Thread: Some multi-channel mixes with low frequencies only on the .1 LFE

Posts: 48
Page: prev 1 2 3 4 5 next

Post by mandel July 21, 2005 (31 of 48)
csuzor said:

ON THIS TOPIC:
I hope the 5 main channels are not being high-passed, with low frequencies only in the LFE channel, because I dont use a sub. Doing this should clearly be banned, and such disks labelled appropriately.

Don't you have your player set to redirect the LFE channel to the main speakers? If not then you will be losing some low-end on all discs that have any LFE information!

Post by csuzor July 22, 2005 (32 of 48)
mandel said:

Don't you have your player set to redirect the LFE channel to the main speakers? If not then you will be losing some low-end on all discs that have any LFE information!

That's an interesting thought... I believe there is no extra info on the LFE channel for music, just the low-passed mixed bass from the other channels. As such, it has phase inaccuracies (mixing low bass from different recording points will give phase errors). For movies, yes, there are special effects on LFE channel only.

Can someone tell me if I am wrong, and what sacd have info on LFE not present in any other channel?

As for mixing the LFE channel back into the other channels, that could be a mistake due to phase conflicts, and usually requires that the DSD is converted to PCM (for mixing) before the DAC... degrading the sound. Only expensive players do it in DSD domain. And my preamp doesn't do LFE -> Mains, but Mains -> LFE (on external inputs).

I listen to the original DSD source channels with as little degradation as possible.

Post by mandel July 22, 2005 (33 of 48)
csuzor said:

That's an interesting thought... I believe there is no extra info on the LFE channel for music, just the low-passed mixed bass from the other channels. As such, it has phase inaccuracies (mixing low bass from different recording points will give phase errors). For movies, yes, there are special effects on LFE channel only.

Can someone tell me if I am wrong, and what sacd have info on LFE not present in any other channel?

As for mixing the LFE channel back into the other channels, that could be a mistake due to phase conflicts, and usually requires that the DSD is converted to PCM (for mixing) before the DAC... degrading the sound. Only expensive players do it in DSD domain. And my preamp doesn't do LFE -> Mains, but Mains -> LFE (on external inputs).

I listen to the original DSD source channels with as little degradation as possible.

There will be some bass removed from the main 5 channels whenever there is bass lowpassed to the LFE. If the low-end was simply duplicated then people with floorstanders + sub would have double the intended bass!

I can understand what you are saying about not degrading the DSD signal, unfortunately the tradeoff will be losing the proportion of the bass signal that has been placed in the LFE channel.

Post by mdt July 22, 2005 (34 of 48)
mandel said:

There will be some bass removed from the main 5 channels whenever there is bass lowpassed to the LFE. If the low-end was simply duplicated then people with floorstanders + sub would have double the intended bass!

I believe the idea of the sub is to transfer frequencys at which full range floorstanders are droping off, smoothening and extending the very low bass range.
So people with floorstanders and sub would have the correct frequency response and people with small speakers and sub would use bass management to transfer whatever frequencies the mains dont transduce to the sub.
This way transfering frequencies from sub to mains is never necessary, the other way round bass mangement sytems exist for use with small-satelite plus sub systems.Also with the sub channel being used like this, someone with floor standers would have only a minimal drawback in the extreme low bass range if they dont use a sub.
A statement by DG in theire SA-CD booklets seems to confirm the use of the sub as described above: "If your system isn't connected to a sub-woofer, don't worry- the LFE (Low Frequency Effect)channel is only used to add a little more "spice" to the overall surround sound mix."

Post by sledge19 July 28, 2005 (35 of 48)
csuzor said:

ON THIS TOPIC:
I hope the 5 main channels are not being high-passed, with low frequencies only in the LFE channel, because I dont use a sub. Doing this should clearly be banned, and such disks labelled appropriately.

Thank you for coming back to the topic :-)) I agree, this should be banned, however, some labels do it.

Post by sledge19 July 28, 2005 (36 of 48)
mandel said:

Don't you have your player set to redirect the LFE channel to the main speakers? If not then you will be losing some low-end on all discs that have any LFE information!

This is only a one way street: bass management only works the other way - it can shift the low frequencies to the sub not vice versa.

Post by sledge19 July 28, 2005 (37 of 48)
mdt said:

A statement by DG in theire SA-CD booklets seems to confirm the use of the sub as described above: "If your system isn't connected to a sub-woofer, don't worry- the LFE (Low Frequency Effect)channel is only used to add a little more "spice" to the overall surround sound mix."

That's the way it should be, however, like I said before, some labels mix 5.1 meaning that the sub is essential. There should be a specific labeling for that.

Post by mandel July 28, 2005 (38 of 48)
sledge19 said:

This is only a one way street: bass management only works the other way - it can shift the low frequencies to the sub not vice versa.

Well I don't know about your SACD player but mine has the option to run as "5 large" or "front large" without a separate sub.

Post by mdt July 28, 2005 (39 of 48)
sledge19 said:

That's the way it should be, however, like I said before, some labels mix 5.1 meaning that the sub is essential. There should be a specific labeling for that.

The DG recordings i'm mentioning are also mixed 5.1, that's not the issue, the issue is WHAT goes to the.1 channel. If the ITU standard is for 5 full range speakers i dont see why anyone should mix anything else then very low frequencies to the sub. also if this were done it would make no sense for hardware manufacturers to come up with bass management, this is only needed if recordings are mixed for 5 full range speakers (plus possibly sub) and someone wants to play theme using smaller main speakers.

Post by sledge19 July 31, 2005 (40 of 48)
mandel said:

Well I don't know about your SACD player but mine has the option to run as "5 large" or "front large" without a separate sub.

Well, SACD players allow for a certain set up (mine - Denon 2900 - is also set 5 large + no sub. however it doesn't help, bass management cannot work the other way, because, the .1 channel (according to ITU) may also be used in a different way (height channel, 2+2+2, etc.). I also got this answer from Denon directly.

Page: prev 1 2 3 4 5 next

Closed