Stereo and AV Receivers: Channels and Inputs

Two channels or seven: sizing a receiver to your speakers

Channel notation tells you how many speakers an amplifier can drive. In 7.2 or 9.2, the first number counts amplified speaker channels and the second counts subwoofer outputs, so a 7.2 receiver powers seven speakers and feeds two powered subwoofers. A two-channel stereo receiver suits a pair of speakers and music listening. A multichannel AV receiver adds surround decoding for films and lets you grow from 5.2 to more speakers later, but a small room rarely benefits from channels you will not place.

Power ratings are only comparable when impedance and the number of driven channels are stated. Check the speaker impedance, usually 4 to 8 ohms, against what the receiver supports, and favor headroom if your speakers are inefficient or your room is large. Full-size models are about 17 inches wide and need open space above for cooling, while the small Bluetooth receiver boxes and headphone amplifiers in this category do not drive speakers at all.

Phono, HDMI and Bluetooth: the inputs that decide daily use

Count the sources you own before you count watts. A turntable with a moving-magnet cartridge needs a receiver with a phono input, which the spec list may describe as phono to line level conversion, unless the deck has a built-in preamp or you add a separate one. For a TV, look for HDMI inputs and an ARC or eARC port, which sends TV sound to the receiver over the same cable that carries the picture. Bluetooth listings show codecs such as SBC and AAC, and network models add streaming from your phone or home server.

Questions about Stereo and AV Receivers: Channels and Inputs

What does 7.2 or 9.2 mean on an AV receiver?

The first number is the count of amplified speaker channels and the second is the number of subwoofer outputs. A 7.2 receiver can drive seven speakers and connect two powered subwoofers. You do not have to use every channel, so a 5.1 speaker set works on it.

Can I plug a turntable straight into a receiver?

Only into a phono input, and only if the receiver handles your cartridge type, usually moving magnet. Without a phono input, use a turntable with a built-in preamp or add a separate phono preamp, then connect it to any line-level input such as AUX or CD.

Is a Bluetooth receiver the same as an AV receiver?

No. A Bluetooth receiver is a small adapter that adds wireless input to speakers or an amplifier you already own. An AV receiver is a full amplifier and switching hub that powers speakers and handles several video and audio sources.