These two RC networks are for stability purposes. The speaker being inductive will have a high impedance out of band at the high frequency end. The resistor in parallel clamps the maximum impedance to the resistor value.
These two RC networks are for stability purposes. The speaker being inductive will have a high impedance out of band at the high frequency end. The resistor in parallel clamps the maximum impedance to the resistor value.
The term "clamps" doesn't fit the circuit function exactly, I think. The impedance of the RC circuit get's real above the characteristic frequency of about 1.6 MHz, it cancels a partly negative output impedance of the amplifier. The dampening circuit got known as bocherot cell, see this refernce: Boucherot cell - Wikipedia, the free encyclopedia
I mean that it limits the impedance. Any impedance in parallel with one ohm will be less than one ohm. This occurs at higher frequencies where the series capacitor looks like a short circuit.