What Are the Different Types of Tweeter Speakers?

The speaker is also called a "horn". It is a very commonly used electro-acoustic transducer, and it can be seen in sounding electrical and electronic equipment.

Speaker operation method

According to the place of use and the requirements of sound, combined with the characteristics of a variety of speakers to select speakers. For example, for outdoor voice-based broadcasts, electric horn speakers can be selected. If higher sound quality is required, electric speaker boxes or sound columns should be used: for general indoor broadcasting, a small speaker made of a single electric paper cone speaker can be selected. : And for the appreciation of music or for high-quality conference speakers, you should choose a speaker box with a combination of high and low speakers.

Pay attention to the following points when using speakers:

(1) The power obtained by the speaker should not exceed its rated power, otherwise, the voice coil will be burned or the voice coil will be scattered. The working voltage of electromagnetic and piezoelectric ceramic speakers should not exceed 30V.

(2) Pay attention to the impedance of the speaker and the output line. For details, refer to the section of the amplifier.

(3) Select the correct speaker model. If you use it in the square, you should choose a tweeter; if you use it indoors, you should choose a paper cone speaker, and choose a good speaker. The high and low speakers can also be made into speaker groups to extend the frequency response range.

(4) When arranging the speakers, make sure that the sound is even and sufficient. If a single (point) speaker cannot meet the needs, you can set multiple points so that each listener can get almost the same sound level and improve The clarity of the sound; with good orientation, the speaker should be installed more than 3 meters above the ground, so that the audience can "see" the speaker, and try to make the horizontal azimuth (sound source)-vision (speaker) as much as possible Consistent, and the distance between the two speakers should not be too large.

(5) The electric horn speaker must be put on the horn before it can be used, otherwise the sound head will be easily damaged.

(6) When two or more speakers are used together, attention must be paid to the phase problem. If it is reversed, the sound will be significantly weakened. The easiest way to determine the phase of the speaker is to use a high-sensitivity meter head or a multimeter's 50 ~ 250A current block, connect the test meter to the speaker terminal, hold the paper tray with both hands, and push it hard. Direction to determine their phase. If the phases are the same, the hands move in one direction. At this time, the voice coil lead-out connected to the positive test lead can be regarded as a "ten" level.

Speaker installation tips

The horn loudspeaker is still widely used in some markets in rural and urban areas. Once the sound film of the horn loudspeaker is lost, it is necessary to ensure the correct installation of the sound film. The following introduces a method that can easily solve this problem. Installation can be performed in two steps.

The first step is to select paper of appropriate thickness and cut two pieces of paper with a width of ~ 10mm and a length 20mm larger than the diameter of the center piece. Then place the two paper strips on the center piece perpendicular to each other (the position should be centered). To prevent them from moving, you can stick them with a little paste. Insert both ends of the paper strip into the magnetic gap. Align the voice coil on the sound film with the magnetic gap and gently press it down. Due to the existence of the paper strip, the position of the voice coil at this time is exactly in the middle of the magnetic gap without being deflected. Measure and apply universal glue on the edge of the sound film, and cover the top of the sound head. Align the screw holes and tighten the screws. And remember the relative position of the upper cover and the sound head in the appropriate position. Leave it for 8 hours. After the universal adhesive is completely dry, you can unscrew the screws and remove the upper cover. At this time, the sound film was stuck on the upper cover.

The second step is to solder the leads to the terminals. Remove the two pieces of paper, and then put the cover back on, paying attention to the mark made originally. At this time, you can use the multimeter R × block or 1.5V dry battery. While constantly touching the two terminals to make a click sound, tap the cover to the maximum click sound, and there is no friction sound. Gradually tighten the fixing screws. When tightening the screws, they should be tightened alternately, instead of tightening one screw, then tighten the second screw.

Speaker technical parameters

Speaker parameters refer to the specific performance parameter values of the speakers tested by the dedicated speaker test system. The commonly used parameters include: Z, Fo, 0, SPL, Qts, Qms, Qes, Vas, Mms, Cms, Sd, BL, Xmax, Gap gauss. The following are the physical meanings of these parameters.

Z:

Refers to the speaker's impedance value, including: rated inductive reactance and DC resistance. (Unit: ohm / ohm), usually refers to the rated impedance.

The rated impedance Z of the speaker is the minimum impedance mode value after the first maximum value of the impedance curve, that is, the impedance value corresponding to point B in FIG. 1.

Advanced speakers

It is the benchmark for calculating the speaker's electrical power.

DC resistance DCR: refers to the impedance value tested by passing a DC signal when the voice coil is stationary. We usually say 4 ohm or 8 ohm refers to the rated impedance. (ACR AC impedance: the resistance value measured under the voice coil dynamics)

Fo (lowest resonance frequency): refers to the frequency corresponding to the first maximum value of the speaker impedance curve. Unit: Hertz (Hz) The impedance curve of the speaker is a curve of the speaker impedance mode value measured with the constant current method or constant voltage method as a function of frequency under normal operating conditions.

