Moving up from 5.1 to 7.1

[Woochifer]

I'm not as sold on the timbre matching though. I have 7 speakers from the same line now, but I didn't always. You can quite often get away with incredibly pleasing results using non-matched speakers as rears in a 5.1/6.1/7.1 setup (too big a difference would suck though). It is, however, very critical that the front 3 speakers be matched as closely as possible.

I agree with you to a point. With most movie soundtracks, the front and back sound elements are kept sufficiently separate such that timbre matching between the front and surround speakers is not as critical. However, with multichannel music and an increasing number of movies, more of the sound elements are mixed into the front and surround channels at nearly equal levels. With those soundtracks, timbre matching is a lot more important because mismatches sound much more distracting when all of the speakers are reproducing the same sounds.

I frequently turn the surround backs off so I'm running in 5.1 mode as a comparison, and I can honestly say, I cannot think of one situation where it the sound wasn't improved at least a tiny bit. There are some movies that don't really make much difference (dialogue intensive movies like JFK without special effects). Anything with good ambient soundtracks or a few special effects really comes off sounding better. And the odd time you do get a 6.1 encoded DVD, the results are even better still.

If you repositioned the L/R surrounds so that they are more to the side than slightly behind the listening position, it will sound fine with the back surrounds active, but leave a fairly large hole in the rear soundfield with the back surrounds switched off. I'm presuming that you use direct firing surround speakers.

Also, it really depends on the soundtrack, not just whether or not effects are in the surrounds. With a 5.1 soundtrack that has a more or less monophonic mix in the surround channels like Raiders of the Lost Ark, Glory, or Lawrence of Arabia, the EX/ES decoder will collapse a lot of sounds into the middle, and in those instances I don't think that 7.1 playback would be beneficial.

2 more speakers is a hefty chunk of money though. Make sure your room dimensions and decor (WAF) can accomodate such a setup though. I have no doubt poorly placed speakers would really suck.

And definitely, make sure you've gone as far as you can with 5.1 before adding more speakers.

Good advice. As you add more speakers, the level of complexity with optimizing the setup increases. The back surrounds represent two more opportunities to mess things up! That's why I question whenever people claim that they don't need a SPL meter to do the level calibration on a multichannel setup. With a two-channel setup, it's easy to tweak with the system by ear, but going to 5.1 or 7.1, you need to account for a lot more variables and compensating adjustments (i.e. delay timing, positioning, etc.).

[kexodusc]

However, with multichannel music and an increasing number of movies, more of the sound elements are mixed into the front and surround channels at nearly equal levels. With those soundtracks, timbre matching is a lot more important because mismatches sound much more distracting when all of the speakers are reproducing the same sounds.

This is true...good point, wasn't thinking about that.

If you repositioned the L/R surrounds so that they are more to the side than slightly behind the listening position, it will sound fine with the back surrounds active, but leave a fairly large hole in the rear soundfield with the back surrounds switched off. I'm presuming that you use direct firing surround speakers.

I guess what I'm trying to describe here is that 5.1 speakers sounded good...so much that I didn't notice any deficiencies...when I added 1 rear center channel I wasn't impressed, even when I slid my 2 rear surrounds forward and to the sides (I had them slightly behind in the ITU 5.1 setup for multichannel audio basicall, that worked best for me). It wasn't that there was a noticeably gaping hole in the rear. With the 6th speaker it really became obvious when the processor channeled a sound to the rear center channel and didn't sound "real" (for lack of better terminology).

With 2 surround backs, I could angle the side surrounds differently, a bit more forward and to the side (much like a movie theater setup). The rear channels no longer became distracting, it was more ambient. Arrows in Gladiators DTS ES were transitioned alot better. The part where that guy swings his mace was awesome...it totally circles the room. There's no "quiet spot".

In normal 5.1 tracks, the processor does a good job of limiting "echo" effects, it just adds some rear ambience as well. It sounds what I felt my old dipole setup SHOULD have sounded like.

