As for headphones ..... Senheiser are certainly a "top brand", but a bit expensive. In the past, I've found Philips medium priced headphones pretty good - maybe more suited to European Ears - although current stuff labelled "Philips" is presumably all from Asia ........
That would suggest that Philips kit is merely relabled from another brand. Maybe that's the case, I don't know.
What I do know is that items manufactured in the Far East/Asia can, and often are, manufactured to a European specification. Something doesn't have to be manufactured in Europe to meet European standards.
Sorry, i'm phrasing my question badly - which will just result in further gibberish ......
WHat I should have said, is, the method used in dolby surround to indicate position is a phase difference between the L (+j) and R (-j) surround channels.
Absolutely correct, Dolby Pro Logic is not discrete, it is a matrixed system. No one is arguing that point, at least I'm not.
But Dolby Pro Logic isn't Dolby Digital 5.1, which is a completely different system and has little, if anything in common with DPL or DPLII.
DD5.1 uses 6 completely independant, completely discrete, channels of audio. It is possible to place 5 monophonic recordings on each speaker, if the engineer so wished. Plus a sixth monophonic channel consisting of a low frequency recording.
Yes, you could indeed use 5 discrete channels for 5 mono recordings. Since there's no crosstalk. But this entirely misses the point.
The 3 front channels are matrixed together, as stereo.
the 2 rear channels are matirxed together, as phased surround.
The ".1" is sensurround, low frequency bleed-off ..........
All the dolby surround systems use the same basic sq matrix.
As they have to, to be back compatible with:
1. Dolby TM ( = theatre matrix, original system).
2. Stereo
3, Mono (let's not forget).
Any other way of doing things would not be back compatible. For example, if 5.1 used "surround stereo", then that wouldn't be back compatible with the SQ used in TM.
If you think the system used in 5.1 isn;t SQ, then, what do you think it is ? Let's have an answer, please, instead of name-calling ..........
No one is calling anyone names (I hope) merely trying to help you understand.
To that end, I point you to post #83.
It doesn't in my amplifier. If can't output DPL if the input is DD5.1. Other amplifiers which don't have the DD5.1 chip use the 2.0 stream to up-scale to DPL. If it doesn't have a 2 channel source, or a DD5.1 source then you will get silence.
Take a look at your own AV Amp. You'll see that if you feed it with a DD5.1 stream, then it won't down-sample to a lesser format, unless the source only outputs the 2.0 stream. You can often enforce that via the source device's menu.
No one is calling anyone names (I hope) merely trying to help you understand.
To that end, I point you to post #83.
It doesn't in my amplifier. If can't output DPL if the input is DD5.1. Other amplifiers which don't have the DD5.1 chip use the 2.0 stream to up-scale to DPL. If it doesn't have a 2 channel source, or a DD5.1 source then you will get silence.
Take a look at your own AV Amp. You'll see that if you feed it with a DD5.1 stream, then it won't down-sample to a lesser format, unless the source only outputs the 2.0 stream. You can often enforce that via the source device's menu.
As I've repeatedly siad, there's no such thing as pro logic coding, only surround decoding.
regardess of what the actual chips will or wont do, the same basic system is used all versions, and nobody is answering any of my questions.
What happens when you feed either 5.1 or 2.0 to a pro-logic 2 (4 rear speakers)? How can this possibly be "discrete" ?
How can feeding 5.1 to (typically) 20 rear speakers - in a cinema - possibly be "discrete" ?
Feeding 5.1 discrete channels to DPL doesn't work (I challenge you to try it, but I don't know of any equipment which will do that). If you feed the DPL chip with 2.0 channels (via digital or analogue), provided it is correctly configured it can extrapolate DPL from the phase differences.
I've just looked again at the DOlby Labs site. Basically, just a giant advert, with no expalnation of how any of their systems work.
This is strange, considering Dolby originallly used SQ without paying rooyalties, then tried to avoid royalties by claiming 5.1 doesn;t use phase encoding ......
Feeding 5.1 discrete channels to DPL doesn't work (I challenge you to try it, but I don't know of any equipment which will do that). If you feed the DPL chip with 2.0 channels (via digital or analogue), provided it is correctly configured it can extrapolate DPL from the phase differences.
Well, duh! That's because it works exactly the same way.
The 2 matrixed surround channels have exactly the same information as the 5.1 discrete versions.
The DPL link I posted above - written by a Dolby Person - specifically mentions DPL as working from 2 channels. 5.1 is not even mentioned. Please do no confuse container and contents.
The mixing desk has five discrete output channels. The participants in the piece of work are mixed into a position within the resulting encompassing space. So volume and timing are used to fix that participants performance in position. Think of it as a 3 dimensional version of stereo.
