The most frequent obstacle

1. How to handle the antimagnetic problem in speakers?

We introduce in entire antimagnetic design for all our satellite speakers, which makes no side effect even place them beside the TV or displayer, but in order avoid the may happened magnetic interference or magnetization phenomenon due to using large magnetic steel in some speakers, we advise to place the speaker a little bit away from the displayer, what’s more, we can also obtain a good stereo enjoyment through doing this. Some SUBWOOFER SPEAKER do not use antimagnetic design, so please kindly to keep the speaker away from the monitor or TV more than 50cm.

2. Why speakers occur noise?

EARISE speakers have low noise characteristic. We should know that some sources (such as VCD/DVD/PC sound card) have background noise which is much louder than the voice comes from speaker’s amplifier. Once the noise occur, first we should unplug the audio input signal to check whether any noise heard out of 50cm, if not, then judge to be the problem of input signal, if does, then judge to be the problem of speaker, you should contact with the salesman to solve it  under this circumstances.

3. How to deal with the silent problem in speaker?

Please check if the power switch is opened, the outlet is in the electrifying state; Whether any signal output from the source, any problem happen to the connection cable.

4. Some speakers keep silent, how to deal with it?

First check if the audio cable is connected well, poor contact will cause the mono silent. Then exchange the audio plugs on the real panel, if the speakers can work normally, then means there has no fault in speaker basically, please remember to re-check whether other audio input signals is normal so that to make sure the speaker totally fine.

5. why only mono sound when connect with PC ?

It was generally due to the CD-ROM cannot match with the link of PC’s sound card, one of the signal occur earth short circuit. Please refer to the relevant instructions to re-arrange the connection pin order.

If you still have other doubt, please call the service phone of the company or to the dealer.

Dictionary for Speaker

1. [Hi-Fi]

A hi-fi is a set of equipment on which you play CDs and tapes, and which produces stereo sound of very good quality.

2. The main technical index of power amplifier.

1) Power output

A. Rated output power: RMS. It is the continuous sine wave signal power amplifier can put out

When the frequency characteristics of the amplifier and harmonic distortion coefficient can reach the technical specifications prescribed by (ordinary power amplifier distortion less than 1%, high-fidelity power amplifier distortion less than 0.1%)

B. The maximum output power of power: PM. It means the maximum output power of harmonic signal of the rated load resistor when under the condition that the amplifier can meet the demands of basic parameters.

C. The maximum useful rated power: It means the 10% distortion of output harmonic when input 1kHZ into the load resistor.s

D. Peak power: P.P. It means the power gained after Exchange rated output voltage into the peak voltage. Because the peak voltage is equal to 1.414 times the RMS voltage, so the peak power is equal to 2 times rated power.

E. Music power: MPO. It is the instantaneous output power when input dynamic music signal under the condition of no voltage drop on from power adaptor. The MPO output power is generally 4-6 times to the rated power of RMS.

F. Peak Music Power：PMPO. It is the gained power after convert the effective voltage into the peak voltage. So the PMPO is 2 times than MPO.

2) The total harmonic distortion (THD)

It is the comprehensive of various harmonic components caused by the nonlinear element caused after audio signal through power amplified. Usually it use the percentage of RMS new increase total harmonic components with the original signal effective value to represent. The THD of general amplifier is about 1.2%; high power amplifier is about 0.01~0.003%. The current method of measuring distortion is a single sine wave, which can not reflect the overall amplifier. The actual music signals is the comprehensive of different rates of composite wave, which including rate conversion, transient response and dynamic index. So some high-quality amplifiers sometimes will indicate the intermodulation distortion, distortion transient, transient intermodulation distortion parameters.

A. Intermodulation distortion (IMD): It is the gained intermodulation distortion factor from the load resistor, which is the result of inputting signal synthesis wave (combined 125Hz and 1kHz at the ratio of 4:1) from intermodulation distortion meter

B. The transient distortion (TIM): It express through the maintain ability of output waveform envelope when input the Fang Bo signal to the amplifier. Such as amplifier slew rate is not enough, the square wave signal which will produce deformation, and also caused transient distortion. This mainly reflected in the rapid mutation signals such as music, percussion, piano, xylophone, such as transient distortion is large, crisp tone will be vague.

