Why doesn't the DVD-2900 downmix LFE? (1 Viewer)

[Rob Gillespie]

That's not the problem though. The RGB output from the 2900 looks 'different' to the same from a couple of cheapy players I've got. The colour balance is different - and I'd probably say it's 'off'. You cannot adjust colour controls whens using the RGB input so I'm stuck with it. I just use S-Video.

 

[Brian L]

I may have lost the plot here, but I have a couple comments regarding those that are asking/commenting about using a 2 CH setup....

DD/DTS do have a mode that will downmix to 2 CH, although your player, receiver, or pre/pro may not support it. However, DD will discard the . 1 channel when downmixing (do not know about DTS).

Now, I do not think DVD-A or SACD have such a mode, no matter how you set the player. However, for hi-rez formats, ALL SACD's have a dedicated 2 CH mix. Most, but not all DVD-A titles I own have a 2 CH mix. And it you have a dedicated 2 CH mix, there is no .1 channel to loose. If you rig does have a sub, and the L/R pair are set to small, you would like to have BM work, but many players do not do so.

But, if you are wanting to play these titles in 2 CH on a rig w/o a sub, no problem, just select the 2 CH mix. And for DD, its looses the .1 by design, so there's nothing you can do there.

And lastly, the players that I know of that have BM issue normally do handle BM correctly with DD/DTS; its just the hi-rez stuff thats FUBAR'd.

So, if you set the system for Large L/R, small C and Surrounds, and No Sub, you should properly redirect the .1 to the main L/R for DD and DTS.

BGL

 

[Bill Blank]

Rob,

Have you emailed Denon for an explanation and advice?

It's a shame that the engineers designing these machines make bass-management so much more of an issue than it should be, often mucking it up in the process.

Bass management in source components and receivers/pre-pro's should follow one standard and offer the flexibility for any configuration. I guess that's even asking a bit much as the SACD and DVD-A camps can't even decide on standards for the LFE channel themselves...

As an aside, I have my 2900 connected to my Rotel RSP-1066 using it's MCH Analog Outputs for SACD/DVD-A and via it's Optical Output for DVD-V. My Rotel is able to compensate for the 10dB difference in the LFE channel and ALL bass-management is handled in my Rotel.

My only issue with the 2900 is it's chroma bug on some movies.

Bill

 

[ScottCHI]

the plot is still (mainly) simply that when you set these players up with a "NO sub" option, they completely drop the LFE channel when playing back multichannel material that DOES contains an LFE track.

so, if you have 5 (or 2) large speakers in your setup with NO subwoofer, and want to decode ANY material that has a .1 LFE channel (be it dd, dts, sacd, OR dvd-a) with the player (analog multichannel connection), and not your receiver (digital connection), YOU COMPLETELY LOSE THE LFE CHANNEL. there are some other configurations where it gets dropped, as well.

this has nothing really to do (directly) with multichannel vs. 2-channel playback or the 10dB LFE difference.

it's easy to demonstrate the "bug" to yourself if you have AVIA (or something else that you KNOW has some "pure LFE" material). AVIA's LFE channel, low frequency sweep is "pure LFE". set your player up with all your speakers as LARGE and NO sub. make certain you playback AVIA via your analog, multichannel connection NOT your digital connection. if you have a receiver/pre/pro that bass manages the external/multichannel inputs, make sure you're not managing them. playback AVIA's "low frequency sweep, LFE" track. you shouldn't hear it with this configuration.

 

[Rob Gillespie]

Nope because the link provided earlier seemed to answer the question. It's a major oversight in the design but it affects other players too.

 

[Jigesh Patel]

When one plays a 5.1 source to a 2-ch set up, only the front two of the 5.1 will be playing and the rest will simply be not played because the rest of the speakers are not there (there's no downmix of rest of the channels into the front two).

In a same way, if .1 is designed to go to a sub, if sub is not there, it won't be played. How can it be an oversight?

May be I am mixing up something..?

 

[Rob Gillespie]

OK - 5.1 signal from DVD, playing into a 5.0 setup (no sub).

Turning sub OFF on the player does not result in the LFE signal being routed to the mains. Instead, it just drops it completely - i.e. no point in having the sub-off option!

 

[Brian L]

Jigesh,

You are perhaps blending two different issues?

Bass management, which should redirect the .1 to a large L/R mains in the absence of a sub, and 2 CH mix down, which to my knowledge is done correctly with DD/DTS but is NOT a feature of SACD and DVD-A.

Rob's initial complaint was that BM did not redirect the .1 channel to his main L/R, a problem shared by many, many hi-rez players.

Whether or not that's an oversight, a bug, or a conscious design choose matters little to the poor folks that need this feature but find it unsupported with their gear.

FWIW, many of the 1st and second generation Uni players did many things wrong with BM. In fact, I just read a review of the new Marantz 8400 (I think thats the model) and it too is totally screwed up with its implementation of BM.

And that situation is money in the bank for firms like Outlaw that make a proper BM solution!

BGL

 

[ScottCHI]

that's absolutely NOT true. that's the whole point of the downmix capability of these receivers (phantom center, no surrounds, etc.). ANY decent piece of home theater equipment, receiver or player, when setup as 2-channel, WILL downmix the center channel and the surround channels into the front channels.

and MOST (if not all) A/V receivers will mix the ".1" or LFE channel into the fronts in this situation when there is NO sub. that's why we're so baffled and are carrying on so (well, i am anyway.)

this is a problem specific to the way the players (not just denons) handle the LFE channel when the player is used to decode the LFE-containing material.

