Hello Lorenz Meier，
Thank you for writing in.
80W+80W is the output power of dual channel.
If you want to have 80W+80W output power, the input voltage should be DC 34V and the independence of the speaker should be 8Ω.
Here are the parameters of the product:
Features:
Amplifier chip: TDA7498
Output power: 100W+100W (Vcc = 36 V, RL = 6Ω, THD: 10%)
Output power: 80W+80W (Vcc = 34 V, RL = 8Ω, THD: 10%)
Wide range single power supply: 15-34VDC(recommended 24V)
Applicable speaker impedance: 8 ohm best(4 ohm or 6 ohm also works)
Four fixed gain settings available: 25.6 dB, 31.6 dB, 35.1 dB and 37.6 dB
Adopts differential input to minimize common-mode noise
Protection: short-circuit protection, over temperature protection
With standby and mute features
High efficiency: 90%

Description:
The TDA7498 is a 100W+100W dual-BTL class-D audio amplifier with single power supply designed for home theater and active speaker applications. It adopts 36-pin PowerSSO packaging with exposed pad up (EPU), more convenient to mount a separate heatsink.

Mode:
The TDA7498 has three kinds of modes: standby, mute and normal working mode(you can set the mode by shorting the pins shown on pictures).
Standby mode: all circuits closed, at a low power state;
Mute mode: all input signals connects ground, the duty cycle of forward/backward PWM output signal is 50%;
Normal working mode: the amplifier works normally.

Hope this can help you.
Best regards