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Discussion Starter · #1 ·
Hi all (didn't know whether to post here or PS3 thread/Blu-ray Players forum),


I was testing DD/DTS tracks on regular DVDs. I know that bitstream and PCM from the PS3's decoding should sound the same (other than possible overall level differences), but that's not what I'm getting and can't figure out why!
I don't know if there's an issue with the PS3 or the Denon AVR-1909. I initially posted in the Audyssey thread thinking it was only an issue with the Dynamic EQ "boosting" feature. But it's actually just that its boosting magnifies the difference which I still hear even with Dynamic EQ Off .


The overall level of midrange, voices, etc. is close enough that I can't tell the difference between bitstream and PCM (after adjusting a couple dB if necessary). But the dynamic "impact" of the bass, mostly the lowest frequencies it seems, is definitely greater with bitstream. I can even make the overall level of bitstream a bit lower than PCM, and still have noticeably more bass. Combine this difference with the bass boost Dynamic EQ provides, and it's not subtle; anyone would notice it.


Any ideas what could be going on? I'm not a newbie and think I mostly know what I'm doing
, so you don't waste your time going over the basic things that I know could make a difference.
It's an HDMI connection, of course. The PS3's "Dynamic Range Control" is Off, Off, Off -- I see that all the time switching between Bitstream/Linear PCM.
Isn't that the only PS3 setting that would affect its PCM output? Oh no, there's its output level setting too (Volume it's called?), but that's at Normal (middle default). Any and all receiver Dynamic Range Compression stuff is Off, although those would only apply to bitstream stuff anyway (and only DD, not DTS?), which has NO problem with dynamics.
Receiver's LFE level is at 0 for everything: DD, DTS, MPCM. Speaker configuration/levels are always the same (what Audyssey set). I'm not kidding when I say everything is exactly the same with bitstream and PCM, as far as I can tell, except what I'm hearing.
I'd sure like to know why!


From my second post in the Audyssey thread: I don't have any Blu-rays except the demo disc that came with the PS3, and I checked out its TrueHD trailers (Dynamic EQ On) for Casino Royale, Harry Potter, Spiderman, and Underworld (just 2.0). Comparing the TrueHD over PCM and the bitstreamed DD "secondary" audio, the latter sounded noticeably more "dull," particularly on Harry Potter and Spiderman. Same I guess for CR, except one blip of bass sounded a bit louder with lossy DD. Underworld's 2.0 sounded pretty much the same either way.


Well at least with that BD, I absolutely didn't feel the DD bitstream sounded more dynamic, like the DVDs, compared to the PS3-decoded lossless. Then I jokingly wonder if the TrueHD should be more dynamic than I heard.
Or if the PS3 has an LFE decode problem, maybe those trailers didn't use much/any LFE... Maybe the PS3's BD lossless decoding is correct, but it has an issue with either (a) DVD tracks, or (b) decoding lossy formats. Either would seem strange, but I'd like to figure out this annoying difference!



Any other PS3 users notice a difference in bass between the 2 methods when playing DVDs or other lossy formats?


Thanks if anyone has an idea. At this point, I just can't imagine having them sound identical, bass-wise...
 

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Since where the signal is decoded shouldn't matter as far as SQ, maybe this has something to do with how your particular AVRs handle PCM versus bitstream.


That is something that has been discovered in a few threads.
 

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Bitstream and PCM may sound different as they might be at a different volume. They are on my PS3/RX-V3900 setup. I have tested it with a sound meter and a Dolby Digital soundtrack. Other people have reported the same thing - bitstream is louder.


For some reason, the gain seems to be different somewhere..


Besides a volume difference, I would not expect a difference between the two.


There's no reason not to use PCM all the time that I know of. Of course if you are convinced bitstream is better, you can always select bitstream for DD/DTS tracks, and change back to PCM if you want to hear lossless tracks.


As for WHY bitstream is louder, I can't say. Ideally, it would not be.
 

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The usual reason for this complaint is that the receiver is not applying the standard 10dB boost to the LFE channel when fed HDMI LPCM input.


Most modern receivers will do this by default, but some have settings to disable this, which a confused user might very well do.


To see if this is your problem, play test tones from a calibration disc and compare LPCM vs. Bitstream for each channel. Of course for the PS3 you will need to do this for a lossy test track -- DD5.1 or DTS.


Use an SPL meter. If the LFE IS 10dB low when using LPCM from the PS3 (compared to what you get with Bitstream), then look for an LFE boost setting in your receiver you may have set incorrectly. NOTE: The PS3 is known to put out correct levels.


You will need to use a test track that has LFE content rather than just bass on the main speaker channels. To check that, temporarily set all your speakers Large. That way only LFE goes to the subwoofer. So if you are still getting bass out of the sub when playing that test track, then it must have real LFE content. If not, use a different test tone track that actually produces output on the LFE channel.


All receivers get the 10dB boost right when fed DD or DTS Bitstreams. But some older receivers get it wrong for LPCM or require the user to make a setting change to get it right. If you find this is your problem and you can't find a setting in the receiver that fixes it, then go to the thread for your receiver and ask for help. You may need a firmware update for it.

--Bob
 

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Excellent information Bob. Thank you for sharing.


I just wish the PS3 could bitstream the Dolby and DTS HD tracks so I could see the cool little symbols light up on my AVR. As it stands now, it just says Multichannel or something like that when sent PCM from the PS3.
Still sounds fantastic though, since I keep my output at PCM all the time, and that is what I used to balance my sub to my main speakers when running my calibration tones.


