The Installation image for reference
Circuit design for reference
Here is the test waveforms:
Test conditions: Two 24V/400W cattle, 8 ohm resistive load, AP professional tester, computer.
Many of my friends do not understand the AP instruments, professional audio companies or laboratories
will be some local noise and frequency response, total harmonic distortion oscilloscope FFT, etc.
These are not competent to complete the full by the AP, the product is good a scan immediately see seen.
Amplifier board test conditions: left and right channel volume, subwoofer volume and total
volume potentiometer adjustment Max:
Frequency response of a left and right channels: left and right channel volume knob
adjust the treble and bass maximum can be seen in the curve below 500Hz and above 3KHz
larger gain adjust left and right channel bass response and consistency are very good.
Left and right channel frequency response two: left and right channel treble knob
largest bass volume knob adjust the minimum, the curve shows the bass and treble is attenuated increases.
Left and right channel frequency response three: left and right channel treble knob smallest,
largest bass volume knob, empathy increases treble bass is attenuated
Left and right channel frequency response four: left and right channel volume knob adjust
the treble and bass minimum, 500Hz 2KHz more bass and less treble attenuation reserved Alto
Corresponding to the left and right channel output power of distortion: the abscissa is the output power,
the vertical axis is the output power level corresponding to the amount of distortion,
distortion power of 80 W, 0.03% of distortion is essential in the human ear
can not perceive the noise, the letter noise ratio is very high.
Left and right channel FFT (1KHz): FFT can measure the noise floor products,-80dB less
ear close to the speaker can only hear a small hum,-90dB is basically the human ear
can not hear any noise of exchange.
Low audio sound: 50Hz-150Hz frequency range frequency response is perfect,
so the frequency response of the subwoofer is connected to hear any of the human voice.
Subwoofer output power corresponding distortion: distortion power of 160 watts,
it is worth mentioning is that this section of the upgraded version of the original bass
distortion ratio is much smaller shop that paragraph, an upgraded version of the bass
more powerful, higher signal to noise ratio, you can understand the contrast curve.
Subwoofer FFT: BTL subwoofer is pure DC feedback circuit, knowledgeable friends
appreciate subwoofer speaker is eating power, and pure DC feedback circuit is characterized by intensity,
but the distortion would be loss (relative voltage feedback), the most important indicator
is the subwoofer power and intensity.