Made up words to justify printing magazines and blogs just don't cut it. I listen for emotion. That's all I need. You can blame the founding fathers of the critics set and magazine editors for making up words to describe noise.
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I thought audio waves moved at the speed of sound, and light waves moved at the speed of light? This is the kind of crap I’m talking about.At most frequencies, audio waves that are in the form of electrical signals travelling through cables travel at a substantial fraction (generally upwards of 100,000 miles per second) of the speed at which light moves through a vacuum (approximately 186,000 miles per second). The exact speed varies depending on the characteristics of the cable, especially what is known as the "dielectric constant" of its insulation. An exception to that is audio at deep bass frequencies, which travel through cables more slowly but still at speeds of thousands of miles per second. Audio waves that are in the form of sound travelling through air travel vastly more slowly, at roughly 0.2 miles per second, depending on the humidity and several other variables. As mentioned, the speed of light in a vacuum is approximately 186,000 miles per second. It is somewhat slower in other media, such as glass, just as the speed of electrical signals is dependent on the characteristics of the cables that are conducting them. I hope that addresses the concerns expressed in the second of the two sentences that I quoted from your post. Regards, -- Al |
roguemodel – your statement cannot be more accurate or appropriate…including your deduction. Atmasphere...I thought audio waves moved at the speed of sound, and light waves moved at the speed of light? This is the kind of crap I'm talking about. Just listen to the music, if it moves you, you have a great system. If you will allow me to shed some light on this topic. As it turns out I have probably more research into this very topic than anyone. I can only say this because I have hard evidence that the way sound reproduction systems operate is no longer a mystery but rather bound by physical laws that are predictable. To correctly understand it is to be aware of the basic requirements needed to achieve sound reproduction that is (not realistic) but in fact, real. Regarding the speed of an audio signal through the electrical medium. Atmosphere mentioned the example of the marble filled hose. By adding one marble to the input side (A) – one marble exits on the output side (B). The observed speed it took for the “energy” to travel from point A to point B is virtually simultaneous. That speed is both very fast and more importantly it is a fixed speed. However - The other speed to observe is the speed (rate) that the marbles are loaded into (a). At the other end (B) they will be exiting at the same speed. That speed can vary. (One marble per minute or one marble per second) Whatever the rate is – it will be the same at both ends. The understanding is that we can reference 2 separate speeds happening at the same time depending on where and how you observe it. Electricity travels at the (roughly) the speed of light (no need to bicker over the exact number) Sound waves travel a Mach One (approx. 750 mph depending on environmental conditions). It is important to realize that these are “observed” or “apparent” speeds. IOW you are not monitoring a single electron entering a wire and making its way to the other end at the speed of light. Instead it is the response time of the medium – in this case the wire quickly drops off an electron (not the same one added) at the output end. Here is the difference. (In an excerpt from the white paper on distortion.) Observing the sonic event from the beginning… I will use a live orchestra performance as an example here because it is rich with many instruments and is among the most difficult sound events to reproduce properly. We see the live performance as a sound event in which there are natural “sound waves” traveling away from the stage. These waves flow freely because they are traveling in medium of air. The music enjoyed by a live audience member seated in the 10th row center comes to him or her by a delivery system which includes the air present in the auditorium. The air serves as the perfect medium allowing the sound vibrations generated by the various instruments on the stage to “travel” as waves uninterrupted. The speed at which it flows is known as Mach One. These waves ultimately arrive and enter the listener’s ear canals (still at Mach One). What really happened just then? Everything that was vibrating on the stage simply increased or decreased the instantaneous air pressure as a result of squeezing (compression) or stretching (rarefaction) the local air pressure surrounding the instruments. This is nothing new. However, what was propelled toward the listener was only the result or influence impressed upon, and carried by the medium (a wave of sound). When we say the “sound” has arrived we are really verifying that the result or influence has arrived. We call it a “sound wave” because it is in a medium that allows sound waves to exist and flow freely. For the local listener in the audience, it is “mission accomplished”. Music from the stage was delivered or “streamed” directly to the listener’s ear canals using sound waves to communicate the event through the medium of air. The local air molecules surrounding the (violin string) are still there. They never left the stage. Only the exact disturbances in pressure have arrived, to be decoded by the ear-brain system and recognized as a real live event. So the only thing that “traveled” was the WAVE – not the original air molecules pushed away from the violin string. Sticking with the actual attendance of a live concert – audience members sitting many rows back from the stage will hear the same music that the people in the first row hear. (allowing for delay and distance cues such as the slight roll off of highs due to the drop in energy level. The SPL will be weaker but not slowed down. Can the person in the first row claim that what they are hearing is more live than the person many rows back because it gets to them first?. Of course not. The same way that the person in the back is hearing more of a slice of “history” due to the offset (travel) it time. To them it is just as live. The only way to destroy the “live” nature of the music is to tamper with one of the properties associated with sound. Sound has two properties: 1) Pressure 2) Time. That’s it. If you maintain both those properties – they will equal live. If you look on an oscilloscope at a musical signal and you see the jagged lines (vertically) that represent a violin or percussion instrument – this is the instantaneous “pressure” measurement. If you look at the horizontal reference line most of you know that this represents time. A soon as one of those two properties is altered it is no longer perceived as live. The medium of air is constant and will not alter either one. The ear-brain system is intimately familiar with the properties of air. It is how sounds are “fed” to us. An electrical medium that is not constant will never transfer the true “feeling” of live. The emphasis in the amplifier business has been all about the vertical axis “pressure” with not enough attention paid to what it takes to nail down the timing issues. This is where my research has taken me. The constant speed or velocity of a sound wave has to be included in the amplifying process.
Just listen to the music, if it moves you, you have a great system.roguemodel - you are right. If it moves you (like a feeling of live) then you do have a more accurate system. If you can deliver accurate pressure and timing of sound waves, what you get back is 100% live. It is possible and it does work. Roger |
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