So you get 5 discrete channels which are decoded only at the listening position. (Remember, stereophonic is simply two entirely discrete channels - Monophonic is one discrete channels and quadrophonic is four discrete channels - DD5.1 is 6 discrete channels - they all work in exactly the same way).
With DPL phase difference is used. That is you have, say, a pair of microphones ostensibly recording the performance in front of them. However, if there is, say, an audience or other instruments behind the microphones that information is captured "out of phase" with the front recording.
So 5.1 puts 5 microphones pointing inwards, while DPL or other similar systems have at lease a pair microphones pointing outwards, towards the main performance.
Of course, other tricks are used in the mixing desk to "tinker" with the effects - because not all instruments are recorded at the same time.
You can often pick up mistakes in older recordings which didn't take into count the secondary effects of phasing - sometimes resulting in some very odd effects when replayed through a DPL or similar chip.
With DD5.1 everything is "in phase". With DPL the front is the only information that is "in phase" and the rear is "out of phase".
"Dolby Digital is the name for data and audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994."
ie, it's the same basic system, except delivered digitally.
"Dolby digital is loosely based off SQ quad. Any Marantz quad with a SQA adaptor can do a damn fine job in taking that dolby signal and giving you surround".
"Dolby Digital is the name for data and audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994."
ie, it's the same basic system, except delivered digitally.
"Dolby digital is loosely based off SQ quad. Any Marantz quad with a SQA adaptor can do a damn fine job in taking that dolby signal and giving you surround".
"5.1 is the common name for six channel surround sound multichannel audio systems. 5.1 is considered "standard" or "traditional" surround sound as it is the most commonly used in both commercial cinemas and in home theater. It uses five full bandwidth channels and one low frequency channel. [1] Dolby Digital, Dolby Pro Logic II, DTS, and SDDS are all 5.1 systems. 5.1 is also the standard surround sound audio component of digital broadcast and music. [2]
All 5.1 systems use the same speaker channels and configuration, having a front left and right, a center channel, and two surround channels. Speaker placement is defined by ITU-R BS 775-1, with the center channel speaker being placed at zero degrees, the left and right channels being placed at ±30 degrees, and the surrounds being placed at ±110 degrees. [3]"
Correct! Note the speaker placement angles are quite specific, because the surround channel is PHASE ENCODED. If it were AMPLITUDE ENCODED, then this wouldn;t really matter ........
Also note, it's important the speakers are placed in a circle, ie equal radius from listener, again with amplitude encoded stereo this wouldn't matter. It's because the SQ matrix is universally used ........
The Pro Logic decoder is a particular way of treating the audio soundfield, to give enhanced direction cues. As correctly described in the various links I've given.
It makes little difference in principle to pro logic operation whether the input is derived from 2.0 or 5.1.
The mixing desk has five discrete output channels. The participants in the piece of work are mixed into a position within the resulting encompassing space. So volume and timing are used to fix that participants performance in position. Think of it as a 3 dimensional version of stereo.
So you get 5 discrete channels which are decoded only at the listening position. (Remember, stereophonic is simply two entirely discrete channels - Monophonic is one discrete channels and quadrophonic is four discrete channels - DD5.1 is 6 discrete channels - they all work in exactly the same way).
With DPL phase difference is used. That is you have, say, a pair of microphones ostensibly recording the performance in front of them. However, if there is, say, an audience or other instruments behind the microphones that information is captured "out of phase" with the front recording.
So 5.1 puts 5 microphones pointing inwards, while DPL or other similar systems have at lease a pair microphones pointing outwards, towards the main performance.
Of course, other tricks are used in the mixing desk to "tinker" with the effects - because not all instruments are recorded at the same time.
You can often pick up mistakes in older recordings which didn't take into count the secondary effects of phasing - sometimes resulting in some very odd effects when replayed through a DPL or similar chip.
With DD5.1 everything is "in phase". With DPL the front is the only information that is "in phase" and the rear is "out of phase".
That's complete utter rubbish, as you can easily see by reading an account of what the DECODER actually does!
The +j and -J phasing is how the surround channel is encoded onto the 2.0 format. It's nothing to do with how the sound is reproduced, which depends on the acutal decoder used ..........
Yet again - i'm getting sick of this - the 2.0 format encodes the surround position as phase. How a decoder works depends on which type. Pro Logic is NOT an encoding format .......
Digital broadcasting is a stream of 0's and 1's. All the channels in a transponder are multiplexed onto the same carrier, the tuner sorts out which belongs to each channel with zero crosstalk. Discrete digital audio is just the same the stream identifies which data is to be sent to each of the 6 discrete channels in the case of 5.1/DTS, exactly the same way hence zero crosstalk. If the same audio data is sent to each of the 5 full frequency channels at the encoding stage then each speaker will output an identical and in phase sound.
