Can I downmix L,R,C,LFE but not surrounds into RCA output? - Page 2 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #31 of 50 Old 06-17-2014, 03:41 PM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Quote:
Originally Posted by BassThatHz View Post
I just tested my 105 and it works.

and LFE is applied to the R and L and SR and SL (if set as Large).
Quote:
Originally Posted by sivadselim View Post
Not doubting you, but curious as to how you confirmed the LFE rerouting.
Quote:
Originally Posted by BassThatHz View Post
I used ac3filter in manual matrixing mode to 7.1LPCM over HDMI.
I assume Dolby and DTS would matrix the same with this chipset.


It's still not clear (it's me, not you). The player has an HDMI input?

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
Sponsored Links
Advertisement
 
post #32 of 50 Old 06-17-2014, 04:13 PM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,275
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 382 Post(s)
Liked: 444
The 105 is of sufficient quality that you can ditch the preamp altogether.
The only reason I bought an Emotiva XSP-1 pre-amp was to get a few more volts output, that and, I wanted to power stereo subwoofers via XLR.

My 105 took about 48 hours to break-in. Fresh out of the box it was overly bright sounding.

The only reason I'd even consider an AVR would be to get Dolby Atmos for movies when the new UHD Bluray's and AVR's in Christmas-2014 come out.

I wasn't happy with the SQ of mainstream AVR's back in the early 2000's and I've been out of the AVR scene ever since.
mtn-tech likes this.
BassThatHz is offline  
post #33 of 50 Old 06-17-2014, 04:15 PM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,275
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 382 Post(s)
Liked: 444
Quote:
Originally Posted by sivadselim View Post
It's still not clear (it's me, not you). The player has an HDMI input?
https://www.oppodigital.com/blu-ray-...05-Back-hr.jpg

BassThatHz is offline  
post #34 of 50 Old 06-17-2014, 05:57 PM
AVS Special Member
 
mtn-tech's Avatar
 
Join Date: Feb 2013
Location: Nevada
Posts: 1,078
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Liked: 150
Quote:
Originally Posted by sivadselim View Post
ICBM?
The ICBM is an Outlaw Audio 6 channel crossover - I actually do own one but I'm not using it right now.

I have two bass equalizers - the Velodyne SMS-1 and SVS AS-EQ1. I'm using the Velodyne right now - it uses proprietary DSP equalization with an auto setup mode and user adjustable bands and boost / cut. My newly acquired SVS AS-EQ1 uses Audyssey MultEQ XT32 and can equalize dual subs - looking forward to setting it up!

I don't use room correction for anything above the bass management crossover frequency - 80Hz for me.

2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD
mtn-tech is offline  
post #35 of 50 Old 06-17-2014, 10:23 PM - Thread Starter
Senior Member
 
meli's Avatar
 
Join Date: Jun 2003
Location: New York City
Posts: 265
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 11
Quote:
Originally Posted by mtn-tech View Post
I connect my Oppo directly to the inputs of the Adcom (balanced inputs for me since I have a BDP-105) and use it for all 2 channel listening - 2 components to control (Oppo and preamp), very easy to use..
Until you inferred to it here, I didn't realize that the Oppo had variable analog outputs that could be adjusted with the remote control. That makes everything much simpler. A side question: can the Oppo downmix SACD and DVD-Audio discs to 4.0 using the same method?

Quote:
Originally Posted by mtn-tech View Post
Then for multi-channel or movies, I just engage the HT bypass and my Oppo sends decoded surround directly to the amps (through the Adcom for L/R mains)...
Do you mean the processor switch on the GFP-750? It shows how long my preamp has been in the closet that I forgot it has that function. To be honest, I think I never truly knew what it was for or how it worked. I'm afraid I still don't totally get it. Would you mind detailing how you have it connected? As I understand it you use the balanced outputs on the Oppo for stereo listening. For surround material, do you use the FL/FR RCA outputs of the OPPO? I don't totally get where the processor loop comes into play. I appreciate your help.

