The Home Theater Receiver Guide
5.1 vs. 7.1 - Which is Better?

One very important consideration when planning a home theater receiver purchase is whether to opt for a 5.1- or a 7.1-channel solution. It is a decision that has significant financial implications, but not only.

As we will see in this short guide to 5.1 vs. 7.1 AV receivers, both options have their advantageous and disadvantageous.

And these depend not only on what you are after in your home theater audio set-up, and therefore on your own personal preferences, but also on the source components and outputs you plan to connected to your AV receiver.

The 5.1-channel home theater receiver represents the basic solution for surround sound. It delivers all necessary channels for a proper surround sound setup - the front left and right channels which carry the majority of the soundtrack, the center channel necessary to properly anchor the dialog within the soundstage, the two left and right surround channels necessary to create the surround effects and ambience, and the Low Frequency Effects or subwoofer channel.

As expected, the 5.1 receiver solution represents the least expensive option, so it may be the best option for those looking to setup a home theater on a budget.

It also represents the ideal home theater receiver for the small to medium size home theater room - where it is capable of delivering a perfectly immersive sound stage. Moving to a 7.1 solution in the smaller environment would hardy yield any benefits in terms of overall surround sound experience.

A 5.1 AV receivers may still be used in the larger home entertainment room. In fact, many of those who opt for a 7.1 AV receiver solution still use a 5.1 speaker setup.  However, using a 5.1 receiver solution in the larger environment would not deliver the same fullness in the ambience of your sound stage as a 7.1 receiver, though admittedly, the quality of the surround sound is not just a matter of the number of channels used in your playback setup.

In any case, should you decide in favor of a 5.1 home theater receiver for the larger room, ensure that you opt for an AV receiver with more audio output power per channel. How much power do you need depends on your preference. But more information on amplifier power is available in our article here.

The 7.1/7.2 Home Theater Receiver

A 7.1 or 7.2 surround sound receiver includes two additional back surround channels as further explained in our multi-channel speakers system guide here. The difference between 7.1 and 7.2 is that 7.2 systems include a second subwoofer output. Note however that some 7.2 systems are actually nothing more than 7.1 multi-channel home theater receivers with a second subwoofer output wired internally in parallel with the first!

In either case, a 7.1/7.2 surround sound setup helps deliver a more realistic surround soundfield in medium to large home theater environments by adding more depth to the surround experience thanks to the two additional back surround speakers. The result is a fuller and more immersive soundstage in the larger home theater room.

While there are only a couple of Blu-ray soundtracks that come in 7.1, yet a 7.1 home theater receiver would enable you to play Dolby TrueHD, DTS-HD Master Audio high definition audio formats and 7.1 channel uncompressed PCM audio in their full glory if available.

In addition, most home theater receivers can generate a 7.1 playback out of a 5.1 sound mix through the use of Dolby Pro Logic IIx; this builds up further on the Pro Logic II Dolby surround sound decoder by transforming any stereo or 5.1-channel signal into six or seven-channel full-range surround sound.

In the case of Dolby Pro Logic IIz and Audyssey DSX 7.1-channel playback, these surround sound extensions create additional two extra front speaker channels in the form of two front height speakers instead of the two back surrounds; in the case of Audyssey DSX, these two extra front speakers may also be used as 'wide' channel speakers instead. This yields improved flexibility in your front speakers setup.

But 7.1 receivers carry a few advantages even if you would not be installing a 7.1 multi-channel speaker system. Once you cross the $400 to $500 price mark, moving onto a 7.1 AV receiver option would enable you to enjoy a few features that are not generally found on lower-priced home theater receivers, especially if you will be implementing a 5.1 speaker solution.

Many 7.1 home theater receivers would enable you to play over a 5.1 speaker setup while using the remaining two channels in a 7.1 receiver to drive speakers in a second room, in which case, depending on the home theater receiver supported features, it may be possible to play a second stereo stream to the second room while listening to a totally different 5.1 surround sound track in your home theater.

Another possibility is that of wiring the extra two channels to deliver more power to the main front left and right speakers if your front speakers support Bi-amping. There are some benefits when Bi-amping with identical amps. By Bi-amping, you will be driving the fronts with dedicated amplifiers for the high pass (mid-range speakers) and low pass (woofers) portions of the two main front speakers. This should help with the woofer response of the front speakers as well as in the overall fidelity.

Bi-amping also introduces electrical isolation between highs and lows of the speaker system as now they are driven through separate amplifiers; this should help reduce crosstalk if the internal crossovers are electrically isolated from each other.

The Bottom Line:

A 5.1 home theater receiver is perfectly adequate to deliver excellent surround sound performance; it represents the ideal solution for the small to medium size home theater room. Instead, the 7.1 AV receiver is more suited to fill the larger home entertainment environment.

However, if you plan to spend more than $400 to $500 on your home theater receiver, consider moving to a 7.1 home theater receiver option.

A 7.1/7.2 AV receiver offers a number of advantageous even if you still plan to have a 5.1 speaker setup since you can use the two extra amplifier channels either to drive a multi-room audio installation or with Bi-amping. In addition, the 7.1 home theater receiver leaves your future speaker expansion open since you can always upgrade to a 7.1 speaker set-up by adding the extra two back surround speakers should you desire so without replacing your home theater receiver.