Rear speakers - what do they add?

[Artsfols]

Please pardon my subjective response. Immersion in the sound field and the sense of the loudspeakers disappearing is what I appreciate of having 5 channels playing my some 200 classical titles. The effect is subtle only at first. One might wonder why bother, but in my case, I wish all of my 3,000 CDs were multichannel. Popular program material seems largely artificial to me though I'm sure there are good mixes. I've read that up-mixing of 2 channel is desirable, but the programs in my old AVR belie that. One day...

If it matters, I found this useful and descriptive and apropo to the question.

 

[Artsfols]

It is amazing what getting a little older does for your concern about what others think of what you do. I'm almost 57, hard to believe and I am at that place where I am totally fine with what I'm fine with.

I have a nice Sonos system that allows for me to mix with seperate volume controls a group of speakers that fire towards me from the front, two sides and two rears. Because it is not really multichannel I have to accept that I'm creating my own musical soundscape. I'm sure some people would find it just not what they like, but for me it is pretty darn enjoyable and immersive.

I think this reaction might change depending on genre. I loved playing loud rock through my 4 channel system in the 1970s. Shake the house down. I still enjoy that (3.1 though) but not for more than 15 minutes, and that's when my spouse isn't home.

 

[DVDdoug]

... this is one of those things that I only say in my own head... never aloud... and NEVER on ASR... lol.

I admit it and I usually add that, "This is hi-fi heresy, not listening accurately as-intended."

But I've also had my speakers in a dance hall for DJ gigs a couple of times and the speakers sound so much better with the natural large-room reverb coming from all directions, than they do in my living room.

 

[2Sunny]

I do not know how one objectively measures the effect, but on my sound system the difference between 2 channel music and music output with Sony's 360 Reality or Dolby Atmos is quite dramatic. Music created with either format has very precise instrument placement and creates a sound stage that isn't in front, but rather all around. Now whether or not one prefers a sound stage to be all around or in front is a matter of preference. I believe there is no question that having rear speakers allows for the creation of sound effects not possible with your 3.1 system, but how one might objectively show the benefit, I have no idea. I think you're stuck with subjective recommendations or simply trying it for yourself and seeing if you like the change brought by the addition of rear speakers.

I will add two additional comments. First is that when I listen to music on Spotify (which I have only recently begun doing) I find that I much prefer the sound to be 2 channel using the "direct" setting on my Sony AVR UNLESS the song was specifically mixed for Dolby Atmos. Music specifically made for Dolby Atmos is amazing, but the vast majority of music I listen to seems not to benefit from "upmixing" to multi-channel. Second, as far as I understand the topic, spinorama data that correlates with the clarity and placement of instruments that you talked about wanting IS available and includes early reflections and directivity, but how that is impacted by the addition of rear speakers I have no idea except to point to what I said in the previous paragraph.

 

[Bruce Morgen]

I started out with rear ambience difference speakers wired to the output of the stereo speakers decades ago then had a Yamaha DSP1 which added ambience via extra 4 corner speakers which were convenient to locate.

Yup -- that's why if/when my DSP-1 gives up the ghost past the point of "NRTS" (not repairable this station), I'll just nab another one on eBay or some such. Combined with the DSR-100 Pro, it allowed me to set up a 7.1 configuration that's "convenient to locate" in my man cave, which has dual double-hung windows to the left and a big two-door closet to right, precluding Dolby-recommended side-firing "surround" speakers.

 

[Chrispy]

Does it downmix? Or does it just drop 2 of the channels, and if so, which?

I'm pretty sure when playing multi-track through my 3.1 system the AVR just drops the rears and surrounds.

My multich units can downmix if needed, but many multich tracks come with different built in layers (core 2.0, 5.1 etc). It shouldn't in 3.1 just drop the information for surrounds/rear surrounds, it should downmix, you lose some of the spatial information but not content.

 

[Chrispy]

Therein lay my problem with no satisfactory solution

I started out with rear ambience difference speakers wired to the output of the stereo speakers decades ago then had a Yamaha DSP1 which added ambience via extra 4 corner speakers which were convenient to locate.

When I got a Marantz 7704 surround pre and I chose 5.1 it didn't offer me rears - which I had and were conveniently positioned - just sides, which I have no space or convenient location for.

Then add the requirement that the speakers each need to be equally spaced to a listening position, neither practical in my shaped room nor feasible with a family of 6 such that surround sound will always have to be a bodge for me.

It is better than nothing with film effects but I don't bother to use it for music, not least since 99% of my music is stereo.

