Surround Sound: 5.1 and 7.1 Theatre Systems
Ever since 7.1 channel home theatre systems came on the market, debate has raged as to whether they’re worth the extra money and hassle to purchase and install.
Ever since 7.1 channel home theatre systems came on the market, debate has raged as to whether they’re worth the extra money and hassle to purchase and install. Indeed, when these systems were first introduced, there was little reason to purchase one immediately. After all, why buy a system when there was very little seven channel content in existence?
However, the market has changed considerably since then, and there’s now more than enough content in 7.1 surround sound on Blu-ray discs and to a lesser extent DVDs. But just because there’s content out there isn’t necessarily a reason to plunk down the extra money and deal with the increased complexity of a 7.1 channel home theatre system.
5.1 Versus 7.1: What’s the Difference?
Before going any further, it would be helpful to illustrate the difference between 5.1 and 7.1 channel systems. What exactly are you getting with those two extra channels?
In practical terms, you’re getting two additional speakers which are positioned on the wall behind the listener. In this configuration, the front three speakers will remain as they are, but what were called the rear speakers in a 5.1 channel system will be to each side of the listener, while the additional two speakers will be behind them. The net effect of all this is to create a smoother, more natural sound and a more immersive experience for the listener, provided of course that the source material is encoded in the proper format.
Newer DVDs, which are encoded using DTS-ES or Dolby Digital EX, carry an extra rear channel. This channel is matrixed, meaning you’ll hear the same sound coming from each of your rear speakers. Most Blu-ray discs, however, contain two discrete rear channels, meaning you’ll be able to hear different sounds emanating from the rear left and right speakers.
When sound designers have more channels to play with, they can dip deeper into their bag of tricks to come up with some truly breath-taking soundscapes. For instance, a helicopter flying directly over camera is going to sound much more lifelike on a 7.1 channel system than on a five channel one. Music will also have a richer, fuller sound.
Who Should Purchase a 7.1 Channel Home Theatre System?
The sound characteristics of a 7.1 channel home theatre system are clearly superior to those of a 5.1 channel setup. So why would anyone want to go with the latter? There are a few reasons a 5.1 channel system might be just as good or even better than a 7.1 system, depending on your situation.
Price is one reason to stay with a 5.1 channel system. If budget is a primary concern, saving the $100 to purchase a 5.1 channel system may be worthwhile. This is especially true if you have a DVD player and are not considering upgrading to Blu-ray in the near future.
The other reason why a 7.1 channel system may not be a good idea is that it may be overkill if the theatre is to be set up in a small space, say less than 3x5 meters. This is due to the fact that the configuration of the room will require that the side and rear speakers be placed too close together for optimum sound output. In fact, doing so could seriously degrade the overall sound of your home theatre.
However, for the majority of home theatre setups with enough room and a budget of at least $500, a 7.1 channel system will provide that indefinable quality that makes movies and music sound truly lifelike, especially if your home theatre is equipped with a Blu-ray disc player.