Thread: Height Channel: Big Mistake or Bad Idea

Posts: 8

Post by randy August 9, 2003 (1 of 8)
(Apologies to Dave Barry.)

Is anyone enamored to the concept of use of the LFE channel of SACDs as a "height" channel?

I noticed in the liner notes of "Tchaikovsky: 1812 Overture etc. - Cincinnati Pops/Kunzel"
http://sacdinfo.com/showtitle.php?title=190
that this was done with this disk, and that Telarc is planning to release more like it.

According to Telarc: "The vast majority of home theater surround receivers and preamplifiers have Bass Management features that allow the listener to derive the subwoofer (LFE) signal from the main audio channels." My Sony STR-DE985 does not seem to be able to do this with the multichannel analog inputs, and if it did it would be done through DSP. If I wanted the sound to be degraded to PCM I would buy DVD-A!

Telarc recommends attaching a separate amplifier directly to the SACD player's LFE output. This would mean that the overhead volume would have to be controlled separately from the volume of the remaining channels! Also Bass Management could not be applied to this channel. Perhaps instead I could use the receiver's rear channel for this, adding an external speaker switch to switch between the height and rear speakers. Or perhaps this is what the receiver's rear channel preamp out is for.

Telarc also recommends using (presumably non-full-range) dipole speakers for the height channel. This is curious, since in listening to this channel by itself on the above SACD I am finding that so much of the program is low bass that I might as well continue sending the channel to the subwoofer.

Thoughts?

Post by oryan_dunn July 17, 2004 (2 of 8)
randy said:

(Apologies to Dave Barry.)

Is anyone enamored to the concept of use of the LFE channel of SACDs as a "height" channel?

I noticed in the liner notes of "Tchaikovsky: 1812 Overture etc. - Cincinnati Pops/Kunzel"
http://sacdinfo.com/showtitle.php?title=190
that this was done with this disk, and that Telarc is planning to release more like it.

According to Telarc: "The vast majority of home theater surround receivers and preamplifiers have Bass Management features that allow the listener to derive the subwoofer (LFE) signal from the main audio channels." My Sony STR-DE985 does not seem to be able to do this with the multichannel analog inputs, and if it did it would be done through DSP. If I wanted the sound to be degraded to PCM I would buy DVD-A!

Telarc recommends attaching a separate amplifier directly to the SACD player's LFE output. This would mean that the overhead volume would have to be controlled separately from the volume of the remaining channels! Also Bass Management could not be applied to this channel. Perhaps instead I could use the receiver's rear channel for this, adding an external speaker switch to switch between the height and rear speakers. Or perhaps this is what the receiver's rear channel preamp out is for.

Telarc also recommends using (presumably non-full-range) dipole speakers for the height channel. This is curious, since in listening to this channel by itself on the above SACD I am finding that so much of the program is low bass that I might as well continue sending the channel to the subwoofer.

Thoughts?

I noticed that as well. It almost seem like more trouble that it is worth to set that up like they say you should. Since most people use SACD in a home theater setup with a dvd player that also plays SACD, it is ridicules for them to do that. In the .001% of setups dedicated to SACD, most would want that .1 to go to a sub anyways. If SACD players had 6.1 outputs to a 6.1 receiver, then they could use the rear center as a height channel, but to expect people to change around their setup for just one label's recordings, that seems short-sighted to me.

Ryan

Post by Dan Popp July 18, 2004 (3 of 8)
oryan_dunn said:

, but to expect people to change around their setup for just one label's recordings, that seems short-sighted to me.

Ryan

Ryan,
In defense of labels that are doing odd things like this, what you're seeing are their attempts to make some reasonable use out of a channel that is useless for music reproduction. If you want low bass, the subwoofer signal can be extracted from the full-bandwidth signal. Thus the LFE (Low Frequency EFFECTS), or what film people call the "boom" channel, is wasted.

If people really want 3-dimensional audio, as they claim they do... a height channel is necessary.

Yes, we're seeing some weird, proprietary uses of this "extra" channel - as we would expect for any infant format.

Post by oryan_dunn July 18, 2004 (4 of 8)
Dan Popp said:

Ryan,
In defense of labels that are doing odd things like this, what you're seeing are their attempts to make some reasonable use out of a channel that is useless for music reproduction. If you want low bass, the subwoofer signal can be extracted from the full-bandwidth signal. Thus the LFE (Low Frequency EFFECTS), or what film people call the "boom" channel, is wasted.

If people really want 3-dimensional audio, as they claim they do... a height channel is necessary.

Yes, we're seeing some weird, proprietary uses of this "extra" channel - as we would expect for any infant format.

Would you agree that most of the people that listen to multichannel SACDs do so in the same setup as their home theater? I doubt very much that many people have a separate SACD player with a separate amp and 5 identical full range speakers for SACD. I would personally love to have a setup like this, but money and space do not permit this. Since most people spinning the mc mix of SACDs do so in a multitasking room, and many in a multitasking player, they will have the .1 hooked up to the sub. Those who do not use the 6 channel outs for DVD movies (most people, but my receiver isn't DTS, so I need those for DTS), could theoretically implement this solution, as then they would only need to connect 5 channels, and run the .1 to a separate amp for this purpose. This works great as long as they have full range speakers all around. Many people (probably not audiophiles) use a 5 small satalites and a sub. With this configuration, and using 5 channel analog in, would require the persons amp to do bass managment on the analog inputs, to filter out the bass from the 5 channels and send it to the sub. Many that I'm aware of do not do this, not in the price range of someone with a 5 sat, sub config would have. Even if they would use 6 channels from the player to the amp, many mc mixes don't use the .1 anyways, so they still can't use their amp for bm, but must rely on the player to implement bass managment for SACD.

