As you have probably heard, Harman demonstrated the QuantumLogic system (QLS) at CEDIA 2011. This was done in their mobile truck and is a precursor of what is to come in the Lexicon MP-20 processor.
The demonstration started surprisingly and pleasantly so by Dr. Gil Soulodre who was the chief inventor of the algorithm. He has 18 patents in his name and 30 years in the audio industry in addition to being an AES fellow and winner of a Technical Emmy.
The system is more ambitious than the ones coming from it. The cornerstone of the system is stream and reverb extraction algorithm. Stream extraction is aimed and finding specific components in the source and creating a separate channel from it. This can for example be a predominant instrument. Reverb extraction is exactly that. It identifies the reverberations and separates from the source of the same. These reverbs then can be played in a different channel than the remaining “dry” component of the same and by doing so, increase the sense of spaciousness.
One key component of the system is that the sum total of all the streams gives you back the original track unchanged. Such a reversible decomposition is critical in preserving the full fidelity of the presentation and proof point that nothing is added to the sound that was not there in the source soundtrack/music.
Next step is speech and mono detection. After this, the output is fed to an “Aesthetic Engine” which is a euphemism for putting the listener in the driver’s seat as to where each one of the extracted streams should be steered to and how much. Indeed, the elevator pitch for this system can be that instead of the music producer/engineer deciding where everything goes, you get to do that!
The demonstration started with them extracting the vocals from the music and playing each stream separately. And then summing them together. The latter was most impressive to me as it sounded like the original proving the lossless aspect of it. The separated streams achieved pretty high level of extraction. Yes, there was small amount of bleed through but since the final goal is to still play all of these streams together (as opposed to just playing the one stream by itself) that was not a harmful effect.
The process can drive 5 additional height channels/speakers (see the picture of the back of the room below). In the truck configuration, they were in a smaller circle than the main speakers due to space limitations. As you see, they used pretty low cost speakers for that. Someone in the audience commented about small tonal change when the height effect was triggered. This was no doubt due to the small sonic differences between the main (JBL) speakers and the height. That said, I did not hear the difference and think that low cost ceiling speakers can be used to satisfactorily play this role. The notion of using identical speakers up in the ceiling is probably not very practical
.
The next demonstration was extracting the reverb. The result was quite effective, playing the “dry” non-reverb version separate from the reverb track. The A/B comparison against the original was pretty striking.
They then brought on Nathan Kunkel who proceeded to play some of the music he had mixed. It should be noted that he had time with the system to decide what settings he should use. He said that after it was all said and done, he found one set of dials that worked across all of his music and indeed, they played them that way. The effect was pretty remarkable. The level of liveliness shot up through the roof. In a dance piece, it took a dull front speaker only track and distributed it across the whole room making you want to get up and dance.
The final demo was the Matrix soundtrack. By then I had moved to the back of the room and standing next to the wall, I did not get anything out of it. But my colleague who was sitting up front loved the enhancement.
I should note that in one of the streams they played back, there was fair bit of pre-echo distortion. This is due to use of large window transforms. That distortion vanished however when the track was played with the rest of the music.
As you see in the screen snapshots below, the system has a lot of controls. I asked how the final system would work and they said it would have a few simple dials that you could turn. One would be how far the streams spread. Imagine the minimum being your current front speakers for stereo and maximum being completely spread into the rear speakers. Similar control determines the height of how much the content is pulled up into the height speakers. Another control would manage what happens to reverb.
The engineer in me marvels at what they have done, but more importantly, why no one else thought of it! Certainly currently state of signal analysis allows such capabilities with the challenge being the reversible nature of it and making it computationally efficient to run on consumer gear while it is doing everything else (in case of Lexicon MP20, 16 channels of EQ).
