FAQ: Where Did My Multi-Channel Analog Inputs Go?

[gene]

So you're getting ready to purchase a new AV receiver when you look on the back and realize there are no multi-channel analog inputs on it to play multi-channel SACD files in native DSD. Are you out of luck? Read the following FAQ article to give you your options and see.

Read: FAQ: Where Did My Multi-Channel Analog Inputs Go?

 

[TLS Guy]

The problem is that if there are no analog inputs, then external switching needs to be applied. The speaker layout for US and European CDs are different. If I have my pre pro do the decoding the rear sounds come from the surrounds. This is OK for US SACD but not European ones. So you would require a switch to get the surround to come from the correct speakers.

I think the European layout is the correct one by the way.

For a work like Britten's War Requiem which to be really understood and enjoyed has to be antiphonal, you need the sound of the chamber orchestra, boys choir and the war poems to come from the rear.

So I have my SACD players surrounds plugged into the rear backs. That is the way it should be.

This is the reason I have my most powerful and best speakers at the front and as the rear backs.

By the way I only have European SACDs.

 

[fitzcaraldo215]

I have thousands of SACDs, mostly in Mch. There is no difference between US, European, Japanese, etc. discs or between channel assignments in processors and players. They never use the back channels for SACD.

The issue appears to be a question of the sound you prefer vs. standards used in recording. Almost all, that is >> 95% of Mch SACDs, BD-A music discs too, are recorded, mixed and mastered assuming the ITU speaker layout with speakers at 0, +- 30 and +- 110 degrees. Feel free to google the ITU 5.0/5.1 layout. I have been to Mch recording studios, seen this in action and discussed this with recording engineers.

There are a few other caveats assumed by ITU. It assumes equidistant, identical monopole speakers. The equidistant requirement is handled by distance correction in DSP in the processor or player if your speakers are not physically equidistant.

The identical requirement may be more difficult, but you can get a close approximation by using similarly voiced speakers from the same manufacturer. Bass management to a sub or subs also helps when smaller surrounds are used. DSP EQ is a great help by voicing all channels similarly, in addition to applying room correction.

The monopole speaker issue might be a problem for some who have bought into side surrounds using the common angled dipole or bipole speakers sold as "surrounds". Those are intended for THX (normally at 90 degrees) and are not ideal for imaging in the ITU setup. They tend to provide a more vague, fuzzy wuzzy sound. I never liked THX as a playback idea, especially not for Mch music, but also for movies.

So, in my 7.1 system, there is never a problem playing all my SACDs with my speakers in ITU configuration. The back channels are silent, of course. The sound is terrific, coming consistently much closer than stereo recordings to the sound at live classical concerts, which I frequently attend. If I wanted to, I could use processing like Dolby PL IIz to provide a synthetic fill via the back channels, but I definitely do not prefer that.

The system also works fine for me with movies, using the back channels only if they are in 7.1. But, my experience with 7.1 tells me it was a waste of money. Relatively few BDs are in 7.1, and my feeling is the back channels do not usually add very much vs. 5.1 playback. My back channels, incidentally, are at +- 150 degrees.

But, if you prefer having surround come at you from the back as opposed to the side surrounds, that is your choice, even though that is not what the recording/editing/mastering engineers intended or heard themselves. You would have to reconnect the side surround outputs to the back speakers. However, in doing so, any DSP distance correction, sub crossovers and/or EQ set up in the processor would be applied to the wrong speakers. It is possible in some PC software, like JRiver which I use for music/movie playback, to reconfigure the channel assignments without these complications. But, I do not need or want that. I want my surround channels at +- 110 degrees as per ITU.

 

[TLS Guy]

I have thousands of SACDs, mostly in Mch. There is no difference between US, European, Japanese, etc. discs or between channel assignments in processors and players. They never use the back channels for SACD.

The issue appears to be a question of the sound you prefer vs. standards used in recording. Almost all, that is >> 95% of Mch SACDs, BD-A music discs too, are recorded, mixed and mastered assuming the ITU speaker layout with speakers at 0, +- 30 and +- 110 degrees. Feel free to google the ITU 5.0/5.1 layout. I have been to Mch recording studios, seen this in action and discussed this with recording engineers.

