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Resolved: the "LFE channel" should never be utilized on SACD/DVD-A. (1 Viewer)

Ken_McAlinden

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The LFE channel is useful if you have ... low-frequency effects. There is very little in most music to which I listen that requires a dedicated bass channel with 10dB of headroom built in, and as such, little use for the LFE in music. I agree with Rich's initial post. I am 100% confident that there are some mixes being done with an LFE channel for no other reason than that some people will complain if their LFE light does not turn on.

Regards,
 

Brian L

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Steve, I believe all the Chesky discs are 4.0 with the option of going 5.0 if you wish to use their "height envelope channel".
Actually, the two Chesky DVD-A titles I have (Ultimate Test DVD and Swing Live) offer 4.0 or 6.0. The 6.0 mix (using the center and LFE channel) calls for two additional speakers mounted in front of the listener on the side walls. They are suggested to be forward of the mains, but not as far back as the normal surrounds.

I do not think they represent "height" information, so much as early reflections. At least thats what I took from the booklets in the CD case.

And just to repeat myself, the choice of the number recorded channels, or the presence of lack of a .1 channel is totally and completely irrelevant if BM is done properly. IMHO, or course.

My 45A does NOT do DVD-A BM correctly. As such, I am more screwed with a 4.0 or 5.0 then I am with a 5.1 disc (is there such a thing as being partially screwed???? Perhaps Bill Clinton will chime in).

Of course, like everyone else similarly effected, I did an ICBM which cured all my bass management ills.

Until the manufacturers get it right, everyone with half-ass BM (which is to say just about EVERYONE) will be hosed to one degree or another, LFE or no LFE.

BGL
 

Ed St. Clair

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Ed, you've totally missed the point.
No, Rich Malloy,
You "totally missed the point" of discreet [direct] vs. matrix [maded up]!
You can run your audio channels through as many crossovers as you like!
Just let me have my discreet channels, please.
htf_images_smilies_yum.gif
 

LanceJ

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Ah heck just go buy five BIG manly speakers with good ol' 12" woofs in them--you know you want to!

If the wife objects, just tell her to go back into the kitchen and make sure she doesn't burn your dinner!

:D

LJ
 

Steve_AS

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Actually, the two Chesky DVD-A titles I have (Ultimate Test DVD and Swing Live) offer 4.0 or 6.0.
The DVD-A surround *setup* tracks of the disc, though, appear to be in 5.1 (3/2.1). The musical selections are in 4.0 (2/2) and 6.0.

That said, the setup tracks don't behave like other DVD-A 5.1 tracks I own. 6 channel DVD-A from regular music discs appear to get bass managed properly by my 45a; but the ostensibly 5.1 bass management test track on the Chesky disc does not.

Still haven't figured that one out.
 

Brian L

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That said, the setup tracks don't behave like other DVD-A 5.1 tracks I own. 6 channel DVD-A from regular music discs appear to get bass managed properly by my 45a; but the ostensibly 5.1 bass management test track on the Chesky disc does not.
I agree that the test tracks are 5.1, and further, those tracks show that the BM does NOT work on the 45A, but I also think it is flawed with the DVD-A music tracks.

Although I have an ICBM in the signal path, I set all speakers to Bypass, such that it is really not doing anything. Playing any of the music tracks on the disc (I like the Latin Jazz cut for this) and there is NOTHING coming out of my sub (note that this is with the 45A set to all small, sub on just for that test. Normally its all large, sub on so that the ICBM can work its mojo).

In that scenario, if the player WAS doing BM, the bass from the main tracks would be routed to the sub.

That matches what various other posters had reported in the 45A threads a while back. Of course, I have done so many frickin' tests with this frickin' player, that I would not rule out an error....but I digress.

In any event, that behavior is why I feel that not using an LFE while still having FUBAR bass management is not going to solve anything for anyone unless they have 5 full range speakers and no sub. Note to LanceJ: please DO NOT touch your keyboard at this time:D)

Its the BM that needs to work right, and if it did, most users would not care if there is an LFE channel or not. Cripes, when the Tarzan DVD came out, there was an uproar because it did NOT have a .1 channel, like that meant it had NO bass. Yup, it had no bass if your rig did not get BM right.

BGL
 

Rich Malloy

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No, Rich Malloy,
You "totally missed the point" of discreet [direct] vs. matrix [maded up]!
You can run your audio channels through as many crossovers as you like!
Just let me have my discreet channels, please.
(sigh)

I'm tired of trying to explain it to you.
 

