From: dhunker@hotmail.com   
      
   "Kevin McMurtrie"  wrote in message   
   news:513967da$0$52738$742ec2ed@news.sonic.net...   
      
   In article ,   
   "djh"  wrote:   
      
   > I got a Yamaha RX-V750 7.1 AV receiver this past weekend. I have it   
   > configured for 5.1 surround sound and use an over-the-air television   
   > antenna   
   > for viewing local programming (no cable). The audio signal I receive from   
   > NBC fluctuates significantly, this occurs in programs as well as   
   > commercials. An example would be while watching the local news the volume   
   > will be at a normal listening level throughout the entire news cast but   
   > when   
   > the station goes to commercial the sound level drops to a far less audible   
   > level for some of the commercials, not all. When the news resumes the   
   > sound   
   > level returns to normal. It is not limited to commercials only. It drops   
   > the   
   > sound level for certain programs such as The Tonight Show. When I try to   
   > watch The Tonight Show I turn the volume up to a normal listening level   
   > but   
   > the sound has a muffled quality to it.  I do not have this problem with   
   > the   
   > other national networks.  Although I have noticed some distinct sound   
   > variations on other networks such as background sound is somewhat   
   > diminished during some programming as well as commercials,  but certainly   
   > not as pronounced as NBC.  I had a Sony 5.1 AV receiver but replaced it   
   > with   
   > the Yamaha but I did not have this sound trouble with the Sony.  Am I   
   > missing something in the setup of the receiver? I've followed the setup   
   > guide to balance the speakers using the microphone. I'm using optical   
   > cable   
   > to connect the television to the receiver. Has anyone else run into this   
   > problem? Thank you for any help or advice you might have.   
      
   It sounds like Dolby Dialnorm problems with AC-3 decoding.  It's a   
   headroom adjusting hack designed accommodate low and high dynamic range   
   programs.   
      
   A perfect receiver will not fix the problem.  Many TV stations don't   
   pass through the correct Dialnorm value.  Even when they are, it's   
   probably wrong from the program too.  The Tonight Show with Jay Leno is   
   an excellent example of how Dialnorm should not be used.  It uses a high   
   dynamic range profile but it's recorded with a very compressed dynamic   
   range.  In a feeble attempt to create a "live" atmosphere, people mixing   
   the sound crank up the volume for a moment when they notice that the   
   crowd is reacting.   
   --   
   I will not see posts from Google because I must filter them as spam   
      
   Thank you for pointing dialnorm out to me. I found a post at   
   hometheaterforum.com that described my predicament precisely.  My thanks to   
   Michael Reuben for his insight.   
   "The theory behind dialnorm is to allow DD signals to be adjusted so that   
   dialogue is always at a constant level when switching among soundtracks. The   
   dialnorm setting achieves this by instructing the decoder to raise (or   
   lower) the overall volume by a set amount. The feature would be useful in   
   things like TV broadcasts, where it could be applied to maintain a constant   
   volume across different channels -- if only it were used correctly. But it   
   almost never is. For example, I receive one cable channel that has a   
   dialnorm setting of 0 DBFS, because some idiot in the broadcast chain   
   obviously thinks that's a "neutral" setting, when in fact it drops the DD   
   volume by 31db (27 more than a typical DVD), which makes it almost   
   inaudible."   
   Again, thank you for your time and pointing out this answer for me.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)