How much power does my amplifier need?
How much amplifier power you need depends on the speakers you use, the size of the room and how loudly you want to play.
Amplifier power is usually specified in watts per channel.
What affects the power requirement?
Speaker sensitivity
High-sensitivity speakers normally need less power to reach a given sound level.
A low-sensitivity speaker may need considerably more power to play equally loudly.
Room size
In larger rooms and at longer listening distances, more power may be needed to reach the desired sound level.
Listening volume
If you mainly listen at moderate volume, you normally need less power than if you want to play very loudly.
Musical dynamics
Music and films often contain brief peaks that require considerably more power than the average sound level.
An amplifier with sufficient power headroom can handle these peaks without significant distortion.
Is 50 watts per channel enough?
For many common speakers and listening situations, 50 watts per channel can be quite sufficient.
In other situations, such as with low-sensitivity speakers or at high sound levels, a more powerful amplifier may be suitable.
There is therefore no wattage that suits everyone.
Are more watts always better?
No.
The amplifier’s ability to handle the speakers’ impedance, deliver current and reproduce sound without distortion is also important.
It is also important to compare power specifications under equivalent conditions.
An amplifier rated at 100 watts into 4 ohms cannot be directly compared with another rated at 100 watts into 8 ohms.
How do I know which amplifier is suitable?
In particular, check:
The speakers’ impedance.
The speakers’ sensitivity.
The manufacturer’s recommended amplifier power.
The amplifier’s power at the relevant impedance.
The room size and desired sound level.
Tip: It is often better to choose an amplifier with sufficient power headroom than to push a weaker amplifier into severe distortion.