's not something that requires rocket science. Just a listen. With many of these recordings, there is not just an "immersive" track, but also a 5.1 track...and also the stereo track on the same blueray. When listened to on a complete system you can switch between them instantly and compare them in real time to hear the difference.

I strongly suggest you try doing so...and then form an opinion.

Strong reflections from the ceiling could shift the perceived sources upwards but with visual cues they're kept stuck to the stage.


Here's a paper on Perception of vertically separated sound sources in the median plane

https://aaltodoc.aalto.fi/bitstream/handle/123456789/29103/master_Kim_Tae_2017.pdf

 

[Kal Rubinson]

If the multich front speakers are similar, position same, room acoustics the same, then of course they will sound the same. But different practical considerations leads to differences, at least for movie/home-th vs 2-ch rooms.

Understood but if those "different practical considerations" do lead to differences, the audio setup is, indeed, flawed. They need not.

If you simply add surround speakers to a 2-ch room system, the that will of course not destroy anything at all, and gives the opportunity to experiment with upmix or using a dsp to add delayed sound and increase ambience.

Or compare the stereo directly with discrete multichannel.

 

[Kal Rubinson]

I am primarily interested in classical music and in most instances classical music is performed in front of the listener.
And in my experience as listener of both live and reproduced classical music a "real" stereo recording (2-mic, or 2-main+2-ambience to 2-channel to L&R speakers) produces the most realistic soundscape.
........................................................................................
Not having listened to a decent multi-channel system I cannot comment on its performance but I can understand both the appeal and the potential effectiveness of adding surround ambience cues again as long as it's in "real" stereo (1-mic to 1-channel to 1-surround speaker); personally I don't feel the need for them, I am quite happy with having the soundstage recreated between my two speakers and perfectly capable of the level abstraction required for listening to 2-channel stereo.

Let me recount (again) an old experience. I was playing an SACD with both stereo and multichannel tracks on a player which permitted almost instantaneous switching between the formats. It was of a solo cello in a nicely reverberant performance space. A/B comparisons were as you might predict: The MCH track offers an enhanced sense of the space but both formats sound good.

However, and just by chance, I made a switch from MCH to stereo just as the player lifted his bow from the last note of the piece so that there was no direct sound from the instrument. What I experienced was an almost violent wave of all the hall ambience flowing from my room and rushing forward beyond my front speakers. It was a stark demonstration that the venue ambience that is an important element of good stereo is, nonetheless, flawed because it is dislocated in space.

 

[DDF]

What I experienced was an almost violent wave of all the hall ambience flowing from my room and rushing forward beyond my front speakers. It was a stark demonstration that the venue ambience that is an important element of good stereo is, nonetheless, flawed because it is dislocated in space.

+1

Repeating myself "Once taken away (reverting to stereo), its absence is stark and unrealistic. It's unmistakable."

The effect is so obvious and self explanatory that to doubt its existence is to not hear 5.1 properly set up in a room that doesn't destroy it.

 

[Xulonn]

Yeah but, nice as it can be, it no longer fools me.

Please never invite me to your place to listen to music, Kal. I'm never experienced hi-fidelity multichannel music, and on my pension and in a tiny room, could never afford to purchase and implement it.

A visit to hear one of your systems would probably ruin my life.

 

[Thomas savage]

Please never invite me to your place to listen to music, Kal. I'm never experienced hi-fidelity multichannel music, and on my pension and in a tiny room, could never afford to purchase and implement it.

A visit to hear one of your systems would probably ruin my life.

Ignorance is bliss .... And cheap

 

[Kal Rubinson]

Please never invite me to your place to listen to music, Kal. I'm never experienced hi-fidelity multichannel music, and on my pension and in a tiny room, could never afford to purchase and implement it.

A visit to hear one of your systems would probably ruin my life.

Never invite me to your place to listen to music. I've been to Panama once on business and found it beautiful and fascinating. Now that I am retired, it's unlikely I'll get there again but, if I did, I might stay.

 

[Blumlein 88]

Imagine if the alternate version of stereo had been chosen. A few were pushing for it to have a front speaker, and a rear speaker back in the mid 20th century. A purist recording would likely have been a microphone on stage, and one in the rear of the hall.

 

[Kal Rubinson]

Imagine if the alternate version of stereo had been chosen. A few were pushing for it to have a front speaker, and a rear speaker back in the mid 20th century.

Really? Do you have a link to anything serious?

A purist recording would likely have been a microphone on stage, and one in the rear of the hall.

So you would need one speaker in your face and another up your ................................

 

[Ron Texas]

Is this thread from an alternative universe. Have I been locked down for too long? I bet Kal's multichannel system is awesome, but I make so many mistakes setting up my stereo plus subs that multichannel might throw me off the horse. I need to go to Panama when things open up again and buy David a few beers.

 

[Xulonn]

I need to go to Panama when things open up again and buy David a few beers.

LOL! Thanks Ron. We have 5 beers here and "Balboa" is my favorite (LINK) - although it's not a great beer, it's drinkable and cheap.

We have a very expensive brew pub in town, and world beers are available at grocery stores and my favorite Bar/Restaurant - Mike's Global Grill.

And in Panama, alcohol sales and consumption are prohibited during the lockdown, but things are looking up, and a phased-in relaxation of restrictions is anticipated for mid-May.

 

[Kal Rubinson]

Have I been locked down for too long? I bet Kal's multichannel system is awesome, but I make so many mistakes setting up my stereo plus subs that multichannel might throw me off the horse.

We don't post about mistakes.

 

[ReaderZ]

Sound stage and accurate directional sound.

 

[Blumlein 88]

Really? Do you have a link to anything serious?

So you would need one speaker in your face and another up your ................................

No I don't. It was in articles from the early 1950's about the various people working out what the LP would be. There were some people who thought it should be a front and back channel. I think some of that was motivated by the idea they could add reverb to existing mono recordings and resell them as the new two channel LP. Sound like a familiar strategy? Selling your recordings to you a second time.