0 (speaker efficiency): refers to the ratio of the speaker's output sound power to the input electrical power.

SPL (Sound Pressure Level): refers to the speaker when the voltage of electrical power with a rated impedance of 1W. At a point 1m from the horn on the reference axis. Unit: Sound pressure generated in decibels (dB).

Qts: The total figure of merit of the speaker.

Qms: The mechanical quality factor of the speaker.

Qes: The electrical quality factor of the speaker.

Vas (effective volume of the horn): refers to the volume when the sound pressure of the air enclosed in a rigid container is equal to the sound pressure of the speaker unit.

Mms (vibration mass): refers to the sum of the masses of the various parts of the speaker that are involved in the vibration during the movement, including the drum paper part, voice coil, and wave. Unit: Gram. And the air quality involved in the vibration.

Cms (force compliance ): refers to the compliance of the supporting components of the speaker vibration system. The larger the value, the softer the entire vibration system of the speaker. Unit: Millimeter / Newton (mm / N)

Sd (vibration area): refers to the effective vibration area of the drum paper / diaphragm during the vibration process of the speaker. Unit: square meters (m ² ).

BL (magnetic force): The product of the gap magnetic induction strength and the effective voice coil line length. Unit: (T * M).

Xmax: The linear stroke of the voice coil during vibration. Unit: millimeter (mm).

Gap Gauss: Gap magnetic induction. Unit: Tesla.

Speaker troubleshooting

Open circuit fault: The resistance between the two pins is infinite, it appears silent in the circuit, and there is no sound in the speaker.

Paper cone rupture failure: A direct inspection can reveal this failure, and the malfunctioning speaker should be replaced.

Poor sound quality fault: This is a soft fault of the speaker. Usually, no obvious fault characteristics can be found, but the sound is unpleasant. The faulty speaker must be replaced.

In the amateur condition, the speaker can only be tested by listening test and multimeter.

The audition test method is to connect the speaker to the output end of the power amplifier and subjectively evaluate its quality by listening to the sound.

Testing a speaker with a multimeter is also rough.

Measure DC resistance: Use R * 1 to measure the DC resistance between the two pins of the speaker. It should be slightly smaller than the nameplate speaker impedance under normal conditions. For example, the resistance measured by an 8 ohm speaker is normally around 7 ohms. The measured resistance is infinite, or much larger than its nominal impedance, indicating that the speaker has been damaged.

Listen to the sound of Karaoke: When measuring the DC resistance, disconnect a pin intermittently, you should hear a Karaoke sound from the speaker. The louder the better, the absence of this sound means the speaker voice coil is stuck .

Intuitive inspection: check the speaker for cracked paper cones.

Check the magnetism: Use a screwdriver to test the magnetism. The stronger the magnetism, the better.

Speaker influencing factors

International Environment

The current world economic situation is still grim, uncertain and unstable factors are increasing, and China's exports are facing increasingly strict trade protection policies of various countries. According to statistics from the Ministry of Commerce, in 2011, China's export products suffered 69 trade remedy investigations, involving a total of 5.9 billion US dollars, of which the United States and China have the most frequent trade frictions.

Although foreign trade is facing a more complicated and severe situation, the core competitive advantages of China's manufacturing industry will not change significantly in the short term, and the effects of a series of policies and measures that promote stable economic growth and promote foreign trade and expand imports will gradually emerge. The world economic situation, especially the European debt crisis, will no longer continue to deteriorate. In 2012, the foreign trade of China's speaker industry is expected to achieve the planned growth target of 10%.

Downstream related industries

As a supporting industry of home appliances, computers, mobile phones, automobiles and other industries, speakers are closely related to its development. According to estimates by the China Electroacoustics Association, it is estimated that by 2015, 450 million speakers will be required for televisions, especially high-definition digital flat-panel TVs will begin to spread, which will bring new opportunities for the development of speakers; 200 million speakers are required for home theater and combined audio Only 150 million speakers are needed for car audio; 365 million speakers are needed for microcomputer multimedia systems. Driven by national policies, China's domestic demand market will be released, and home appliances, computers, mobile phones, automobiles and other industries will maintain a rapid development trend, and the speaker industry has a good development prospect.

Technical factors

3G applications are becoming more and more popular around the world. New products such as Internet TVs, smartphones, tablets, and netbooks continue to appear, which will drive the demand for miniature speakers / receivers.

Consumer electronics are developing in the direction of multifunctionality, personalization, portability, and high-fidelity, which promotes the development of miniature electro-acoustic components in the direction of ultra-miniaturization, digitalization, integration and modularization. Like consumer electronics, miniature electro-acoustic components have shorter and shorter life cycles, faster and faster replacement, and increasing market demand for miniature microphones and miniature speakers / receivers. ^[4]