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MACCA350

**warning** Dts-hdma Bitstreamed Can Cause Speaker Damage!

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Came across this on AVS and thought I'd post it here as a heads up

link

I've run across several posts now saying they have had issues with dts masters when bitstreamed to their receivers. Apparently it causes an extremely loud popping sound that can damage your speakers. (reminds me of when you would send bitstream dts to an incompatible receiver)

-The Fly

-Fantastic Four

-The Golden Compass

-Chronos

It is unknown if this is a disc, player or receiver problem but it only happens when Masters is bitstreamed to your receiver.

Please test at your own risk!!!

Even low volumes can damage your system!!!

If you have watched any of these movies AND are bitstreaming DTS masters to a 1.3 receiver please post your results and what player and receiver you are using.

Also, if you run across any other titles please post.

The Fly (At the beginning of the movie when Jeff Goldblum goes to the magazines office, the main editor greets him and then walks out of his office door leaving Jeff Goldblum and Gina Davis in the office. Right when the door closes the audio goes ballastic.)-jsmiddleton4

Fantastic Four (Its the first scene where Reed and Victor are negotiating in his office. Right around the time they shake hands on the 75/25 deal.)-strange_brew

Chronos (near the end of the movie arouind 38:50 to 38:55 (38:52 exactly I think) where the camera is looking up at the cathedral ceiling with the lights shining thru)-kinglerxt

Involved Equipment:

Player-receiver

Panasonic BD30-Onkyo 705

Panasonic BD30-Yamaha 1800

Panasonic BD30-Onkyo 805

Panasonic BD30-Onkyo 605

Panasonic BD30-Onkyo Pro PR885

First reported links:

Link

Link

Link

Edited by MACCA350

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I notice one common feature here....... Pana BD30! <_<

I wonder if these problems are pre or post the most recent firmware or independent of it? :huh:

Given I was looking a pairing this player with my Onkyo 705 I would be interested in finding out........

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Hi

I just re-read your Post and noticed it mentioned in the opening paragraph,when they first put DTS on CD's similar stories of blown Amps and speakers emerged ,the problem is trying to separate the facts from fiction and urban-myths.

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interesting,

though never had a prob bitsreaming from either the tosh xe1 or pio lx70a to denon 4308

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When I first saw the title at AVS I thought it was going to be similar to Telarc's 1812 Overture warning :unsure:

Edited by MACCA350

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I know speaker popping has always been an issue with Onkyos / Integras. Mine have been known to "pop" from time to time but not from DTS HD MA bitstreaming.

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Interesting and Scary :(

I'm bitstreaming from a Samsung 1400 to a Yammie 3800 without issue so far.

edit: Although I havn't watched those movies. scared now...dts-MA is my preferred format as a rule :(

Edited by monkeychow

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I notice one common feature here....... Pana BD30! <_<
How many BD players are there on the market now that are able to bitstream?

cheers

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So amps do not have speaker protection circuits in them for this very same reason!

cheers laurie

IIRC they normally only protect the amp against overdriving and overheating, so depending on what this 'pop' signal is it probably will get past the protection circuitry.

cheers

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If these are the masters, then more than likely the encode itself has not been calibrated to 0db for each particular encode.

Many post production houses (ours included) master soundtracks to exceed 0db (within the master, not the final).

In digital terms this clips the sound during mastering causing popping/noise (for one example).. others cause excessive boosting of the LFE, as in the signal exceeds or fluctuates through the standard 120hz (Dolby) and 112 (DTS) filters.

But the saving grace here is the fact the the final encode is actually dropping the global gain and using DR settings to bring this mix into tightly packed compressed streams.

We KNOW thevolume and freq levels will drop once we encode, so we compensate.

As these particular encoded freq's are not compressed "per se" then these mastering anomolies are also included in the final lossless encode as DR compression is usually not used with these codecs.

If it IS used (as in DDplus and DD5.1, or EX,) then we compensate that drop in gain by boosting the gain within of the master.

If we know its going to drop by -6bd after its encoded, then we ADD +6db before its encoded

Once its encoded, its then a clean flat 0db

One offsets the other see

It seems to me that theyre encoding lossless straight from a master without checking their mastered levels for each codec.

More than likely the masters are calibrated for DR Compressed formats (DTS or DD5.1)

Some amps wont allow thresholds above 0db simply because they run their own filters, but those amps that dont have these filters, will more than likely experience this glitch/anomoly/spike in freq or gain.

I could be wrong, but from the sound of the problem and from what we've been told about it in regard to how to manage the encoded format, it seems to be the case.

Edited by Padre

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What Padre says is quite plausible imo . Onkyo in particular have a history of white noise problems with dts lossy until they installed a mute circuit to give the avr a chance to lock on to the bitstream. Ive no doubt the mastering of some discs from particular studios [anecdotally] is not done with the care of others . ;)

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i got a bd30 and a yammy 1800 and have not had any problems yet but i haven't seen those 4 movies either

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Ive no doubt the mastering of some discs from particular studios [anecdotally] is not done with the care of others . ;)

That my friend, is what is called the human element ;)

Edited by Padre

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I posted about this issue when I purchased the XE-1 and bought Rambo-First blood on HD-DVD. My first DTS-HD MA disc and I had this problem (just after the guy asked for the bazooca to take out Rambo in the cave) and yes it scared the crap out of me. I thought my Krell amp had blown an amp or something. It's extremely load especially if your watching a movie at your normal lisytening level. Sounds like a fire cracker or a voltage spike going through every speaker. I took the movie back to JB got a replacement and it was still there so got a refund. Running an Oynko SR-805 as pre-pro via HDMI.

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How many BD players are there on the market now that are able to bitstream?

cheers

Chronos SE 13188kbps DTS 1536 kbps 1920x1072 1080p streamed on the PopcornHour but not to the speakers :-)

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How many BD players are there on the market now that are able to bitstream?

cheers

Pana BD30

Samsung 1400

Pio lx70 (?)

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