Quote:
Originally Posted by mtn-tech View Post
I had my sub set to "off" in the Oppo and I don't think I was getting LFE downmix to my "Large" front main speakers - I am very curious what Oppo has to say
Here's the response from Oppo.

Yes, you can set the Center, Surround Back Left/Right and LFE to OFF and and the main speakers to LARGE with the Surround set to SMALL. The player will redirect the Center, Surround Back Left/Right and LFE to the main speakers and send normal audio through the Surround Left/Right.

Best Regards,
Customer Service
OPPO Digital, Inc.

Quote:
Originally Posted by BassThatHz View Post
The 105 is of sufficient quality that you can ditch the preamp altogether.
I have a couple of other stereo sources to connect. A tuner, though I guess I don't use that much. A Wii, I could probably do without that until my kids ask for it. A PS4, maybe I could connect that to the OPPO HDMI input. But I may get a Roku or Apple TV, so then I would need the preamp or an HDMI switcher in the loop before the Oppo HDMI input. And for CD playback I wonder if the the audio quality would be better keeping the Oppo outputs at default and using the Adcom to adjust the levels.

Last edited by meli; 06-17-2014 at 11:24 PM.
meli is offline  
post #36 of 50 Old 06-18-2014, 09:31 AM
AVS Special Member
 
JHAz's Avatar
 
Join Date: Mar 2009
Posts: 4,043
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked: 167
Quote:
Originally Posted by sivadselim View Post
Not doubting you, but curious as to how you confirmed the LFE rerouting.

FWIW, IIRC, there was testing several years ago that demonstrated that at least some AVRs, even then, mixed the LFE channel to left and right when "no sub" was indicated. This was, at the time, different from what most players would do, because they followed the downmix "instructions" in the DD stream. I THINK you could set that to mix LFE to the mains, but by default it was turned off.

Wouldn't surprise me in the least if Oppo's device followed its own downmixing rather than the embedded uh "suggestion" from the DD track.

It's been a long time since I paid attention but, again, as of a few years ago, on the movies with bass thread, it was clear that the LFE channel content was already contained in left and right channels in most if not all mixes. SO adding the LFE channel is more about getting the level back up to where it should be than entirely missing out on the content. And with speakers that roll off in the 30 to 40 Hz range (and compress at high levels) the relative impact of adding the LFE back in might be minimal in the real world with a given system. That said, I'd want it rolled in, even if playing back through my little Paradigm Studio 10. Might as well get all of what there is to get within the speaker's passband, eh?

I always thought the downmix itself occurred post-decoding, but I could be wrong. That would mean that whether the original signal was PCM, DD, or DTS would be irrelevant at the downmix stage because it all would be PCM at that point. It seems way unnecessarily complex to implement separate mixing algorithms to take care of different lossy compression schemes, when it all has to become PCM in order to go to the DAC and be turned into analog sound. Just one algorithm for the PCM seems more efficient. But I could be completely wrong about how things actually work.
JHAz is offline  
post #37 of 50 Old 06-18-2014, 09:49 AM
AVS Special Member
 
Frank Derks's Avatar
 
Join Date: Jul 2002
Location: Region A,B,C
Posts: 1,897
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Liked: 89
downmix and/or other processing is after decoding in pcm.
Frank Derks is offline  
post #38 of 50 Old 06-18-2014, 09:57 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 104
Quote:
Originally Posted by BassThatHz View Post
I used ac3filter in manual matrixing mode to 7.1LPCM over HDMI.
I assume Dolby and DTS would matrix the same with this chipset.

If you use AC3Filter, then you are using a PC somewhere in the circuit. That is hardly a standard scenario.
J_Palmer_Cass is offline  
post #39 of 50 Old 06-18-2014, 10:02 AM
Senior Writer @ AVS
 
imagic's Avatar
 
Join Date: Dec 2005
Location: Philadelphia, PA
Posts: 6,436
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 1758 Post(s)
Liked: 3087
Quote:
Originally Posted by J_Palmer_Cass View Post
Where is the HDMI input on that unit?