C. The transient intermodulation distortion: It is the total intermodulation distortion effective value and the original sine amplitude percentage amplifier the input 3.15kHz square wave signal with 15kHz sine wave signal according to the peak amplitude ratio of 4:1. If the amplifier using the depth of giant negative feedback, the transient intermodulation distortion generally will be larger, specifically reflects sound dull, rigid, no telepresence; conversely, the sound will be smooth, delicate, natural.

3) Frequency response

Within the allowed range of frequency, it is the frequency range that the amplifier can repeat within the allowed amplitude range. We usually use dB to describe the uniformity of the ratio of the maximum and minimum output voltage within the rated frequency range. General amplifier frequency response is between 20Hz-20kHz (+ / -) l-3dB; high quality power amplifier frequency response is between 20Hz-20kHz about +/-0.1dB.

4) Signal to noise ratio (S/N)

It is the ratio between the rated output voltage and the measured noise voltage under no signal input., usually expressed in decibels. Signal to noise ratio: 301og (the rated output voltage and noise voltage) general efficacy of SNR is about 6O-90dB; Professional efficacy signal-to-noise should greater than 100dB to require.

3. Audio terminology

1) loudness

Sound intensity is called strength, which is composed of a rapidly changing amplitude pressure. But the subjective feeling of strength and the objective actual strength is not uniform, people call the subjective feeling of strength loudness, the units of measurement is DB (dB), which is based on the 1000Hz sound in different intensities of pressure ratio, commonly use 1 / 10 of the log koc to set the value. People have different feeling for the sound with equal strength but different frequency; The sound pressure level is higher, the audio frequency characteristics of human is flat; The sound pressure level is low, the auditory frequency range is smaller; The frequency F < 16-20Hz and F > 18-20KHz, no matter how high level, the ear cannot heard. Ear auditory frequency is between 20Hz - 20KHz, this we called audio frequency; The most sensitive frequency is between  3KHz - 5KHz. Most people cannot feel frequency below 3dB, so the sound system often base 3dB as to allow the frequency response curve range.

2) Tone

It is the signal with a specific and stable pitch, popular means sound level degree. It mainly depends on the frequency and the intensity of the sound. High frequency sound response to the human ear response is a high tone, low frequency response in the human ear is low pitch. Pitch with frequency (Hz) changes base a logarithmic relation. Different instruments playing the same frequency note in different timbre but the same tone, it means the fundamental frequency is the same.

3) Timbre

It is a distinguish feature between two different sound. Different instruments play the same tone with different timbre, this is because they have the same fundamental frequency but have different harmonic component. Therefore, the timbre not only depends on the fundamental frequency but also closely related to the harmonic wave, which makes each kind of musical instrument and every person have different timbre.

4) Frequency response

It is the frequency range that the sound system capable to replay, and the signal changes in this range, also called frequency characteristic. We usually use the Y-axis of db scale to represent power and use the abscissa of logarithmic scale to describe the frequency , and this two consist the frequency response curve. When the acoustic power lower than normal low power 3dB, the power point called the peak frequency response of the cutoff point and the low-frequency cutoff. The frequency between High frequency cut-off and low-frequency cutoff frequencies between, we name it the device frequency response or frequency characteristic; in this range the more flat frequency response curve is, the better the response is. Theoretically speaking, the 20 - 20O00Hz frequency response is enough. Below the 20Hz voice, although cannot be heard but can be sensed by other organs, this was called the capability that people are aware of bass strength. In order to perfect play all kinds of instruments and the speech signal, the amplifier have to achieve high-fidelity target, that can stream out the harmonic tones are reproduced perfectly. Therefore, expand the amplifier bandwidth to 20Hz below, upper limit should be increased to more than 20000Hz.

The signal source (radio head, deck and CD player) frequency response have different method to express. For example, FM stereo radio regulations of the European Broadcasting Union use the frequency response between the 40 - ten 15000Hz / 2dB, the International Electrotechnical Commission on deck specified frequency response minimum index: 40 - 12500Hz ten / - 2.5 / - ten 4.5dB (ordinary belt), but the actual achieved index are significantly higher than this value. For Laser phonograph it’s peak frequency response limit is 20000Hz, the low frequency can be very low, only a few Hz, which is one of the reason that laser phonograph playback quality is so good.

