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Audio Systems/Bizarre audio echo home theatre


QUESTION: My home theatre system has a weird issue and looking for resolution. I have Samsung Lcd and Onkyo receiver. Setup on tv is audio output to receiver, with tv speakers muted. Audio is great with exception of just channel KSTP. When and only when kstp is on, I have an audio echo. And, to make this bizarre, it occurs only after a commercial is broadcast; after which echo is continuous. I can stop the echo by switching channels and returning to kstp. But, when a comercial is broadcast, the echo begins snd stays. If I tune any other ch, audio is great and no echo

The echo failure occurs when sourcing from cable, and from antenna air, but does not occur when sourced from Direct TV.
Is this a function of my Onlyo receiver, or Samsung Tv?  Any andwers?

ANSWER: My guess is the tv has an automatic feature causing the switching of the tv to listen to both cable and antenna simultaneously. This makes sense because there is a delay in the cable system due to its processing time required to convert to cable distribution system.

Try disabling the antenna connection and see if it goes away.

Hope this helps.  Let me know the outcome.

---------- FOLLOW-UP ----------

QUESTION: No, issue occurs with just cable connected, with just antenna connected, and with both connected. If this was a tv defect, then why not an echo all the time ? Why just when tuned to kstp, and why only after a commercial is played ?

ANSWER: Then it must be related to the signals coming from KSTP.  I don't know anything about this station in particular. I went into their web pages to see if they are broadcasting any ancillary services but couldn't find anything of interest.  But, there could be a digital signal buried somewhere in their stream which triggers the audio delay circuitry in the receiver.

Here is what I suggest you try: Next time you get the audio delay (echo, you call it) go into the tv menu and reset the audio stream such as stereo to mono.

Also, try at the receiver to see if somehow you are getting audio signal from both hdmi and digital optical connection.

Let me know the outcome of that!

It's a good mystery - but surely has a solution.

---------- FOLLOW-UP ----------

QUESTION: I have tried your suggestion before. When echoing I have reset my tv audio settings and this stops echoing only until kstp broadcasts the next commercial, then fault recurs. When echoing is present all changes to receiver settings had no effect on the echoing. This seems to imply my tv audio processing sees some kstp digital signal and causes the fault-echoing.

I don't know why source from my direct tv never has the issue. Do you think Direct tv processes the kstp signal and filters the signal that my equipment is sensitive to ?

Note, at present my tv sources are Direct Tv, and antenna (i dropped cable-comcast some months ago but fault was present from that source as well as from antenna).

Do you have any information confirming kstp (Fox 9) indeed broadcasts some weird signal when broadcasting every commercial ?

Your thoughts?

There is always a delay difference between satellite and off-air.

There many digital information and operational codes sent with tv signals.  Especially with commercials.  Even the commercial itself is coded by the station depending on your account information and personal profile in the provider account file. In fact, some close by neighbors find out that watching the same exact program channel they get different commercials. So, there is switching going on for both video and audio feeds.  I don't know if Fox does this or not but the local station could be doing it as well.

It is a mystery to me still.  Have you talked with the station or with the provider?

Have you experimented with switching channels during the commercial or just prior to it ending?  Have you tried using only the internal speakers on the tv and leaving the external sound system OFF?  That kind of experimentation may lead to an understanding of where the problem is emanating  from.

I'll keep thinking on it.


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Audio Design Engineer; systems, loudspeakers, cd/dvd players, etc. I am knowledgeable in all high end audio equipment and installations. MAKE SURE YOU GIVE A MAKE AND MODEL NUMBER AND CAR IF IT IS AN AUTO QUESTION. Note: I am getting some who ask good questions that take a lot of time to research but then the questioner fails to read the answer. Please don't ask questions unless you are seriously looking for an answer. If you find an answer to your question otherwise then let me know with your reply. Thank you.


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