Rich Malloy

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In any event, that behavior is why I feel that not using an LFE while still having FUBAR bass management is not going to solve anything for anyone unless they have 5 full range speakers and no sub. Note to LanceJ: please DO NOT touch your keyboard at this time)

Its the BM that needs to work right, and if it did, most users would not care if there is an LFE channel or not.
Indeed, we have a hardware problem here. But the existence or lack of an "LFE" channel won't resolve that and really has no bearing upon it. This is an important and related but separate issue. Why? Full-range signals are still sent to speakers that can't handle it even in the absence of an encoded "LFE" channel (unless you have 5 real full-range speakers all around). Bass management is problematic regardless of the presence/absence of an LFE channel.

But what you're hinting at here is a potentially very real problem I see looming on the horizon... not with Chesky, not with Telarc, not with any of the studios that care about presenting the very best music reproduction. I'm talking about the Sonys and Universals and Warners and other mainstream music providers (this might even be worse on the DVD-A side). And that problem? Pre-encoded "bass management". A one-size-fits-all approach. And if it's one size fits all, which size will be it be fitted to? Hmmmm.... how many Bose cube systems are sold in this country?

Brian, since you have an ICBM-1, why worry over the Pioneer's bass management capabilities (or lack thereof)? Do you need it for level-matching between channels?
 

Brian L

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Brian, since you have an ICBM-1, why worry over the Pioneer's bass management capabilities (or lack thereof)? Do you need it for level-matching between channels?
Well, yes, I slayed the BM dragon when I bought the ICBM, so I am no longer worried about it per se. I am cheezed off that I had to buy it though.

Truth be known, when I bought the ICBM, I was doing it to get an 80Hz crossover required by my Bijoux EQ. I was unaware that the DVD-A BM was hosed until it was reported in a 45A thread, and I confirmed it with the Chesky disc. So, the ICBM fixed a problem I did not know I had.

And no, it is not needed in my rig to sort out the channel level issues (I assume by that you mean the Low LFE level that the Denon 2900 boys are now discovering?).

BGL
 

Rich Malloy

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And no, it is not needed in my rig to sort out the channel level issues (I assume by that you mean the Low LFE level that the Denon 2900 boys are now discovering?).
Actually, I wasn't speaking to the "low LFE level" thing (or the 10DB DD/DTS boost, or whatever), but rather level-matching your center and rears and mains. The ICBM won't do this; the onboard bass management of my Sony player allows this (as does the Pioneer and other players, I presume), but using it degrades the sound quality so much that I bypass it altogether.
 

Brian L

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Actually, I wasn't speaking to the "low LFE level" thing (or the 10DB DD/DTS boost, or whatever), but rather level-matching your center and rears and mains.
I see.

In my rig, the 6CH in on the receiver has independent level controls (separate from the level controls for internally decoded sources), so that is how I level match. I leave the player set to "fixed" on all channels.

That said, I think the level matching capability is independent of BM in the 45A, and I have never used it, so I am not sure what effect it would have.

BGL
 

Ed St. Clair

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Unless the music is completely electronically generated, is there even such a thing as discrete LFE? Discrete in terms of spatiality has nothing to do with the .1 channel.
Is this a joke?
What format of music reproduction isn't "Completely electronically generated"?
Yes, the LFE channel (or .1) is discrete.
For DD 5.1, DTS 5.1, DVD-A 5.1, & SACD 5.1.
This allows the LFE channel to be discrete from the mixing board to your sub. And when recorded for 5.1, from "THE" bass to your 'bass'.
Of coarse, you could always have someone take that discrete info, re-mix it back into the mains, have your pre take the LFE info out again (crossover) and then send it to the sub.
But, why?
Has someone built a perfectly flawless crossover I haven't heard about?
 

Javier_Huerta

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Ed, I might be repeating myself from my first post.

The way I see it, the .1 channel should NEVER be used for music.

Why?

Scenario 1: You have a 5.1 channel mix.

1) People with NO subwoofer support won't get the whole mix. Because the .1 channel should never be mixed with the mains.
2) People with a subwoofer will get bass from their mains, and from their sub. Depending on whether they are redirecting bass from their mains to their sub, they'll get all kinds of results.