There are a few other caveats assumed by ITU. It assumes equidistant, identical monopole speakers. The equidistant requirement is handled by distance correction in DSP in the processor or player if your speakers are not physically equidistant.

The identical requirement may be more difficult, but you can get a close approximation by using similarly voiced speakers from the same manufacturer. Bass management to a sub or subs also helps when smaller surrounds are used. DSP EQ is a great help by voicing all channels similarly, in addition to applying room correction.

The monopole speaker issue might be a problem for some who have bought into side surrounds using the common angled dipole or bipole speakers sold as "surrounds". Those are intended for THX (normally at 90 degrees) and are not ideal for imaging in the ITU setup. They tend to provide a more vague, fuzzy wuzzy sound. I never liked THX as a playback idea, especially not for Mch music, but also for movies.

So, in my 7.1 system, there is never a problem playing all my SACDs with my speakers in ITU configuration. The back channels are silent, of course. The sound is terrific, coming consistently much closer than stereo recordings to the sound at live classical concerts, which I frequently attend. If I wanted to, I could use processing like Dolby PL IIz to provide a synthetic fill via the back channels, but I definitely do not prefer that.

The system also works fine for me with movies, using the back channels only if they are in 7.1. But, my experience with 7.1 tells me it was a waste of money. Relatively few BDs are in 7.1, and my feeling is the back channels do not usually add very much vs. 5.1 playback. My back channels, incidentally, are at +- 150 degrees.

But, if you prefer having surround come at you from the back as opposed to the side surrounds, that is your choice, even though that is not what the recording/editing/mastering engineers intended or heard themselves. You would have to reconnect the side surround outputs to the back speakers. However, in doing so, any DSP distance correction, sub crossovers and/or EQ set up in the processor would be applied to the wrong speakers. It is possible in some PC software, like JRiver which I use for music/movie playback, to reconfigure the channel assignments without these complications. But, I do not need or want that. I want my surround channels at +- 110 degrees as per ITU.

I know for certain that BIS and Pentatone and other European Classical labels master like I said. Some of my SACDs even show this arrangement as the correct way to listen to the disc in the booklet. It makes absolutely no sense to master antiphonal classical works with the usual surrounds. If the sound is coming from a back balcony that is where it needs to come from. I also have recordings where there are two organs front and back. The cathedral in St Paul Minnesota has this arrangement for one.

European classical labels master with front left and right, center and two speakers right at the back of the room. Some also have a sub track, like My Britten War Requiem has. To play that with the sound on the rear surrounds makes a total travesty of the composer's intentions.

I run analog from the SACD player which on my pre pro puts the unit into pure direct mode. I then throw a switch which changes the system to my bass management and not the pre/pos which is then inoperative..

Fronts.

Rears.

You can see a surround on the left.

The BIS recording of the AHO 12th symphony begins with Laplander circular drumming. There are drums all round the room, a large orchestra up front, and chamber orchestra in the rear and brass choirs front back and sides. All reviews I have read say the SACD is unplayable. It is not, and is a fantastic demo of this system. The drum do rotate around the room and the system throws up good phantom images of the brass choirs at the sides.

It really does take a speaker system like this with the horse power to bring that incredible recording to life. The effect would be totally lost using the usual surrounds rather then the rear. I know I'm playing it the way it was mastered.

 

[fitzcaraldo215]

We will have to agree to disagree. I think you are totally misinformed about BIS and Pentatone and "other European labels". Why not drop them an email to end speculation?

I am very good friends with a Grammy-winning recording engineer who specializes in Mch. He has worked for Channel Classics in Budapest and elsewhere in Europe, and with the Sound/Mirror team, which has done recordings for BSO Live, Chandos, Reference, Mariinsky and many others, both here in the US and in Europe. He absolutely confirms what I told you about ITU. He is also quite familiar with what other recording teams do. His 5.0 speaker setup in his own studio is pure ITU for all Mch recordings he listens to on all labels. I have been there. Many pros use a template/protractor to set up their monitors according to ITU. I have seen it.