The surround pre should have had an option for both delay/level to accommodate odd positioning somewhat. Being more to the sides than rears is fairly key, in surround sound, tho....as opposed to quad. They can be both to the rear and side, but directly behind isn't generally the way to go for rear surrounds, but fine for rear surrounds (assuming some distance between back wall and seating). Most of my music is recorded/purchased in 2ch but my multich collection is growing and more often used...and some 2ch stuff upmixes well, too but that's more a matter of taste I think than aiming at some sort of staging accuracy (which is not a big deal for me in any case as it's often just contrived for the recording).

 

[Chrispy]

I think this reaction might change depending on genre. I loved playing loud rock through my 4 channel system in the 1970s. Shake the house down. I still enjoy that (3.1 though) but not for more than 15 minutes, and that's when my spouse isn't home.

Surround is just a bit different from the old quad systems/recordings, tho you can do both, just don't use typical surround speakers and use what you have up front (or really similar) for that added capability when it's more quad than surround. Size of room comes into play as well of course and amplification, speaker capability, etc Good luck on finding what you want....but since you appear to be maybe my age, take it easy on the old ears, too.

 

[Dumu]

Here are my takes on pretty limited experience.

1. Multichannel mixes definitely sound better with 5.1 than with just 2.1 or 3.1.

2. Stereo mixes played with "5ch stereo" creates more enveloping sound and gets rid of most, if not all, "nulls" in the freq response that result from room geometries. But in my ears it also sounds more complicated and can be fatiguing. The benefit also depends on how "large" the main speakers sounds (enveloping is more noticable with smaller sounding speakers).

3. Dolby upmixing to 5.1 can sometimes sound very nice, but it is entirely dependant on the specific track.

If just listening to stereo tracks, I would stay with 2.x system and put the money to extra sub, dsp or EQ capabilities.

 

[Artsfols]

So to move on to the inevitable second question.
Which speakers to buy?
The choices I see, given the small room, are: KEF LS50 Meta, ELAC Uni-fi Reference UBR62, more Totem Arros. In the case of the KEF and ELACs I will try them as front speakers and move the Arro's to the rear.

 

[MattHooper]

The question is - given the audio sources I use, and the proposed setup, how would the aural experience change for the better.

The confusing thing is that you said you didn’t want to hear anything subjective on the matter.

But the subjective effect is what matters in the end. And you seem to want to know the subjective results. For people who went from two channel to surround, what exactly did you want to hear from them?

Ultimately, it’s going to differ, depending on what set up and circumstances.

I have a very good 7.0 surround system in my listening room, as well as a separate set of 2 channel floor standing speakers driven by separate amplifiers and sources. So basically I get to compare the two different experiences all the time in the same room.

I like the surround system for the scale and sometimes the surround effect and immersion.

I like the two channel system for its more coherent spatial, tonal qualities and more three-dimensional imaging precision.

 

[Artsfols]

The confusing thing is that you said you didn’t want to hear anything subjective on the matter.

But the subjective effect is what matters in the end. And you seem to want to know the subjective results. For people who went from two channel to surround, what exactly did you want to hear from them?

Ultimately, it’s going to differ, depending on what set up and circumstances.

I have a very good 7.0 surround system in my listening room, as well as a separate set of 2 channel floor standing speakers driven by separate amplifiers and sources. So basically I get to compare the two different experiences all the time in the same room.

I like the surround system for the scale and sometimes the surround effect and immersion.

I like the two channel system for its more coherent spatial, tonal qualities and more three-dimensional imaging precision.

To be precise I said I was not interested in exploring anything that was purely subjective.
First of all, I don't own the forum and not even this thread, so people can post whatever they like. I was just indicating my own interest and hoping it might stretch people's thoughts a bit.
Subjective means "based on personal opinions and feelings". In fact, your post is both subjective and objective. You described the surround system versus the two channel system in terms of fairly factual sound characteristics, and then indicate a subjective response to those characteristics.
A purely subjective response is something along the lines of "I enjoy the surround system much more than the two channel system" and leave it at that.

My interest in going to surround at this point would be more for those select recordings that have been engineered for even better imaging and fidelity than offered for stereo. But I do like an aural blast now and then. With Brian Wilson's passing, I played the 2004 Bluray of "Smile" the other day which was recorded in 5.1 sound (at least). There are some intense, aurally dense passages that sounded great on my 3.1 system. It would have been even better in 5.1 I'm pretty sure. I'm also a big fan of Clapton's Crossroads concerts. I have every one on disc. But I think that the 5.1 system will be only a minor part of my listening experience.

 

[krabapple]

Something else to accidentally knock over?

