Why Do You Need Time Correct Speakers?

Historical development of hearing Over millions of years of evolution, the hearing of living things has optimized for two aspects: Locating prey and detecting danger. In both cases, the impulsive character of acoustic signals, i.e. transients, plays the decisive role. Every natural sound event begins with a sound, a transient. These transients contain a broad spectrum of pitches. Accordingly, the auditory system first evaluates those signal components for the evaluation and rough localization of signals, which are generally referred to as the "first wave front". The transients (transient processes) are of particular importance for the perception of loudness. The nerve signal rate of the auditory sense (nerve impulses from the auditory system to the brain) is about 30 times higher within the first fractions of a second of a sound event (the transient) than for the following decaying sounds. This is the result of the evolutionary development of hearing with the survival requirement to respond with extremely high attention to abrupt changes, clearly demonstrating where the sense of hearing has its highest sensitivity. It is astonishing that these signals are evaluated within only about 10 microseconds. This time converted into a frequency (with the formula f = 1/t) results in a frequency of 100,000 hearts! The cracking branch A quote from Manger (manufacturer of the Manger transducer): "In the 10- to 100-microsecond range, sound values are signaled directly to the brain without transducer wave propagation time for direction and character determination. Despite the recognition of sound taking place, tonal sound hearing does not yet occur. The fastest possible sound detection has taken place. (Alert)."' For the prominent transients, there is the maximum heightened attention of the auditory system along with its ability to signal these transients to the brain even before frequency analysis. And this happens even before the "travelling wave" crosses the basilar membrane and independently! The cracking of a twig - a natural transient - serves as an illustrative example. Or also the clapping of hands or the fine click of a small glass bead bouncing on a stone floor. These sound events consist of an extremely short-lived impulse structure. If we calculate the equivalent frequency mixture that makes up these sound events, the lowest frequencies contained therein are often above what we can hear at all in hearing tests with continuous tones. And yet we can hear these sound events, distinguish them from one another and locate them in the frontal range with directional accuracy to within one degree and at a distance. Impulse structures with frequency components down to the midrange are our daily bread in the acoustic sense. For the human auditory organ, they form the essential sound component for recognition and location. They contain the highest amplitudes in natural sound events. This is where the sensitivity of the auditory system is most pronounced. This has evolved evolutionarily, it makes the most sense to us. The recognition and localization ability decreases increasingly towards the bass range and almost disappears in the low bass range. If, on the other hand, we break several short, dry twigs about 1 cm thick, each crack sounds different and the locating ability works perfectly. Such a noise, with the low-frequency components missing in it, does not trigger the travelling wave required for frequency analysis in the basilar membrane at all. We hear, locate and characterize a crackling branch without frequency analysis, just by detecting transients! If we want to draw conclusions about the audibility of something, we cannot avoid sound structure analysis. We can hear the "sound difference" of different cracking branches, we hear accordingly the "sound difference" of different transients. By far the greatest problems in following a signal structure are not encountered by the electronics of a reproduction chain, but by the electro-acoustic transducers (popularly called loudspeakers). The constant re-tuning to the next signal shape is almost without exception impossible for loudspeakers. In wide ranges of the transmission bandwidth, not even the simplest signal shapes can be reproduced. The asynchronous transient response of loudspeaker drivers within a loudspeaker leads to strong, sometimes even one hundred percent distortion of impulses. Each such loudspeaker model generates its own artificial impulse structure. The sound of the impulse reproduction of the various loudspeaker models differs in much the same way as the sound of the various branches mentioned above. In fact, in a certain sense, something like sameness is produced, since the response to different impulses, such as the cracking branches, results in largely similar pressure-time structures artificially produced by asynchrony. In the process, the original sonic character of the sound events is lost. The following articles (right) from Biology in Our Time, 1996, describe further background on the function of hearing. Myro Musikus 2006 Part1.pdf Biophysics of hearing, part 1 (4,6 MB) Part2.pdf Biophysics of hearing, part 2 (3,9 MB)

Impulses in music "To reach the source, one must swim against the current." Chinese proverb Reproducing transient states is what today's "already good speakers" do reasonably well. But that is only part of what we hear in music. However, we hear speech, noises and music. Their sound structure is characterized by constantly changing dynamic sound pressure events. Here, too, nothing is more constant than change! Music and other sound events are characterized by erratic changes, transients. Musical instruments such as drums, glockenspiels, plucked string instruments or upright and grand pianos generate numerous impulse-like signals, and even softly played instruments such as violins can also initially generate an impulse-like signal when the first note is played. The waveforms of the sound pressure events vary rapidly and to such an extent that repetitions are practically non-existent. A technically conditioned antiphase from overtones to fundamental tones or from overtones to other overtones always produces a changed sound (tone) structure. For the shape of the sound curves it is essential whether harmonics are added or subtracted. The result is a different wave structure. And we hear this characteristic of wave structures. This should be less relevant for overtones at the upper end of the spectrum, because there the resolution by our hearing organ decreases. The components of a sound reproduction system must therefore have the ability to transmit these constantly changing signal forms, in electrical and acoustic form. Steady, quasi-static states practically do not occur. | Myro Floor Monitor

If the speaker can't reconstruct the first half-waves, then you miss the loudest parts of the music. Transient tones almost invariably exist in the decay of tones in natural music. These are quiet in relation to the attack and are of little importance for recognition and spatial localization. Music is also rhythm, it lives from impulse dynamics. In music, just as in natural ambient sounds, e.g. in a film, we recognize and locate sound sources and reflections, receive information about spaces and distances through the temporal coherence of events. This is acoustic three-dimensionality. Perfect transmission behaviour of the loudspeaker of impulses in the time domain thus contributes decisively to an authentic reproduction of music.
Most loudspeakers, however, produce distortion during transient response in orders of magnitude that we would not tolerate in other devices. With a digital-to-analog converter, for example, we demand bit-perfect conversion of the music data. Most loudspeakers, on the other hand, distort transients on a scale that resembles a digital data blackout. Already the first hundredth of a second of the transient contains 7056 zeros and ones in the CD format, at 24 bit / 192 kHz it is even 46080 bits, which they jumble arbitrarily during the transient, as if one would make a CRAP from the word CARP. These loudspeakers thus produce artificial and false sound waves, which do not correspond to the music recording. In contrast to the influences of digital formats on the signal structure, loudspeakers produce a different, loudspeaker-typical structure. The loudspeaker is also most likely to have its own sound. However, it does not follow from this that it does not matter whether a loudspeaker converts correctly or not. Just like a D/A converter, a loudspeaker is also a transducer, an electro-acoustic transducer, with the same claim to the fulfilment of its task.

Maximum resolving power is essentially achieved by five design features:

1. Accurate transmission path with fast power amplifiers with load-matched or load-independent damping.

Torsionally stiff speaker cones (beryllium, diamond, ceramic, titanium/aluminium/magnesium, hexacone, HDA) with clearly correctable resonance behaviour, as constant as possible at all angles. Timed transient response with correct summation, linear phase in the pickup areas, wide transmission range with minimum phase rotations at the transmission ends; damping of all resonances for fast, uniform decay

1. Homogeneous radiation (only one main radiation lobe and 3rd fulfilling)
   
2. Mechanical stability / damping of all components that are excited to oscillate (cabinet, crossover, cable, amplifier, etc.)

<zurück: Myroklopädie>
<zurück: Myro>