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

Rich Malloy · 04-23-2003, 03:44 PM

I'm considering adopting the following Manifesto:

Every studio producing music SACDs and DVD-As should encode full range signals to all 5 primary channels, and never redirect any bass content away from those 5 primary channels to the so-called "LFE" channel.* Bass management should be entirely a function of the playback system, because only the individual user knows the range and limits of his speakers.

*Use of the so-called "LFE" channel for "height envelope" and other experimental playback schemes is permitted so long as the use of this channel is entirely optional.

Or am missing something here?

04-23-2003, 04:01 PM

Man, I feel your pain, but would this be needed if the various manufacturers got BM right in all formats?

Being a Pioneer 45A owner, I surely appreciate that BM is often handled poorly. Hardly ANY manufacturer gets it right. My player will NOT send the LFE to the mains in DVD-A when I have it set to no sub (don't know about SACD), and it also will not send bass from the mains to a sub when I have my mains set to small.

So, without my trusty ICBM, I am screwed with or without bass on the LFE. I think a lot of others are too. As such, I don't know what this buys us. Until BM is done right, everyone is hosed to one extent of another.

It seems like no one ever had grief with BM when all we had was Pro Logic, but as soon as DD and DTS showed up and we got an LFE channel, stuff started going downhill fast. And then when DVD-A and SACD MC players hit the street, the whole outhouse burned right down.

Brian

Justin Lane · 04-23-2003, 04:12 PM

Since most DVD-A and SACD are labeled where applicable as 5.1 releases, I think it is safe to assume that a subwoofer will be used in a system (or why would one purchase 5.1 music?). It is important to keep the LFE channel, especially for mass market acceptance, for those who have small satellites or HTIB type systems. LFE distributed to smallish speakers, with no form of bass management available could be a big problem. Of course if the engineer doing the album sends boku amounts of bass to the mains, you are going to run into trouble anyway.

The ultimate solution is proper Bass management within the Hi-res players, which doesn't look like it is happening anythime soon. I guess another option would be to mandate engineers to send frequencies lower then a certain level to the LFE regardless, but I don't like the possibilities that may hold either. Really it is a sticky issue which has no perfect solution at this point.

J

Kevin C Brown · 04-23-2003, 04:38 PM

I also think a better solution is for the player makers to get the BM issues *correct*, *and* for the studios/producers to agree that the LFE channel should be bandpass limited to < 200 HZ or so. Then it's a heckuva lot more transparent to people with systems already set up for DVD-V (DD/DTS, etc). (Wasn't that the whole idea behind DVD-A in the 1st place anyway?) Make SACD/DVD-A backwards compatible is all I say...

LanceJ · 04-23-2003, 07:59 PM

I will admit I don't like using the LFE channel for music either.

Question: Ever notice all those Panasonic & Sony hi-res HTiB's with tiny satellites? What are THEY using for bass management???

LJ

**HTF Ads**

Wayne Bundrick · 04-24-2003, 12:26 AM

The manufacturers and the recording labels should stand side by side so that we can deliver a pimp daddy bitch slap to both of them, "Three Stooges" style. Because each of them have surely f***ed things up from opposite directions.

I don't agree with the idea of "DVD-A discs are labeled 5.1 so they assume you really have five speakers plus a subwoofer." I also don't agree that LFE should never be used. That's treating the symptom and not the disease.

I seem to recall that before the DVD-A specification was completed, someone had the presence of mind to include a table of "rosetta stone" data on the disc which would give control on a song-by-song basis over exactly how these six channels of audio are to be downmixed by the player in the event that the listener does not have five speakers plus a subwoofer. I want to know why neither the manufacturers nor the recording labels are using it.

A pimp daddy bitch slap, I tell you. Three Stooges style.

Lewis Besze · 04-24-2003, 02:06 AM

If a complete BM is adopted in the players universaly,then it won't matter if the LFE channel is utilized.
The new Denon is very promising,that manufacturers start to "see the light".Sound mixers for music,just like the movie counterpart, are endowed with an "artistic licence",they all have different ideas,as how music should be mixed.

Brian Perry · 04-24-2003, 08:10 AM

If memory serves, the reason the .1 (or LFE) channel was added in the first place was because there was the potential that certain bass-heavy movies would oversaturate the capabilities of the 5 primary Dolby Digital channels and that an extra 6dB or so might be necessary. Otherwise, there would really be no need for the .1, as your pre/pro would simply direct bass from the main 5 channels as necessary.

I don't think DVD-A or SACD has this limitation, so I agree with Rich in that the .1 isn't necessary. That's not to say in some systems a subwoofer isn't required--just that the subwoofer can get all the info from the 5 main channels. (Of course, this is complicated by the lack of a digital interface and that BM needs to be handled by the player.)

Leo · 04-24-2003, 01:13 PM

If we were sold a product that stated it was to handle bass management correctly, and in fact doesn't, wouldn't it be considered a defect that should be corrected as a warranty issue?

Just my .02 cents