5.1 Source Material on 7.1 Systems (1 Viewer)

[Craig Morris]

I have a question regarding pre-pros and receivers when playing 5.1 material over a 7.1 speaker system.

On THX Select or THX EX systems, the product manuals state that you can force the EX mode, but the results depend on the material, and may not be desirable.

On THX Ultra2 systems, the Ultra2 Cinema Mode says that it monitors the rear channels and spreads the sound around the 4 rear speakers in an appropriate manner, avoiding the problem described above.

On non-THX systems, like Outlaw, or Rotel, they have Cirrus Extra Surround, or Rotel XS mode to pump the 5.1 track through the 7.1 system. I guess my question is how good are these modes? I haven't heard any of them, but I have to say, THX Select (or regular EX) sounds like a bad compromise (i.e. your brand new 7.1 system might not sound so hot on 5.1 soundtracks). THX Ultra2 appears to be a great solution (albeit rare and pricey). How do people like their THX Select/EX systems? Do they notice problems when playing 5.1 (i.e. non EX-encoded) soundtracks? How do modes like Cirrus or Rotel XS sound? Good? Adequate? Fantastic?

I'd hate to spend the money upgrading my 5.1 system to 7.1 only to find that it's a waste except for when playing true encoded EX/ES soundtracks.

 

[Dan Keliikoa]

I have a B&K AVR507 with a 7.1 M&K speaker setup. I run all 5.1 (or more) material in '7' mode, which works beautifully.

My 5.1 films sound fantastic, much more enveloping than when I was setup only for 5.1. Of course, the EX/ES stuff sounds sublime But EVERYTHING sounds considerably better to me, and surround effects are much more lifelike.

I don't use any special Cinema modes or special THX modes, either.

Cheers,
Dan

 

[Kevin C Brown]

I have an Outlaw 950. I also (now) have a Lexicon MC-8. The Outlaw has its CES modes, and the MC-8 has THX Ultra2 modes and Logic 7. I was surprised that the Outlaws modes come as close to the Lex's as they do. Now, Logic 7 does give better spatialization, imaging, and more separation in the rear sound field, but if you're not specifically listening for it, Outlaw's CES modes are very close.

 

[Michael Reuben]

I've been playing all of my 5.1 soundtracks through Logic7 since before the first DVD hit the market, which was several years before DD EX and DTS-ES even existed. The results have been, and continue to be, excellent.

M.

 

[Steve Schaffer]

Craig Morris wrote,

On THX Select or THX EX systems, the product manuals state that you can force the EX mode, but the results depend on the material, and may not be desirable.
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Craig,

I've had a Pioneer VSX45TX in a 7.1 setup since last December and run it in forced EX mode for all of the 5.1 material I've played on it. I have yet to experience an undesirable result.

There may be some 5.1 mixes that would sound funny in forced EX, but I haven't run into one yet. An example might be one that has exactly the same sounds encoded on both surround channels, which might cause all the surround information to "collapse" into the rear surrounds.

I even use the forced rear center (or back surround) "on" for 2 channel surround (DPLII processing with forced back surround "on" and THX processing on) and gotten very good results.

Don't let that disclaimer in the manual scare you.

 

[Craig Morris]

Thanks for your replies everyone.

Steve, that's exactly what I was wondering... good to know that you've been happy with the results using THX EX. Makes me wonder what Ultra2 really does...