Need help! Surround sound issues when changing to Tv3...

Forums › Home Theatre (including HTPC and EPG Collector) › Need help! Surround sound issues when changing to Tv3...

nzdj

3 posts

Wannabe Geek

#76680 4-Feb-2011 21:12

Hi,

I recently brought a surround sound system with an Onkyo receiver & Jensen speakers.

The system has an issue whenever I change to TV3 (Digital Freeview) in that the speakers snap. To describe the sound it is like a static hiss and snap. It happens for less than 1 second but ONLY happens when changing to TV3. The odd thing is that it doesn't happen when changing to TV3 Plus 1 which is TV3 an hour behind...

The receiver is connected to the TV via optical audio.

If anyone knows any issues here I can supply more info if it will help in identifying the issue.

I really appreciate any help!

sbiddle

30853 posts

Uber Geek
+1 received by user: 9996

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#435511 4-Feb-2011 21:18

The amp is obviously making the sound switching between the AAC and AC3 audio formats.

nzdj

3 posts

Wannabe Geek

#435515 4-Feb-2011 21:26

Thanks,

Is TV3 AC3 format? Why is ONLY Tv3 a certain format and not TV3 Plus 1?

Are there any ways to fix this issue?

Appreciate the help.

sbiddle

30853 posts

Uber Geek
+1 received by user: 9996

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#435520 4-Feb-2011 21:36

TV3 is the only broadcaster than transmits in AC3, TVNZ have been talking about it for some time but it's never eventuated. TV3+1 isn't because it's not HD so Media Works see no need to transmit AC3.

No idea how to fix it, it's obviously an issue with your amp as it switches between PCM and AC3 and has nothing to do with Freeview.

nzdj

3 posts

Wannabe Geek

#435525 4-Feb-2011 21:47

Ok thanks,

Is AAC the same as PCM?

Does anyone know why my amp would be having issues switching from PCM to AC3?

Ta

fahrenheit

757 posts

Ultimate Geek
+1 received by user: 33

#435607 5-Feb-2011 10:15

Change to AAC (on the TV) and then TV3 will be just like all of the other channels.

I suggest you manually change it to AC3 only when TV3 shows the HD 5.1 logo on the program banner (which isn't all that often).

Jaxson

8172 posts

Uber Geek
+1 received by user: 1332

Trusted

#435789 6-Feb-2011 06:15

nzdj:Is AAC the same as PCM?

Nope.

AAC is the standard 'freeview' 2 channel/stereo audio format.
TV3 also broadcasts the AC3 dolby digital surround sound 5.1 audio format.

When listening to the AC3/5.1 soundtrack:
the centre and surround channels are left silent for shows that are only recorded in 2 channel.
If the show really does have 5.1 you get sound from all channels.

When listing to the normal AAC / freeview basic sound:
You only get two channels of sound, front left and right.

Some receivers can 'make up'/guess sound to go to all speakers when they are given only a 2 channel source.

Anyway, that's the guts of it. Back to your problem, no it sounds like simply the way the receiver switches between the two audio formats.

I don't know that you're going to get around that easily, unless you do as suggested above and change the default audio track for TV3 to AAC like every other channel. Your freeview box may allow you to do this. If you can, just remember to change it back to AC3 if you watch a real 5.1 show like CSI etc on TV3.

Lego

Shop now for Lego sets and other gifts (affiliate link).

cyril7

9073 posts

Uber Geek
+1 received by user: 2499

ID Verified

Trusted

Subscriber

#435816 6-Feb-2011 10:01

When your TV decoder is receiving an AAC stream it passes it down the spdif channel as PCM as there are no or few external AAC decoders about, hence for all intence and purpose you AVR is seeing PCM (decoded from AAC) or AC3.

I suggest you talk to Onkyo as to why it snaps, but this issue is not uncommon with some brands of AVR.

Cyril

robjg63

4161 posts

Uber Geek
+1 received by user: 1425

Subscriber

#435854 6-Feb-2011 12:06

nzdj: Hi,

I recently brought a surround sound system with an Onkyo receiver & Jensen speakers.

The system has an issue whenever I change to TV3 (Digital Freeview) in that the speakers snap. To describe the sound it is like a static hiss and snap. It happens for less than 1 second but ONLY happens when changing to TV3. The odd thing is that it doesn't happen when changing to TV3 Plus 1 which is TV3 an hour behind...

The receiver is connected to the TV via optical audio.

If anyone knows any issues here I can supply more info if it will help in identifying the issue.

I really appreciate any help!

It will be the switchover from 2 channel stereo signal to the 5.1 feed as mentioned above.
I have my Panasonic plasma and Denon amp hooked up with optical lead for the audio. It doesnt 'pop' but the amp does click a little as it switches to the new input signal - I think 'some' noise is expected - just not too much.

What sort of TV is it? Might be worth googling that - could be the TV thats causing the pop?

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler