Tips And Precautions for Matching Amplifiers And Speakers

                Tips and precautions for matching amplifiers and speakers

Regarding the matching problem between power amplifiers and speakers, in addition to the soft matching of timbres (timbral matching is often divided into soft and hard, which are based on the characteristics and personality of the designer's design and materials for the timbre trend), there are also some technologies A hard match on the indicators. Soft matching is based on the accumulation of experience and personal preferences based on actual feelings, while hard matching is determined by data and basic technical knowledge. The following is a brief introduction to the issues related to hard matching.

Impedance matching

1. When the vacuum tube power amplifier (tube amplifier) is matched with the speaker, the output impedance of the amplifier should be equal to the speaker impedance, otherwise the output power will be reduced and distortion will be increased. Fortunately, most amplifiers have variable output impedance matching interfaces such as 4-8-16 ohms, which makes impedance matching with speakers easier.

2. For the matching of transistor amplifier (stone amplifier) and speaker impedance

A) When the speaker impedance is higher than the output impedance of the power amplifier, there will be no other impact except that the output power will be reduced to varying degrees.

B) When the speaker impedance is lower than the output impedance of the power amplifier, the output power increases proportionally, and the distortion generally does not increase or the increase is negligible. However, the speaker impedance cannot be too low when matching, such as as low as 2 ohms (referring to two 4 ohm speakers in parallel). At this time, only the power amplifier has a large amount of power, and high-power tubes and multi-tube parallel push-pull tubes with good performance are used. , generally has no effect on such power amplifiers. On the contrary, generally, the power of ordinary power amplifiers is not large, and the PCM and LCM of the power amplifier tube are not large. When the volume is turned up very high, the distortion will increase significantly, and in serious cases, the box may be destroyed, so be careful.

Power matching

1. In principle, when the rated power of the speaker is inconsistent with the rated power of the power amplifier, the power of the power amplifier is only related to the impedance of the speaker and has nothing to do with the rated power of the speaker. Regardless of whether the power of the speaker is the same as that of the power amplifier, it has no impact on the operation of the power amplifier, but is only related to the safety of the speaker itself.

2. If the impedance of the speaker meets the matching requirements and the power it withstands is smaller than the power of the amplifier, then the driving power is sufficient and the sound is very comfortable. This is often said that the reserve power of the power amplifier must be large in order to fully express the full connotation of music, especially the low-frequency part of the music, which will be more vivid and powerful. This is a better match.

3. If the rated impedance of the speaker is greater than the rated power of the power amplifier, although both can work safely, the driving power of the power amplifier is not enough at this time, and the loudness will be insufficient. It often appears that it has reached saturation, the distortion is aggravated, and you still feel Powerless. This is a poor match.

Match by damping coefficient

When choosing a pair of Hi-Fi speakers, there should be the best specific resistance damping requirements (responsible speaker manufacturers should provide this data, which refers to the requirements for the power amplifier damping coefficient. To make it clear, if you want to match this Speaker, what is the required damping coefficient of the power amplifier it is equipped with?). Generally speaking, a higher damping coefficient of the power amplifier is better. When the damping coefficient of a low-end power amplifier is less than 10, the low-frequency characteristics, output characteristics, and high-order harmonic characteristics of the speaker will deteriorate. (The damping number of home power amplifiers is generally between tens and hundreds.)

Wire matching

There are various types of fever cords, ranging from more than 10,000 yuan to thousands to several thousand yuan (of course there are also those under 100 yuan). The effectiveness of their use is a matter of opinion. Good wires will generally improve some deficiencies in audio equipment. Its transmission theory is too complicated to describe and can only be briefly described. The material and structure of the transmission line determine three important parameters, namely resistance, capacitance, and inductance (as well as electromagnetic effect, skin effect, proximity effect, reactance, etc.). Regardless of the small differences in these parameters, they will directly affect the frequency of the audio system. Characteristics, damping characteristics, signal rate, phase accuracy, as well as timbre orientation and sound field positioning, etc. Its main functions are high-speed transmission (minimizing signal loss as much as possible), anti-vibration, anti-noise, and anti-interference (mainly radio wave RFI radio frequency interference and EMI electromagnetic wave interference, etc.)