5) S/N ratio

It is ratio between Noise power under one pointed signal and inherent noise power output under no signal input, usually we use dB to describe. For example, the s/n of a tape recorder is 50dB, that means the output signal power is 50dB larger than the noise power. The higher the ratio ,the noise is small. The International electrotechnical commission minimum require that for the front set amplifier, the signal-to-noise ratio should greater than or equal to the 63dB , for the real set amplifier the S/N ratio should greater or equal to 86dB, for the combined amplifier should greater than or equal to 63dB. Combined amplifier signal to noise than the optimum value should be greater than 90dB; For Radiohead: 50dB FM stereo is fine, but in fact more than 70dB is preferred; 56dB for tape seat (ordinary belt) , but after the Dolby noise dealing , SNR is improved greatly. Such as after the B Dolby noise dealing, the signal-to-noise ratio will reach 65dB, by Dolby C the signal-to-noise ratio will reach 72dB (above refers to the ordinary belt); laser jukebox to-noise ratio can reach more than 90dB, the more high-grade above l10dB.

6) Dynamic range

It is the ratio between the strongest and weakest sound. Usually express in dB. For example, the dynamic range of a band is 90dB, which means that the weakest part of power is 90dB lower than the loudest part. Dynamic range is the power ratio, has nothing to do with the absolute level of sound. As mentioned before, the dynamic range of the human ear can hear is from 0 to 130dB. The dynamic change of voice range in the nature is great. The general language signal only have about 20 - 45dB, some Symphony dynamic range can up to 30 —130dB or much higher. But because of some restrict factors, the dynamic range of audio systems can rarely achieve dynamic range of band. Usually we set the dynamic range of the sound signal to be 0-100dB, therefore if the dynamic range of the audio equipment can reach to100dB, that will be perfect..

7) Stereo separation

Refers to the signal mutual interference ability between double channel, also means the isolation degree, usually expressed in D-level of electric level between one signal channel and the other channel which bear the leakage level. If the stereo separation degree is bad, then the stereo should be reduced. The Stereo separation minimum specifications made by IEC is: when the signal is 1kHZ, the stereo separation should greater than or equal to 40dB, and it will be better to reach to 60dB; Stereo separation degree of FM stereo radio of the European Broadcasting Union is > 25dB, and it will be better if can reach to 40dB. The balance of stereo channels reflect on  the left and the right channel gain difference, generally reflect in the max level output D-value of the left and right channel. If the imbalance is too large, the stereo image will deviate from the position, the indicators should be less than 1dB.

8) Damping coefficient

It refers to the ratio of amplifier rated load (speaker) impedance and the actual impedance of the power amplifier. The damping coefficient large means the output resistance of the power amplifier is small, the damping coefficient is the ability to control the loudspeaker cone body movement after the signal input fade out. For a amplifier with high damping coefficient is more like a short circuit, it will stop the vibration when the signal fades out. The output impedance of  the power amplifier will directly affect the Q value of the low frequency of speaker system, thus it will affect the frequency characteristics of the system. The speaker system’s Q value should not be too high, generally in the range of 0.5 to l will be better, the output impedance of power amplifier is the rising factors of Q value, so the output impedance of the power amplifier generally should be small, the damping coefficient should be high. The genera damping coefficient is about tens to hundreds, some professional power amplifier can up to above 2O0.

9) Output power

Various manufacturers will have different marking method for the output power amplifier, for example: rated output power, also known as RMS (sinusoidal RMS) power: refers to the index output power of total harmonic distortion of the amplifier when drive a 8O speaker Output within range of 20 to 20000Hz. Music power: refers to burst out barnyard power in a short time, generally 3 - 5 times the rated output power. The peak power: refers to the instant maximum output power, it is 8 - 10 times to the rated power.

4. Home theater audio system

1) CD

A digital music CD that made by Sony and Philips company jointly , it has 12cm in diameter and 8cm in diameter two specifications, the former is the most common, it can provide high quality music for 74 minutes.

2) CD-ROM

ROM CD for computer data storage.

3) VCD

It is a video that Using MPEG-1 compression coding technology, the sharpness of the image is almost like VHS video.

4) Super VCD

The improvement  VCD products, which use MPEG-2 encoding to improved the sharpness of image.

5) DVD

A kind of large capacity disk who‘s shape similar to the CD , it will be widely applied to high quality video recording and used as computer mass storage devices.

