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Rayman

subwoofer crossover hz / L.F.E. signals

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Could use some input... im pretty sure that the L.F.E. / .1 channel of both D.V.D. and blue-ray are from 10hz or so up to 120hz where it hits a brick wall, no 121hz signal at all. so it is best to run the sub crossover at 120hz or by-pass it. Question is about SACD multichannel 5.1 discs... does the same 120hz "brickwall" cut off apply and it is best to run the sub as above, OR does the receivers crossover points set up for small speakers (in my case 60hz) do the bass management? I guess a better way to say it is ... are ALL .1 L.F.E. signals 120hz and below, reguardless the source.... D.V.D. / BRD / SACD?

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Could use some input... im pretty sure that the L.F.E. / .1 channel of both D.V.D. and blue-ray are from 10hz or so up to 120hz where it hits a brick wall, no 121hz signal at all. so it is best to run the sub crossover at 120hz or by-pass it. Question is about SACD multichannel 5.1 discs... does the same 120hz "brickwall" cut off apply and it is best to run the sub as above, OR does the receivers crossover points set up for small speakers (in my case 60hz) do the bass management? I guess a better way to say it is ... are ALL .1 L.F.E. signals 120hz and below, reguardless the source.... D.V.D. / BRD / SACD?



I was always under the understanding that it was 20-120 Hz. From
my understanding they do put filters on both sides but no filter is 100% full
proof so there is always a roll off. Where
did you hear that it was a brick wall at 120 Hz?



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Could use some input... im pretty sure that the L.F.E. / .1 channel of both D.V.D. and blue-ray are from 10hz or so up to 120hz where it hits a brick wall, no 121hz signal at all. so it is best to run the sub crossover at 120hz or by-pass it. Question is about SACD multichannel 5.1 discs... does the same 120hz "brickwall" cut off apply and it is best to run the sub as above, OR does the receivers crossover points set up for small speakers (in my case 60hz) do the bass management? I guess a better way to say it is ... are ALL .1 L.F.E. signals 120hz and below, reguardless the source.... D.V.D. / BRD / SACD?

If your bass management is set to "global" ALL sources should see the same crossover points.

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120hz, is awful high for sub crossover, IMHO. Your mains are probally good to at least 80hz.

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dont remember what magazine it was, but i did read it because it struck me odd that there was not a slope on the bass roll off, so do you think that the sub crossover point on SACD/DVD/BR 5.1 signals should always be 120hz as not to lose ANY bass info? (with the .1 being a discreet channel)

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dont remember what magazine it was, but i did read it because it struck me odd that there was not a slope on the bass roll off, so do you think that the sub crossover point on SACD/DVD/BR 5.1 signals should always be 120hz as not to lose ANY bass info? (with the .1 being a discreet channel)



Any 5.1 I would recommend the lfe to 120 Hz or no crossover (same).
If you set it lower then 120 you can end up with a small hole in the lfe
content. Example: you set the sub to 80 Hz; you would have a hole from 80-120
Hz. One could easily argue that the hole is so small it wouldn’t matter I guess.
However if you add content (more than just lfe) to your sub by setting your
speakers to small you might have to run it lower than 120. I’m always trying to
think of best way to explain this. The part I think that gets overlooked with
setting speakers to small is this. If each channel (5.1) was a river of water all
flowing with just their channels content (everything is set to large). The sub
only gets the .5 channel of content and nothing else. By setting speakers to
small you redirect the filtered content to the subs channel (river). When you
do it to all the channels what you can end up with is a waterfall of bass
content sent just to the sub on top of the lfe content. With a waterfall of
bass content coming from every channel you almost have to set the sub to a
lower crossover point or the sub will just rattle the house and not sound
smooth and deep. But if the sub is only running the lfe content and not bass
from the other speakers then setting a sub to 120 hz will sound great. 120 hz
is pretty easy for any sub 18” or smaller.



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Because the Low Frequency Effects
channel requires only a fraction of the bandwidth of the other audio
channels, it is referred to as the ".1" channel; for example "5.1" or
"7.1".[citation needed]


The LFE is a source of some confusion in surround sound. The
LFE channel was originally developed to carry extremely low "sub-bass"
cinematic sound effects (with commercial subwoofers sometimes going down
to 30 Hz,
e.g., the loud rumble of thunder or explosions) on their own channel.
This allowed theaters to control the volume of these effects to suit the
particular cinema's acoustic environment and sound reproduction system.
Independent control of the sub-bass effects also reduced the problem of
intermodulation distortion in analog movie sound reproduction.