Some other thoughts:
1) What happens if the album's producer mixed all bass to the .1 channel? Well, people with no subs won't get any bass. It's as simple as that.
2) What happens if he decides to mix some bass to the LFE, and some to the mains? Well, *some* people will get some of the bass, others will get all the sonic information.

Scenario 2: You have a 5.0 mix.

1) People with no subwoofer get all the sonic information from their own main and / or surround speakers.

2) People with a subwoofer get their bass output redirected at the crossover frequency they choose to their bass module, and the rest of the mix will go to their main speakers.

Scenario 2 is the only one I can think of where the results are predictable in both situations.

You seem to think a crossover in the bass region for a sub is a bad thing. I cannot disagree more. I wouldn't let *any* producer dictate the crossover point of my speaker setup by using one channel for mids and the other one for highs. Why would I ever let him choose the crossover point of my subwoofer setup?

Bottom line is, the .1 channel should *never* be used for music. It's intended as a "special effects" channel - hence, its ".1" designation. It works pretty well as intended - but I think using it for music is too much of a stretch.

EDIT: I really need to get my hands on an ICBM. I hate the bass management on my DVP-NS900. 120 Hz crossover point? What was Sony thinking???
 

Ed St. Clair

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You seem to think a crossover in the bass region for a sub is a bad thing. I cannot disagree more. I wouldn't let *any* producer dictate the crossover point of my speaker setup by using one channel for mids and the other one for highs. Why would I ever let him choose the crossover point of my subwoofer setup?
Maybe, could have, should have, would have, "quoted" more of your statement, but here goes.
Multi channel music formats where announced at least as far back as '98.
Can I help it if 'someone' doesn't have the 'proper' (re: five full range spks & at least one sub) speaker system?
No!
Should I suffer, because people do not have the capability to 'handle' a 5.1 movie/music mix?
No!
Like I said, run the audio channels though as many crossovers as you wish and/or need too!
Just don't ask me to do the same.
I built my system to 'handle' seven discrete channels (six, full range & one or more LFE) so that I could take full advantage of the format.
Now, people want to 'dumb down' 5.1, because some people own Bose systems?
Give me a break!
The idea was/is, that said "any producer", would use all five full range channels, full range!
Imagine that!
That why the 5, represents full range speakers, guy's!!!
The .1 represents LFE, of coarse because DD is mostly associated with movie soundtracks.
However, it is used for low frequencies only, in movies & music.
"Any producer" is NOT "choosing" the crossover for your LFE channel!
Bass & ONLY BASS, is in the LFE channel!
It's not "crossovered", as this thread advocates.
The appropriate low frequencies are in the low frequency channel.
That's all.
Not what's supposed to be in the center channel.
Not what's supposed to be in the main channels.
Not what's supposed to be in the surround channels.
The "any producer" who you trust to capture the musical event on your chosen format. Now get's to direct, discretely, the right frequencies too the right channels.

I thought this was a good enough idea to build my system around.
And I have been very please when this has been done in the past.
Now people what to "take away" the sub on this thread & the center channel in another thread.
Cause their systems are not set up to 'handle' 5.1.
Boo woo!
 

Ken_McAlinden

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Is this a joke?
No, but thank you for your condescension.

I was talking about the generation of music moreso than the reproduction. Most music is not performed/generated with a discrete mono signal for low bass. In terms of using multiple channels to capture the (or create a) spatial element of a music signal, the LFE channel is not required. I agree with the concern that as it is employed for music, it pre-supposes the bass-management needs of the listener and as such will be wrong most of the time.

Regards,
 

Javier_Huerta

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Ed, I give up, too. :frowning:

It's a good thing you have a properly set up and calibrated 7.1 system. Most of us have one, too. That has nothing to do with music being properly reproduced with / without a .1 chnnel.
 

Brian L

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EDIT: I really need to get my hands on an ICBM. I hate the bass management on my DVP-NS900. 120 Hz crossover point? What was Sony thinking???
And once you do get an ICBM, the issue of how a disc is mixed (LFE or no LFE, bass in the main channels or not, etc.) will be totally and completely irrelevant. You will then have some of the best, most flexible BM available.

Agree on the bogus 120Hz crossover. I think the 100Hz crossover on my 45A is crap to, thus the ICBM now has a place of honor in my rig.

So the solution to this whole problem is for vendors that screw-up BM MUST buy their customers an ICBM:D

All in favor, say Aye!

BGL
 

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