Choosing the right receiver amplifier
Selecting an amplifier or receiver that provides continuous watts (sometimes referred to as “RMS”) in accordance with the speaker’s continuous power handling rating will provide you with the optimal balance of power and performance.
To give you an example, the Klipsch RP-8000F is a floorstanding speaker with a nominal impedance of 8 Ohms and a continuous power rating of 150 Watts.
It would therefore be OK to use any receiver or amplifier that delivers around 150W per channel at 8 Ohms with a complete frequency bandwidth of 20Hz to 20,000Hz.
To guarantee that your speakers are not damaged, Klipsch recommends that the AV receiver or amplifier you choose has a continuous power handling rating of no less than 80% and no more than twice the recommended continuous power handling.
For example, the RP-8000F requires an AV receiver with a bare minimum of 120W per channel (8 ohms) and a maximum of 300W per channel (for the highest quality sound) (8 ohms).
Never be fooled by a speaker’s peak power rating; although it can be much greater (600 Watts in the RP-8000F, for example), remember that peak power represents only a brief period of exposure to sound.
To expect any speaker to perform at peak power for more than a split second is to invite failure. This is especially true for high-powered speakers.
The use of the proper amplifier, one whose power is well-matched to the speakers, will also eliminate the need to overdrive the components in question (play them too loud).
Over-driving, on the other hand, can result in clipping, which distorts the signal and can cause major damage to the tweeter or even the woofer if done repeatedly.
Furthermore, believe it or not, under-powered speakers may inflict just as much damage as over-powered speakers when it comes to sound quality.
Using an under-powered system at high volume, for example, increases the likelihood of damaging or blowing out the tweeter(s).
So, just make sure that the power output rating of your receiver/amp is approximately equal to or more than the continuous power rating of your speaker.
If you have numerous speakers in your system, each with a different power rating, you will want to determine the output power rating of the receiver based on the power rating of the speaker with the highest power rating in your system.
This will most likely be your front left, front right, or even your center channel speaker in most situations
However, it is critical that the RMS power of your chosen receiver is not more than double the minimum continuous power of the smallest speaker, unless otherwise specified.
This is why it is critical to ensure that the size and power handling of the speakers in your system are not radically different.
Klipsch horn-driven speakers, for example, are significantly more energy efficient than their direct radiating counterparts and require significantly less power to provide excellent sound.
Maintaining the receiver’s output in precise alignment with the speaker specs will assure years of trouble-free functioning.