Receivers, 5.1 - 5.2 - 7.2 what to look for?

[rcarlberg]

With all due respect... I think you're talking bullshit. I've never heard of "per track compression" nor does it make sense that different ratio limiting would be used for individual instruments versus a whole band recording. Can you point me to any source online which mentions this?*

"Low ratio" versus "high ratio" limiting -- which incidentally is a whole different animal than compression -- is probably what's better known as "hard limiting" versus "soft limiting" and that just defines how much much a waveform is distorted to fit within given dynamic range.

Compression OTOH brings up the lower volume elements to closer to the maximum deflection signals.

By any measure, digital has about TEN TIMES the dynamic range of analog ... and since dynamic range is logarithmic, that means 100x the volume differences.


* - I Googled "per-track compression" and came up with this article which misunderstands some basic definitions in audio processing (much as you have done).

[rdclark]

In analog recording, compression of an individual instrument or a submix going onto an individual track was common in order to maximize signal-to-noise ratio. A very dynamic instrument would otherwise have to be recorded at a relatively low level to avoid distortion, but tape noise is a constant. So you might well compress a saxophone or a percussionist.

In the digital era, the noise floor is a lesser issue -- as is the availability of tracks -- so more such processing is done in the mixing phase. Compression is used frequently as an effect by musicians, of course, who usually need to be able to hear the effect as they play.

Overall compression of a mix is still common, for all the normal reasons. (And let's not forget that "riding the gain" during mixdown or mastering is still a form of compression, even when done manually.) Compressing an individual track may also be done for effect or for clarity. You isten, and you do what's needed.

But these DSP modes offered by consumer playback equipment that claim to restore dynamics are generally just snake oil. They may create the effect of greater dynamic range, but they have no way of determining what was done to the original track, and so can't possibly "restore" anything. If using the DSP features on your receiver or car stereo or phone makes you happy, please be happy. But don't be fooled; it's just more artificial processing.

[rcarlberg]

That sounds about right. You can't restore what's been permanently lost.

[Jack in Wilmington]

I'm currently using a Yamaha RX-A830 7.2 receiver, but running it in 5.1 mode. I have a full Usher speaker setup and really love the sound on BluRays. I go to the movies almost every week and still prefer my home theater for sound. I was impressed with the sound system in the theater when we went to see Rogue One. You could actually feel the sound in the closing sequence.

[rdclark]

I'm currently using a Yamaha RX-A830 7.2 receiver, but running it in 5.1 mode. I have a full Usher speaker setup and really love the sound on BluRays. I go to the movies almost every week and still prefer my home theater for sound. I was impressed with the sound system in the theater when we went to see Rogue One. You could actually feel the sound in the closing sequence.

Did you go to the Atmos theater at Westown Movies in Middletown Delaware? Best 2D room in the region, IMO; we'll drive 45 minutes to see A-list movies there. Our 7.2 system uses Definitive Technology speakers with Emotiva subs and a Denon AVR. All middle-of-the-range stuff, but very satisfying.

Right now listening to the multichannel remix of XTC's "Skylarking," an all-time favorite album competely reborn in this new version. There is no substitute for a good surround system if immersion, clarity, and detail are important to you.


It's amazing, though, how generally we can get better sound in our home theaters than in typical multiplex movie theaters. And now, with a big enough 4k display, the image quality and visual immersion is catching up as well.

[rcarlberg]

I was impressed with the sound system in the theater when we went to see Rogue One. You could actually feel the sound in the closing sequence.

Some of the explosions seemed to rattle the screen where I saw it too. A couple of nights later I saw another movie in a neighboring screen in the Cineplex, and all you could hear was Rogue One coming through the walls.

More explosions than story, actually

[Jubal]

All modern AV receivers include settings for subwoofer crossover as part of the basic setup process. You select a crossover frequency for your speakers in pairs or globally, and the set the x-over on the sub itself to "off" or to its highest value, and let the receiver handle the process. This routes to the sub bass from all sources, not just the LFE (low-frequency effects, or ".1") channel on movies.

