Trofius Posted March 20, 2007 Posted March 20, 2007 Just quickly has anyone else noticed that when you switch to HD from SD the volume drops considerably? I have the pioneer HD set top box and when i change to a high def program it is noticably much quieter, and sounds different, maybe its in surround hant really noticed.. Do I have settings screwed up? or is this the way it is?
pheggie Posted March 20, 2007 Posted March 20, 2007 No your settings sound fine. The HD use AC3 format and is quieter than the SD channels that use mp2 format. You probably noticed your DVD player is quieter too because most DVD's use AC3 audio format.
Neon Kitten Posted March 20, 2007 Posted March 20, 2007 AC3 isn't quieter by nature. Australian TV networks have the dialnorm setting on their Dolby Digital encoders set WAY too enthusiastically, that's the reason.
sold Posted March 20, 2007 Posted March 20, 2007 AC3 isn't quieter by nature. Australian TV networks have the dialnorm setting on their Dolby Digital encoders set WAY too enthusiastically, that's the reason. Most of the time dialnorm seems to be -23dB or -27dB, which I can't really comment on for TV shows but for movies this is consistent with what you get on the DVD release.
Neon Kitten Posted March 21, 2007 Posted March 21, 2007 Most of the time dialnorm seems to be -23dB or -27dB, which I can't really comment on for TV shows but for movies this is consistent with what you get on the DVD release. The difference being that movie soundtracks have massive dynamic range, while broadcast TV soundtracks have very little. Similarly on many music DVDs, when the AC3 soundtrack seems "too quiet" it's due to a misguided dialnorm setting. With digital TV, basically the MPEG audio stream reflects the true intended level of the audio, as it's simply a straight in, straight out lossy codec. When setting up their AC3 encoders, channels should be looking to match that perceived level.
Craig M Posted March 21, 2007 Posted March 21, 2007 When setting up their AC3 encoders, channels should be looking to match that perceived level. No, No. That would mean setting an incorrect DialNorm level. You'll probably find the DialNorm level currently employed by the Networks is quite correct. It is meant to be set to the average dialog level across multiple genres of programmes. So when you switch from programme to programme, channel to channel, there is consistency in the level of dialog. Artificially inflating the DialNorm value simply to 'fix' the level difference in the stupid simulcast MPEG audio/AC-3 mistake (which should never have been allowed) is simply wrong, technically. The reason AC-3 *seems* too low is that it is allowing for a huge increase in level, if required, by wide dynamic range movies. Craig.
Neon Kitten Posted March 21, 2007 Posted March 21, 2007 No, No. That would mean setting an incorrect DialNorm level. You'll probably find the DialNorm level currently employed by the Networks is quite correct. It is meant to be set to the average dialog level across multiple genres of programmes. Yes, but that doesn't take into account the massive dynamic range compression the networks run their audio through before encoding. The reason AC-3 *seems* too low is that it is allowing for a huge increase in level, if required, by wide dynamic range movies. And therein lies the problem. That dynamic range is never utilised on broadcast TV, only in the cinema and on DVDs.
Craig M Posted March 21, 2007 Posted March 21, 2007 That dynamic range is never utilised on broadcast TV, only in the cinema and on DVDs. You obviously haven't listenend to DD 5.1 movies on Nine HD then. No compression or limitation whatsoever. Craig.
BribieG Posted March 21, 2007 Posted March 21, 2007 I notice that when changing from ABC SD to ABC HD upconverted to 720p, there is an instant 'improvement' in the sound quality, not so much volume but 'clarity', 'crispness' and 'presence' - everyone is just so much easier to understand.
Craig M Posted March 22, 2007 Posted March 22, 2007 I notice that when changing from ABC SD to ABC HD upconverted to 720p, there is an instant 'improvement' in the sound quality, not so much volume but 'clarity', 'crispness' and 'presence' - everyone is just so much easier to understand. That might be because they run an audio processing device for the SD sound, but none for the HD sound. Craig.
kootaberra Posted March 22, 2007 Posted March 22, 2007 I notice that when changing from ABC SD to ABC HD upconverted to 720p, there is an instant 'improvement' in the sound quality, not so much volume but 'clarity', 'crispness' and 'presence' - everyone is just so much easier to understand. No the audio is the same on SD and HD for the AC3 stream. However there is very mild compression for the SD Mpeg audio. I see a 1-2 db level difference in the AC3 between SD and HD AC3.
digitalj Posted March 22, 2007 Posted March 22, 2007 I find with HD that if my HD STB is programmed to output PCM, it sounds quieter, than if it was output as DD.
Guest JimboTHX1138 Posted March 26, 2007 Posted March 26, 2007 Yeah the DD is louder than PCM, also some STB's have a Audio Variable setting, my LG has this and can dim the volume when set to on.
tonygib Posted March 26, 2007 Posted March 26, 2007 yup, HD tends to be softer then SD and Ten SD is softer then 7 or 9 SD, at least in Adelaide it is. Would be darn annoying, if I watched enough and channel jumped enough on FTA TV.
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