Product Specifications
Product Overview & Control Functions
Operation Steps​
Warranty Information
About Fosi Audio

Product Specifications

Thank you very much for choosing our products! Please read this manual carefully before using the product.  

Max Power

100W*1 2Ω


Full frequency response



The speaker matches the impedance




Output 1W @ 0.03%





Input sensitivity



Product Dimension



Bass cutoff frequency range adjustment






Slope of bass attenuation

-12dB Slope


Package Size                                                     L257*W215*H65MM


Product Overview & Control Functions

  1. Turn on/Off.
  2. Power Light.
  3. Full frequency/bass working mode switcher.
  4. Bass cutoff frequency control knob. (the knob only works in bass mode)
  5. Volume knob. (increase clockwise and decrease counterclockwise)
  6. Audio input interface. (for example, CD, DAC decoder, mobile phone, TV, red to right channel input, white to left channel input)
  7. Subwoofer output. (Connect the active subwoofer,Synchronous output with power amplifier)
  8. Speaker interface. (red positive terminal, black negative terminal)
  9. Power interface. (DC power shall not exceed 35V)

Operation Steps​

  1. Make sure the VOL button to the minimum.
  2. Connect the speaker according to the rear board interface, and distinguish the positive and negative poles.
  3. Connect the audio source you want to use.
  4. Connect the power.
  5. Select the required working mode (PBTL or SUB).
  6. Press the switch.
  7. Turn the knob clockwise to select the required volume.
  8. Under SUB operating mode, the bass cutoff frequency can be changed by adjusting the SUB FREQ knob.
  9. The gain parameters of the switch with gain adjustment can be selected according to the following parameters.


1: All cables are connected, but no sound output?

  • Check if the POWER indicator is on, and turn on the POWER if it is not on. When the indicator light is still not on after turn on the power, you can find a laptop power and connect to test whether it is the machine fault or a power failure.
  • If the indicator light is on, check whether the VOL knob is in the minimum position. If so, turn clockwise to normal Volume
  • If both of the above are normal, check the input device if it is paused, mute, or the volume is minimized.

2: Why does the sound break?

  • when the output power exceeds the normal power of amplifier, there will be a large distortion. You can turn down the front volume or the power amplifier volume, then it is ok.

3: Why do loudspeakers make a lot of electric noise?

  • If you are not using the original factory standard power supply, please replace the power supply before testing. Many power supply in the market have large interference coefficient, which willcause a lot of current sound.

4: Why connect signal line, not play music have interferential sound?

  • If you use unshielded signal lines, there will be interference signals entering the power amplifier. If you hate the sound, you are advised to use the shielded signal lines or unplug the signal lines.

5: Why does the amplifier stop working after a period of time? After a period of time off, it was working again?

  • Normally in this case, the amplifier is overheat protected, and the output power may have exceeded the designed power, so you can lower the volume a little and try again.

6: why does the volume of the machine stay the same, while the sound of different audio sources (such as CDS and mobile phones) is different?

  • The output range of different types of audio source devices is different, the mobile phone is usually 0.35mV, and the CD is 1V.The signal output amplitude of the sound source will directly influence the volume.

7: Why the sound of the power amplifier is not very good at the beginning, the high frequency is not clear, but after working for 8 hours the sound is normal?

  • Speaker and amplifier is a very sensitive equipment, also need to know each other, and the matching process, usually the sound will be good after the new power amplifier and the speaker work more than ten hours.


1. Please do not open the shell without permission. Improper operation may cause the danger of electric shock.
2. Please use the power supply of the regular manufacturer, otherwise it will damage the machine.
3. Please do not use the machine in a high temperature and humidity environment.

Warranty and Maintenance

  • All Fosi Audio products have an 18-month limited warranty on parts and labor from the date of purchase. Please contact us if you have any problems.

About Fosi Audio​

  • Fosi Audio designs and builds innovative audio products with all your music in mind. Great sound, simple but elegant designs, high-quality materials, and truly useful features are what Fosi Audio is about. We sincerely hope you get as much enjoyment from our products as we’ve had to create them!

Our website: www.fosiaudio.com

Amazon store: www.amazon.com/fosiaudio 

Our Youtube channel: Fosi Audio

Our Facebook page: Fosi Audio

WhatsApp: +8613716612254

Call us: +49 33389171782

After-sale Service and Technical Support Email:  support@fosiaudio.com