Surround Oddity

[Tornado Red]

I've noticed something strange surround wise about my Yamaha RX-V671....or more than likely it's just me (nothing new for me to read something the wrong way). Bought this AVR last spring (it's a 7.1 I should add) and it's performed flawlessly. Until a month ago, I was only running 5.1 with 2 rears, no sides. I bought the immersion copy of Wish You Were Here and noticed a bunch of instruments MIA on the blu-ray pcm. No background 12 string on the WYWH track opening, missing effects from Welcome To The Machine. Hmmm. Ran the audio check on the speakers from the AVR, no problems. Tried the blu-ray on my son's equipment, it's fine. About a month ago, I finally bought 2 side surrounds. Put the WYWH blu-ray back in, everything I was missing is there...on the side surrounds. Today I got my first 2 SACDs to go with the new Oppo 103, Brothers In Arms and Tommy. Both awesome btw, thanks to the folks on here for their recommendations. The 5.1 they're playing in utilizes the side surrounds as well, no rear action. Am I just nuts or is this the way it should be? I have no issue with it at all, sounds great but I thought these discs would use the rears, not the sides at 5.1. I did check my hook up on the AVR btw, and did another sound check after turning it into 7.1. and the speakers are all in the locations they should be. Thoughts (about this issue, or my sanity, your choice)?

[txcoastal1]

This may be true...hope this helps

http://www.avsforum.com/t/1359273/pl...on-a-7-1-setup

http://forums.soundandvisionmag.com/...stems-and-SACD

[Cuchulain]

When you go into 'set-up' on the 671 it shows you what speakers it will use when choosing 7.1 or 5.1 or whatever. 7.1 can be done with the rear surrounds or front presence( if you have them), but never both. 5.1 uses side surrounds and lets you bi-amp/wire your mains using the rear surround terminals. You can hook up 9 speakers to this AVR but it will only push 7 at any given time for surround sound.

[mdaudioguy]

5.1 is sent to the L&R fronts, center and L&R side surrounds. You can choose to let your AVR process the 5 channels into 7, or just play 5. If you choose 7 (by using something like Dolby PLIIx), anything coming out of the back surrounds is created by the AVR's processor (matrixed from other channels), so it's not surprising some of the content was MIA, and particularly noticeable with a music track that you were obviously familiar with. You weren't really running true 5.1 without side surrounds, and this probably wasn't so obvious with movies.

[Tornado Red]

Thanks everyone, great explanations that clear up a few things. I think you hit it md, what was going on was NOT as noticable with movies when I was running 5 not 7.

[Tornado Red]

Maybe another question if you don't mind, now that the bi-amp issue has been brought up. I haven't tried yet, wondering if bi-amping will improve the fronts in my system. I'm running Polk Monitor 75t and think with the Yamaha 671 I'm likely at the outer edge of having enough power. No pre outs here so I can't stick an amp into the mix as it stands now. If I bi-amp the mains, will I have to give up the rear surrounds? Thanks...

[teekay0007]

wondering if bi-amping will improve the fronts in my system. I'm running Polk Monitor 75t and think with the Yamaha 671 I'm likely at the outer edge of having enough power. No pre outs here so I can't stick an amp into the mix as it stands now. If I bi-amp the mains, will I have to give up the rear surrounds? Thanks...

Bi-amping in this setting will get you nothing extra - you still only have so much power to spread between all of your AVR outs. The only way this would get you a noticeable difference is if your front highs and lows each had separate amps driving them, which without preouts, isn't going to happen. Also, if you do want to just try bi-amping, yes you do have to give up the rear surrounds.

Also, if I'm understanding correctly what you were trying earlier and having problems with, it sounded like you were only running rear surrounds without side surrounds - ? Even if your surrounds, in a 5.1 system, are positioned more behind you than actually being on the sides of your listening area, you need to have them connected to the "surrounds" outputs from your AVR and not your "surround backs". Then, you need to run your calibration program again for that setup. Otherwise, you will lose much information.

[Tornado Red]

Thanks tk. I'm probably looking at upgrading the AVR and adding an amp to power the front 2 (or 3) down the road. Added speakers and an Oppo over the last month, so unfortunately an upgrade will have to wait awhile. I've had the Yamaha for about a year, but only 5.1 till a month ago when I added the other 2 speakers to complete the 7.1. And...I had the surrounds plugged into the rear, not sides when I was doing 5.1, my bad. But like md mentioned, I was unaware during movies, but it showed up with the WYWH blu-ray, and now Brothers In Arms and Tommy SACDs. Who knows what else I was missing? Sometimes ignorance is bliss

[teekay0007]

T-Red: What I did with my setup, which I'm very happy with, might work well for you too. I use an AVR with a little more oomph (130 WPC/2 channels driven) as a pre/pro - using the preouts for the fronts to add a 200 W/channel amp to drive my SDA2B fronts - letting the amplifier section of the AVR drive my surrounds and center. I find that it does a far-more-than-adequate job. However, I'm only running a 5.1 system. A similar setup might work well for you, or you might want to consider a 3-channel amp to power your fronts and center, considering the fact that you're running a 7.1 system.

[Tornado Red]

That's pretty much my intent too tk. You know, I'm not real unhappy with the Yamaha...if it had preouts, I'm sure it could run my surrounds. So, I'm thinking along the same lines as you, up the ante a bit on an AVR with a little more power and use it as a pre/pro and then an amp to power the mains...and maybe the center, I haven't decided if I should do just the 2 or the 3. The Yamaha can run the Monitor 25c center I have, but it's a timbre match for the 75t's and would I be leaving it behind to just treat the mains and not it? I've been thinking along the lines of an Onkyo 809 or Yamaha a2000, with perhaps an Emo xpa-3 or xpa-2, depending on whether or not I include the center. The xpa-3 might serve me well, but it sure would be nice to have the 300 wpc of the xpa-2. Emotiva seems to be a VERY polarizing company around here I noticed. Anyway, just starting to look, I've spent about 2 large since Christmas on my system and, if I buy new, probably around $1500 more for another AVR and amp. Having to wait a bit to save enough for the next purchases will be a good thing for me, I need to educate myself quite a bit more. Thanks for your help and tips, much appreciated...