If a phase shift was involved you would get an echo.
Try feeding a mono signal to a pair of stereo speakers and then reverse the polarity of the connections to one loudspeaker.
Additional channels may be synthesised using matrix or digital sound processing.
Digital broadcasting is a stream of 0's and 1's. All the channels in a transponder are multiplexed onto the same carrier, the tuner sorts out which belongs to each channel with zero crosstalk. Discrete digital audio is just the same the stream identifies which data is to be sent to each of the 6 discrete channels in the case of 5.1/DTS, exactly the same way hence zero crosstalk. If the same audio data is sent to each of the 5 full frequency channels at the encoding stage then each speaker will output an identical and in phase sound.
If a phase shift was involved you would get an echo.
Try feeding a mono signal to a pair of stereo speakers and then reverse the polarity of the connections to one loudspeaker.
Additional channels may be synthesised using matrix or digital sound processing.
Feeding 5.1 discrete channels to DPL doesn't work (I challenge you to try it, but I don't know of any equipment which will do that). If you feed the DPL chip with 2.0 channels (via digital or analogue), provided it is correctly configured it can extrapolate DPL from the phase differences.
That's probably because the downmix metadata forbids it !Only done under specific conditions.
In fact, 5.1 to 2.0 downmixing takes place all the time. For movies, for example, which are shown with 2.0 and 5.1 simultaneously (except itv, who don;t bother, and just use the optical soundtrack).
Who says it is? The rear information for Pro Logic is derived from out of phase information. Dolby Digital 5.1, though, isn't it is created from 6 completely discrete channels of information.
I'm sorry if this simple discription doesn't tally with your view - all I can suggest is you write to Dolby Labs for their view on it.
Really would you like me to demonstrate. If you take two identical waveforms and phase shift one from the other all you do is advance or delay one from the other in time depending on which way you shift one relative to the other. Playing back both at the same time creates an echo (the effect is normally called reverberation). Back in the days of reel to reel recorders with seperate playback heads to the record head then combining the output of the tape with the original signal causes just this effect.
Perhaps you can explain how a single fibre optic cable can carry thousands of simultaneous telephone traffic are they all phase shifted from each other :eek:
Comments
What I do know is that items manufactured in the Far East/Asia can, and often are, manufactured to a European specification. Something doesn't have to be manufactured in Europe to meet European standards.
WHat I should have said, is, the method used in dolby surround to indicate position is a phase difference between the L (+j) and R (-j) surround channels.
What different system is used in 5.1 ?
Yes, you could indeed use 5 discrete channels for 5 mono recordings. Since there's no crosstalk. But this entirely misses the point.
The 3 front channels are matrixed together, as stereo.
the 2 rear channels are matirxed together, as phased surround.
The ".1" is sensurround, low frequency bleed-off ..........
To that end, I point you to post #83.
It doesn't in my amplifier. If can't output DPL if the input is DD5.1. Other amplifiers which don't have the DD5.1 chip use the 2.0 stream to up-scale to DPL. If it doesn't have a 2 channel source, or a DD5.1 source then you will get silence.
Take a look at your own AV Amp. You'll see that if you feed it with a DD5.1 stream, then it won't down-sample to a lesser format, unless the source only outputs the 2.0 stream. You can often enforce that via the source device's menu.
What happens when you feed either 5.1 or 2.0 to a pro-logic 2 (4 rear speakers)? How can this possibly be "discrete" ?
How can feeding 5.1 to (typically) 20 rear speakers - in a cinema - possibly be "discrete" ?
As I've repeatedly siad, there's no such thing as pro logic coding, only surround decoding.
(in fact, it;s the same).
This is strange, considering Dolby originallly used SQ without paying rooyalties, then tried to avoid royalties by claiming 5.1 doesn;t use phase encoding ......
Well, duh! That's because it works exactly the same way.
The 2 matrixed surround channels have exactly the same information as the 5.1 discrete versions.
The DPL link I posted above - written by a Dolby Person - specifically mentions DPL as working from 2 channels. 5.1 is not even mentioned. Please do no confuse container and contents.
http://gilmore2.chem.northwestern.edu/tech/dolby1_tech.htm
Note that DPL is a specific matrix decoder type for home cinema only. It's nothing to do with whether delivery is 2.0 or 5.1. That's the "container".
So you get 5 discrete channels which are decoded only at the listening position. (Remember, stereophonic is simply two entirely discrete channels - Monophonic is one discrete channels and quadrophonic is four discrete channels - DD5.1 is 6 discrete channels - they all work in exactly the same way).