Also, it really depends on the soundtrack, not just whether or not effects are in the surrounds. With a 5.1 soundtrack that has a more or less monophonic mix in the surround channels like Raiders of the Lost Ark, Glory, or Lawrence of Arabia, the EX/ES decoder will collapse a lot of sounds into the middle, and in those instances I don't think that 7.1 playback would be beneficial.

That's just it though, wooch...it doesn't seem to do that with 7 speakers. It did do that with 6. Instead it extends the rear further back from left to right, not focusing on a rear center. It's hard to explain...I assume this has to do with the processing, maybe it has to do with the fact my rears are about 6-8 feet apart as well. Believe me though...there's a center image when there should be (a few scenes in U-571), but with the more subtle sounds (ie: being in a jungle) it seems to have the effect of making the room sound a bit bigger and deeper.

This got me thinking though.. I'm not sure I'd recommend placing 2 rear speakers 1 to 2 feet apart as I sometimes see suggested as the minimum acceptable spacing. That would be a highly focused (collapsed) center sound. Might as well stick with 6.1 (which I didn't feel was substantially better)

Good advice. As you add more speakers, the level of complexity with optimizing the setup increases.

I'm going to go out on a limb here, because you're making me think about this. I've been fortunate, both in my old, and new house to have 2 large 400 sq ft + rooms. Since all the speakers are 8 ft or more away from me I wonder if my placement becomes far more forgiving than if I was in a smaller room (like my old apartment)? Perhaps I'm achieving the right amount of dispersion? Certainly a auto calibrating tool like my RX-V1400's YPAO helps (though I'm becoming less and less impressed with the Parametric EQ part for signals above 200 Hz...not noticing much audible differences).

The back surrounds represent two more opportunities to mess things up!

No argument here...that's why we have AR.com. I kinda think the average HT setup is still a 5.1 unit and only the geeks like myself looking for more horsepower or whatever go the extra distance.

That's why I question whenever people claim that they don't need a SPL meter to do the level calibration on a multichannel setup. With a two-channel setup, it's easy to tweak with the system by ear, but going to 5.1 or 7.1, you need to account for a lot more variables and compensating adjustments (i.e. delay timing, positioning, etc.).

In this regard, YPAO is a blessing. I've fiddled with that so much in the past few months. I've come to realize that a 1 ms delay difference will throw of my center image in 2-channel stereo more than 2-3 dB of volume difference. I kid you not. I was quite surprised. I first noticed this when I tried playing with a few different manual settings. I measured my distances to the inch. YPAO can be off by as much as 1.5 feet for ever 10 feet my speakers are away, but it's a relative thing so I don't think the actual number of feet matters, but what it does with that number. When I tried adjusting the number of my left channel to 1 foot closer (as it should have been) it threw Norah Jones way off to the side. At first I wondered if it could have been SPL? So I started bumping up the SPL. I got a slightly better image, but my SPL meter confirmed YPAO was right in it's settings. The delay made a HUGE impact.

Moral of the story...the less human error the better! No doubt 7.1 isn't for everyone.
Can't wait until 8.2 and 9.2 become the standards (don't get me started on my "stereo bass" experiment).

[KRiTiKaL]

Nope, still sounds great! As for the technicalities of THX I just know it sounds good to me. I am glad to know you guys are so smart about these things. I learn something new all the time here. DTS and the other great 5.1 modes sound good too. Hidalgo just stood out to me in clarity. Thx

[kexodusc]

Waldo's contributions to these forums are nothing short of legendary.
Indeed, he has few peers.

[Geoffcin]

With 2 surround backs, I could angle the side surrounds differently, a bit more forward and to the side (much like a movie theater setup). The rear channels no longer became distracting, it was more ambient. Arrows in Gladiators DTS ES were transitioned alot better. The part where that guy swings his mace was awesome...it totally circles the room. There's no "quiet spot".