Indeed, many modern subs don't even have speaker-level connectors, because in a multichannel system they are of marginal usefulness. Of course, if you are using a pair of speakers with a non-AV amp of some sort, you need to get a sub that does have speaker connectors.

Using the AVR's bass management features is very important in a multichannel system, of course, because it's rare to have full-range center-channel or surround speakers, so low bass directed to them would cause extreme distortion, or even damage.

You misunderstand what I am saying here. My recommendation is to set the speaker setting on the receiver to the "no subwoofer" setting. This defaults the LFO info to the Front left and Front Right channels. If the receiver asks for speaker size of Front Left and Front Right, choose the largest setting. This bypasses any crossover point selected in the receiver. What I am recommending is send the Front Right and Front Left signals to your subwoofer(s) first, and use the subwoofer's crossover setting to determine what will pass through the subwoofer speaker outputs to the Front Right and Front Left channels.
The whole point of this setup is that you get to hear all of your music as well as movies with your subwoofers supplying the low end on ALL source material. The subwoofer outputs on AVRs do not send bass information to the subwoofers if the source material does not have a channel dedicated to LFO. Subwoofers can make a good music system sound great if they are set up right. If you only plug them into the LFO on your receiver, you are not using that sub to play stereo CDs or any analog outputted source material.

[rdclark]

Jubal, perhaps you have a receiver that works that way. Most don't. When you use the receiver's bass management, it routes bass from all sources to the subwoofer.

Don't confuse the concept of LFE (Low Frequency Effects), which is the name of the .1 channel in program material, with the potential content of the subwoofer output on the receiver. You can configure the sub-out to carry only LFE content, but using the bass management assures that it will also include low bass from all sources.

Again, many subs do not even have speaker-level connections.

The "no sub" setting also prevents tha AVR's room correction software from setting the timing, phase, and EQ for the sub separately. This will reault in sub-optimal sound in many rooms.

Your contention that receivers' bass management does not send bass from all sources to the sub is simply incorrect. Bass management will route all bass intended for any speaker set to "small" to the sub. This is why most authorities (such as THX and Dolby Labs) recommend setting all speakers (regardless of their actual size or capabilities) to "small' with an 80Hz crossover, which will route low bass from all sources to the sub.

Many receivers also incluse a "Bass Plus" setting that lets you route bass to both your mains and your subs. This of course produces an insane amount of bass that sounds like crap, but there are people who can't get enough bass, I guess.

[Fracktured]

I was mainly concerned with music and if it was worth the time effort and money because of all the surround sound releases on CD coming out these days. As far as using it as a home theater set up I doubt I would even care about that because I rarely watch movies. Thanks for all the feedback.

[BobM]

To adequately appreciate surround sound you need to have a proper room setup. That is key. If your couch/seat is right up against a wall then those speakers to either side of you aren't going to sound as good as if you have a seat 4' or more away from the back wall, and place those rear speakers behind you. For larger 7.2 and such setups you need even more room behind you so those effects truly sound like they are filling the room behind your head.

In a small room, anything more than basic stereo, with a center channel, is kind of worthless. You will get some effect from ceiling mounted speakers over your head, but that's not nearly as effective as having speakers behind you, with space.

[rcarlberg]

Good advice, Bob.

[rdclark]

Interestingly, current recommendations put the surround-channel speakers in a 5.1 system to the sides of the listener, or just slightly rearward in a sort of over-the-shoulder orientation. Then, if you add rear-surrounds or rear height speakers, those go in back. https://www.dolby.com/us/en/guide/su...5-1-setup.html

But for music things become more ambiguous, because (1) the surround arrangement in the recording is arbitrary to begin with and (2) it's rare to know what the mixer had in mind, or was listening to in the studio. But for live music recordings, as well as for movies and TV, the Dolby recommendations should apply. The "surround" speakers go to the sides; the "rear" speakers, if present, go in back.

[rcarlberg]

Maybe somebody could list some 5.1 music productions where the ambiguity of the surround sound mix has been clarified? Something where the surround sound is more than a gimmick?

