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Today’s Show:

Is a 7.1 System Worth it?

We recently received an email from a listener who was asking whether a 7.1 system was something that he should wire his home with. This got us thinking that there are probably a few listeners that may benefit from a discussion on whether a 7.1 system is worth it for them.

History

Before we get to far into the subject let’s take a brief look at a little multi-channel history. You have to go all the way back to 1975 when Dolby Stereo was released. Dolby Stereo created four channels out of two using a decoder. You may recognize the term Pro Logic and all receivers on the market today can decode Pro Logic. The HT Guys first systems capable of creating a surround sound environment in our homes goes back to the mid-nineties, a full twenty years after the theatrical debut. We were still on the leading edge at that time but it was becoming more commonplace.

Let’s move the calendar forward to 1992 when Batman Returns was the first movie released in the Dolby AC3 format which brought five discrete channels plus a subwoofer. Two years later DTS would introduce their own discrete 5.1 format with the release of Jurassic Park. Both formats would only take four years to crack the consumer market. Soon home theater enthusiasts would be wiring up 5.1 systems everywhere.

To be complete, Sony had their own discrete system known as Sony Dynamic Digital Sound (SDDS). We both worked with the inventor of this format when we were at Sony. This was a seven channel system but instead of adding the additional speakers to the rear, SDDS added the channels to the front. Some of the best audio we have ever heard was on an SDDS soundtrack. This format never gained a consumer following.

To finish our journey let’s move forward to 1999. That’s when Star Wars: Episode I – The Phantom Menace was released. George Lucas and Dolby added an additional channel directly behind the listener. This was called Dolby EX. DTS had a version that was called DTS ES. These were 6.1 setups.  The first official theatrical release in 7.1 was in 2010 with Toy Story 3. Oddly enough Dolby in 2005 and DTS in 2006 developed lossless 7.1 formats in form of Dolby True HD and DTS Master Audio that were designed for home use prior to the 2010 release of Toy Story 3.

Setup

A 7.1 system is very similar to a 5.1, both have the front, left, center, and right speakers. Both also have the left and right surrounds and both have a subwoofer. As stated in the history the additional two speakers in a 7.1 system go behind the listener. There is a surround back left and a surround back right. The proper setup for these speakers is to be behind the listener between 135 and 150 degrees from the listeners ears (Dolby Home Theater Speaker Setup Guide).

5.1 or 7.1

Generally speaking a 7.1 system will provide a better experience with 7.1 content. That’s a pretty obvious statement and really doesn’t help anyone. If we were to ask the question, “should you spend the extra money for a 7.1 system”, the answer is yes but with a bunch of caveats. Let’s dive in!

Space - You really need space behind the seating area in order to hear any benefit. If like many people your seating is right up against a wall, putting the rear surrounds directly overhead won’t really benefit you. You could aim the speakers down and that will add a little effect but not really the way the sound designers wanted. The sound coming from the rear surrounds are supposed to sound like they are behind you and not over you. In this situation you are better off staying with a 5.1 system.

Content - If you are primarily watching TV, and that includes content on pay movie channels, there is no need for a 7.1. Even if you occasionally watch a movie on Blu-ray you are still better served with a 5.1 system because there still aren’t a lot of movies in 7.1 yet. Even if you pick up a disc that has a 7.1 sound track there will be no reason to worry, most receivers will mix the rear channels into the surround channels.

Cost - Installing two more channels will add cost that may result in the purchase of lower quality speakers. With that said you may want to buy a 7.1 receiver for two reasons. First, if it’s solely a cost issue that prevents you from going with a 7.1 system you will be able to add the speakers at a later time. The additional cost of a receiver that does 7.1 is negligible and at this time its mostly the lower end receivers that only do 5.1. The second reason is that a receiver that is 7.1 and is set up in a 5.1 configuration will be able to mix the rear channels to the surrounds.

Bottom Line

A properly installed 7.1 system with 7.1 content will take your home theater to the next level. You will definitely be able to hear a difference, especially with good content like the movie Super 8 (HT Guys Review Blu-ray Review). However, if you are not watching Blu-rays or your room doesn’t support proper placement of the rear surround channels, a better approach would be to upgrade your 5.1 system or just save the money.

Download Episode #578


Posted by The HT Guys, April 11, 2013 10:58 PM

About The HT Guys

The HT Guys, Ara Derderian and Braden Russell, are Engineers who formerly worked for the Advanced Digital Systems Group (ADSG) of Sony Pictures Entertainment. ADSG was the R&D unit of the sound department producing products for movie theaters and movie studios.

Two of the products they worked on include the DCP-1000 and DADR-5000. The DCP is a digital cinema processor used in movie theaters around the world. The DADR-5000 is a disk-based audio dubber used on Hollywood sound stages.

ADSG was awarded a Technical Academy Award by the Academy of Motion Picture Arts and Sciences in 2000 for the development of the DADR-5000. Ara holds three patents for his development work in Digital Cinema and Digital Audio Recording.

Every week they put together a podcast about High Definition TV and Home Theater. Each episode brings news from the A/V world, helpful product reviews and insights and help in demystifying and simplifying HDTV and home theater.