You'll need a receiver or an amplifier to power the speakers of your home audio or home theater system. To narrow down your choices, answer a few key questions.
A receiver is an amplifier that includes a radio tuner and a preamplifier section. You can connect a variety of source components and at least two speakers. There are three different categories from which to choose:
A home theater receiver (also known as an A/V receiver) supplies at least five channels of power for surround sound setups. It also provides video processing and at least one HDMI output for your TV.
A stereo receiver has two channels of amplification for left and right stereo speakers. It also has an AM/FM tuner, of course. But these days, you're likely to also see multiple analog and digital audio inputs, and Wi-Fi and Bluetooth connectivity. Most models can power a second set of speakers, too.
These are home theater receivers that can power speakers in at least two different rooms or "zones" — one surround sound zone and one or more zones of stereo sound.
Why get a separate amp and preamp when you can get a receiver that includes both functions? The short answer is that you can get better sound and more system-building flexibility.
An integrated amplifier is two components in one — a power amp that drives your speakers and a preamplifier for your music source components. The preamp lets you select your sources and control the volume.
Hi-fi stereo amps are for high-performance stereo music systems. They can be used in surround sound systems, though multi-channel amps might make more sense for that purpose.
Monoblock amps have just one channel. Some models are designed to drive a passive subwoofer. Others are meant for audiophiles who like to use a separate amp for each channel of their system.
Multi-channel home theater amps are the companions for surround sound preamp/processors. You'll need at least five channels for a surround system. You can choose a powerful 3-channel amp to drive the front left, right, and center channels. Your surround speakers, which may require less power, can have their own 2-channel amp. If you want to keep things simple, get one amp with enough channels to drive all of your speakers.
A stereo preamp includes connections for your source components, as well as tone, balance, and volume controls. There's a switch to select the component you want to play. Some models include a built-in network music player.
Think of a surround sound preamp/processor as a home theater receiver without the built-in amplifier. It does the video processing, surround sound decoding, input switching, and audio signal processing. Most models come with built-in room correction software that helps fine-tune the sound.
Multi-zone amps are building blocks for a multi-room system. You get at least two channels of power. Some models include as many as 16 channels. Many models include connectors for remote control, power triggers, and infrared signal transmission.
How many watts do you need? Wattage ratings and maximum volume are only loosely connected. For example, a 200 watt amplifier will only play a mere 3 dB louder than a 100 watt amplifier — a barely noticeable difference. To play twice as loud as that 100 watt amp, you would need one with 1,000 watts, a ten-fold increase in power. Look at the recommended power range for your speakers and choose your amp power accordingly.
Many receivers work with multi-room music platforms that let you stream music to compatible wireless speakers you have set up throughout your home. You can create different zones and control what's playing in each room with an app on your phone or by using voice commands.
Bluetooth® lets you enjoy wireless music streaming from any compatible smartphone, tablet, or computer. Some receivers and integrated amplifiers have this feature built in, while others may offer it as an add-on option.