6) MD

A recordable CDs that made by Sony Corp, looking like a 3.5 inch floppy disks, but using the optical pickup system, similar to CD. MD uses efficient compression technology to achieve the recording time as CD , sound quality is close to CD.

7) D/A converter

A device that can exchange the digital audio signal into analog audio signal for digital audio products (e.g. CD, DVD). The D/A converter can be made as a independent machine, use to match with CD disk, we usually called it the decoder under this situation.

8) CD turntable

A machine that apart from the mechanical part of the CD machine.

9) HDCD

(high resolution CD) abbreviation -- an improved CD speech coding system, compatible with the traditional CD, but need to replay or connected to a HDCD decoder can achieve improved results in the HDCD decoding cd.

10) Dolby B, C, S

Series of tape noise reduction system developed by the United States Dolby Inc, for reducing the  "hissing" noise of the tape, and also extended dynamic range. Type B noise reduction system can reduce10dB, type C can reduce 20dB, type S can reduce 24dB.

11) Dolby HX Pro

It’s not the noise reduction system, but a technology that can improved high frequency distortion of the tape recording, also known as "dynamic headroom extension".

12) The AV power amplifier

A kind of amplifier that specifically for home theater use, generally have more than 4 channels and surround sound decoding function.

13) Receiver

A amplifier with audio function.

14) DTS

The Discrete-channel home cinema digital sound system, it uses 5.1 independent channels, it‘s effect even better than the Dolby digital surround sound system, is the strong competitors for the Dolby digital surround sound.

SRS

15) Frequency divider

A circuit device inside the speaker which is used to separate the input music signal into treble, tenor, bass, and then stream to the corresponding treble, tenor and woofer to playback.

16) Power amplifier

17) Power amplifier, an electronic device used to enhance the signal power to drive the sound system. Power amplifier without signal source selection, volume control was called PowerAmp

18) Rated power

The rated power generally refers to the effective value power that the amplifier can output continuously; For the speaker, rated power knowns as a speaker which able to afford this numerical without damage, this does not mean the speaker need so large power amplifier to push move, the complexity of drive the speaker mainly depends on the sensitivity and impedance Yet it does not mean that the speaker cannot be installed a amplifier with output power greater than speakers’ rated power. Let’s take car driving for example, driving 300 km per hour is not means there will definitely happen an accident, you can choose not to drive so fast. For the speaker, as long as you do not to increase the volume blindly, the high power amplifier can be equipped with a small power speaker.

19) Noise pollution

The opposite of the nature of music, it is the sounds which get some features from the outside environment, such as the sound that you speaker into a jar which is a typical noise pollution example. Noise pollution means that during signal playback the sound add some (or reduce) components, this is obviously a distortion.

20) Sound pressure

Representation of a physical quantity of sound intensity.

21) Sound pressure level

Expressed in decibels of sound pressure.

22) Sensitivity

The sensitivity of amplifiers generally refers to the input signal voltage when reach to the rated output power or voltage, also called the input sensitivity; For the speaker, sensitivity refers to DB value in front of a horn 1 meters away when input 1w into the speaker.

23) Burn machine

Preheating process before using the new electrical equipment, so that to make the equipment sound into a stable state.

24) AC（Alternating Current）

25) Alternating current, the power supply with a current direction that periodically change, it usually express in 60Hz in US and England, our country use 50Hz to express.

26) Fancier (Audiophile)

Those people show preference on the audio technology.

27) Band width

28) It means the frequency range that a sound system that can deal with or bear. For example, Dolby surround c, hannel’s bandwidth is 100Hz-7kHz. The frequency range that can be heard by the human ear is 20Hz-20kHz. When it comes to electrical or acoustic equipment bandwidth, it often refers to the frequency range between 0-3dB.

29) Bass

 Usually means the frequency that below 500Hz.

30) Blanketed

A treble shortcomings, especially in the sound box front hanging blanket, sound-absorbing material and sound to suck empty.

31) Rendering (bloated)

32) Refers to the bass is strong within 250Hz area. The damped harmonic oscillation is not enough for the low frequency and the resonance.

33) Ambiguous (blurred)

The transient response is poor, a stereo image is fuzzy and poor cohesion.

34) Muffled (boxy)

It means that heard music sounds like coming from a closed box and there occur some resonance. Sometimes it refers that the sound is a little bit strong within the 250-500Hz frequency range.