[rdclark]

Maybe somebody could list some 5.1 music productions where the ambiguity of the surround sound mix has been clarified? Something where the surround sound is more than a gimmick?

My comment about ambiguity was perhaps a bit ambiguous.

When you listen to a live surround recording of, say, classical music in a concert hall or jazz music in a club, the intent is unambiguous: To re-create the acoustics of the original venue inside your own listening space. You are sitting in a specific location in a specific place. Such recordings are usually mixed conventionally, so that a conventonal surround sound speaker setup (such as Dolby's setup, linked above) will reproduce it properly.

Studio recordings remixed for surround are more ambiguous, for two reasons. First, just as with stereo mixes, the channel assignments -- the array of instruments -- is entirely arbitrary. It bears no relationship to where musicians physically were during their performance. It is constructed, artificially, entirely for aesthetic reasons.

But often, surround mixes of music are done on five full-range speakers, something few home systems employ. This is why correct setup of the home system, with correct bass management, can be critical; The same instrument may appear in a front main speaker or a surround speaker. These were identical speakers in the control room, but in the home one may be a tower and the other a small satellite. If those speakers' timbres don't match, if they weren't EQ'd, and if the low frequencies they can't handle aren't routed to speakers that can, the imbalances will be plainly obvious.

I don't understand what you mean by "gimmick." When I was a kid, my parents though stereo was a "gimmick." Surround is a means to create better musiic reproduction -- by also reproducing the acoustic space within which it was performed, or by better separating the instruments so that you can hear them better, or sometimes both.

[Firth]

My comment about ambiguity was perhaps a bit ambiguous.

When you listen to a live surround recording of, say, classical music in a concert hall or jazz music in a club, the intent is unambiguous: To re-create the acoustics of the original venue inside your own listening space. You are sitting in a specific location in a specific place. Such recordings are usually mixed conventionally, so that a conventonal surround sound speaker setup (such as Dolby's setup, linked above) will reproduce it properly.

Studio recordings remixed for surround are more ambiguous, for two reasons. First, just as with stereo mixes, the channel assignments -- the array of instruments -- is entirely arbitrary. It bears no relationship to where musicians physically were during their performance. It is constructed, artificially, entirely for aesthetic reasons.

But often, surround mixes of music are done on five full-range speakers, something few home systems employ. This is why correct setup of the home system, with correct bass management, can be critical; The same instrument may appear in a front main speaker or a surround speaker. These were identical speakers in the control room, but in the home one may be a tower and the other a small satellite. If those speakers' timbres don't match, if they weren't EQ'd, and if the low frequencies they can't handle aren't routed to speakers that can, the imbalances will be plainly obvious.

I don't understand what you mean by "gimmick." When I was a kid, by parents though stereo was a "gimmick." Surround is a means to create better musiic reproduction -- by also reproducing the acoustic space within which it was performed, or by better separating the instruments so that you can hear them better, or sometimes both.

If you aim for surround sound as good as the theatres, you'll have got what you need. For the novice, ideally full range all around, but even the theatres don't do the lowest freqs in all channels, dedicating subwoofers or large towers in the front for 80 Hz and below. If you buy a Pioneer Elite receiver with calibration, as long as you tell it what speakers you have, it will determine what freqs to send to each speaker. I love the final EQs and delays it determines, although I crank the subwoofer a few dB up. I have stayed with the Eq it suggests and over time it becomes my preference for EQ. I don't want to mess with it because EQ isn't just amplitude, this system EQs the gain and pause over frequency, for each speaker. Surprising is the fully integrated response. It is easy but if you listen to the audio geeks, you'll never get without a lot of work. When the system is caled like that, the stereo extend function that uses all speakers is amazingly accurate, but larger in scope. It's more like listening to a good concert outdoors with an accurate J line-array.

[rcarlberg]

I don't understand what you mean by "gimmick." When I was a kid, my parents though stereo was a "gimmick." Surround is a means to create better musiic reproduction -- by also reproducing the acoustic space within which it was performed, or by better separating the instruments so that you can hear them better, or sometimes both.

