Choosing the correct amplifier/receiver/AVR
Amplifier is an essential element of a passive speaker system. The speakers will not work without one. The amplifier choice will impact the volume potential and audio quality of the system.
Amps will vary in amount of speakers they can run - single channel mono blocks, 2 channel stereo amps, multichannel amps, integrated amp.
Amplifier topology - Amplifiers design principle in how it delivers power to the speaker. Below is a largely generalized basic difference between the amplifier types - as there are excellent hi fidelity amps in every design option available these days.
- Class A design is the least efficient but has the highest sound fidelity.
- Class B design is a little more efficient, but has a lot of distortion.
- Class AB design packs a punch with power efficiency and superb sound.
- Class D design offers the highest efficiency but isn't quite as high-fidelity.
You want to choose an amplifier that -
- has the correct amount of channels to power up all of the passive speakers in your setup.
Each passive speaker in the setup should be connected to a dedicated amplifier channel. Ex. if you have 2 speakers to power a stereo amplifier would work. 5.1.4 atmos setup will require a 9 channel amplifier.
- has enough power to drive the speakers that you have to the desired volume.
You want to have enough power output to drive the speakers in your setup to a desired volume without the amplifier overloading. This will depend on a few factors - Speaker efficiency, distance from the speakers to the audience perspective and personal preference.
Most amplifiers will operate best below 70-80% of their max output capacity. Beyond that the amplifier may overload and distort/clip.
This state, when the amplifier is overloaded and is working close to its peak range of output - can cause issues resulting in passive speaker component damage/amplifier damage.
One of the most recommended ways to match the power is choose the amplifier that slightly exceeds the RMS power handling of the passive speaker connected to it - this way the amplifier will be able to drive the speaker to its full volume capacity but that isn't always necessary.
Lower powered amplifiers (5-50watts per channel) can work safely with speakers that have high power handling ratings as long as the amplifier is not pushed beyond its distortion point. This may work well for some users especially with high efficient speakers.
- Matches the impedance range to drive the desired speakers.
Mismatching the impedance between speakers and amps can create too much of a load for the amplifier, causing it to overheat and stop working. Make sure the speakers impedance matches the amplifier impedance range. If the amplifier has selectable impedance - match the speakers posted impedance.
Example - you don't want to run a 2 Ohm impedance speaker with the amplifier capable of running 4-16Ohm speakers.
Understanding power ratings with multichannel receivers.
Commonly multichannel receivers will have several power ratings posted. We recommend using the 2 channels driven 20hz-20Khz power rating as it is most common scenario the system will be ran(even it is a 5+ channel system).