8121C Noise Generator

Model-8121C generates " Pseudo Random Noise " by using Digital Technique, this is the most advanced method for generating the audio white noise.

The conventional noise generator practically generates only the white noise & pink noise, it needs to combine with weighting filter、power amplifier and true rms voltmeter ( a total of 4 circuits) before it can be used to test the loudspeaker. 8121C consists of all the aforementioned 4 circuits, it can generate pink noise, white noise & 3 other kinds of weighted noise that comply with the standards of the countries mentioned .

If special noise spectrum is needed, the user can insert a self-made weighting filter between the noise signal output and power amplifier input terminals.

1. Continuously load test of the loudspeaker, headphone、speaker system and crossover.

2. Defines the rated input power of the under testing sample based on the result of continuously load test.

3. Injects noise signal to the loudspeaker , for measuring the sound pressure sensitivity ( dB value ) of the loudspeaker.

4. Measures the frequency response curves of the loudspeaker by combining with the Audio Spectrum Analyzer.

Model-8121B is the old Model, which have already ceased to produce , it is now being replaced by Model-8121C. The only difference between the Model-8121C and Model-8121B is Model-8121B uses the old EIA 426A standard weighting filter (EIA-426A have been abolished) ; while 8121C uses the weighting filter that complies with the newly required EIA 426B standard. Sunlight also provides: Model-8121FT-1C Noise Filter, which complies with IEC-268-1C specification. (It must combine for use with either Model-8121B or Model-8121C).　

Model - 8121FT - 1C

Model-8121FT-1C is the weighting filter being made in accordance to IEC-268-1C specification, it should be combined for use with Sunlight’s Model-8121C / 8121B ( 8121B is old model ) Noise Generator, to generate the weighted noise that complies with IEC-268-1C specification, thereby to undergo life test of the loudspeaker and to define the rated power of the loudspeaker.

Specifications of Model - 8121C

Noise Type :

1. White Noise:

-3dB Bandwidth : 20Hz～100 kHz

Roll off : -24dB / Oct.

Flatness : ±1dB

2. Pink Noise:

-3dB Bandwidth : 20Hz～20 kHz

Roll off : -24dB / Oct.

Crest factor : 4 ( IEEE 219 )

3. Weighted Noise Ⅰ:

Complies IEEE 219, CNS 4785,

IEC 268-5, JIS C5531.

4. Weighted Noise Ⅱ:

Complies EIA RS426B

5. Weighted Noise Ⅲ :

Complies DIN 45573.

Voltmeter :

True rms response with Hi / Lo two ranges:

	Lo	Hi
100 W	0 ～ 6 V	0 ～ 30 V

Accuracy : ＜ ± ( 1% rdg. ＋ 0.5% F.S. )

Amplifier :

1. 100W output is defined at unclipped maximum output of sine

wave.

2. Frequency response : 20 Hz ～ 20 kHz ±0.2dB

20 kHz ～ 100kHz ± 1dB

3. Output : With permanent short circuit protection.

Load Impedance : ≧ 2 Ω.

Sunlight also provides : Model-8121FT-1C Noise Filter, which complies with IEC-268-1C specification . It must combine for use with either Model-8121B ( old model ) or Model-8121C .