pls help

[ganapsin]

my amp has the following output as below
Power Output
90W + 90W Max., 60W + 60W RMS at 10% THD .
55W + 55W RMS at 5% THD, 50W + 50W RMS at 2% THD
and has separate Speaker Outputs 4, 8, 16 ohms.i cant understand wat 60W + 60W RMS at 10% THD means.pls any one explain me clearly

Thanks in Advance

 

[baijuxavior]

These links may help you to understand speaker impedance and Total Harmonic Distortion.

http://www.prestonelectronics.com/audio/Impedance.htm

What is Total Harmonic Distortion? - THD - Definition and Explanation of THD