Setting delays on Casablanca - AVS Forum
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post #1 of 22 Old 05-21-2010, 07:44 PM - Thread Starter
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I am trying to set the delays on my Theta Casablanca but I'm running into a problem. My side speakers are about 2 feet farther than my fronts so I would only need about 2ms delay and the rears are actually 3 feet farther than the fronts. But the problem is that the Theta won't let the delay go below 15ms on the sides and rears. How do I get around this or is it even important?
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post #2 of 22 Old 05-24-2010, 07:13 AM - Thread Starter
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wow! Not one hint?
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post #3 of 22 Old 05-24-2010, 07:28 AM
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Which Casablanca?

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
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post #4 of 22 Old 05-24-2010, 08:04 AM
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How does is sound right now?
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post #5 of 22 Old 05-24-2010, 08:21 AM
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Post your question here:

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

and you will get help.
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post #6 of 22 Old 05-24-2010, 08:25 AM
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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.
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post #7 of 22 Old 05-24-2010, 09:35 AM - Thread Starter
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Quote:
Originally Posted by Ratman View Post

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.

I read that too, I was just wondering what I could do given my room size. Right now, I just have them set to 15 (which is the lowest value allowed) with the fronts and center set to 0.

Quote:
Originally Posted by hd_newbie View Post

Post your question here:

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

and you will get help.

I wouldn't touch that thread! I still love my Casablanca III. I don't care about HDMI yet, I can wait.............
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post #8 of 22 Old 05-24-2010, 11:14 AM
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Quote:
Originally Posted by mitchlampert View Post

I read that too, I was just wondering what I could do given my room size. Right now, I just have them set to 15 (which is the lowest value allowed) with the fronts and center set to 0.



I wouldn't touch that thread! I still love my Casablanca III. I don't care about HDMI yet, I can wait.............

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.
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post #9 of 22 Old 05-24-2010, 11:46 AM
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Quote:
Originally Posted by mitchlampert View Post

I read that too, I was just wondering what I could do given my room size. Right now, I just have them set to 15 (which is the lowest value allowed) with the fronts and center set to 0.

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?
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post #10 of 22 Old 05-24-2010, 12:22 PM
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Quote:
Originally Posted by mitchlampert View Post

My side speakers are about 2 feet farther than my fronts so I would only need about 2ms delay and the rears are actually 3 feet farther than the fronts. But the problem is that the Theta won't let the delay go below 15ms on the sides and rears.

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.

Sanjay
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post #11 of 22 Old 05-24-2010, 01:48 PM - Thread Starter
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Quote:
Originally Posted by sdurani View Post

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.

Is that really true? I can try that! I just figured that would cause a big mess but if the computation is done relative to each channel, then it should work!

Quote:
Originally Posted by Ratman View Post

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?

I set the delay to 15 because that is the lowest you can go. It doesn't add any additional delay, it just won't let you set the surround delays less than 15. It's very annoying.
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post #12 of 22 Old 05-24-2010, 02:01 PM
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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.

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post #13 of 22 Old 05-24-2010, 02:08 PM
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Quote:
Originally Posted by mitchlampert View Post

Is that really true?

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.

Sanjay
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post #14 of 22 Old 05-24-2010, 02:13 PM
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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?
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post #15 of 22 Old 05-26-2010, 10:06 AM - Thread Starter
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Here is the reply I received from Theta:

Quote:


I'd suggest to leave the fronts at zero delay. The 15 ms of delay for the rear channels is Dolby Labs and DTS' required parameter, to ensure that the front channel info always arrives at your ears first. If anything, I'd suggest to add more than 15ms of delay to the rear channels, to give the impression of greater immersion in the sound field!

Happy listening,

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post #16 of 22 Old 05-26-2010, 10:23 AM
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Quote:
Originally Posted by mitchlampert View Post

Here is the reply I received from Theta:

typical help desk BS

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post #17 of 22 Old 05-26-2010, 11:24 AM
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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
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post #18 of 22 Old 05-26-2010, 11:37 AM - Thread Starter
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Quote:
Originally Posted by Ratman View Post

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

15 is the lowest value that can be set. The delay cannot go below 15 for any of the side or surround channels.

I don't know why it would be necessary for DD or DTS to mandate any delay since if they want to ensure a delay, they should impose their mandate at the engineering level, not the end user level where it causes confusion.
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post #19 of 22 Old 05-26-2010, 12:05 PM
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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?
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post #20 of 22 Old 05-26-2010, 01:10 PM
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Quote:
Originally Posted by Ratman View Post

I'll ask again, why is more than 15ms required for ~5' distance?

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).

Sanjay
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post #21 of 22 Old 05-26-2010, 02:10 PM
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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.
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post #22 of 22 Old 06-01-2010, 01:00 PM - Thread Starter
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Quote:
Originally Posted by Ratman View Post

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.

Yup!! I want less delay than the Theta allows. Personally, I think it sucks that a top flight processor (at least they were so many years ago when I bought) still imposses minimum delays when they are no longer needed or wanted and the fix would be a firmware update away!
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