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Thread: ΗΧΟΣ & Phos και άλλα τελώνια

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    ACAPELLA ION TW 1S (Ionic Tweeter)

    The Acapella ion tweeter „Ion TW 1 S“ is a perfected and sophisticated loudspeaker chassis, whose exceptional performance and qualities can only be enjoyed completely if used properly.

    It was designed to reproduce the harmonics of the music as detailed as possible. To reach this goal, a design with the smallest possible mass had to be developed. Relative to its function the Acapella ion tweeter has no mass! To carry out this project, a very unusual kind of design had to be created.

    High voltage within the unit produces a constant arc. This arc is modulated with the musical signal (flame oscillates with the time of the music). This is the reason why the number of electrons within the arc varies. A larger or smaller amount of electrons requires similar space. Due to this variable need of space the surrounding air molecules have to dodge the more or less quickly. This evasive action or bumping of the air molecules generates over-, resp. underpressure and, therefore, sound. In this way, the Acapella ion tweeter is able to reproduce sound without membrane and without mass Regarding transient capabilities and phase stiffness, the obtained sound quality cannot be realised by using conventional tweeters. Comparing the ion tweeter with other tweeter systems, its unobstrusive sound image will attract you. This kind of reproduction is to be attributed to the lack of harmonic and transient distortions.


    Technical data

    Sensitivity (aktive Tweeter): 1,5Volt / 0 dB
    Impedance: 600 Ohm
    Sound pressure level: max. 110 dB - 1 m / 1ms
    Slope Input filter: approx. 12dB/octave
    Frequency response: 5kHz - >50kHz (variable crossover frequencies )
    Mains voltage: 234 Volt / 50 Hz Standard
    Optional 110 -, 117 -, 227 Volt / 50 - 60 Hz
    Dimensions H x W x D: 150 x 300 x 260 mm
    Weight: 15 kg


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    Και αν θέλετε θέματα για σοβαρή σηζήτηση ορίστε και να μένουν στην άκρη οι κοινοτυπίες παρακαλώ...


    Propagation of sound in glow discharge plasma
    Vladimir Soukhomlinov, Nikolay Gerasimov and Valery A Sheverev

    Vladimir Soukhomlinov1, Nikolay Gerasimov1 and Valery A Sheverev2
    1 Research Institute for Physics, Saint-Petersburg State University, Saint-Petersburg, Russia
    2 Polytechnic University, Six Metrotech Center, Brooklyn, NY 11201, USA
    Abstract. Propagation of sound in a medium where the rate of local heat addition is a function of gas density is analysed theoretically and the results are applied for modelling the experimentally observed effect of amplification of acoustic waves by an extended glow discharge in air. The model adequately describes the experimental dependences of the gain on the wave frequency and discharge power density and predicts that the amplification of sound by an unconfined glow discharge in air increases with discharge current density but does not change noticeably with gas pressure when the current density is kept constant. Quantitative estimates indicate that a gain of as high as 1 m-1 (or 9 dB for a 60 dB wave passing through 1 m of plasma) could be realized using a discharge in air with a current density of 100 mA cm-2.
    Print publication: Issue 8 (21 April 2007)
    Received 6 November 2006
    Published 4 April 2007




    Reflection of sound by glow discharge plasma
    Vladimir Soukhomlinov, Valery A Sheverev and Calin Tarau



    Sound amplification in inhomogeneous flows of nonequilibrium gas
    http://www.springerlink.com/content/f88l21pvhl6pv771/


    Hypersound amplification by a superlattice in a nonquantised electric field
    G M Shmelev et al 1988 J. Phys. C: Solid State Phys. 21 L1073-L1077 doi:10.1088/0022-3719/21/33/001
    G M Shmelev, S Y Mensah and G I Tsurkan
    V I Lenin State Univ., Kishinev, USSR
    Abstract. Short-wave sound absorption propagating along the axis of a semiconductor superlattice by electrons of the lowest miniband in a nonquantised electric field is investigated theoretically. The mechanism of the attenuation of phonons is due to Landau damping. The relationship discovered for the absorption coefficient Gamma = Gamma (E) is essentially different from that for homogeneous materials, and, additionally the threshold field at which the absorption switches over to amplification depends on the superlattice parameters and the length of the sound wave. The more important difference between short-wave sound amplification by a superlattice and amplification in the homogeneous materials is the possibility of finding a field E* such that - Gamma (E*)>or= Gamma (-E*). This situation allows in principle the use of a superlattice as a hypersound generator similar to a generator of long-wave sound. The above generator is impossible to construct in the case of homogeneous semiconductors.
    Print publication: Issue 33 (30 November 1988)

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    Εφόσον ενδιαφέρεστε σφάλλων, ή σφάλλετε ενδιαφερόμενος, είμαι αμερικανόφιλος. Σφόδρα.
    ...........



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    Ο κόσμος των ιδεών εκδικείται...

    Γεια σου παππού Πλάτωνα σουρεάλα

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