Stereo was "a gimmick" when it first came out -- instruments panning everywhere, bass all in one channel, drums in the other...

It took a few years for the musical productions to catch up with the technology, and begin recording combos (or orchestras) in realistic-sounding imaging to where stereo became much more than a gimmick -- it became the second dimension (width) of recorded sound.

Which is sorta what I was asking about surround sound.

Seems to me all of the quadraphonic productions I heard in the '70s were gimmicky. Are there any surround sound productions from recent years which use the third dimension (depth) the way modern stereo productions use width?

[Firth]

Stereo was "a gimmick" when it first came out -- instruments panning everywhere, bass all in one channel, drums in the other...

It took a few years for the musical productions to catch up with the technology, and begin recording combos (or orchestras) in realistic-sounding imaging to where stereo became much more than a gimmick -- it became the second dimension (width) of recorded sound.

Which is sorta what I was asking about surround sound.

Seems to me all of the quadraphonic productions I heard in the '70s were gimmicky. Are there any surround sound productions from recent years which use the third dimension (depth) the way modern stereo productions use width?

That would be Dolby Atmos which is based on mixing audio objects in 4 dimensions, 3 spatial and time. It uses height by having speakers in the ceiling, or bouncing sound off the ceiling.

I've said that more speakers across the soundstage could mean that surround approachs mono, in that a sound emanates from a single speaker instead of needing to be represented by 2 which would have to be perfectly matched in order to represent one. On HD multichannel rock recordings that put vocals in the center channel, the vocals sound more realistic.

[rcarlberg]

Does doesn't really answer (or even address) my question. Are there 5.1 recordings out there that aren't gimmicks?

And "HD multichannel rock recordings that put vocals in the center channel, the vocals sound more realistic" would only be true if the vocals are RECORDED in mono. Which is crap engineering.

(But you're right -- crap engineering happens. A lot.)

[Firth]

Does doesn't really answer (or even address) my question. Are there 5.1 recordings out there that aren't gimmicks?

And "HD multichannel rock recordings that put vocals in the center channel, the vocals sound more realistic" would only be true if the vocals are RECORDED in mono. Which is crap engineering.

(But you're right -- crap engineering happens. A lot.)

I would have thought that nearly all vocals are recorded by using a single microphone into a single channel. Then it's the stereo mix process that produces stereo. Give me an example where that isn't true? Whatever, I recommend as good 5.1 recordings you would poo poo, it's the nature of the game. Ultimately one has to form their own opinion. I merely suggest that most issues people have with 5.1 sound come from their own setup. The only HD multichannel recordings I didn't like were transfers of old Quad recordings which didn't benefit from a remix.

[rcarlberg]

I would have thought that nearly all vocals are recorded by using a single microphone into a single channel. Then it's the stereo mix process that produces stereo. Give me an example where that isn't true?

In honor of the late great departed Maggie:

[rdclark]

Seems to me all of the quadraphonic productions I heard in the '70s were gimmicky. Are there any surround sound productions from recent years which use the third dimension (depth) the way modern stereo productions use width?

Quad was invented in order to create realistic recordings of live performances, particularly classical, that reproduced the ambience of the performance space in its correct dimensionality, rather than folding it into the front speakers. This principle apples equally to modern surround recordings. I've heard surround recordings of jazz, made in clubs where I've attended shows myself (such as the Blue Note in NYC) that sound so real that you can easily feel transported there if you close your eyes.

Studio recordings created via multitracking are a different beast -- as is the case no matter how many channels are used to reproduce them. There is nothing "natural" or realistic about the convention of putting the bass energy and lead singer in the center of a stereo mix; this is just a by-product of the best practices for disk mastering, and it sounds "right" to us now because it's what we're heard for the last 40 years.