(which has almost NEVER HAPPENED in my room, I almost swear)

 

[MattHooper]

To be precise I said I was not interested in exploring anything that was purely subjective.
First of all, I don't own the forum and not even this thread, so people can post whatever they like. I was just indicating my own interest and hoping it might stretch people's thoughts a bit.
Subjective means "based on personal opinions and feelings". In fact, your post is both subjective and objective. You described the surround system versus the two channel system in terms of fairly factual sound characteristics, and then indicate a subjective response to those characteristics.
A purely subjective response is something along the lines of "I enjoy the surround system much more than the two channel system" and leave it at that.

My interest in going to surround at this point would be more for those select recordings that have been engineered for even better imaging and fidelity than offered for stereo. But I do like an aural blast now and then. With Brian Wilson's passing, I played the 2004 Bluray of "Smile" the other day which was recorded in 5.1 sound (at least). There are some intense, aurally dense passages that sounded great on my 3.1 system. It would have been even better in 5.1 I'm pretty sure. I'm also a big fan of Clapton's Crossroads concerts. I have every one on disc. But I think that the 5.1 system will be only a minor part of my listening experience.

Ok cool.

I’m curious: how do you have your L/C/R speakers set up?

I ask because very often when there is a centre channel involved, it’s often also doing Home theatre duty for watching movies.

And very often people are dealing with some compromises in terms of where the centre channel goes, which means that coherence isn’t optimum.

Is yours strictly music based?

And if so how was your centre channel oriented between your left and right speakers. Is it the same height? Along the same plane as the L/R speakers or recessed?

As I mentioned before, it can be difficult to set up a surround system with as much flexibility as one might have for a pair of stereo speakers. Therefore, it’s not always an apples to apples comparison. I can pull out my two channel floor standing speakers well into the room, and close to my listening position just as I prefer, and which really optimize the sense of immersion and imaging precision and dimensionality (and even tonality) for two channel listening.

To give you an idea of the type of set up, I was describing: I have my L/C/R speakers flanking my home theatre projection screen.
They put out a very big sound! They are pulled out as far as I can get them from the wall behind them. And they are wrapped in black velvet so that they disappear from view against the black velvet screen wall.

Here’s a photo taken in bright daylight so you can see the speakers:

https://i.postimg.cc/QN72C4tw/IMG-3844.webp

And in these photos, you can get an idea of how far my two channel floor standing speakers are pulled out into the room towards the listening sofa:

https://i.postimg.cc/1zYknbDh/IMG-3847.webp

https://i.postimg.cc/HnBN1TFF/IMG-3862.webp

The photos might help explain why I get less off a “wow” from surround sound immersion versus my two channel system than perhaps some other people. It’s very common to have surround L/C/R speakers involved with video playback as well, and so it would be very unusual to have those speakers pulled out into the room near the listening position like I have for my two channel speakers.

So I find the surround system certainly does create its own sense of immersion: I get a very great cohesive bubble of sound because all my speakers blend really well.

But with my two channel speakers pulled out so far and close to my listening position, it’s also extremely immersive, but the tonal coherency and spatial/imaging qualities are superior. The room just seems to melt away into the recording. So the two channel system still remains my favourite for listening to stereo recordings. (though I also enjoy up mixing stereo surround for my surround system sometimes).

 

[krabapple]

I do not know how one objectively measures the effect, but on my sound system the difference between 2 channel music and music output with Sony's 360 Reality or Dolby Atmos is quite dramatic. Music created with either format has very precise instrument placement and creates a sound stage that isn't in front, but rather all around.

Well, that's pretty much what mixing in more than 2 channels is for.

Now whether or not one prefers a sound stage to be all around or in front is a matter of preference. I believe there is no question that having rear speakers allows for the creation of sound effects not possible with your 3.1 system, but how one might objectively show the benefit, I have no idea. I think you're stuck with subjective recommendations or simply trying it for yourself and seeing if you like the change brought by the addition of rear speakers.

I will add two additional comments. First is that when I listen to music on Spotify (which I have only recently begun doing) I find that I much prefer the sound to be 2 channel using the "direct" setting on my Sony AVR UNLESS the song was specifically mixed for Dolby Atmos. Music specifically made for Dolby Atmos is amazing, but the vast majority of music I listen to seems not to benefit from "upmixing" to multi-channel.

Dolby Atmos isn't an upmixer. An Atmos mix is a multichannel mix made in the studio, and your AVR has to have an Atmos decoder to play it in Atmos.

If you want to upmix stereo , there is probably a function or two specifically for that on your AVR, like Dolby Surround or DTS Neural.

