Setting delays on Casablanca

Which Casablanca?

How does is sound right now?

Post your question here:

http://www.avsforum.com/avs-vb/showt...194907&page=21

and you will get help.

From the "quick start" guide:

* As a licensee of the Dolby Digital, DTS and Circle Surround II formats, the Casablanca III is required to add 15 milliseconds of delay to the surround channels’ output. Therefore the delay adjustments on those channels add more delay to the default 15 ms, if desired.

You misunderstood me. I was not suggesting you get into the bickering on HDMI. Idea is some of those posters in that thread are very knowledgable on Casablanca and will be able to answer your questions.

Anyway, I see you made another thread in the same section. That should also work.

I interpret that as...
If the default automatically adds 15ms (the 0ms relative value), then if you adjust to 15ms, the lowest value is in reality 30ms.

How much delay do you think you need?

Can you set the fronts to 15ms, the sides to 17ms and the rears to 18ms? That should give you the results you want.

When setting time alignment, the delays are relative to other speakers (as opposed to A/V synch delay, where the delay to the entire signal is absolute).

So it's not like you'll actually be delaying the front channels by 15ms, just delaying the sides by 2ms and the rears by 3ms relative to the fronts.

So, I take it that it is the "Casablanca III"? Interestingly, the Casablanca (I) manual describes a distinction between the delays allowable for the "Matrix" versus "5.1" settings for those channels. With "Matrix", 15ms was the minimum allowed. With the "5.1" setting, 0ms was the minimum allowed.

Can't speak for Theta specifically (that forced 15ms delay is a bit weird), but the convention is that time alignment uses relative delays. Otherwise the entire soundtrack would end up out of synch with the picture.

I'm scratching my head.

Maybe the OP should contact the Theta folks for a definitive answer and report back?

Guessing is good for a quick fix, but why not go to the manufacturer and hope for a good answer?

typical help desk BS

Question 1:
What does the statement really mean in post #6? Is 15ms automatically added using 0ms a "starting point"?

Question 2:
Why would more than 15ms be necessary for ~5' distance?

More reading:
http://www.practical-home-theater-gu...nd-system.html
http://www.dtvmax.com/proj_1.htm

Whatever...
I realize that 15 is the lowest value that is "displayed". Re-read my confusion/question in regard to Theta's doc. Whether it's mandated or not, it is what it is. Try to ask the Theta folks for clarifiaction.

I'll ask again, why is more than 15ms required for ~5' distance?
Did the links I provided help?

Because they want the sound from the surrounds to arrive at least 15ms after the sound from the fronts, irrespective of the actual distance that the surround speakers are from you.

But that mandatory delay is based on old matrix decoding, where channel separation wasn't very good and dialogue used to leak into the surrounds. By delaying the surrounds, the dialogue from the front speakers arrived at your ears first, and your brain would ignore the same sound arriving later from the surrounds. This is called the Haas effect or presedence effect. The delay had to be between 10ms to 40ms for the effect to work.

With modern surround processing and discrete multi-channel, the delay should no longer be necessary. (See sivadselim's earlier post re matrix vs 5.1.) Shame that Theta continues to impose this delay. My old Lex allows the option to delay the surrounds 1ms-15ms in PLII/PLIIx mode. But you can always turn it off (set it to 0ms).

Yup, I read and understand all of that Sanjay. That info was contained in the links I provided to the OP. Again I have to ask:
1) Does Theta automatically impose a 15ms delay even though the relative readout states 0ms? Is a setting of 5ms actually 20ms?
2) The OP states that the distance from front to rear is ~5'. Why does the OP feel that more than 15ms necessary?

FWIW... my older receiver only allows delay from 15-30ms with DPL and 0-15ms with DD.

EDIT:
Ah!
To the OP: My bad! Are you saying you want less delay and the minimal value/setting is 15ms and can only be increased? If so, sorry... I misinterpreted your dilemma. As usual, Sanjay has the best recommendation in post #10.