But stereo mixes of multitrack recordings are arbitrary or, at best, art. Not inevitable, and not determined by any analogs to reality. Keyboard sounds are spread all over the mix; if there are two guitars you separate them; drum kits are as wide as the entire soundstage; lead singers are always in the center even if they're playing an instrument that's panned hard left or right.

A cynic would label it all "gimmickry."

Surround mixing of multitrack recordings has the same purpose as mixing of stereo, but offers more options and opportunity to achieve immersion, or clarity, or whatever goal your art seeks. Sometimes the goal (with "live in studio" jazz, for example) is to give the listener a seat amongst the musicians. Sometimes it's to make complex arrangements and performances easier to clarify. Sometimes it's to create a greater sense of intimacy, since surround can have the effect of putting you virtually closer to the performers.

Saturday night I went to see Pat Metheny. As always, Antonio Sanchez was stage left, sideways to the audience. We were in the front row, so thus the drums were effectively all in the "right channel," sonically. But of course in the house mix they were panned much more to the center, and more spread out, much as they would be on a stereo record. The room ambience was, of course, real (and from the front of the room, sounded awful, because the Keswick has terrible slapback echo).

So what's "realistic" and what's "arbitrary" and what's "gimmicky?" What would you want to hear in a recording of that performance?

The front row, where we had accurate positioning of the instruments, but a poor mix because we were too close to the stage?

The sound from the center of the house, where you were hearing only what the mics picked up, remixed and panned as if it were a stereo LP mix?

Or some idealized recording where you could sit on stage with the musicians, hearing the natural sound of the instruments all around you with maximum detail and perfect balance?

Surround is a means to add more possibilities to the toolkit. Sometimes it's remarkably effective in the right hands.

[rcarlberg]

Very good analysis of the issues involved, Clark. Bravo!

Stereo mixes tend to try to reproduce the sound of the band actually playing in your living room. The bass, drum and singer are panned to center stage because that's where you usually hear them in concert (Pat Metheny notwithstanding).

Quad or surround mixes that would place the listener on-stage with the band, sitting right in front of the drum kit (presumably) would perhaps not be ideal. How many musicians complain about not being able to hear each other? Isn't that why in-ear stage monitors were invented?

In most situations the listener would probably want to be in the audience, a few rows back. Therefore the rear speakers would be used for room acoustics, not primary instrument placement. Anything else -- keyboards marching up the aisle, drums coming from the lobby, Hammond organ swirling above you -- would be gimmicky.

[rdclark]

Stereo mixes tend to try to reproduce the sound of the band actually playing in your living room. The bass, drum and singer are panned to center stage because that's where you usually hear them in concert (Pat Metheny notwithstanding).

Except if you listen to most contemporary mixes of rock, they're not actually mixed that way. Drum kits especially -- the kick and snare may be centered, but the cymbals and toms go from far left to far right. If it were a stage, the drum kit would be as wide as the whole band! Similarly, keyboards, which in real bands emanate from somewhere near the keyboard player, but on records are distributed across the stage. Other instruments are distributed across the stereo array for balance and clarity, and may very well be different on every track of an album.

The truth is that studio mixing of multitrack recordings have absolutely nothing to do with any attempt to emulate a live performance. They are an artificial construct, one that has evolved and normalized over the years to the point where live-sound mixers now sometimes try to emulate what recording engineers do, creating all kinds of visual/aural mis-cues, especially in smaller venues. (Obviously, in stadiums etc., all of the live sound is remixed on its way to the audience anyway, and most attendees are too far away to hear stereo from the stage.)

The impulse to evenly distribute instruments across the array and enhance their separation is even stronger now, in the era of earbud listening. If the convention of placing the primary sources of acoustic energy (bass, kick, snare, vocals, guitar solos, etc.) equally in both channels weren't already well established, the MP3 era nailed it down for good.

Surround music can be seen as a strong antidote to music made for iPods. You have to listen to it on purpose, in a room, on good equipment. It's not compressed, it's not lossy, and the mixes aren't done according to long-standing formula. It's made for the experience of critical listening, close listening, repeated listening. And no format rewards close listening by revealing more of the music than surround does.