 

[Rob Gillespie]

As I mentioned earlier, this is part of my problem. My Denon amp will not perform any processing on the analogue RCA inputs - i.e. the analogue connection from the 2900 player. You can adjust treble and bass, but that's it. You get basically a raw feed from the inputs down to the power amps. If it could do downmixing on the EXT-IN input I'd be quite happy.

 

[Jigesh Patel]

Thank you, Scott - my mistake. I stand corrected.

 

[ScottCHI]

you'd STILL be missing your lfe info

 

[Brian L]

Again, not so Scott.

I can not post a link right now, but there is a white paper on the Dolby site that says that DD specifically EXCLUDES the .1 channel when downmixing to 2 CH.

Edit: Here's the link. The very last paragraph:

http://www.dolby.com/Consumer/Techno...ngthemost.html

Maybe DTS does it differently, but for DD, it matters not, the downmix function of the DD decoder deletes the .1 channel.

Rob is seeing what virtually all other owners of universal players has already had to deal with. Poor or non-existent BM and mix down capability of his universal player, as well as the fact that by design, DD does not downmix the .1 channel. If a given title has most of the bass pre-mixed into the .1, he is stuck.

Bill has a unique solution in that his Rotel will apply BM to the 5,1 EXT Input. Thus he runs his 2900 with all large/sub on, and the Rotel takes care of BM. He is also connected digitally, so that the Rotel's DD and DTS decoders take care of BM for those sources.

Not sure anyone here is baffled. The issues that Rob is describing have been clearly explained by John, Bill, and I.

BGL

 

[Rob Gillespie]

And it sucks!

 

[John Garcia]

If you sent 2ch of a m/c track via only a stereo pair of cables, the other channels would, in fact, be missing. Happens to me every time a DVD-A fires up with the m/c track. The receiver only sees what it is sent.

 

[Jigesh Patel]

Interesting, Brian - sounds logical. Thank you.

 

[ScottCHI]

that's not true either

when set up for 2-channel playback, with only front speakers, my denon 3803 downmixes the LFE channel from DD sources into the front 2 channels with no problems whatsoever. i just checked it. and so did my previous entry-level low-end sony. in fact, i've never heard of a receiver that wouldn't.

and when set up in 3-channel mode, with no surrounds, my denon 2200 player WILL mix the surround channel info into the front speakers when the multichannel track of a dvda or sacd is played. i know because i've run my system in 3-channel mode and i was concerned about this and checked it. and there ARE, as you pointed out, a few pre/pros that WILL manage their ext. analog inputs.

rob's problem has nothing to do with 2-channel playback. yes, i'm BAFFLED by the fact that the LFE channel is completely dropped when the player is set up with "NO sub" in multichannel mode. receivers do NOT do this. why should the players, which perform all sorts of other processing duties, not be able to do the LFE properly? to me it's a huge design flaw. it IS quite problematic for someone with no subwoofer who wants to decode multichannel, LFE-containing material at their player, be it dd, dts, dvda, or sacd.

 

[ScottCHI]

well of course if you sent it only the 2 of 5 channels, it would only play 2 back. as i pointed out, it WILL downmix into 2 channels for you. and i think there IS a way to keep the LFE channel in those 2 channels that involves NOT setting the player up in 2 channel mode, but leaving it in multichannel mode, but with NO center and NO surrounds.

 

[Brian L]

OK, time I back out of this one.

But one final attempt to get the point across to those that are not hearing it.

Here's a direct quote from the Dolby site:

"A final factor to consider is that the ".1 track" is ignored by Dolby Digital's downmixing process, so it should include no vital information that would be missed in mono, stereo, or Pro Logic playback."

Take it for whatever you will. Perhaps I should ignore Dolby? Where is Roger Dressler when you need him?

And I would ask, how do you know your receiver is downmixing the LFE? Per Dolby's own site, they suggest that "no vital information" be mixed into the .1 channel.

Could you be simply hearing the bass thats already in the main channels?

And we can certainly agree that not mixing the .1 into the large L/R is a big problem. I solved it with an ICBM.

BGL

 

[ScottCHI]

because AVIA (and many of the other calibration discs, too) does have a pure LFE track, the "low frequency sweep, LFE" track. (be careful, many of avia's subwoofer tracks are not "pure" LFE.)

if i set my receiver up with front speakers ONLY and NO sub (speakers, of course, default to LARGE in this situation), and i play this pure LFE track back through my digi connection and let my receiver do the processing, it comes through my front speakers. this means that the LFE track is being mixed into my front channels.

think about this for a moment. what you are trying to say is that anyone who listens to a strictly 2 channel HT setup is missing their LFE channel and that's simply NOT true. i know many people who have only a 2 speaker setup (and i've had one myself) and i KNOW they have LFE from their DD/DTS material. so do they. a good friend has only 2 big deftech powered towers, wired simply as large fronts, and trust me, he gets his LFE.

now, if i set my receiver up with all 5 speakers set to LARGE, but NO sub, and i play that pure LFE track through the digi connection, and let the receiver process it, i still hear it out of the front speakers. but if i set my player up the same exact way, 5 LARGE speakers and NO sub, and i play that same track back through the analog connection, letting the player do the processing, i hear nothing.