In the original movie theater implementation, the LFE was a separate
channel fed to one or more subwoofers. Home replay systems, however, may
not have a separate subwoofer, so modern home surround decoders and
systems often include a bass management system that allows bass on any
channel (main or LFE) to be fed only to the loudspeakers that can handle
low-frequency signals. The salient point here is that the LFE channel is not the "subwoofer channel"; there may be no subwoofer and, if there is, it may be handling a good deal more than effects.[20]


Some record labels such as Telarc and Chesky have argued that LFE
channels are not needed in a modern digital multichannel entertainment
system. They argue that all available channels have a full frequency
range and, as such, there is no need for an LFE in surround music
production, because all the frequencies are available in all the main
channels. These labels sometimes use the LFE channel to carry a height
channel, underlining its redundancy for its original purpose. The label
BIS generally uses a 5.0 channel mix.

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Thank you! well explained. I guess the problem i was having was trying to figure out the difference between L.F.E.and bass management, so JUST to put this in simple terms... with a TRUE .1 LFE channel such as dvd/blue-ray/sacd multi, use 120hz crossover to get the full signal. with subwoofer bass management thru the avr ( NOT a L.F.E. .1 ) say crossed over 80hz, use that or slightly higher for a crossover point and not 120hz so as not to have "bass bloat" from 80hz to 120hz, again thanks, i wonder how many systems are not set up this way, i know mine wasnt.......also the "small" speaker selection must be taken into account.

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This entire read is confusing. It's basically suggesting the opposite of what this forum usually suggests for crossover/bass management settings. 99% of the replies I normally read go something like "THX spec is 80hz. Set it to that and leave the Sub's crossover wide open"

Could explain a little further, or perhaps clarify ? I read it over and just don't "get" it.

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This entire read is confusing. It's basically suggesting the opposite of what this forum usually suggests for crossover/bass management settings. 99% of the replies I normally read go something like "THX spec is 80hz. Set it to that and leave the Sub's crossover wide open"

Could explain a little further, or perhaps clarify ? I read it over and just don't "get" it.





Most
systems will probably sound better with the sub as a crutch. THX recommendation
is from what would be best for the norm. Because it would be imposable to give
a recommendation for every speaker/amp/room /sub combination they give one recommendation
that would work pretty good in every set up and is probably the optimal set up
for the average ht set up. What they would consider average would be (I read this
a long time ago so I’m guessing a little on this part) 5/7 identical large to
small bookshelf type speakers and a sub. Set up with an avr powering the 5/7
speakers and a separate amp powering the sub. There are many deficiencies in
that set up that can be improved by running everything at 80 Hz (save power and
not over work the speakers). By adding power and using higher level speakers
the need to use the sub as a crutch decreases a lot. You can still set
everything at 80 hz and it will sound great. But you have other options
depending on your ht set up. I know that most people will probably say 80 Hz
but that’s mostly because most of the recommendations they read say that for
all the reasons I gave above. 80 hz is a great staring point if someone’s not
sure, and would be a good setting if someone doesn’t want to tinker too much. But
every set up is different and will sound different so 80 hz isn’t the bible it’s
just a good starting point

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OK so currently I have my speakers set to small, and my receivers sub crossover set to 80hz.

I have fairly large f2 towers that have no problem playing down low to around 45hz or maybe lower.

In this alternative setup, would I set my speakers to large, and the receiver crossover to 120hz or leave it off and set my sub crossover dial to 120hz. Right now the sub amp crossover is wide open.

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If you have Klipsch Synergy F2s then I would reccomend setting them large, setting your receiver crossover to 90Hz so you can still dip them down into the 60hz range but relieve the F2s from the 30 - 40Hz job and set you subwoofer to 80Hz so it can handle the 80Hz to 20-30Hz range. Setting your speakers to the small setting is going to limit a lot of low range frequency.

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If you have Klipsch Synergy F2s then I would reccomend setting them large, setting your receiver crossover to 90Hz so you can still dip them down into the 60hz range but relieve the F2s from the 30 - 40Hz job and set you subwoofer to 80Hz so it can handle the 80Hz to 20-30Hz range. Setting your speakers to the small setting is going to limit a lot of low range frequency.

your logic is flawed. if you're handling the bass management within your AVR, it will perform traffic control of the frequency range amongst the speakers. so if you set it to 80hz, it sends everything below that point to the sub and everything above that point to the mains/center/surrounds. there's no gap, nothing missing, and certainly no overlap. if you set your crossover to 60hz your sub doesnt receive anything above that frequency, regardless of how much knob turning you do on the sub amp.