There are two HDMI outputs, but no HDMI inputs on that unit.
Look harder!

Find out more about Mark Henninger at www.imagicdigital.com
imagic is online now  
post #40 of 50 Old 06-18-2014, 10:07 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 104
Quote:
Originally Posted by imagic View Post
Look harder!

I did. However, you could give someone a few minutes to checkout their postings before you respond!
J_Palmer_Cass is offline  
post #41 of 50 Old 06-18-2014, 10:33 AM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Quote:
Originally Posted by JHAz View Post
FWIW, IIRC, there was testing several years ago that demonstrated that at least some AVRs, even then, mixed the LFE channel to left and right when "no sub" was indicated.
All AVRs do this. A small few may do it differently and, for example, might reroute the LFE channel to all the channels that are set to LARGE instead of just the R and L. Some pre/pros may offer more flexibility in the LFE rerouting, too.

Quote:
Originally Posted by JHAz View Post
This was, at the time, different from what most players would do, because they followed the downmix "instructions" in the DD stream. I THINK you could set that to mix LFE to the mains, but by default it was turned off.
No, there is/was no setting to change the LFE rerouting. Players have always dropped the LFE channel from their analog downmix. This was a requirement of Dolby's. I do not know of any 2-channel player that would do things otherwise. The only question is 'what do (or did) players with multichannel analog outputs do with the LFE channel?'. And in almost all cases, they drop it, too. The OPPO is the only one that I know of, offhand, that doesn't. It wouldn't surprise me if there are some other higher-end or less mainstream players that can reroute the LFE channel, too, though.


Quote:
Originally Posted by JHAz View Post
I always thought the downmix itself occurred post-decoding, but I could be wrong. That would mean that whether the original signal was PCM, DD, or DTS would be irrelevant at the downmix stage because it all would be PCM at that point. It seems way unnecessarily complex to implement separate mixing algorithms to take care of different lossy compression schemes, when it all has to become PCM in order to go to the DAC and be turned into analog sound. Just one algorithm for the PCM seems more efficient. But I could be completely wrong about how things actually work.
There have been a lot of threads here over the years regarding the difference in LFE rerouting in AVRs vs. players. Here is a recent one with some of that same discussion (you participated in it, JHAz):
Does LFE belong in a stereo downmix?

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #42 of 50 Old 06-18-2014, 10:37 AM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Quote:
Originally Posted by sivadselim View Post
Not doubting you, but curious as to how you confirmed the LFE rerouting.
Quote:
Originally Posted by BassThatHz View Post
I used ac3filter in manual matrixing mode to 7.1LPCM over HDMI
Quote:
Originally Posted by J_Palmer_Cass View Post
If you use AC3Filter, then you are using a PC somewhere in the circuit. That is hardly a standard scenario.

I assume he is generating a pure LFE signal and seeing where it goes. Because there really is only one way to definitively answer the querstion and that is to send a pure LFE signal through the system and see what happens to it. It can't be done satisfactorily with measurements.



Quote:
Originally Posted by BassThatHz View Post
I assume Dolby and DTS would matrix the same with this chipset
I would agree that LPCM into the player via its HDMI input is hardly a standard scenario. I would be more curious to see what it did with the LFE track on, for example, the AVIA disc. But even then, that would not tell you what it does with every codec. That said, I DID suspect that the OPPO might reroute LFE unconventionally and it appears, especially in lieu of OPPO's respoonse to the OP, that this is the case. Whether it treats all codecs the same, I do not know, but it would not necessarily be unprecedented if it didn't.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #43 of 50 Old 06-18-2014, 10:43 AM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Curious, now, as to what the OPPO does to the LFE channel with regards to its 2-channel-only analog outputs.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #44 of 50 Old 06-18-2014, 11:30 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 104
Quote:
Originally Posted by sivadselim View Post
I assume he is generating a pure LFE signal and seeing where it goes. Because there really is only one way to definitively answer the querstion and that is to send a pure LFE signal through the system and see what happens to it. It can't be done satisfactorily with measurements.


