Originally Posted by MG428
I don’t know whether my problem qualifies as audio dropout and whether it was previously discussed, but here is what I have experienced: My AVR is Denon AVR-988, which is virtually same as AVR-2808CI spec-wise. I never installed a firmware update on it thus far. 7.1ch is selected under the amp assign settings. I enabled 2 surround back speakers in the speaker configuration setting. Auto Flag Detect Mode is set to off and while the disc is played SB CH OUT is set to DSCRT ON. My BD player is Oppo BDP-83, the non-SE version, with the latest official firmware installed on. Secondary audio is set off. I will dwell on bitstream vs LPCM setting below when explaining the problem.
I have made a very simple test to check whether I really get a discrete sound. I disconnected the speaker wires of all the channels except the surround back speakers. You can hear the discrete sound very easily at the first scene of Episode I when a space craft passes through. If you re-connect the speakers wires of your side surround speakers at the same time, you can easily discern the differences between surround back and side speakers especially in the subsequent scene that takes place within the space craft where you can hear the dialogue through the side surrounds but not from the back surrounds from which you may only hear the hum of the computers inside the space craft.
So there actually is discrete sound. The problem is that when I bitstream the track from my BD player, the same discrete sound comes from the surround back speakers extremely deep and muffled to the extent that it is barely audible. In other words, I can effectively get discrete sound only when I select LPCM in my BD player. To add to the problem, such deep and muffled sound comes from the surround back speakers both in LPCM and bitstream in Episode V and VI -therefore I need to select another mode other than DSCRT ON and off in order to get sound from the said speakers in which case I do not get discrete sound- and further, my AVR automatically turns off the surround back speakers when I mount the discs of Episode V and VI.
As a side note I did not experience this problem in 7.1 TrueHD, DTS HD-MA and LPCM encoded titles. I also did not experience this problem in the only other 6.1 title I own, which is also encoded in DTS HD-MA, namely LOTR EE blu-rays.
Today I upgraded my Denon AVR-988's firmware. Now I can get nice discrete sound (not deep and muffled) while both in LPCM and bitstream in all Episodes.
As to Episodes V and VI, my AVR does not automatically turn off the surround back speakers anymore. Despite this, I still believe there is something odd with the surround back channel of these two Episodes because discrete sound is produced very rarely in comparison to other Episodes. While I am typing this post I also play Episode V: Empire Strikes Back with the TV off and so far (until 33:40 when the snow battle completely finishes) I got discrete sound from the surround back speakers between roughly 04:20 to 04:25 (5 secs), 08:00 to 08:15 (15 secs intermittently), at 16:25, 17:01, 17:08 and 27:40 for just less than a second or so, and between 29:50 to 30:00 (10 seconds). This is weird because in the opening scene, likewise the opening scenes of all or most of the Episodes, a space craft passes through in space, and in all those scenes surround back speakers produce discrete sound. I will not run this test for Episode VI but after a quick look I can tell you I find it surprising that in the Jabba's place where people and some creatures dance there comes no discrete sound at all.
You may of course say that I should not expect frequent production of discrete sound from the surround back speakers for such old titles and you would normally be right. However the oldest title, i.e. Episode IV, seems to have quite frequent discrete sound coming from the surround back speakers.
Anyhow, I will appreciate if you guys can run a 30-minute test on your 6.1 or 7.1 system and look for whether you get discrete sound from your surround back speaker(s) in Episode V other than the times I mentioned above by disconnecting your speaker wires from the front, center and side surround channels. If this is actually what we get as discrete sound from the surround back speakers in Episodes V and VI, then it seems better to matrix the sound to these speakers rather than hearing less than one minute sound in total from these speakers and having them idle in the rest of the movies.
PS. I have just finished testing the entire film. After the 34th minute discrete sound was produced by the surround back speakers only between roughly the following times:
01:43:26-01:43:33 (7 seconds)
01:43:37 - 01:43:47 (10 seconds)
01:55:53 - 01:55:54 (2 sec)
01:59:13 - 01:59:14 (2 sec)
So it makes 45 seconds (some of which intermittent) for the entire movie!!!
If someone can confirm I will really appreciate because I would not use the DSCRT ON mode for my surround back speakers if this is the actual situation. I would rather use any type of matrix mode.