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OK so currently I have my speakers set to small, and my receivers sub crossover set to 80hz.

I have fairly large f2 towers that have no problem playing down low to around 45hz or maybe lower.

In this alternative setup, would I set my speakers to large, and the receiver crossover to 120hz or leave it off and set my sub crossover dial to 120hz. Right now the sub amp crossover is wide open.



You can always tinker with different settings and find what
sounds best. Because you don’t have a power amp it might be good to keep all
your speakers at small to conserve the power you have. But by all means try setting
your fronts to large and leave everything else the way it is. Don’t just pop in
a blu ray and listen for 5min though. Live with it for a few weeks. And see how
you like it. Me personally I like how the subs sound when only handling lfe
content. For my ears when I start flooding more bass content to the subs from
other channels on top of the lfe channel that’s already being sent to the sub. To
me the subs start sounding really muddy. Keep in mind I have 3 subs so I’m not
trying to get extra bass from my other speakers. I’m trying to limit the bass content
sent to my subs without having a hole in the lfe by crossing over the subs under
120. Do you like how your sub sounds right now?



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It seems to me that confusion arises because LFE channel and subwoofer channel are used without proper distinction.

Here is one website.

http://www.genelecusa.com/faq/multichannel/lfe-channel/

But even there, I believe they got it wrong. The orange box at the lower right should be called subwoofer and not LFE.

Here is my understanding.

5.1 and similar numbers always refers to what is on the speaker side of the decoder.

Back in the day Hi-Fi VHS had two good FM modulated tracks derived from an extra head on the spinning magnetic pick-up. (The other head did the video.) But if we look at the subject diagram, we'd say there is only two recorded channels.

Dolby decoders would create extra outputs to the right side of the diagram.

Just L

Just R

Center was L+R (a mono signal)

The surround was L-R (a mono signal) and this would be sent to usually the left surround speaker and the right surround speaker (both the same program) but with some delay.

If you had a sub, it would be fed L+R but only freqs below 70 hz and we'd hope that the other speaker never got anything above 70 hz. This crossover point may have been adjustable. This was the .1 output.

You could play an LP and get some good results. Naturally the center mix was the same as what PWK was doing years before. Ambient or surround sounds picked up by recording microphones tended to be random and thus did not add up in the center. It is complicated but L+R gets a power gain while L-R fed with random does not. (I think. Smile.)

= = = =

Note that there was never 5.1 channels on the VHS tape even though it was used to feed decoders with 5.1 speaker. There were only two input channels. You may say this is an historic point of little interest. But I bring it up to show that we have to be careful to distinguish what goes into a decoder and what comes out -- and what to call them.

= = = = =

The Wikipedia article appears to describe a movie theater system when discrete digital tracks became available and there was a discrete bass channel. That went, pretty much, unprocessed to a sub behind the screen. But that is not our present home situation.

= = = =

Now we have digital storage and transmission systems which are shown on the left side of the diagram. It appear on the table that the LFE channel of storage and decoding puts bass info below 120 Hz into the LFE channel. Important: that is what is going into the decoder.

It is incorrect to jump to the conclusion that the discreted LFE channel on the recording/transmission is what the decoder sends to the sub unless there is some special setting for it (and I don't know if your decoder can do this if asked).

As we've seen, the decoder menu asks all sorts of questions about whether there are mains big or small, a center, and a sub. Importantly, where the crossover point to the sub should be set.

I believe that it does take into consideration that the LFE input up to 120 Hz has to be preserved independent of the chosen crossover point output to the sub. Therefore if the LFE input is up to 120 Hz, and you set the sub crossover to 70 Hz, the LFE channel input signal between 120 Hz and 70 Hz goes to the mains.

= = =

To belabor. The LFE concept is on the storage/transmission end and input to the decoder. The subwoofer concept is on the output / speaker end of the decoder.

WMcD

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It seems to me that confusion arises because LFE channel and subwoofer channel are used without proper distinction.

Here is one website.

http://www.genelecusa.com/faq/multichannel/lfe-channel/

But even there, I believe they got it wrong. The orange box at the lower right should be called subwoofer and not LFE.

Here is my understanding.

5.1 and similar numbers always refers to what is on the speaker side of the decoder.

Back in the day Hi-Fi VHS had two good FM modulated tracks derived from an extra head on the spinning magnetic pick-up. (The other head did the video.) But if we look at the subject diagram, we'd say there is only two recorded channels.

Dolby decoders would create extra outputs to the right side of the diagram.

