7.1 compared 5.1

Polk12

I just set-up my polk surround system (RM 10). I have them hooked up to a 7.1 Onkyo 606 AVR. I currently have the traditional 5.1 setup, and I am wondering is it worth buying 2 more RM 10 speakers and use them as rears to complete the 7.1 setup? My question is how much is broadcasted in 7.1 sound? Also, if a show, dvd, xbox, etc I am watching is 5.1 will the surround sounds come out of the surround and rear speakers or only the surround speakers?

Hopefully my question makes sense.
Thanks

Fongolio

As far as I know there are no broadcast 7.1 signals. Cable Satellite, or OTA. Some (not all) DVD's and Blu-rays have 7.1. Some receivers will do a simulated rear that at times is pretty convincing. Some can be configured to have the surround channels come out both the surround and rear speakers. Most Dolby True HD audio is in 7.1 as is DTS Master HD audio but not all. When on and utilized it sounds pretty cool. Just as good if not better than the theater sound. However when I had it setup I found it was utilized so rarely that the exta space I had taken up with the speakers was just not worth it. I'm back to 5.2 (two subs) and very happy. If you can afford them and curiosity is getting you, go for it. You may love it and wonder how you ever lived without it. I found it more of a curiosity than a neccessity. My $0.02.

comfortablycurt

One thing to keep in mind, is that a properly placed 5.1 setup is going to sound far better than an improperly placed 7.1 setup. Make sure that you have the room to accommodate the surround backs.

Most AVR's will be able to convert any 5.1 soundtrack to 7.1. It either matrixes in the surround back channels, and divides the information between the surrounds and surround backs, or else plays the same track through all 4 surrounds. To the best of my knowledge, there aren't any TV broadcasts that are in true 7.1.

In my experience, there isn't a huge difference between 5.1 and 7.1. That's only in regards to standard DVD's though, as I don't have a Blu-ray player yet. I'd imagine that an actual 7.1 sound track is a lot more convincing.

I was running my HT in 7.1 for a while, then I re-arranged and didn't have enough wire to make the surround back runs. So, I left it in 5.1 for the time, intending to get some more wire and hook up the surround backs shortly after. That was about 4-5 months ago, and I still haven't been bothered to get more wire. After listening to it in 5.1 for a while, I decided that I didn't really need the surround backs. I'm sure I'll go back to 7.1 eventually, but it's not a high priority right now.

Polk12

comfortablycurt wrote: »

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Most AVR's will be able to convert any 5.1 soundtrack to 7.1. It either matrixes in the surround back channels, and divides the information between the surrounds and surround backs, or else plays the same track through all 4 surrounds. To the best of my knowledge, there aren't any TV broadcasts that are in true 7.1.

That is what I was wondering. With my current room arrangement, I would benefit from having rears that would play the same sound as surrounds or even if it divides the info between the surrounds and rears, that would sound good for me.

I might give it a go, if I will get sound from the rears.

comfortablycurt

I run an Onkyo 606 myself...it's got Prologic IIx and Dolby Digital EX, so it's able to convert any source to 7.1...whether it's a 5.1 soundtrack, or 2 channel stereo.

obieone

How big is the space that this set up is in? If it's 14'x18', then I'd say don't waste your time. Going 7 ch. in a space that size won't do much.

danz1906

Polk12 wrote: »

That is what I was wondering. With my current room arrangement, I would benefit from having rears that would play the same sound as surrounds or even if it divides the info between the surrounds and rears, that would sound good for me.

I might give it a go, if I will get sound from the rears.

Welcome to the Club!
I say give it a try, I run 7.1 in my system and I love it;)

wutadumsn23

I'm with Curt on this one. A properly placed 5.1 is going to outperform a cramped 7.1 anyday of the week. The only way you are going to find out for sure is to try it, but if the room isn't big enough you won't gain much from the two additional speakers. Also there isn't all that much out there that is formated in 7.1. Some Blu-Ray's are formated in DTS HDMA 7.1, but IMHO you aren't missing much by not running the two additional speakers. Welcome to Club Polk.


-Jeff

kuntasensei

I run 7.1 and love it. And since the vast majority of movies mixed for the theater are Dolby EX, you can use the rear channels on just about everything by using Dolby Pro-Logic IIx. You'll see a lot of people say that there isn't much out there that is formatted for 7.1, but damn near every release these days is mixed for 6.1 with the rear surround data matrixed into the left and right surrounds (i.e. Dolby EX), so there is a ton of material that will benefit from having the rear surrounds in place. Even lossless 5.1 tracks on BD still contain the rear surround data from the theatrical mix, so applying Dolby Pro-Logic IIx or Dolby EX to these mixes will restore the rear surround found in the theater. In fact, Dolby recommends using DPL-IIx Movie Mode for all EX mixes in the home environment.

7.1 is a home conceit made necessary by the smaller space, whereas the theater uses an array of rear speakers fed the same channel. I'm always befuddled when people say not to use 7.1 in a small space, because that's essentially the point of it - to provide multiple sources of sound behind you to prevent any perceived reversal effects (where the sound appears to be coming from in front of you - a problem in a strictly 6.1 setup in the home). In a larger space, that wouldn't be a problem.

I will agree, however, that if your couch is right up against the back wall, you're not going to benefit much. So long as you can keep the couch a bit off the wall and set your speakers at the proper angles to your listening position (found here), you will definitely get a more enveloping soundfield. I say go for it and hear for yourself.