7.1 vs. 5.1 - Meaningful difference?

I have a Lexicon MC-8, with a 7.1 piega speaker system. I now have cause to consider removing the back surrounds to another room and changing the system to 5.1. I toggled the MC-8 from 7 to 5 channels without noticing any difference. Do people find 7.1 a meaningful upgrade from 5.1? My rear surrounds are lesser quality than the 5.1 system, so maybe that explains the lack of impact? I'd be grateful to hear other experiences.

Ive had 5.1 and 7.1
Honestly, i preffer 5.1, less hassle, less speakers, and the benefits from a 7.1 system just arent worth the added cost in my book.

good for a 2nd zone if it has that capability.

as far as i know, nothing has ever ben recorded in 7.1 anyways. its just another logic processor.
This is another question that can only be answered based on opinion, to me the 7.1 set-up works much better with more space and involvment using di-pole speakers, if you room isnt big enough, if your set up isnt ideal or if you plain just dont see the benefit then go 5.1, true there are only 6.1 material so far but to me 7.1 is much better and more emotional......there is no right or wrong and no matter how hard anyone tries to argue this it is only opinion, the Zone 2 use of your speakers might be a great option for you....so follow your heart and your ears and enjoy!
I think it depends on the size of your room. I have a samllish room, so 5.1 fills things in nicely. If you have a large room and are able to put speakers 3+ ft. behind your listening room it may be worth your while.

DVDs that are "encoded" in Dobly Digital EX and DTS ES have separate information for 6.1 - 7.1 channels. "Gladiator" and "Star Wras - Revenge of the Sith" are 2 that I can think of off the top of my head.

I'm quite surprised you don't hear a difference between 5.1 and 7.1. When I expanded from 5.1 to 7.1 (using Logic 7), I heard a very noticeable improvement is surround envelopment.

Thinking out loud: I assume you are using Logic 7, all speakers play the test tones correctly when setting speaker levels, and distance settings are adjusted.

Are your side speakers directly to the sides of your listening area; i.e., +- 90 deg, and not behind your listening area? Having both sides and rears behind the listening position defeats the purpose of 7.1.

Are the rear speakers spread apart (+- 160 deg) behind the listening position?

Ran across this recently...it's worth a read:


Interesting read. I agree that adding rear channel information; i.e., expanding beyond 5.1, adds spaciousness. That is what I meant by better suround envelopment. And I agree that you do not need to correlate number of source channels with number of speakers used in playback. Logic 7 and/or DPLIIx can generate 7.1 "discrete" output channels from various sources.

I had not heard their explanation before about phase problems with dipole side speakers being the reason for needing 2 rear speakers (7.1) versus a single rear speaker (6.1). I do agree that 6.1 is not a good choice, as a single rear speaker can lead to front to back image reversal as well as not providing the spread of sound intended in the rear, problems that can occur even if you use bipole or monopole sides.

In some rooms, 7.1 is not practical, such as the listening position being flush against the back wall (no room behind the listener for the pair of rear speakers). Room size is not an issue. Based on my own experience, unless your room layout just cannot physically support 7.1, I can't imagine why you would not go with 7.1.

Considering all of the DVD's are 5.1 I am not sure what benefit doing 7.1 would be.

Logic 7 and/or DPLIIx will extract and process the information in the 2 surround channels of 5.1 sources, and generate 4 channels for playback: 2 sides and 2 rears. These algorithms do not add anything that is not already in the surround mix, but distribute the information across 4 rather than 2 discrete playback channels for a better spatial presentation.

2 side speakers alone don't provide good front to back depth. 2 rear speakers alone don't provide good side to side breadth. With both side and rear surround speakers (7.1), you get better envelopment.

The proof of course is in the listening. If possible, recommend you listen to a properly set up 7.1 system (not necessarily that easy to find), and toggle between 5.1 and 7.1.

It depends on the size of the room... but I think it's usually not worth the extra $$$ and effort to make it 7.1

5.1 is just about right for me for now...
not all DVD is 5.1, EX is 6.1

How would the size of the room make a difference on going to 7.1?

Certain room layouts make a difference, but size itself should not be an issue. My room is not large, 13' x 17' x 9.5', and 7.1 works very well.

I should have added Size and Shape...

Works for what though?...

DTS/DD recorded for 5.1 or 6.1? or DVD-Audio? or DPLII/DPLII-EX for music?

7.1 might sound great regardless of the shape and size of the room when listening to 6.1 recorded sound track.

But in reality, most of the movies and DVD-audio are recored 5.1 and the two back channels are 'matrixed'.

If you stuff in 7.1 in a small narrow room and listen to 5.1 recorded sound track, it may not add any value or even effect negatively... Well postioned 5.1 in a proper size room may work best for 5.1 recored sound tracks including movies or DVD-A/SACD


We seem to have two different opinions, which is fine.

For the example of 5.1 DD/DTS sources, I found listening in 7.1, using Logic 7, to provide a much better surround envelopment than listening to the same source in 5.1.

When Logic 7 is extracting 4 surround channels of output from the 2 surround channel sources in DD/DTS 5.1, it can change the spatial presentation across all 4 speakers. It doesn't just extract two matrixed channels for the rear speakers and leave the side channels as is.

If a sound is intended to pan from the back left of the room to directly left of the listener, then Logic 7 can steer the sound such that it starts out in the left rear speaker only, then is spread across both the left rear and left side, and ending up in the left side speaker only. Its much harder to try and do that with only 1 surround speaker on the left side of the room.

I can only suggest that those interested listen to a properly set up 7.1 system, toggle between 5.1 and 7.1, and judge for themselves.

Dredging up an old thread.
Thinking about why my Lexicon won't do 7.1 analog bypass. I'm set up for it otherwise and now in the world of blu-ray 7.1 is a reality.
I have been using 7.1 for four years. It has more effect than I would have anticipated. My Pre/Pro matrixes or synthesizes 7.1 from all 5.1 source material, and now most Blu-Rays are 7.1 discrete on-disk. When the rear surrounds are off, the soundfield thins out and is thrown forward; the soundfield doesn't feel as complete or enveloping without those rear surround channels.
I found the improvement so substantial in my smallish HT room that I can't say it's simply a subjective difference. I upgraded the receiver and disk player to Blueray and added two more of the same speakers. Even with 5.1 media and cable the matrixing my receiver does with the side and rears is surprisingly well done.

When I bring it down to 5.1 the sense of space is dramatically reduced and the fronts and rears have a more discrete presentation that is clearly less enjoyable.

I recently helped my in laws with a 7.1 upgraded using very inexpensive components in a small space and again, after the room correction was run the improvement was very noticeable. I would guess you may have issues with the processor or the setup.