I think this will make a fun system and lots of tweaking to be had to tailor the music and movie soundtracks to our liking. I suspect in some cases “off” would also be a good setting. But hopefully that gets used a lot less than it is with current systems.
surround speakers:
Stream Extraction:
Extracting Voice:
UI Control (for PC prototype, not final product)
Architectural Logic Flow
The demonstration started surprisingly and pleasantly so by Dr. Gil Soulodre who was the chief inventor of the algorithm. He has 18 patents in his name and 30 years in the audio industry in addition to being an AES fellow and winner of a Technical Emmy.
The system is more ambitious than the ones coming from it. The cornerstone of the system is stream and reverb extraction algorithm. Stream extraction is aimed and finding specific components in the source and creating a separate channel from it. This can for example be a predominant instrument. Reverb extraction is exactly that. It identifies the reverberations and separates from the source of the same. These reverbs then can be played in a different channel than the remaining “dry” component of the same and by doing so, increase the sense of spaciousness.
One key component of the system is that the sum total of all the streams gives you back the original track unchanged. Such a reversible decomposition is critical in preserving the full fidelity of the presentation and proof point that nothing is added to the sound that was not there in the source soundtrack/music.
Next step is speech and mono detection. After this, the output is fed to an “Aesthetic Engine” which is a euphemism for putting the listener in the driver’s seat as to where each one of the extracted streams should be steered to and how much. Indeed, the elevator pitch for this system can be that instead of the music producer/engineer deciding where everything goes, you get to do that!
The demonstration started with them extracting the vocals from the music and playing each stream separately. And then summing them together. The latter was most impressive to me as it sounded like the original proving the lossless aspect of it. The separated streams achieved pretty high level of extraction. Yes, there was small amount of bleed through but since the final goal is to still play all of these streams together (as opposed to just playing the one stream by itself) that was not a harmful effect.
The process can drive 5 additional height channels/speakers (see the picture of the back of the room below). In the truck configuration, they were in a smaller circle than the main speakers due to space limitations. As you see, they used pretty low cost speakers for that. Someone in the audience commented about small tonal change when the height effect was triggered. This was no doubt due to the small sonic differences between the main (JBL) speakers and the height. That said, I did not hear the difference and think that low cost ceiling speakers can be used to satisfactorily play this role. The notion of using identical speakers up in the ceiling is probably not very practical
.The next demonstration was extracting the reverb. The result was quite effective, playing the “dry” non-reverb version separate from the reverb track. The A/B comparison against the original was pretty striking.
They then brought on Nathan Kunkel who proceeded to play some of the music he had mixed. It should be noted that he had time with the system to decide what settings he should use. He said that after it was all said and done, he found one set of dials that worked across all of his music and indeed, they played them that way. The effect was pretty remarkable. The level of liveliness shot up through the roof. In a dance piece, it took a dull front speaker only track and distributed it across the whole room making you want to get up and dance
. The final demo was the Matrix soundtrack. By then I had moved to the back of the room and standing next to the wall, I did not get anything out of it. But my colleague who was sitting up front loved the enhancement.
I should note that in one of the streams they played back, there was fair bit of pre-echo distortion. This is due to use of large window transforms. That distortion vanished however when the track was played with the rest of the music.
As you see in the screen snapshots below, the system has a lot of controls. I asked how the final system would work and they said it would have a few simple dials that you could turn. One would be how far the streams spread. Imagine the minimum being your current front speakers for stereo and maximum being completely spread into the rear speakers. Similar control determines the height of how much the content is pulled up into the height speakers. Another control would manage what happens to reverb.
The engineer in me marvels at what they have done, but more importantly, why no one else thought of it!
Certainly currently state of signal analysis allows such capabilities with the challenge being the reversible nature of it and making it computationally efficient to run on consumer gear while it is doing everything else (in case of Lexicon MP20, 16 channels of EQ).I think this will make a fun system and lots of tweaking to be had to tailor the music and movie soundtracks to our liking. I suspect in some cases “off” would also be a good setting
. But hopefully that gets used a lot less than it is with current systems.surround speakers:
Stream Extraction:
Extracting Voice:
UI Control (for PC prototype, not final product)
Architectural Logic Flow
