Axiom Home Page Forums General Discussion Home Theater my onkyo 797 back surround not working issue

Hello,

I just wanted to share this info to those owning an onkyo tx-ds797 receiver, who are experiencing a back surround not working problem (or maybe it's just only me). Anyway I finally found out the reason why, but before that let me give you the history of the problem:

A month ago, I posted here that my 6 channgel back surround is not working, the sound comes out on my left/right surround speaker instead on my back surrround speaker. Cheesero(did I got the spelling right?), informed me that maybe the problem is on my DVD player, so i tweak around the player, i set the TVS feature to off ( and maybe I did something on the receiver as well, but i don;t remember), and then all of the sudden, when I run the Dolby digital 6 channel test of S&V, the back surround spekear is now working as expected, but then my DTS-ES matrix test failed with same problem, though DTS-ES discrete works fine. After a few days, I watched John Q movie (DTS not ES but my receiver DTS-ES was set to ON instead of Auto, with this it will play the movie in DTS-ES matrix mode), and there was actually sound coming out on my back surround speaker, so I suspected that there is a software bug on the S&V cd. Then last night, my Son ask me to play Star Wars 1, while we are watching, i notice that my back surround is not working again, my wife said that our Son played around the receiver remote, so once I again I did some tweak which I did before, but this time it's no longer working. I am already thinking of borrowing my friends DVD player, just to isolate the problem, but I tried one more time, this time tweaking around the receiver settings. After a few hours of tweaking, i finally found the reason why, so in case you are insterested here's the reason:

Under the "Input Settings"(DVD)--> "Listening Mode", under Dolby D. If you select Dolby Digital, the receiver will only output the sound to your Left/RIght Surround Speaker for the Back surround even under "Surround Settings" you explicitly specified SurroundEX ON instead of Auto. In order for the 6 channel to work, I have to select THX. So now I finally got the answer to my problem, I even posted this problem to Sound and Vision forum as well as email the ONKYO support, and all I got from them were "Under Surround Settings, select L/R+B", "make sure the Zone2 settings is off", "run the receiver test tone make sure there's a sound coming out from the back speaker if not check your wiring" etc etc which are all basic settings that I know and already been done. Anyway just want to share this info to everyone.

My Apology for the long post....

Thanks for posting your message. I am going through the exact same thing with my Onkyo 787 right now....for the life of me I can't the rear surround to work. Using the THX test that comes on the star wars dvd, when it plays the rear sound...the exact same sound is sent to the left and right surround speakers. Not sure how the 787 differs from the 797, but it seems that the 787 doesn't decode the EX format, it will only work if you have a multisource 7.1 or 6.1 input. Really frustrates me, cause I had purchased it thinking it would decode 6.1 EX stuff.

Cheers...Amer

I use an outboard 2 channel amp (Denon PMA 500V) 85 watts each with my Onkyo TXDS 797 THX receiver. I use the preouts for the back surrounds L+R (mono though) into the amp and out from the amp to my back surround speakers. All 7 channels work fine even while watching Fox News.

Amer, I don't have the 787, but the Onkyo specs state that it does THX Surround EX, essentially the same as the 797 and supplies a 6th back surround channel. The owner's manual makes the point that it's necessary to select THX as the listening mode, as Sam states in the final paragraph of his opening message. Have you done that and carefully followed the other instructions for THX in your owner's manual?

I get 6 channel out-put (7 speakers plus subs) in "all channel" and THX settings.

Sure, but only with the added expense of having to run a seperate amp to achieve this in all modes.

Hello John
Correct. However, in my case, I bought the Denon at a garage sale for $50 (dead quiet and clean). Without the 2nd amp I'd only have 6 channels (797 is a 6 ch. amplified receiver). I picked up a pair of Mission 77ds bipole wall mounted speakers for $29 from uBid, and it was worth it to me to get the modest used outboard amp to use the Missions in 6 and 7 position. Someday I may upgrade my Merak horn center to a VP150 and my Missions to QS8s, but in the meantime, I'm styling for cheap.

Now, a word in defense of 'stylin' for cheap.' If any of us were willing to throw lots of money at the speaker problem, we wouldn't be driving Axioms. We'd have $5,000 or 7,000 speakers. For me, the game of it all is getting the best possible sound at the best possible price. I'm very price sensitive, a function of my psyche rather than the weight of my purse. I love a good deal. Axioms are a great deal. My $50 amp, a great deal as are my $29 Missions. Now, I have no doubt but that the Axiom QSx speakers are much better, but uBid let me steal a pair, what could I do?

Then you did very well, I think that if I came across the same deal I would certainly jump at this.

You are very correct in stating that the axioms are a great deal. I have put my 80's up against a lot of my friend’s speakers that cost several hundred to several thousand dollars more, all with the same response. "Those speakers only cost HOW MUCH?" Which is then followed by "DO know what I paid for these ...." Always makes me smile!

Sounds like you have built yourself a great system and considering the price paid, Well Done!

Cheers
John.

Same here, counselor. Nice buys. I learned a long time ago that "high-end" sound doesn't require high-end money.

Thanks guys, finally figured it out last night after reading the posts here. I guess the problem was that I had sent set the DD6.1 and THX EX and DTS-ES functions as Auto (factory default) and thought the receiver would figure it out (silly me). Set them to ON instead of auto and now it works fine and I can enjoy my new axioms in full surround sound!

Regards....Amer