The other point is this, if you think about it. A standard is absolutely necessary. Mch music recordings would be a disaster if the speakers had to be repositioned specially in custom fashion for each disc, particularly when there is nothing on the jacket to indicate what the speaker positioning should be. (The defunct Telarc label at one time did include a brochure with each disc describing the ITU layout they always employed.)

And, ask yourself, why would music recording engineers and commercial labels use channel assignments alien to the common setup in Mch playback gear, which is derived mainly from Home Theater? If you look at DTS and Dolby speaker layouts for 5.1, you will find that ITU for music is completely consistent with them.

You may like the sound a certain way, and you may think it therefore "needs" to be that way, even believing that is how they "must" have done it or "should" have done it, but that is, in fact, not how they operate.

What you prefer is similar to the old 4.0 layout assumed in the disastrous Quad LP era of the 70's with back surrounds. That has been dead for a long time. The ear is measurably far less sensitive to sounds and directional cues from the rear, which is why 2D surround in the modern era has emphasized sounds from the sides and slightly behind. Take a close look at your ears in the mirror to see why that might be so. They are canted forward via lobes extending only a little bit to the rear. Sounds from back channels are going to be more diffuse, striking more on the back of your head and behind your earlobes.

I am not trying to argue with what you say you like. You are entitled to like what you like. I am merely telling you that what you prefer is a spatial distortion of how the recordings were actually made.

The facts, in any case, as to Mch speaker layout for music recordings should be quite easy for you to check with whatever label you wish.

 

[rojo]

The ear is measurably far less sensitive to sounds and directional cues from the rear, which is why 2D surround in the modern era has emphasized sounds from the sides and slightly behind. Take a close look at your ears in the mirror to see why that might be so....

Hopefully to avoid a diatribe, let's take it as said that TLS Guy is better acquainted with the physiology associated with hearing than most. I wouldn't be surprised if he's had a rotation or two in otolaryngology.

I'm enjoying this discussion though. I love it when smart people debate.

 

[markw]

I have thousands of SACDs, mostly in Mch. There is no difference between US, European, Japanese, etc. discs or between channel assignments in processors and players. They never use the back channels for SACD.

That's a pretty broad brush you're painting with there, buddy.

http://www.musicdirect.com/m-81-AUDIO-FIDELITY.aspx

http://www.thedigitalbits.com/site_archive/reviewsdvdasacd/pinkfloyddarksidesacd.html

 

[sterling shoote]

The only universal players that I know of today which decode multi-channel SACD for RCA output appear to be ones from OPPO. If you buy a Sony player you will get multi-channel SACD only from HDMI out and you would therefore need to have an HDMI input on pre/pro or receiver, or you would need to buy an HDMI to multi-channel RCA converter.
Sienoc Hdmi Digital Audio Decoder Hdmi to Hdmi+vga+spdif+5.1ch+hp...
by SIENOC

Also, it appears that most SACD players today do not play multi-channel at all, having only stereo RCA output.

I have a Sony TA-P9000ES analog preamp which is designed for input of multi-channel SACD from SACD players with multi-channel RCA output. I can therefore use an OPPO for multi-channel SACD enjoyment, or I can use an HDMI to multi-channel converter to send multi-channel to preamp from a current universal player which only has HDMI output.

 

[Bizarro_Stormy]

Rear...

TLS... you've got a huge rear...

 

[fitzcaraldo215]

That's a pretty broad brush you're painting with there, buddy.

http://www.musicdirect.com/m-81-AUDIO-FIDELITY.aspx

http://www.thedigitalbits.com/site_archive/reviewsdvdasacd/pinkfloyddarksidesacd.html

Thanks, but I am not seeing your point.

Some older Mch remasterings on SACD are in 4.0, mainly from '70s Quad-era masters, as are even a very few newer Mch recordings, like Isomike, now defunct. That just means there is no center channel signal.