Just L

Just R

Center was L+R (a mono signal)

The surround was L-R (a mono signal) and this would be sent to usually the left surround speaker and the right surround speaker (both the same program) but with some delay.

If you had a sub, it would be fed L+R but only freqs below 70 hz and we'd hope that the other speaker never got anything above 70 hz. This crossover point may have been adjustable. This was the .1 output.

You could play an LP and get some good results. Naturally the center mix was the same as what PWK was doing years before. Ambient or surround sounds picked up by recording microphones tended to be random and thus did not add up in the center. It is complicated but L+R gets a power gain while L-R fed with random does not. (I think. Smile.)

= = = =

Note that there was never 5.1 channels on the VHS tape even though it was used to feed decoders with 5.1 speaker. There were only two input channels. You may say this is an historic point of little interest. But I bring it up to show that we have to be careful to distinguish what goes into a decoder and what comes out -- and what to call them.

= = = = =

The Wikipedia article appears to describe a movie theater system when discrete digital tracks became available and there was a discrete bass channel. That went, pretty much, unprocessed to a sub behind the screen. But that is not our present home situation.

= = = =

Now we have digital storage and transmission systems which are shown on the left side of the diagram. It appear on the table that the LFE channel of storage and decoding puts bass info below 120 Hz into the LFE channel. Important: that is what is going into the decoder.

It is incorrect to jump to the conclusion that the discreted LFE channel on the recording/transmission is what the decoder sends to the sub unless there is some special setting for it (and I don't know if your decoder can do this if asked).

As we've seen, the decoder menu asks all sorts of questions about whether there are mains big or small, a center, and a sub. Importantly, where the crossover point to the sub should be set.

I believe that it does take into consideration that the LFE input up to 120 Hz has to be preserved independent of the chosen crossover point output to the sub. Therefore if the LFE input is up to 120 Hz, and you set the sub crossover to 70 Hz, the LFE channel input signal between 120 Hz and 70 Hz goes to the mains.

= = =

To belabor. The LFE concept is on the storage/transmission end and input to the decoder. The subwoofer concept is on the output / speaker end of the decoder.

WMcD

Not positive if I understood what you meant but to be clear

the .1(lfe channel) is 100% separate from the other channels. It doesn’t take

any information from other channels unless you send it there by setting

speakers to small and setting a crossover point for those speakers(Bass

management). Then and only then does your sub handle bass content from other

channels other than the lfe channel. Before we had Dolby digital 5.1 your right

the processors took the stereo 2 channel information and then split it into separate

channels based on all the info we gave it and it’s processing. But from the very

first 5.1(someone might jump in with an earlier one) system tell now we have completely

separate channels that have all their own info including a separate lfe channel

stored right on the disc. Bass management is where we reroute the low frequencies

from those channels (l/r/c/sr/sl) to the sub (on top of the lfe info). Audioholics

had a great article on this they did blind fold testing to find out what frequencies

really where non directional (it’s said to be 120 Hz). They found that 60 Hz

was actually the magic frequency and anything above 60 Hz is where people could

stat pointing out where they had placed the sub in the room. So he said when possible

run the lfe(sub) at 120hz and the other speakers no higher than 60 Hz. So you don’t

get any extra content to the sub from other channels above 60 Hz. This is just

one article of one person’s opinion so it’s not facts. Sometimes depending on

what speakers we have 60 Hz isn’t an option.

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It seems to me that confusion arises because LFE channel and subwoofer channel are used without proper distinction.

Here is one website.

http://www.genelecusa.com/faq/multichannel/lfe-channel/

But even there, I believe they got it wrong. The orange box at the lower right should be called subwoofer and not LFE.

Here is my understanding.

5.1 and similar numbers always refers to what is on the speaker side of the decoder.

Back in the day Hi-Fi VHS had two good FM modulated tracks derived from an extra head on the spinning magnetic pick-up. (The other head did the video.) But if we look at the subject diagram, we'd say there is only two recorded channels.

Dolby decoders would create extra outputs to the right side of the diagram.

Just L

Just R

Center was L+R (a mono signal)

The surround was L-R (a mono signal) and this would be sent to usually the left surround speaker and the right surround speaker (both the same program) but with some delay.

If you had a sub, it would be fed L+R but only freqs below 70 hz and we'd hope that the other speaker never got anything above 70 hz. This crossover point may have been adjustable. This was the .1 output.

You could play an LP and get some good results. Naturally the center mix was the same as what PWK was doing years before. Ambient or surround sounds picked up by recording microphones tended to be random and thus did not add up in the center. It is complicated but L+R gets a power gain while L-R fed with random does not. (I think. Smile.)