Personally, I upmix all stereo to fit my surround configuration (using Dolby Surround, though I wish I still had DPL IIx). It just sounds better -- bigger and more 'immersive' as the Harman folk would say, and I don't lose imaging/detail. Fairly commonly there are even multichannel-mix-like effects -- 'discrete' sounds or instruments coming from the rear channels or moving around (anything highly phased, like Jimi Hendrix, will do it for sure)

 

[olds1959special]

I prefer stereo for listening but 5.1 is the standard for film.

 

[Chrispy]

Well, that's pretty much what mixing in more than 2 channels is for.



Dolby Atmos isn't an upmixer. An Atmos mix is a multichannel mix made in the studio, and your AVR has to have an Atmos decoder to play it in Atmos.

If you want to upmix stereo , there is probably a function or two specifically for that on your AVR, like Dolby Surround or DTS Neural.

Personally, I upmix all stereo to fit my surround configuration (using Dolby Surround, though I wish I still had DPL IIx). It just sounds better -- bigger and more 'immersive' as the Harman folk would say, and I don't lose imaging/detail. Fairly commonly there are even multichannel-mix-like effects -- 'discrete' sounds or instruments coming from the rear channels or moving around (anything highly phased, like Jimi Hendrix, will do it for sure)

Seems to me I have an Atmos upmix option on my Denon. Then again I don't have Atmos speakers, so not sure what it does particularly....but may only be DS,

 

[Miniyouuuu]

>95% of currently produced music is stereo, Music reproduction try to merge the listener in a concert atmosphere where you hear the music in front of you (180°)
>95% of currently produced films is multichannel. Spectator receive a 360° sound around its position mainly focused in voice clarity and sometimes huge explosions.

For music reproduction stereo amps translate in a simple way the recorded sound to a pair of speakers that emit sound to both ears.

A stereo layout with concentric full range speakers in a 60° layout is the simplest way you have to ensure perfect alignment

The more drivers you implement in your room, the more complexity you introduce to your system. More crossovers, more time alignment, more independent volume regulation… and every room is different.

Consumer audio has a lot of technology to simplify that problem: Dirac / Trinnov/ Audissey… and even calibrated mics at decent price. Now you can measure your room and apply filters, delays, crossovers both manually and automatically. The later is more focused on voice clarity than musicality.

Our ears have huge precision to detect the position of every instrument and we detect minor delays or little phase variations due to driver cancelations. We require deep real time processing in order to ensure smooth multichannel reproduction and sometimes there is an unconscious feeling of unnatural sound in this overprocessed reproduction.

Realtime processing is improving by the years and soon we’ll be able to get a perfectly align sound from every driver. But nowadays we still fighting against our rooms and these automated PEQ solutions still sound less natural or smooth than analogue solutions specially for music reproduction

In this regard, a simple way to increase the music soundstage consist of 2 speakers reproducing directional sound and 2 or more woofers reproducing sub-60hz sound. Subwoofers increase atmosphere but won’t affect the ping-pointing precision of high class speakers in front of you.
.

 

[Frank Dernie]

The concern I had with installing a multi channel system at home was that it is not possible to mount the multiple speakers in the recommended locations (and even then relative to a single listener) in my room.

I also listen to stereo in a slightly less than 60 degree triangle, partly room layout partly positioning the speakers to minimise room mode excitation, and that may be a compromise but it seems not too bad but having the sound sources in my listening room in the wrong place relative to each other, or at least different to that the mixing engineer mixed for, seems like it would sort of defeat the object of having immersive sound.

The only thing my processor can compensate for is timing error, not the sound coming from the wrong direction.

 

[polmuaddib]

So what I'm getting is that 5.1 mixes are distinctly different from 2.0 mixes.

Not all 2 channel music is mixed the same way, and that goes for multichannel music also.
You have producers who prefer to preserve the instruments spatial and tonal properties, while others mix everything up, trying to create some new experience, different from live. It is exactly the same in multichannel realm: While some use surround, rear and height channel to preserve reverb, atmoshpere of the musical event, others use those channel for effects.
A good example is how most Classical multixhannel mixes are done, preserving the atmosohere and then you have Pink Floyd multichannel mixes that have variuos effects and that creates another kind of experience, almost surreal.
Now, I wouldn't judge and I enjoy both approaches. But I have to admit, there are some gimmicky MC mixes out there...

As for the question of what you get from going from 3.0 to 5.1 or even better 7.4.2? Well, I have a setup that allows me to hear pure 2 channel and multichannel, and when I go from multichannel to pure stereo, I immediately feel deprived of content. It's as if someone turned off half the lights in the room, or something similar.
Upimixing is very complicated subject that has several threads on ASR.