Dan
 

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Quote:
Originally Posted by gluvhand /forum/post/16929638


maybe i missed something in the op, but, you are aware you can't send the hd audio bitstreamed from the ps3. The ps3 will only internally decode.

+1


so bitstream and PCM from the PS3 are different for obvious reasons.
 

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Quote:
Originally Posted by gluvhand /forum/post/16929638


Maybe I missed something in the OP, but, you are aware you can't send the HD audio bitstreamed from the PS3. The PS3 will only internally decode.

The OP was speaking of both lossy and lossless codecs. You can bitstream lossy with the PS3. I was referring to his first test.


Darklord has a BRP that allows bitstreaming of anything.
 

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Discussion Starter · #11 ·
Thanks for the replies guys!
I was going to reply to more of your posts individually, but after seeing Bob's post the other day, I wanted to check things out more, so last night I burned the DIY Audio Test DVD from a member here...


I noticed strange results with its LFE test tones between bitstream/PCM, and it turns out I was able to fix it by turning the MultEQ room correction feature Off! See my post in the Audyssey thread for more... Something is screwy when it's enabled, causing the differences I heard. With it Off, I went back and checked the DVD scenes and there's absolutely no difference between bitstream and PCM -- exactly the same.



I was glad to eliminate the PS3 and find the root of the problem. Now I'll see what happens next... Guess I'll get a properly working MultEQ receiver somehow!
 

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A friend pointed out this thread to me, I have a similiar problem as the OP. When I bitstream non HD formats, my center sounds great, when I LPCM HD formats, it is a little subuded. I have to turn it up to get the same volume level. I saw one post referenced the LFE channel, mine seems fine. I have an Onkyo 806, PS3, Paradigm v5 cc-690.
 

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I did not notice the center channel problem. I did not notice an LFE problem (but was not listening for it.)


I did notice an overall volume difference, and the SPL meter confirmed it.
 

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Suprised no one else has noticed this. We watch some B rated non BD movies that are non HD and that is where I noticed the difference. As you said Bitstream just seems louder while LPCM is noticeably lower. I have not used an SPL meter, but if my ears can hear it, I am sure an SPL meter would confirm it. The difference is not super drastic, so its more of an annoyance than anything else. I have checked the settings on the PS3 and my Onkyo more times than I can remember, guess the PS3 or Onkyo is doing something funny.
 

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Hi,


I found this thread through google. I too am experiencing the exact same issue as the original poster.


My setup comprises of an Onkyo TX-SR507 (which has Audssey 2EQ) and Sony PS3 (fat version - non TRUEHD bitstreaming).


I noticed the difference in subwoofer activity particularly in one scene from my favourite DVD, "The Matrix". The scene I'm talking about is the lobby scene where Neo is confronted by security, opens his coat to which the guard exclaims, "Holy S#!t", and then punches the guard in the chest.


With the PS3 set to Linear PCM this punch has zero weight behind it, it's more of a "thwack" than anything else. However, with the PS3 set to Bitstream, there is weight behind the punch. The sub here is active where it was not before.


I'm yet to try turning off Audyssey 2EQ on the Onkyo and do an A/B again.


I was thinking that it had something to do with the PS3 not handling the LFE properly when it does the decoding. But after reading this, I'm not so sure anymore.


I hope someone finds a fix, it really is an annoying issue to have. I'm very tempted to put my fat PS3 up for sale, and replace with the new slim line ps3 which can bitstream TrueHD.
 

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Ok, looks like I have exactly the same symptoms, but things are slightly different.


Turning off Dynamic EQ under the Audyssey settings does nothing, and turning off Audyssey entirely also does nothing.


There is something I was missing before. When setting the PS3 to send PCM, Audyssey on the receiver does NOT turn on.


When the PS3 is set to Bitstream, Audssey turns on.


That's probably why I'm hearing the differences. There's no EQ being applied to Linear PCM.
 

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I have the exact same problem than the OP. I posted this in the denon 590 thread:


I have hardly any bass with multi-channel PCM over HDMI. My PS3 is set to decode internally and output as multi-channel PCM over HDMI and there's a definitely lack of bass on PCM soundtracks in comparison with their Dolby/DTS equivalents (same movies, but PS3 set to bitstreaming).


I can't see why only multi-channel PCM is affected, because is the same input and same HDMI cable. It's like the amp isn't doing any bass management (or audyssey) with multi-channel PCM sources. So ridiculous that a regular Dolby or DTS soundtrack sounds a lot better than their High definition counterparts.


I haven't tried turning the MultEQ room correction feature Off yet, but if it fixs the problem, then the Denon receiver is screwing things up.


I can't believe very few people noticed this issue before. Turning MultiEQ off would be a really bad solution.
 

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Figured out the problem with mine.


I made a big newbie mistake. The problem I was experiencing had everything to do with the DSP settings.


I had inadvertantly changed the way the receiver handled PCM. I had the DSP set to "Direct", when it was supposed to be set to "MultiCH".


I've since set "MultiCH" instead of "Direct" for PCM sources, and now bitstream and PCM sound exactly the same.
 

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Glad to hear you figured it out!


I suspect that a lot of the "bitstream sounds different than PCM" problems come down to settings problems like that. Unfortunately, due to the complexity of setup menus and lack of standardization of terms, it's hard to verify those settings unless someone else happens to have the exact same hardware and, in some cases, even the same firmware revision.
 
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