I'm going to go out on a limb here, because you're making me think about this. I've been fortunate, both in my old, and new house to have 2 large 400 sq ft + rooms. Since all the speakers are 8 ft or more away from me I wonder if my placement becomes far more forgiving than if I was in a smaller room (like my old apartment)? Perhaps I'm achieving the right amount of dispersion? Certainly a auto calibrating tool like my RX-V1400's YPAO helps (though I'm becoming less and less impressed with the Parametric EQ part for signals above 200 Hz...not noticing much audible differences).


Moral of the story...the less human error the better! No doubt 7.1 isn't for everyone.
Can't wait until 8.2 and 9.2 become the standards (don't get me started on my "stereo bass" experiment).

It was only a few weeks ago that I got, (what I feel) is close to optimum out of my 7.1 system. Actually it's 7.1+2 if you take into account that I'm running two sets of mains. It was only when I realized that I should set my CSW T500's to SMALL, and send all of the bass signal to my subs that things really came alive. When set to small there's no signal going to the T500 woofers, so the speakers are acting more like standmounts. The maggies blend well with the Velodyne subs, and OK with the rest of the dynamic speakers, but NOT with the woofers of the T500.

I agree, a big room helps alot. If you think you want to do 7.1 make sure you have about 4-5 ft behind your seats or it won't work correctly. When it does it really adds to effects. We watched X2 the other day and there's a lot of info going to the rear surrounds in that movie. Even little things; like when Striker blows up the wall of ice to get to Wolverine you can hear the ice falling BEHIND you! 5.1 just coudln't give you that effect, or if it could you'ld need to be sitting exactly in one spot. There's something very startling about hearing noises behind you, and 7.1 gives you that effect when it's called for.

[kexodusc]

It was only a few weeks ago that I got, (what I feel) is close to optimum out of my 7.1 system. Actually it's 7.1+2 if you take into account that I'm running two sets of mains. It was only when I realized that I should set my CSW T500's to SMALL, and send all of the bass signal to my subs that things really came alive. When set to small there's no signal going to the T500 woofers, so the speakers are acting more like standmounts. The maggies blend well with the Velodyne subs, and OK with the rest of the dynamic speakers, but NOT with the woofers of the T500.

I agree, a big room helps alot. If you think you want to do 7.1 make sure you have about 4-5 ft behind your seats or it won't work correctly. When it does it really adds to effects. We watched X2 the other day and there's a lot of info going to the rear surrounds in that movie. Even little things; like when Striker blows up the wall of ice to get to Wolverine you can hear the ice falling BEHIND you! 5.1 just coudln't give you that effect, or if it could you'ld need to be sitting exactly in one spot. There's something very startling about hearing noises behind you, and 7.1 gives you that effect when it's called for.

Sweet Jebus Geoffcin, you got 11 speaker boxes in that room??? Superbowl at Geoffcin's everyone!!! I agree totally with setting the mains to "small"...I tried this about 4 or 5 months ago

Even during a the average comedy/chick flick with limited it does seem to fill up the room behind you, really adding to the ambient effect.
I've heard several people swear that dipoles/bipoles are ideal for rears in the 7.1 setup, might have to test that out someday.

[Geoffcin]

Sweet Jebus Geoffcin, you got 11 speaker boxes in that room???

Then I invite them over for a movie, or concert DVD and they change their mind. I'm still trying to justify a front projector but the need for total light control has me a little spooked. (that and $1000+ for a good screen!)

[kexodusc]

You have to tell me how you get the significant other to agree to all this? My second sub lasted 2 days before I lost that battle.
I got 2 systems in 2 different rooms, but 11 boxes in one room...you got room for screen?

You weren't kidding when you said it's pain to get right...my simple little 7.1 seems primitive by comparison.

[Aldo WIngate]

7.1 is just a marketing ploy to get people to spend more money. 5.1 sounds the same.