Considerations in choosing an amp
When choosing an amplifier for a loudspeaker system, there are a number of factors to consider.
It is important that the power rating of the amplifier not be too low; otherwise you will not be able to utilize the full SPL potential of the loudspeaker system.
A low power amplifier with inadequate power can actually damage loudspeakers by being driven into clipping. Clipping occurs when an amplifier is asked to produce output beyond its designed limits.
When an amplifier undergoes severe clippings, DC voltage is produced when a sine wave or complex wave (AC) is cut off at the electrical ceiling and floor of an amplifier. The power output is doubled.
The DC voltage will heat up the voice coil of the loudspeaker causing the glue, holding the voice coil to melt; the voice coil itself will exceed its thermal limitations and will expand. This expansion will cause it to get stuck in the voice coil gap.
Also it is important that the power rating of the amplifier not be significantly more than the loudspeaker can handle because it becomes easy to destroy the loudspeaker with excess power or with excessive excursion causing the driver to “bottom out”.
The amplifier must be able to drive the collective load of the loudspeakers if it is connected in a series or parallel or series-in-a-parallel connection. The impedance of each individual loudspeaker & the NET load impedance must be calculated.