With DPL phase difference is used. That is you have, say, a pair of microphones ostensibly recording the performance in front of them. However, if there is, say, an audience or other instruments behind the microphones that information is captured "out of phase" with the front recording.
So 5.1 puts 5 microphones pointing inwards, while DPL or other similar systems have at lease a pair microphones pointing outwards, towards the main performance.
Of course, other tricks are used in the mixing desk to "tinker" with the effects - because not all instruments are recorded at the same time.
You can often pick up mistakes in older recordings which didn't take into count the secondary effects of phasing - sometimes resulting in some very odd effects when replayed through a DPL or similar chip.
With DD5.1 everything is "in phase". With DPL the front is the only information that is "in phase" and the rear is "out of phase".
"Dolby Digital is the name for data and audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994."
ie, it's the same basic system, except delivered digitally.
http://en.wikipedia.org/wiki/Dolby_Digital
"Dolby digital is loosely based off SQ quad. Any Marantz quad with a SQA adaptor can do a damn fine job in taking that dolby signal and giving you surround".
http://webcache.googleusercontent.com/search?q=cache:NjgsG3I5qScJ:www.audiokarma.org/forums/archive/index.php/t-212924.html+dolby+digital+sq+matrix&cd=9&hl=en&ct=clnk&gl=uk
Dolby Stereo is a discrete two channel system, from which out of phase information can be used to extrapolate the rear information.
Whether stereo is digital or analogue makes no difference whatsoever to that.
DD5.1 isn't DD2.0.
The basic surround info - excluding extra channels - is exactly the same phase shif encoding in all versions.
I ask yet again. What other way do you think it's done ? So far, i;ve had no answers to any ofo my questions .........
"5.1 is the common name for six channel surround sound multichannel audio systems. 5.1 is considered "standard" or "traditional" surround sound as it is the most commonly used in both commercial cinemas and in home theater. It uses five full bandwidth channels and one low frequency channel. [1] Dolby Digital, Dolby Pro Logic II, DTS, and SDDS are all 5.1 systems. 5.1 is also the standard surround sound audio component of digital broadcast and music. [2]
All 5.1 systems use the same speaker channels and configuration, having a front left and right, a center channel, and two surround channels. Speaker placement is defined by ITU-R BS 775-1, with the center channel speaker being placed at zero degrees, the left and right channels being placed at ±30 degrees, and the surrounds being placed at ±110 degrees. [3]"
http://en.wikipedia.org/wiki/5.1_surround_sound
Correct! Note the speaker placement angles are quite specific, because the surround channel is PHASE ENCODED. If it were AMPLITUDE ENCODED, then this wouldn;t really matter ........
Also note, it's important the speakers are placed in a circle, ie equal radius from listener, again with amplitude encoded stereo this wouldn't matter. It's because the SQ matrix is universally used ........
The Pro Logic decoder is a particular way of treating the audio soundfield, to give enhanced direction cues. As correctly described in the various links I've given.
It makes little difference in principle to pro logic operation whether the input is derived from 2.0 or 5.1.
That's complete utter rubbish, as you can easily see by reading an account of what the DECODER actually does!
The +j and -J phasing is how the surround channel is encoded onto the 2.0 format. It's nothing to do with how the sound is reproduced, which depends on the acutal decoder used ..........
Yet again - i'm getting sick of this - the 2.0 format encodes the surround position as phase. How a decoder works depends on which type. Pro Logic is NOT an encoding format .......
.......or a single soundfield mike with 4 capsules ......
http://www.soundfield.com/soundfield/soundfield.php
If a phase shift was involved you would get an echo.
Try feeding a mono signal to a pair of stereo speakers and then reverse the polarity of the connections to one loudspeaker.
Additional channels may be synthesised using matrix or digital sound processing.
gibberish!
That's probably because the downmix metadata forbids it !Only done under specific conditions.
In fact, 5.1 to 2.0 downmixing takes place all the time. For movies, for example, which are shown with 2.0 and 5.1 simultaneously (except itv, who don;t bother, and just use the optical soundtrack).
I'm sorry if this simple discription doesn't tally with your view - all I can suggest is you write to Dolby Labs for their view on it.
Really would you like me to demonstrate. If you take two identical waveforms and phase shift one from the other all you do is advance or delay one from the other in time depending on which way you shift one relative to the other. Playing back both at the same time creates an echo (the effect is normally called reverberation). Back in the days of reel to reel recorders with seperate playback heads to the record head then combining the output of the tape with the original signal causes just this effect.
Perhaps you can explain how a single fibre optic cable can carry thousands of simultaneous telephone traffic are they all phase shifted from each other :eek: