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In search of a noiseless system

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  • In search of a noiseless system

    I thought I would share some thoughts on a noiseless system. Parts of this is taken of my thread from another forum. There are many here that are familiar with my clumsy at times experiments....but they do bear significant fruit. I'm sure our host Myles who is on the cutting edge has observations on resonance or micro vibration control. I'll post some current photos of my system and how I have increased what I call the "weld" to improve the mechanical coupling and rigidity of my racks and components.

    Also I talk about "psycho acoustics" and how I think with a noiseless system it is the future of 2 channel stereo....

    "
    Originally Posted by jkeny View Post


    It's good to see this focus on system noise, again - well done, Roger. What fascinates me is that there are such widespread & fundamental perceptual differences from what are currently unmeasured changes in the signals.

    What I came across some time ago was, to my mind, the explanation for this - research into auditory processing called auditory scene analysis - ASA (this is fundamental to the volume control algorithms in the Dolby link given earlier).

    What ASA reinforces is the realisation that the processing aspect is the kernel of our auditory perception. Lots of people admit this but don't actually absorb the implications of this fact, I believe. We actually seldom have enough signal cues to unambiguously create the auditory scene from processing of these signals - rather what we perceive is the scene we are continually adjusting as we journey through the processing of incoming signals. So we are continually faced with unresolved aspects of the scene, some of which get resolved by the next signals being processed & some open up other unresolved aspects. From my understanding, this is the continual moment to moment process occurring & it's not surprising that anything which more quickly resolves this uncertainty relieves this underlying uncertainty. We often resolve it through using our sense of sight - notice how when we close our eyes our sense of surety is reduced

    But another aspect, fFor instance, is that processing of signal patterns can expose & reveal more (to our perception) from the signal than listening to the same signals but in unpatterned format - in other words the patterning of the sounds together with our innate auditory models, can reveal aspects in the sound that we wouldn't normally hear. In other words we are continually creating an auditory scene from the perceived patterns & other aspects of the signal stream. Hence, in explanation for the above low level noise phenomena, small changes in aspects of these patterns can change an auditory scene in fundamental & core areas. A lot of times these are the "night & day" differences that are often reported in listening.

    So how might this low level noise result in such fundamental perceptual differences? This noise is not a separate perceptual layer of noise, like tape hiss or groove noise - it's not present when there's no signal. It is intertwined with the signal & therefore not perceptually separable into a different auditory stream, as in tape hiss. My hunch is that it affects how we perceive the attack portion or risetime of a signal - this is a hugely important part of the signal for our perception - the A of ADSR signal envelope. It is this part of the signal that is heard first & determines the spatial, timbral & other important characteristics of the sound.

    IMO, better formation of this risetime signal from silent to maximum energy not only locates the start of this signal in time more accurately but also portrays the energy profile of this attack portion more accurately.


    Although ASA is a very interesting area of research into auditory processing, it is still trying to tease out the basics of it's operation. Since reading my way into ASA I've come to realise that what we are often experiencing & describing in this hobby is not yet the concern of ASA - they are still working out (& making great headway) in teasing out the fundamental operation of what is a pretty complex sense.

    jkeny thanks,
    I have had my psycho acoustics circuit since the 1980's and it was designed by a audio engineer friend that manufactured speakers,sub's,and electronics which I still use. The circuit is passive and originally worked with a single pair of speakers driven off the main amplifier. I added another center pair and they now have a dedicated amplifier.
    The circuit has always produced a expanded soundstage adding micro detail and ambient information while increasing the total amount of information to the listener. The circuit corrects the time domain (delay) in the room,at least that's what I remember,as it was explained to me many years ago.
    The system is fairly easy to setup and align so that all the speakers and their dispersion patterns produce a expandable soundstage with great focus and clarity. If the information has been captured by the microphone and the RE intends to make a faithful rendition the result can be stunning.
    I have found that signal grounding can make a larger difference in lower overall distortion. A engineer who has since passed away published a study that finds the signal travels a long the skin of the conductor and also travel a long the shielding. In my experience 10 gauge wire seems to be adequate for creating a large enough pathway to ground.
    I'm not a scientist,but resonance control seems to have a greater impact on sound quality. I have heard amplifiers with very heavy chassis that were extremely quiet. Much like pumping water through pipes, the amount of interference will limit pump pressure performance. I think this is a good analogy for what happens in equipment when the signal is effected by outside resonance. The greater the circuit remains physically stable,the less noise is delivered down the chain. This seems to have a dramatic effect on the resolution and transparency produced by the speakers. As the noise level is lowered the sound field expands and the reproducer becomes more efficient which requires less current from the amplifier,volume levels increase. With this the listener is moved much closer to the music or I should say the music comes to the listener.
    So with all this unmasked information it is apparent to me that "all" the data in the recording is captured. What the microphone hears is for most part transferred in the recording process. The result is the "gap" is closed in digital,there is little gain to be realised in higher sampling rates.
    With psycho acoustics now the brain can process this flood of information that no longer is reaching the ear out of time. Without the time delay there is no cancellation,no unscrambling to deal with,just like sound in the real world that pattern is uniform and complete. Is it perfect no, but it is a vast improvement over a sound reproduction system without it. In sum the improved sound field produces a far more lifelike illusion.
    In terms of audiophile jargon,there are certain things that stand out that in lower resolution systems that are less noticeable. The natural decay of the instrument which now seems to be more complete. Speed or in time as the music has much improved pace. Power as instruments now are portrayed with more energy. Reverberation as with the improvement of space and time the concert hall actually becomes a part of the recording or illusion. Time and space as the movement of the performers and the energy released by the instruments now takes on quality of realism.
    The recording is now revealed with all the good and bad. The good being, the best now can defy the limits of the walls and ceilings of the listening room and the illusion that the brain now produces in a more natural analog process becomes 3 dimensional. The listener is part of the environment of the recording venue.
    Anyway this is my civilian attempt to explain psycho acoustics which I think is the next frontier in 2 channel stereo,and it remains a 2 channel system. It is a beautiful experience.
    Jkeny...I think you added the bolded part,as I wrote my reply without reading this part. I think my observations match yours....interesting...thank you. Roger



    http://webpages.mcgill.ca/staff/Group2/abregm1/web/
    Preamp Accuphase C200 modded, Agtron Platinum Mono Blocks,ParAcas Satellites,dual subwoofer,Velodyne FSR18,Monarchy NM24 modded tube DAC,NBS Statement ,Master,Pro cables,Crown 844's & 824 R2R,Technics table,Linn LP12,Ampex R2R MR70's,AG440B-C,350,Studer C37

  • #2
    I see Wilson put a price tag of $685,000 for his "psycho acoustics" speaker......speechless!
    Preamp Accuphase C200 modded, Agtron Platinum Mono Blocks,ParAcas Satellites,dual subwoofer,Velodyne FSR18,Monarchy NM24 modded tube DAC,NBS Statement ,Master,Pro cables,Crown 844's & 824 R2R,Technics table,Linn LP12,Ampex R2R MR70's,AG440B-C,350,Studer C37

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