【School】 sound weak in English terms explained (amplifier type)..

<br> output power (outputpower): that the load of the power amplifier output power in a certain size, usually marked on the instructions in the amplifier 8 ohm load, 4 ohm or 2 ohm load the output power under load, but also .that. amplifier in bridged mode, 8 ohm or 4 ohm load when the load when the output power.. The output power of said power amplifier rated output power, rather than the maximum or peak output power.. <BR> Load impedance ( .loadimpedance): show that the amplifier's load capacity, the smaller the load impedance that the current amplifier through greater ability, in general, most of the power amplifier minimum load impedance of 4 ohms, good quality. amp minimum load is 2 ohms.. Dual .-channel amplifier to the load 4 ohms in bridged mode to load a minimum of 8 ohms, dual channel power amplifier able to load 2 ohms, bridged state can load 4 ohms.. Under the bridge can only load 8 ohm power amplifier, can not .lower the load impedance, otherwise it will create too large amplifier because the current is burned.. <BR> Stereo (two-way) mode (stereomodeordualmode): a general power amplifier with two independent internal amplifier, were treated to two different signal .amplification and output, respectively, such working conditions as stereo (two). mode <BR> bridge mode (bridgemode): Bridge mode is to use the internal amplifier push-pull between the two amplifier circuits, resulting in greater output voltage mode amplifier .is set to bridge mode, as a mono. channel amplifier, can only accept one input signal amplification, the output for the two between the positive terminal of power amplifier output.. <BR> Parallel input mode (parallelmode): This two- .way amplifier input signals in parallel channels, only the input signals to simultaneously drive all the way to the two amplifier circuit, output signals of two identical outputs.. <BR> Frequency range (frequencyrange): show that the amplifier can amplify the work .of the band, usually 20-20000 Hz, usually followed by a suffix of this data, such as -1 / +1 dB, which represents the error or the frequency range. floating range, this number about a small, indicating that the frequency .range of the frequency response curve is more flat.. If the amplifier's frequency response range to -3 dB for the test conditions, the amplifier out of the sound may not so straight out.. <BR> Total harmonic distortion (THD): .show that the amplifier work, the inevitable oscillation circuit generating the second harmonic or third harmonic superimposed with the actual input signal, the output signal at the output is not simply. the composition of the input signal exactly the same, but includes the harmonic components of .the signal, the harmonic components of the extra out of the input signal and the actual contrast, expressed as a percentage called with a total harmonic distortion.. In general, the total harmonic distortion in the vicinity of 1000 Hz minimum, so most of the .total harmonic distortion power amplifier that is 1000 Hz signal for testing, but some manufacturers also provide a more stringent range of 20-20000 Hz Total Harmonic Distortion. data.. Total harmonic distortion below 1%, generally do not distinguish between the ears out of .more than 10% can clearly hear the distortion components.. The smaller the value of total harmonic distortion, the more pure tone.. Total harmonic distortion products in general are less than 1% @ 1kHz, but the smaller the value, the higher the .quality of that product.. <BR> Intermodulation distortion (IMD): intermodulation distortion is due to the internal transistor amplifier operating characteristics which cause the waveform distortion sine wave generated.. The presence of intermodulation distortion, directly affecting the sound quality, there .is no tube amplifier intermodulation distortion, so there is no general sense of transistor amplifier tube amp sounds so soft and comfortable.. Intermodulation distortion values generally greater than 0.1% if this amp sound felt stiff, astringent, do not express exhibition.. < .BR> Common-mode rejection ratio (CMRR): common mode rejection is a measure of the amplifier rejects common mode signals are indicators of the extent of a comprehensive, detailed definition does not go into details, this parameter is generally expressed by negative values, .such as-60dB, the. indicator is also seriously affect the amplifier's sound quality indicators, this indicator lower the number, the better the sound quality amplifier.. <BR> Damping (dampingfactor): This is the amplifier internal resistance and the ratio .of load impedance, speaker impedance damping coefficient = ÷ (the internal resistance of amplifier + speaker line impedance), high damping factor of the amplifier to the speaker control unit. strengthen, allowing the reaction unit closer to the requirements of power amplifier output signal, .but too high will cause the speaker's low frequency damping variation scalability, sound dry and hard.. Damping low bass can get soft, but the damping is too low will cause the bass to become excessively bureaucratic, not clean.. 200-1000 amplifier damping .in general @ 8 ohms.. Poor quality speaker cables, line resistance will affect the power amplifier large damping, resulting in less control over the speaker amplifier, sound change scattered.. <BR> Input sensitivity (inputsensitivity): This is a voltage .concept, that when the amplifier reaches full power output when the signal voltage at the input size, the average voltage of amplifier's input sensitivity 0.775v (0dB) to 1.5v (+6 dB.), with sensitivity higher the voltage, the lower the .input sensitivity.. Some high-quality power amplifier, low input sensitivity is due to the negative feedback circuit with a deeper, it has lower distortion, wider frequency response and better sound quality.. <BR> Signal to noise ratio (S / .NorSNRorHumandNoise): refers to the amplifier signal voltage and the ratio of the background noise voltage, the greater this value, indicating that the lower the noise amplifier.. General professional products are 100 dB signal to noise ratio of about marked by positive, the higher .the better (some amplifiers with negative labeling, lower, the better.). Amplifier's input level attenuation gain (volume knob off a small amplifier) will reduce the amplifier signal to noise ratio.. <BR> Channel crosstalk (crosstalk): means .that the amplifier between the two internal amplified channel crosstalk generated by the coupling circuit, this indicator is not good, it will signal a channel to another channel to the string, resulting in another. does not produce a clean sound channel, the channel crosstalk value .is generally about -60 dB.. This value is marked with a negative value, the lower the value, that the separation between two amplification channels higher the degree of sound more clean.. <BR> Conversion rate (SlewRate): measure the .response speed of the amplifier with a voltage slew rate is generally defined as the voltage at 1 microsecond rise time, amplitude, square wave if it is measured, then rose to the peak voltage required by the trough. time, the unit is V / us ., the greater the value the better the transient response, said, feeling the sound speed, energy is concentrated.. Professional power amplifier slew rate can generally be 40V/us above.. Amp slew rate less than 20V/us feel out of procrastination and .divergent voices.. <BR> High-pass filter (highpassfilterorHPF): sound system, sometimes there will be some very low frequency infrasound (infrasonic) audio signal is mixed in among all these ears infrasound signals were not seen, but this signal into .the speaker to. will lead to self-excited generation woofer and cause speaker damage, all, some of the internal amplifier with sub-sonic filter to eliminate some settings in the rear panel switch, you can remove unnecessary when needed, 30 Hz or 40 .Hz frequencies below. to protect the speaker's security.. <BR> Limiter (limiter): This is one of the measures of protection amplifier, the amplifier input voltage exceeds the input sensitivity voltage, limiting the input signal in order to avoid because of .high input voltage power amplifier clipping distortion.. Some of the amplifier limiter is automatically activated, and some power amplifier installed in the rear limiter switch to control the startup limiter active.. <BR> HkCF5? S/bC10905 earth switch (groundleft) .: amplifier power transformer shielded chassis generally connected to amplifier chassis also has a ground, but the "ground" and signal "to" different.. When there is interference power of the ground, the grounding switch to open the amplifier chassis ground to .reduce hum phase contrast interference, if the ground does not interfere with the power to not connected.. <BR>..