This is what I do. I take any commercial DVD that has the THX Optimizer in the setup menu. I run the audio channel test and monitor individual channels with AC3Filter.

The Pirates of the Caribbean (COTBP) DVD has THX Optimizer in the setup menu, and I have verified that my copy uses discrete channel test tones including the LFE channel.

If the LFE channel is dropped anywhere in the playback chain with whatever settings you apply, you can tell by listening to the test tones for that THX Optimizer. You could also measure channels if you have that urge, but why?
J_Palmer_Cass is offline  
post #45 of 50 Old 06-19-2014, 04:23 PM
AVS Special Member
 
mtn-tech's Avatar
 
Join Date: Feb 2013
Location: Nevada
Posts: 1,078
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Liked: 150
Quote:
Originally Posted by meli View Post
I didn't realize that the Oppo had variable analog outputs that could be adjusted with the remote control.
Yes, and the built in volume control is so good that I cannot hear the difference between its volume control and the volume control of the preamp (in active mode). I have heard of others with volume range issues (min volume / max volume) connecting directly to amps, but I have not had any problems - I get very low volumes at 20 and have never listened to anything above 80.


Quote:
Originally Posted by meli View Post
A side question: can the Oppo downmix SACD and DVD-Audio discs to 4.0 using the same method?
Yes, as far as I know, the Oppo can downmix any multi-channel source to match the configured speaker setup.


Quote:
Originally Posted by meli View Post
Do you mean the processor switch on the GFP-750? It shows how long my preamp has been in the closet that I forgot it has that function. To be honest, I think I never truly knew what it was for or how it worked. I'm afraid I still don't totally get it. Would you mind detailing how you have it connected? As I understand it you use the balanced outputs on the Oppo for stereo listening. For surround material, do you use the FL/FR RCA outputs of the OPPO? I don't totally get where the processor loop comes into play. I appreciate your help.
Exactly, the processor switch on the GFP-750 - a feature ahead of its time - one of the reasons I wanted one of these in the first place. When disengaged, you can use the preamp and its inputs for your 2ch analog sources. When engaged, the HT bypass routes the signals from the "Processor In" inputs to the unbalanced and balanced outputs (at unity gain bypassing the volume control) as if no 2ch preamp was in the chain - it is meant to be used with an external multi-channel preamp / AVR preamp output (in my case the Oppo) to feed the Front L/R speakers - very nice.

Connected this way:
  • 2ch analog sources connected to Adcom GFP-750 via RCA (tuner, etc)
    2ch balanced source connected to Adcom GFP-750 via XLR (if you have this)
    Surround decoder output from Oppo (Front L/R from 7.1 multi-channel RCA outputs) connected to Adcom GFP-750 "Processor In"
    Adcom GFP-750 preamp outputs connected to amplifier input - Front L/R (RCA or XLR)
    Remaining 7.1 multi-channel RCA outputs from Oppo () connected directly to amplifiers

That's it - the system is actually simple to connect and easy to use. It has over 20 fewer connections than my previous system which had a seperate PrePro and DAC.

When I was putting my system together last year, I was going to buy a separate PrePro surround decoder, a high-res DAC with balanced outputs, and an SACD capable Blu-ray player - the Oppo does all of these things in one box and was cheaper.

Quote:
Originally Posted by meli View Post

Here's the response from Oppo.

Yes, you can set the Center, Surround Back Left/Right and LFE to OFF and and the main speakers to LARGE with the Surround set to SMALL. The player will redirect the Center, Surround Back Left/Right and LFE to the main speakers and send normal audio through the Surround Left/Right.

