【 Weak current College 】 amplifier and speaker with four elements

In the design, installation of a sound system, inevitably encounter power amplifier and speakers of IP issues. In tone, will note whether its mix of warm and cold affordable, hardware and software is moderate, eventually the whole set equipment restore tone is neutral, it is only considered from art. From a technical aspect to consider power amplifier and speakers with elements: one, two, power matching, power reserve match, three, four, impedance matching, damping coefficients of the match. If we recognise in matching the above point, makes the equipment performance is adequate, the biggest play.
Power match
In order to meet the requirements of high-fidelity listening, rating should be based on the best listening to sound pressure to determine. We all have this feeling: the volume, sound weak, thin, dynamic out, Matt, low frequency difference significant missing, chubbiness, sounds like condensation inside out. Volume is appropriate, sound natural, clear and mellow, soft, supple, strong and dynamic out. But the volume is too large, the sound is not muted, rough and hard, pierced ears. Therefore to burst pressure level and sound quality is more related to listen to the tempo of the sound pressure level best to 80 ~ 85dB (A weighted), we can hear the tempo to the speaker's distance and speaker features a sensitivity to calculate speaker's rated power and power amplifier power rating.
Power reserve match
Speakers: in order to enable them to withstand the programme signals in bursts of intense impact without damage or distortion. Here is an experience value may refer to: the selected speaker nominal power rating is calculated by the theoretical power of three times.
Power amplifier: tube amplifier and transistor amplifiers, the required power reserve is different. This is because the vacuum tube amplifier overload a gentle curve. On top of the musical signal, electron tube amplifier does not clearly clipping phenomenon, just to the top of the sophisticated variable round. This is what we used to say of flexible shear peak. The transistor amplifier in overload, nonlinear distortion rapidly increase, signal have severe clipping, it does not make the top variable round it neatly cut cut. Someone with resistors, inductors, capacitors, composed of composite of impedance analog speakers, on several high-quality transistor amplifier for the actual output capacity of the test. The results show that there is a phase-shifting load, including a logo that 100W amplifier, distortion of 1% is the actual output power only 5W! this for transistor amplifier reserves selection:
Gaobaozhengong placed: 10 times
Commercial-grade power amplifier: 6 ~ 7 times
Civil mid-range power: 3 ~ 4 times
While electronic tube power amplifier you can considerably less than the above ratio.
For the system's average sound pressure level and maximum sound pressure level shall be kept of the number of allowances. Should be considered broadcasting under the program's content, the work environment. The redundancy of minimum 10dB, modern pop music, playing music, such as di need 20 ~ 25dB redundancy so that you can make sound system security, stability and work.
Impedance matching
It refers to the amplifier's rated output impedance, and speaker impedance rating. At this point, the power amplifier is in the best design load line status, so you can give a maximum distortion power, if the speaker impedance rating is greater than the amplifier's rated output impedance of the amplifier's actual output will be less than the rated output power. If the sound is less than the rated impedance of the amplifier's rated output impedance of the audio system can work, but the power amplifier is in danger, call the overload power amplifier has a comprehensive over-current protection measures to address, on the tube amplifier, impedance matching requirements more stringent.
Damping coefficient of matching
Damping coefficient KD is defined as: KD = amplifier rated output impedance (equal to speakers rated impedance)/internal resistance power amplifier output.
Because of the power amplifier output resistance does become speaker of damping devices, we have decided the KD value sound damping of the electrical. KD the higher the value, the heavier the electrical resistance of course power amplifier KD value is not a better value than General Assembly, KD to speakers, ranging from electric damper overweight so pulse frontier establishment time growth, reduce the transient response indicators. So when you select the power amplifier should not be one-sided pursuit of KD value. As household gaobaozhengong on damping coefficient has an experience value of reference, the minimum requirements: transistor amplifier KD value is greater than or equal to 40, electron tube amplifier KD value greater than or equal to 6.
Ensure playback of steady-state characteristics and transient characteristics of good basic conditions, should pay attention to the speaker of the effectiveness of quality factors such as (Qm) and amplifier damping coefficient (KD), and this combined with the speaker of the feeder as part of the audio system as a whole. The speaker of the feeder equivalent resistance is small enough, small and speaker impedance rating is negligible in comparison. In fact, speaker feeder power loss should be less than 0.5dB (around 12%) to achieve this.