Gaz37 said:
So what is the quoted 20hz - 20khz?
Specifications Power output: 80 watts per channel into 8Ω (stereo)
Frequency response: 20Hz to 20kHz
Total harmonic distortion: 0.005%
Damping factor: 70
Input sensitivity: 0.2mV (MC), 2.5mV (MM), 150mV (line)
Signal to noise ratio: 74dB (MC), 93dB (MM), 108dB (line)
Output: 150mV (line)
Dimensions: 420 x 435 x 162mm
Weight: 14kg
Finish: black (A-616), silver (A-616S)
Year: 1988
That is the FTC* standard for declared power. 80W RMS at 8ohms, measured at 20Hz-20kHz, both channels driven, with no more than 0.05% THD.
Measured at 1kHz it may produce 100W RMS at 8ohms both channels driven with 0.05% THD. Measure just one channel driven, you get even more power output. Go higher in distortion, you get even more. Measure at 4ohms, even more power. If you really want to fool the kids don't use RMS but PMPO power. Suddenly you have a rubbish boombox doing 1400W on paper. The FTC standard serves so manufacturers don't overhype the specs and fool the customer. Everyone should declare the FTC standard first so the customer has a comparable data for all competing products. Then manufacturer can specify whatever they want, bloated specs, brag about real performance etc.
The power bandwith specification shows us the full capability of the amp, beyond that 20Hz-20kHz FTC standard.
Pioneer A-656 will do 5Hz-80kHz at 8 ohms with no more than 0.05% THD at rated power (80Wpc RMS).
*FTC - Federal Trading Commissions (US), Competition Bureau (Canada), ASA - Advertising Standards Authority (UK)