That also does not change the standards for SACD Mch, which is designed for 5.0/.1 playback with standard channel assignments on playback compatible with Home Theater 5.0/.1. The back channels are not defined or used in those standards, and, of course, there is no signal in the back channel outputs from a player with SACD via analog or HDMI.

And, recording producers do not produce Mch recordings that would require or assume reconnection of the signal leads or moving speakers around on playback of their recordings, with a few weird exceptions. One was Chesky in their old and tiny Mch catalog which was a 6.0 system that was totally nonstandard, ergo they stopped doing it. Another is the tiny German MDG label and their 2+2+2 system, still active, which prefers using front height speakers conveyed by the normal center and .1 LFE channels, although they allege that it is also compatible with a normal 5.0/.1 playback system. It is and they do not sound bad in 5.1, though the center channel output is actually one of the two recorded height channels, and the .1 channel contains the other height information, mostly filtered out by the crossover if using a sub.

 

[markw]

Thanks, but I am not seeing your point.

My point is that you said this:

I have thousands of SACDs, mostly in Mch. There is no difference between US, European, Japanese, etc. discs or between channel assignments in processors and players. They never use the back channels for SACD.

That seems pretty black and white to me. Is that clear enough for ya?

 

[mtrycrafts]

My point is that you said this:
They never use the back channels for SACD.

That seems pretty black and white to me. Is that clear enough for ya?

I wonder if he means that the back channel as in a 7.1 system but rather use the side speakers at 110 degrees.

 

[markw]

I wonder if he means that the back channel as in a 7.1 system but rather use the side speakers at 110 degrees.

I don't think SACD supports those 6th and 7th channels. I believe hey are unique to DD/DTS video applications.

 

[mtrycrafts]

I don't think SACD supports those 6th and 7th channels. I believe hey are unique to DD/DTS video applications.

That's why I think he meant no back channels but side ones as Dolby shows for a 5.1 setup, about 110 deg.

 

[sterling shoote]

The confusion here is the word back is being used to describe rear. Multi-channel SACD is indeed a 5.1 product.

 

[fitzcaraldo215]

My point is that you said this:

"They never use the back channels for SACD"

That seems pretty black and white to me. Is that clear enough for ya?

Well, SACD has a maximum of exactly 6 channels in the Mch program. You can look that up. The standard definition of those 6 is Front L, Front R, Center, LFE (= Sub = .1), Surround L and Surround R. The nomenclature gets a bit squirrelly at times, depending on the equipment manufacturer. You might see Surrounds designated as Side Suroounds or Backs designated as Back Surrounds, Surround Backs, Surround Rears, etc. But, the essential idea remains the same

If you have an SACD player with analog outputs, the only signal comes from the 6 output jacks labeled that way or in a way similar to that. The player, assuming it is a common Universal player, probably also has two more output jacks labeled Back L and Back R so that it can also play BDs that might be 7.1. But, an SACD will never output any signal from the disc from those two Back jacks because the SACD disc only has up to 6 channels. (That is unless it applies synthetic recreation of the Back channels, like Dolby PLIIz or others, as mentioned previously. That can be turned on/off, but it is rare or nonexistent on a player, though. Mch processors often have it to be used optionally.)

A few caveats, which I mentioned. Some Mch SACDs are recorded or mastered in 4.0. They have no signal on the disc in the Center channel or the LFE channel. I even have some old Mercury and RCA recordings from the '50s-'60s that were recorded in 3.0. They have no signal on the disc in the Surround and LFE channels. Most, but not all, Mch SACDs are 5.0 and do not have any signal in the LFE channel. (The LFE input is just mixed into output channels as directed by bass management in your processor, most often to the processor output for your subwoofer(s), but depending on how you have configured the processor.)

I also mentioned in a previous post non-standard use of the channel assignments by a few rare companies like Chesky and MDG. But, they are insignificant exceptions.

