# MPEG4 AAC SBR for HDTV broadcast versus audio quality for high end or descent systems



## HIFIbeginnin (Jan 30, 2013)

Hello to everyone:

i was wondering if MPEG 4 AAC SBR or HE profiles meets the audiophile grade requirements for a good audio experience in HDTV television broadcasts? 

i am wondering because where i am from we adopted an system of HDTV that uses MPEG4 for video and M4A AAC SBR for audio which is the ISDB-TB system but i find the audio that offer the broadcasts of television just do not have the audio full body sound, lack bass and midranges and excessive trebles, just have noticed that somebody else which gets HDTV in format MPEG4 have noticed something similar , i have an PDP panasonic connected via Toslink to the receiver and just the audio from HD channels is not with body so i do not know if is just me who have noticed that or everyone else have noticed this in M4A AAC SBR OR HE profiles sound deficiency.

any input would be appreciated

best regards
Francisco


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## ericzim (Jun 24, 2012)

Here in the states HD broadcasts are in AC3 Dolby surround or AC3 2 channel with what I perceive as low bit rates to keep the majority of bandwidth available for HD video. Some broadcasts are better than others as far as bass/body is concerned. I use AAC on my DVD rips to my server for DLNA as AAC is better balanced at lower bit rates than AC3 and saves space on rips from DVD masters with poorly mastered audio. On good rips of good source material I haven't noticed any drop in quality of audio using AAC. Perhaps the audio sources used are not very good?


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## HIFIbeginnin (Jan 30, 2013)

well we here use as codec M4A AAC in the profiles SBR althought the book that put normalization in the japanese system of HD says that must be in HE profile but already i do not find that have the sound produced as body and even in the voice or speechs programms the voice is mainly composed by high frequencies and not midranges even in male voices , as far as i know in the States is used the ATSC system with the codec Dolby AC3 in 5.1 or 2.0 either but the demonstrations recorded from there the sound is more smooth and defined than what i heard in my local HD programming.


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## ericzim (Jun 24, 2012)

Is HD music also poor there?


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## HIFIbeginnin (Jan 30, 2013)

almost all what i heard is just poor audio , a lot of trebles and bass and midranges zero in the HDTV broadcasts in fact if i use dolby pro logic in mode Cinema just get the audio of the center channel and must use in music mode to get the audio from left-right and center also


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## ericzim (Jun 24, 2012)

HIFIbeginnin said:


> almost all what i heard is just poor audio , a lot of trebles and bass and midranges zero in the HDTV broadcasts in fact if i use dolby pro logic in mode Cinema just get the audio of the center channel and must use in music mode to get the audio from left-right and center also


What receiver do you have and does it have any type of EQ setup like Audysee?


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## HIFIbeginnin (Jan 30, 2013)

i hqave an denon AVR 1312 and do not have multieq or audysse system of calibration, also the audio from the High definition television just is poor what i get from the digital toslink to the receiver


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## ericzim (Jun 24, 2012)

I am very familiar with the shortcomings of the Denon 1312, in fact before I picked up the Denon AVR 1612 I briefly owned the 1312 and returned it the next day for the 1612. I couldn't get the rear surrounds to balance out. The entire system had an almost dull sound to my likings and even my wife noticed how poor the over all audio sounded. Speaking from my experience your problem may not be the AAC audio signal at all but just a very poor performing receiver.


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## HIFIbeginnin (Jan 30, 2013)

Perhaps but have discovered had my system wrong set up also


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## ericzim (Jun 24, 2012)

HIFIbeginnin said:


> Perhaps but have discovered had my system wrong set up also


Getting the EQ settings setup and the speaker distances set just right can be a daunting task on the 1312 for sure. I like the Audysee auto config for just that reason.


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## HIFIbeginnin (Jan 30, 2013)

The distances were wrong so had to measure again just delays settings are like uncovered have in 24ms by an calculation of an software for Android for calculate delays


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## ericzim (Jun 24, 2012)

Glad to hear you have it all sorted.


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