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Apparently there are some odd things going on here. The subwoofer channel, with or without bass management, may contain both bass and LFE information. LFE information should be boosted in the processor to play at plus 10dB SPL. Obviuosly, this should happen before bass management mixes LFE and "regular" bass.All of my DVD-As play back on my Denon DVM-4800 at appropriate levels, leading me to conclude that DVD-A (as a group) and Denon are somewhat clear on this. As I understand it, LFE content is flagged and handled appropriately. However, if I play back a movie through my 5.1 analogue outputs (instead of through my AVR-4800), the bass is down by 10 dB.
There seem to be a lot of complaints about bass levels from the multichannel SACD camp. Outlaw, the masters of bass management, have stated that some players automatically attenuate the bass by 10 dB and some studios are mixing the bass at -10 dB.
Curiouser and curiouser. Can anyone shed some light on this?
Follow Ups:
Jim,While I can't speak authoritatively on the topic....
You have two conflicting requirements here. Movies require a +10dB Pad on the subwoofer channel. Music (generally) does not.
A properly designed player would allow for selection of padding the subwoofer channel by +10dB for DD and DTS decoding, and leaving it as is for DVD-Audio/SACD.
What's happening is that too many places are trying to fix the issue at the same time, which could (and apparently is) causing problems for both formats.
One of the issues, is that the 6th channel is not necessarily a subwoofer channel, so arbitrarily padding (or not padding) blindly is a mistake.
This is one area that DD and DTS have a marked advantage, in that they have defined specs to be adhered to.
As I understand it, the processor filters the LFE content and adds the gain. The new Denon 2900 allows you to set the Filter OFF, but curiously this adds only 5 dB to DVD-A but 15 dB to SACD!Telarc mixes all of the bass content (below 80 Hz) from all channels on the .1 channel, a move I applaud. (Purportedly, there is also height information on this channel, which you need to use an external crossover to extract.) This is exactly how I set up my system - I send all bass below 80 Hz to the subwoofer and the low pass filter it at 35 Hz.
As an owner of a new Denon 3800, which also allows you to switch OFF this filter, I am not sure if I should leave the filter ON or OFF for DVD-Audio discs.The reason I ask is my old Technics DVD-A10 had greater output from the subwoofer/LFE channel, whereas the Denon with the filter ON has much less. When I switch the filter OFF with the Denon the LFE/Subwoofer channel with regards to DVD-A discs seems to mirror what I had with the Technics DVD-A10.
It is entirely possible that the Technics had it all wrong and Denon has it correct, but I am still confused whether the correct way to listen to MCH DVD-A is with the filter ON or OFF with the Denon 3800?
What should be the correct setting for DVD-A discs with the Denon - filter ON or filter OFF where it boosts the LFE sub output by 6db?
You only need to have the filter set to "ON" when you are using bass management (i.e. some speakers are "small" or are not there).In summary: If you have a full 5.1 system and all speakers are "large" then turn "OFF" the filter.
By the way, even if your rears / center are small-ish, then I'd still set them to "large", and filter to "off".
Jim,This is one area that standardization (Dolby, DTS and THX) has improved the delivered experience to the consumer.
I must be missing something in your description though, because you mention placing a 35Hz LPF on the subwoofer channel. Unless you are sending > 35Hz info to a (nearly) full range speaker, not clearly stated, and has its own peril/issues with cancellation effects within the crossover region.
As far as inserting an arbitrary crossover (as Telarc is doing), that's great although those with full range speakers will feel they are being ripped off a little. Telarc's arbitrary choice is as good as any other though, and will work fine on almost every system. I'm sure there's some setup out there somewhere where this is not an ideal solution.
Telarc mixes all the bass below 80Hz into the LFE channel but does NOT remove it from the main channels. Thus, you do not have to use a sub and, if you do, you have the choice of adding a HP filter to the main channels or not. If you do not, you also have the option of adding a height amp/speaker running off the "LFE" channel on many of their discs.
Then those who do nothing end up with an exaggerated FR from 80Hz down to the -3dB point on their main speakers.Now that I've typed a little more, I'd say this is a bad practice, as it assumes the end user will place some type of LPF on their subwoofer channel.
So the end user has to remember "Oh, this is a Telarc disc, so I have to implement that Low Pass Filter on the subwoofer".
Perhaps Michael Bishop can chime in on this topic, because the more I think about it, the worse it seems.
on the Hi Rez Highway under The Emperor's New Format. Obviously, he believes that no discerning audiophile would use bass management on SACD with current players. On the other hand, most of us have a low pass filter on the sub.
Who doesn't have a LP filter on the sub?
Kal,Sorry, let's try this one more time, so I can make my point clearer:
Subwoofer inputs can be filtered or unfiltered. Well designed subwoofers have both filtered and unfiltered inputs.
For movies, which will engage the crossover in the Processor/Receiver, you would want to use an unfiltered input, or for a sub lacking an unfiltered input, you'd set the subs internal LPF as high as possible (150+ would be ideal).
However, with Telarc's method, assuming you have mains with solid response down to 40Hz, you have an octave of information which will be doubled up. So you turn the LPF down to about 40Hz to correspond with the speakers -3dB point. Cool. That handles the mains. Any material on speakers (say surrounds and CC) which don't have the same response characteristics (say a 60Hz -3dB point) you've lost information between the -3dB point and the LPF engaged on the subwoofer.