The issue posed by the OP is connecting those standard 6 SACD output channels to the inputs for his system. He prefers connecting the player Surround L and R analog outputs to the analog inputs for Back L and R on his system's Mch processor when playing an SACD. Presumably, he switches back and uses the normal, standard connections when he plays a 7.1 BD.

My point was that is not how nearly all Mch SACD recording producers intended they be heard. They miked, mixed and mastered the recordings with the idea that the Surround channels were going to reproduced by Surround speakers, which are ideally at 110 degrees from the sweet spot per ITU. The definition of Surround speakers in all other major Mch system setups, like DTS and Dolby, also places the Surround speakers in the same general area: 90 to 120 degrees. Back speakers for 7.1 are normally at about 150 degrees or thereabouts in most all common systems.

HDMI, incidentally, carries those same standard and intended channel assignments to the Mch processor from the disc and player. But, you normally cannot change those assignments like you can by swapping analog interconnections. When you play a Mch SACD via HDMI, the Surround channels from the disc always show in the processor as Surround channels, never as Back channels. You could still change the analog connection between Mch processor outputs and amp/speaker channels. But, what rational recording producer would expect you to reconnect your system for their recordings when standard angular definitions for Surrounds vs. Backs exist across the industry?

Incidentally, I have an on-screen display in my system of all 8 channel signal volume levels side-by-side. That completely bears out what I have said in playback of SACDs

Clearer?

 

[markw]

I have thousands of SACDs, mostly in Mch. There is no difference between US, European, Japanese, etc. discs or between channel assignments in processors and players. They never use the back channels for SACD.

In spite of all your eloquent verbosity, this statement is pure garbage. ...and now you're trying to baffle us with bull. We're not talking the ".1" channel. We're talking the two rear channels on a SACD. We're not talking the 6th and 7th channels on a DD or DTS blue ray. We're talking a SACD where 5.1 is it's limit.

I'm familiar with the RCA Living Stereo 3.0 remasters. I'm also familiar with the current batch of 4.0 (Pentatone?)releases from Audio Fidelity. In either case, this is moot to your overly broad statement. In cast, the latter actually proves your statement false.

Again, you said They never use the back channels. for SACD and, if you haven't realized by now that that's false, well, that says more about you than you think.

Don't feel bad. We get many people her who think they are God's gift to this hobby. They either wise up or leave if they can't stand being called on it.

 

[TLS Guy]

In spite of all your eloquent verbosity, this statement is pure garbage. ...and now you're trying to baffle us with bull. We're not talking the ".1" channel. We're talking the two rear channels on a SACD. We're not talking the 6th and 7th channels on a DD or DTS blue ray. We're talking a SACD where 5.1 is it's limit.

I'm familiar with the RCA Living Stereo 3.0 remasters. I'm also familiar with the current batch of 4.0 (Pentatone?)releases from Audio Fidelity. In either case, this is moot to your overly broad statement. In cast, the latter actually proves your statement false.

Again, you said They never use the back channels. for SACD and, if you haven't realized by now that that's false, well, that says more about you than you think.

Don't feel bad. We get many people her who think they are God's gift to this hobby. They either wise up or leave if they can't stand being called on it.

That is the point. The back channels are definitely intended to be used on some SACDs and not the side surrounds.

You mention the Pentatone remastered Philips Quad recordings for one. Those remasters sound wonderful, but the surround speakers need to be at the back.

In addition the circular drummers on the Aho symphony No. 12 recording are all round Latte Hall.

The drummers do what Laplanders are prone to do, and that is beat in a fashion, that makes the drumming whorl round the room. That will not happen if you use the movie 5.1 set up. In addition the rear will not be distinguishable from the side brass choirs.

If you play this recording using very capable rears, and believe me this recording requires five very powerful beefy speakers and a response down to 20 Hz from either good full range speakers or the use of good subs in addition, you need to use the rears. If you don't then it makes nonsense of the circular drumming and you will loose the effect of the side brass choirs.

This recording works marvelously using the rears as the engineers intended. Only an idiot would master it any other way. The drums locate round the whole room as they are banged sequentially in a circular fashion. All the five brass choirs image perfectly.