It's just to complicated for the average user to get working. Granted the target audience for such a feature isn't the mass market, it still shouldn't be overly complicated to execute.

It would be great to have the resources to implement this, and some recognition needs to go to Telarc for trying something new, but I doubt that the "height" channel will actually get very far off the ground (pun intended).

Ryan

Post by Dan Popp July 19, 2004 (5 of 8)
oryan_dunn said:

Would you agree that most of the people that listen to multichannel SACDs do so in the same setup as their home theater?

Ryan,
Sure. Would you agree that 2,822.4 bits per second is a lot to waste? Do you blame the company for trying to turn waste into an extra dimension of sonic information, which is what MC proponents say they want?

What harm does it do if Telarc makes a height channel you won't use instead of a LFE channel they won't use?

Just don't use it.

You have to understand that to people in the recording industry, 5.1 is a mixed blessing at best. The people who came up with the DVD-A spec basically just accepted what the film people gave them. By the time SACD came to market, there probably wasn't much choice. It's a shoe that doesn't fit, and right now the industry is trying it on in various different ways to try to get it to fit better.

Bravo to Telarc, I say, for trying to actually push the AUDIO forward a notch. Our benevolent 5.1 gurus didn't have the guts.

Post by oryan_dunn July 20, 2004 (6 of 8)
Dan Popp said:

Ryan,
Sure. Would you agree that 2,822.4 bits per second is a lot to waste? Do you blame the company for trying to turn waste into an extra dimension of sonic information, which is what MC proponents say they want?

What harm does it do if Telarc makes a height channel you won't use instead of a LFE channel they won't use?

Just don't use it.

You have to understand that to people in the recording industry, 5.1 is a mixed blessing at best. The people who came up with the DVD-A spec basically just accepted what the film people gave them. By the time SACD came to market, there probably wasn't much choice. It's a shoe that doesn't fit, and right now the industry is trying it on in various different ways to try to get it to fit better.

Bravo to Telarc, I say, for trying to actually push the AUDIO forward a notch. Our benevolent 5.1 gurus didn't have the guts.

I agree that the 6th channel is usually wasted on SACD releases and I also think that Telarc is innovative in its use of that channel. I just belive that it wont get used that often by most of the SACD listeners (I know that I can't at this time, and probably wont as even if I had the resources, I'd still have two volume controls). I enjoy my muiltichannel, but I think that there has to be a limit on the number of speakers. If it keeps up, someday we'll have 32.1 sound systems for a speaker at every 15 degree mark on a sphere around the ideal listening place. I'm not saying that a height channel wouldn't add more to the multichannel sound, but (having never actually heard the height channel) I doubt it adds that much to the sound that I would feel I needed it in my home.

Anyone else care to add their opinion on the subject?

Ryan

Post by LC July 20, 2004 (7 of 8)
oryan_dunn said:

If it keeps up, someday we'll have 32.1 sound systems for a speaker at every 15 degree mark on a sphere around the ideal listening place.

22.2, actually:

http://www.pc4d.com/tv_video/44/uhdv_ultra_high_definition_video_the_next_level_of_ultimate_.shtml


I would definitely want to try the height channel if I could, although Telarc does emphasize that it is completely optional. Telarc lists the options below for height channel set-up. Is any of them practical? What about getting a Bryston SP1.7 or, if you're really going to go all out, a Theta Digital Casablanca II? Those must allow you to do this easier. Of course, they are not cheap. But just wait until UHDV hits the market and even the Theta is 12 channels short!

http://www.bryston.ca/sp17_m.html
http://www.thetadigital.com/product/cb2/prod-info.htm



Full-range main speakers:

* Disable receiver/preamplifier "Bass Management" so that receiver LFE output is full-range.
* Connect receiver LFE output to optional height speaker(s).

OR

* Connect player LFE output to an independent single-channel amplifier, then to height speaker.

OR

* Connect player LFE output directly to a self-amplified speaker(s).

Satellite main speakers + Subwoofer:

* Set receiver/preamplifier Bass Management to derive the subwoofer signal (LFE or ".1") from the main audio channels rather than from the LFE track of the disc.
* Connect player LFE output to an independent single-channel amplifier, then to height speaker.

OR

* Connect player LFE output directly to a self-amplified speaker(s).

Post by mdt July 20, 2004 (8 of 8)
Dan Popp said:



What harm does it do if Telarc makes a height channel you won't use instead of a LFE channel they won't use?

Just don't use it.

Agreed to that, since the remaining 5 channels are full range they should still provide a good 5.0 playback; the height channel is just a bonus for those who wish to make use of it.
As for how to use the 6 channels i believe the 2+2+2 recording system is a good solution since it is specially designed to give uncompromised results wether the listener may choose a 2, 4 or 6 channel set-up; in 6 channel mode this sytem also provides height info.
(except that with sacd the stereo info should be seperately layed down once more on a dedicated stereo track even if it is an integral part of the 6 channel version, else owners of stereo-only SA-CD players can't access the DSD layer)

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