= = = =

Note that there was never 5.1 channels on the VHS tape even though it was used to feed decoders with 5.1 speaker. There were only two input channels. You may say this is an historic point of little interest. But I bring it up to show that we have to be careful to distinguish what goes into a decoder and what comes out -- and what to call them.

= = = = =

The Wikipedia article appears to describe a movie theater system when discrete digital tracks became available and there was a discrete bass channel. That went, pretty much, unprocessed to a sub behind the screen. But that is not our present home situation.

= = = =

Now we have digital storage and transmission systems which are shown on the left side of the diagram. It appear on the table that the LFE channel of storage and decoding puts bass info below 120 Hz into the LFE channel. Important: that is what is going into the decoder.

It is incorrect to jump to the conclusion that the discreted LFE channel on the recording/transmission is what the decoder sends to the sub unless there is some special setting for it (and I don't know if your decoder can do this if asked).

As we've seen, the decoder menu asks all sorts of questions about whether there are mains big or small, a center, and a sub. Importantly, where the crossover point to the sub should be set.

I believe that it does take into consideration that the LFE input up to 120 Hz has to be preserved independent of the chosen crossover point output to the sub. Therefore if the LFE input is up to 120 Hz, and you set the sub crossover to 70 Hz, the LFE channel input signal between 120 Hz and 70 Hz goes to the mains.

= = =

To belabor. The LFE concept is on the storage/transmission end and input to the decoder. The subwoofer concept is on the output / speaker end of the decoder.

WMcD

Not positive if I understood what you meant but to be clear the .1(lfe channel) is 100% separate from the other channels. It doesn’t take any information from other channels unless you send it there by setting speakers to small and setting a crossover point for those speakers(Bass management). Then and only then does your sub handle bass content from other channels other than the lfe channel. Before we had Dolby digital 5.1 your right the processors took the stereo 2 channel information and then split it into separate channels based on all the info we gave it and it’s processing. But from the very first 5.1(someone might jump in with an earlier one) system tell now we have completely separate channels that have all their own info including a separate lfe channel stored right on the disc. Bass management is where we reroute the low frequencies from those channels (l/r/c/sr/sl) to the sub (on top of the lfe info). Audioholics had a great article on this they did blind fold testing to find out what frequencies really where non directional (it’s said to be 120 Hz). They found that 60 Hz was actually the magic frequency and anything above 60 Hz is where people could stat pointing out where they had placed the sub in the room. So he said when possible run the lfe(sub) at 120hz and the other speakers no higher than 60 Hz. So you don’t get any extra content to the sub from other channels above 60 Hz. This is just one article of one person’s opinion so it’s not facts. Sometimes depending on what speakers we have 60 Hz isn’t an option.

Wait, run the sub at 120hz? I don't understand...shouldn't the sub be set to run everything UNDER 60hz?

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Also that article you linked is exactly what I have been

saying in this thread about how it all works together. The 5 to 7 channels are

all Full bandwidth (20-20,000 Hz) but they don’t handle any of the lfe content

unless you have an avr function like double bass turned on where you send the

lfe content to the fronts. All that full bandwidth means is that those channels

have the ability and flexibility to have the full bandwidth of information to

them from 20-20,000hz. I think when people see full bandwidth they immediately think

it means that all their speakers are getting the full load as well as lfe content

unless they set the speakers to small. That would be false because there only

getting the content from their separate channel. So when making a movie and

mixing the audio channels they aren’t going to be sending a lot of super low end

content in the 20-75 Hz range to the surrounds or even the center anyways. So setting

those speakers to small in most cases (other than 5 channel music like cds) doesn’t

really do too much (unless you crossover really high like over 100 Hz). The fronts

however do get a pretty good amount of low end bass content (but it’s not lfe content).

The biggest issue with setting your mains to large is phase and timing issues

with your subs. Because speakers normally use basic analog crossovers and an

avr uses a digital processor. The speeds in processing are usually different from

each other. So it’s easy to end up out of phase. So in most cases it can take

some time getting your sub or subs integrated with your front speakers if you

set them to large. And as I can attest to that can definitely take some time

and tinkering to get right.

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Brunt LFE is mixed at 20-120 Hz so the sub itself when

watching a movie should never be crossed over under 120 Hz or you could be losing

bass content in the movie. But when using bass management in your avr by setting

speakers to small, what he’s saying is to not crossover those speakers that are

set too small to over the 60 Hz range. Or you increase the odds of adding

content to your sub that will make it more localizable. (Wow that’s actually a

word lol)

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