When I play the Motet SACD of the two great organs of Cologne Cathedral, I want them front and back. I don't want one of them playing over my head, or the rear one in front of me if I sit in my second row.

The other thing is my fronts and rear cast a wonderful perspective and it really sounds like the front organ is way in the front and the rear organ way in the rear. There is a huge dynamic range on this recording and it is positively atmospheric.

In Helmuth Rilling's recording of the War Requiem, the musicians are located as Benjamin Britten instructed for the dedication of the new Coventry Cathedral. This will NOT play back correctly if the arrangement is traditional 5.1.

If the rear channels are used just for ambience then the traditional 5.1 arrangement works fine.

For antiphonal music the 5.1 traditional arrangement only works if the antiphonal choirs are front and side to side. It does not work for front and rear, which so much of it is.

Optimally systems should be able to switch the surround channels to the rear.

I do not agree that 7.1 is a waste of time. More movies should be 7.1 War Horse for instance is superbly recorded and on this rig things like vehicles can move seamlessly between front and rear. The 7.1 puts you much more in the middle of the battle field than 5.1.

In addition PL II x music works much better in a 7.1 set up then 5.1. Others have noted this also.
This algorithm works very well for minimally miked ambient recordings.

My own masters using intensity stereo rather than phase difference using an M-S technique with a Neumann SM-69 FET is as good as discreet recordings. The applause and audience clapping almost all comes from the four rear speakers and not the three fronts. Due to the way M-S works with a center microphone it makes the front three essentially discrete.

The BPO concerts are recorded in multichannel but mixed to 2 channel for streaming until they move to multichannel streaming. They issue some of their concerts in DTS Master Audio5.1.

The Pl II x does a really good job of returning those recordings back to multichannel. If the phase relationships in the recording can be preserved, Pl II x actually works wonderfully well and returns preserves the ambience of the recording venue very well.

I agree for pop music those algorithms are awful and not recommended.

 

[fitzcaraldo215]

In spite of all your eloquent verbosity, this statement is pure garbage. ...and now you're trying to baffle us with bull. We're not talking the ".1" channel. We're talking the two rear channels on a SACD. We're not talking the 6th and 7th channels on a DD or DTS blue ray. We're talking a SACD where 5.1 is it's limit.

I'm familiar with the RCA Living Stereo 3.0 remasters. I'm also familiar with the current batch of 4.0 (Pentatone?)releases from Audio Fidelity. In either case, this is moot to your overly broad statement. In cast, the latter actually proves your statement false.

Again, you said They never use the back channels. for SACD and, if you haven't realized by now that that's false, well, that says more about you than you think.

Don't feel bad. We get many people her who think they are God's gift to this hobby. They either wise up or leave if they can't stand being called on it.

Ok, so if my statement is wrong, where are the back channels defined in the SACD spec? Which specific SACDs have any signal output from the back channel outputs in either analog or HDMI?

It seems there might be some misunderstanding, because that is all I said in that statement. Still think the statement is false?

Sorry, if you do not like my style. But, what are you calling, exactly? You have not presented any facts yourself that in any way refute anything I said. You are essentially saying you don't like it and it is bull. But, show me where I am wrong.

 

[markw]

Ok, so if my statement is wrong, where are the back channels defined in the SACD spec? Which specific SACDs have any signal output from the back channel outputs in either analog or HDMI?

I provided links to more than a few examples to illustrate my point. If you're too blind to see that, then you're beyond hope.

And, if you're trying to play semantic games by saying to allude the channels 6 & 7 on DD/DTS, give it up. We all know they don't exist on SACD.

Screw the spec. They are out there. Drop on the 5.1 version of Pink Floyd's Dark Side of the Moon and then tell me there's no information back there.

My cheapo Denon 1940 CI has no problem generating them. I don't see how your equipment can't. Go ahead.

If you can say they aren't there, then either your equipment is faulty or you're simply a liar and enjoying this game of mental masturbation. If that's what it is, I'm done playing with you. You can continue playing with yourself.