DD EX vs THX EX????? (1 Viewer)

[Gary Hensley]

Just got back my Onkyo 989V2 upgrade yesterday and plugged everything back in.

I have a question regarding THX-EX and DD-EX. I was always under the assumption that they were one and the same thing. DD-EX was in the theaters and THX-EX was for hometheater. With the latest upgrade from Onkyo there is now a seperate mode for DD-EX mode and for THX-EX mode.

I am guessing that there are EX DVD's out there that are not THX Certified and therefore you would use the DD-EX mode instead of THX-EX? Or possibly that the DD-EX mode does not incorporate some of the THX Re-EQ functions?

Gary

 

[Dalton]

Or possibly that the DD-EX mode does not incorporate some of the THX Re-EQ functions?

I believe this is the correct answer.

 

[Geoff S]

DD EX is that actual decoded format, a 5.1 matrix where embedded data in the 2 surround channels is extracted and matrixed into the 6th channel, i.e the "rear center" or "surround back".

THX Surround EX is just a Post Processing Alogrithem, like 'THX 5.1' is to Dolby Digital or DTS 5.1 or like how Pro-Logic is to a 2 channel source.

THX Surround EX will encorporate Re-EQ, Adaptive Decorrelation, and Timbre Matching in the digital post processing domain, just like other versions of THX Post Processing do.

One added benifit to haveing a receiver with THX Surround EX is that it can turn standard 5.1 sources into EX by creating the 6th channel inforation from the surrounds. I haven't used it before (On my Denon 4802 I have a 5.1 setup and not 6.1) but from what I hear it works pretty well... that is if you choose to spend the extra money on a THX receiver.

 

[Wes Stover]

Actually Geoff is mistaken. The initial version of EX was developed by Dolby and THX together and released initially as THX EX. The contract has now reached its end and Dolby can market EX without the THX moniker. Check the Dolby site.

 

[GordonL]

No, Geoff is correct. THX Surround EX includes the THX post-processing. Dolby EX does not. The only thing they have in common is deriving the 6th matrixed channel.

 

[Wes Stover]

I still stand by what I wrote. Initially Dolby EX did not exist as a consumer format. Only THX EX. Dolby Digital EX was developed together but not released in consumer equipment until recently. The only equipment able to decode the EX signal had the THX EX monikers.

 

[Gary Hensley]

I agree with Gordon when I first asked the question this AM my onle guess what that the THX-EX added the Re-Eq where DD-EX doesn't.

I am going to try and play an Auto-Detected DVD (From Hell or JP3) tonight and see if I can hear a sonic difference between the two. I am hoping it will automatically engage DD-EX and THX-EX when I choose the surround mode/thx mode.

Still seems odd to me that they added this.

 

[Gary Hensley]

There is a press release on Dolby's website that mentions DD-EX licensing.
http://www.dolby.com/press/wb_pr_020...roduct_A4.html

 

[Lewis Besze]

The only equipment able to decode the EX signal had the THX EX monikers.

Wrong!
The only equipment that could market it as "EX" have to had a THX moniker but any pseudo EX chip could have decoded it,since this format did not use any "flag" for a long time.

 

[Wes Stover]

Lewis,

I stand corrected. I didn't even give thought to the pseudo chips.