You are also forced to change the setting of the LPF when you change between movies and Telarc's authoring standards OR use two seperate connections (one to filtered, one to unfiltered) if your subwoofer has appropriate inputs.
BTW, some of us use passive subwoofers, driven by regular amplifiers which don't have low pass filters.
So as I said, the more I think about it th emore potential issues I see.
On my Denon AVR-4800 you choose "LFE + Mains" and the bass from all channels from 35 Hz to 80 Hz is handled by the Studio 100s, even though the subwoofer is low pass filtered at 35 Hz. And much more nimbly than a Servo 15 would handle it.
Jim,This continues to stray ever farther from the defined standards.
LFE+Mains is a nice feature that has very little support in the industry. I haven't worked with Denons receivers, save the 1802, which didn't have this option.
It doesn't change the fact that the vast majority of installations will be problematic, though does it?
This isn't even remotely the "I'll look after you, automatically." type of bass management that consumers need.
Merely another complication in an already overly complex area. As a user of (fairly) full-range speakers all around, I have no problems with the Telarc arrangement.That said, I do now see your point and does require one to make a choice of default setup. Movies are relatively unimportant to me.
Kal,My breakdown is about 60% Music, 40% HDTV and Video, so it's more important to me. I suspect that in the world of multi-channel the norm is going to be much more balanced in music/movies.
As I said earlier, the standardized implementations of DD and DTS do have benefits in terms of ease of use.
We haven't really discussed the differing requirements of implementing the Telarc Height configuration vs MDG and Tacet's 2+2+2 vs. the Chesky 6.0 configuration.
With flexibility comes compexity which has to be deat with somehow.
That is precisely what I do through the "bass enhancer" circuit of my Denon DVM-4800 or through the "mains plus sub" option in the AVR-4800. The result is very convincing bass from the combination of the Paradigm Studio 100s four 8" woofers and the Servo 15, filtered at 35 Hz. You've got to move a lot of air to get convincing bass.Outlaw and Atlantic Technologies are both offering this type of "full range" bass management for the 5.1 inputs on their new processors.
If your system is already set up to mix the bass from the main channels and deliver it to your sub along with the content from the .1 channel, then on Telarc titles you're going to get double the bass to your sub. It might not be as noticeable since you're using a low crossover, but it's still a bad approach IMO, if this is what Telarc is actually doing.
I started this thread to point out non-standard bass implementations in Hi Rez. Personally, I think that the Telarc method could sound good on many players using no bass management - they will get the same result as I'm getting as long as their sub is low pass filtered. But it might sound horrendous on my system or on a system where the sub is not low pass filtered.
It would seem that Telarc's approach only makes sense if you assume the playback system has full range speakers all around. Then you can either use the 6th channel as a height channel or use it to drive a sub with a really low crossover (e.g. 30-40 Hz) to fill in below the main speakers. But how many people have a multichannel setup with full range speakers all around, and how many of those people are going to set up their system just to take advantage of a handful of Telarc titles?It could also work OK for some people who have small speakers all around that just happen to drop off conveniently around 80 Hz so that no additional filtering is required. But presumably, those people will already be employing some sort of bass management so they'll probably end up with the bass being 3dB too high because the .1 channel is getting each channel's bass mixed in twice. Sure they can disable the BM, but who wants to change their setup just to listen to Telarc's material? And what about all the people who have a mix of large & small speakers?
In my worthless opinion, there is only one solution that makes any sense. Everybody who is producing music SACDs and DVD-As should treat all 5 main channels as full range and should never, ever redirect any bass to the .1 channel. Bass management should be entirely the responsibility of the playback system, because only the end user knows how his/her speakers are set up. In fact, I think it's best not to put any music content in the .1 channel at all; leave it for LFE use by DVD-V and DTS. I know it would be nice to use the 6th channel for optional purposes like a height channel, but a lot of systems out there will end up boosting it and sending it to the sub.
While I think that most will agree that Telarc puts out consistent and often amazing recordings, I agree with Dave's assesment of that "redirected" bass via the producer -- Telarc -- and the fact that it shouldn't be done this way. Let the end user have the final say, as he/she is the only one who knows what capabilities exist in his/her playback system.This is just one more problem that needs to be addressed by the recording community and the product manufacturers. Is it really that hard for these two groups to get together and discuss what process will get the most from the new high resolution formats?
As for a "height" channel for channel #6 (the .1), I haven't heard this implemented, so I can't say for sure if this is a good idea vs a discrete rear surround channel a la DTS-ES 6.1 Discrete (for movies). I can see a "height" channel for "effects" in a movie, but I'd think that music is another matter (at least until I've heard it, but I'm not a fan of multichannel for music as it is, so...). Maybe we need a discrete 7.1 system so that we can also have a height channel for movies? Anyone for DTS-ES 7.1 Discrete? It is an option for the codec...
If the Telarc method was standard, you would only need bass management if you had small speakers that really needed to be high pass filtered. Otherwise, you would simply low pass filter your subwoofer to get the best blend between the subwoofer and your speakers. What I don't like is that their approach is non-standard and largely undocumented.
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