you oughta look closer at what they base their statements on.
Or is the specification determined when all channels are driven simultaneously?
These represent the widest frequency range that a human can possibly hear.
D&M Holdings / Sound United
However, that doesn’t take into account the amplifier’s power output capability when all channels are driven.
In a home theater receiver, not all channels require the same power at the same time.
Variations in audio content affect the requirements for each channel at any given time.
Based on those conditions, a power specification rating phrased in context is more practical to real-world conditions.
This is more than enough for an average size living room.
This represents a very clean sound output.
Decibels
Sound levels are measured inDecibels (dB).
Our ears detect differences in volume level in a non-linear fashion.
Ears become less sensitive to sound as it increases.
Decibels are alogarithmic scaleof relative loudness.
An amplifier rated at 100 WPC is capable of twice the volume level of a 10 WPC amp.
An amplifier rated at 100 WPC needs to be 1,000 WPC to be twice as loud.
This follows the logarithmic scale mentioned above.
An amplifier that exhibits excessive noise or distortion at loud volume levels can be unlistenable.
Distortion specifications are expressed by the termTHD (Total Harmonic Distortion).
However, when comparing distortion ratings between amplifiers orhome theater receivers,things can get cloudy.
Signal-to-Noise Ratio (S/N)
Another factor that affects amplifier quality isSignal-to-Noise Ratio(S/N).
This is a ratio of sound to background noise.
In amplifier specifications, S/N ratios are expressed in decibels.
An S/N ratio of 70 dB is more desirable than an S/N ratio of 50 dB.
This is important in home theater applications, where extreme changes in volume and loudness occur during a film.
This specification is expressed asDynamic Headroom.
Dynamic Headroom is measured in decibels.
The Bottom Line
When shopping for a receiver or amplifier, be wary of wattage output specifications.
Plus, pay attention to theefficiencyandsensitivityof thespeakersyou use.
An amplifier or receiver may be the centerpiece of your audio orhome theater system.
Base your buying decision on what you hear with your ears and in your room.