Best Regards,
Customer Service
OPPO Digital, Inc.
That is great - I didn't think that it worked that way since we've had that same discussion before. I guess I believe it if Oppo says so. I would like to find a test disc that has each channel - then I would know for sure.

2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD
mtn-tech is offline  
post #46 of 50 Old 06-19-2014, 06:14 PM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,275
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 382 Post(s)
Liked: 444
Quote:
Originally Posted by meli View Post
Here's the response from Oppo.

Yes, you can set the Center, Surround Back Left/Right and LFE to OFF and and the main speakers to LARGE with the Surround set to SMALL. The player will redirect the Center, Surround Back Left/Right and LFE to the main speakers and send normal audio through the Surround Left/Right.

Best Regards,
Customer Service
OPPO Digital, Inc.
If oppo said that, then it is "probably" codec invariant.
I'm guessing the chipset converts everything to LPCM 7.1 where it then applies the downmix matrixing.

If you set it to "small" but say 40hz, I wonder if it still has the 120-40hz LFE added to it?
BassThatHz is offline  
post #47 of 50 Old 06-20-2014, 08:43 AM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Quote:
Originally Posted by mtn-tech View Post
I would like to find a test disc that has each channel - then I would know for sure.
The track on the original AVIA DVD entitled "Low Frequency Sweep, LFE" is encoded entirely in the LFE channel and is useful for determining what is happening to the LFE channel. At least with DD material. I do not know anything about what the hirez AVIA version has, though.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #48 of 50 Old 06-20-2014, 08:45 AM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked: 69
Quote:
Originally Posted by BassThatHz View Post
If oppo said that, then it is "probably" codec invariant.
I do not know whether you can assume that or not. The 980 (Mediatek chip) bass managed different codecs differently.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #49 of 50 Old 06-20-2014, 10:41 AM
AVS Special Member
 
mtn-tech's Avatar
 
Join Date: Feb 2013
Location: Nevada
Posts: 1,078
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 186 Post(s)
Liked: 150
Quote:
Originally Posted by sivadselim View Post
I do not know whether you can assume that or not. The 980 (Mediatek chip) bass managed different codecs differently.
That is one of the reasons that I use external bass management. I hate that manufacturers give us so little control of something so important as bass management. Especially if you have two way monitors for your front mains - it is critical to have bass management correct for both multi-channel and 2 channel programming - but especially 2 channel and that is where the bass management is the worst.

It is somewhat understandable with mainstream AVRs, but it is inexcusable with a product as nice and high-end as the Oppo. I never understood all the restrictions, but now that you say that it can be limitations of some of the hardware and the Codecs available - that makes a lot of sense. Oppo just uses what is available - there are of course restrictions built into those chip sets and Codecs which are tailored for mainstream AVRs - they don't re-invent the wheel everytime they make a disc player.

2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD
mtn-tech is offline  
post #50 of 50 Old 08-25-2014, 10:51 AM - Thread Starter
Senior Member
 
meli's Avatar
 
Join Date: Jun 2003
Location: New York City
Posts: 265
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 11
This is the Original Poster. I received the Oppo 103D a few weeks ago. I have 2 main and 2 surround speakers. I have the subwoofer set to “off” and the main speakers are set to "large". For movies with a Dolby soundtrack the LFE is successfully re-directed to the main speakers. But on discs with DTS audio the LFE signal does not seem to be re-directed to the main Left & Right speakers.

I’ve checked this on a couple test discs, most recently the Disney WoW disc (which has DTS audio) and a DTS test on the Blu-Ray disc of “Under the Skin”. On these tests, when the LFE signal is played there does not seem to be any signal coming form the main speakers. On test discs with Dolby audio (I used Avia and “Toy Story”) the LFE signal is correctly sent to the main speakers.

Can anyone confirm these results?
meli is offline  
Reply Audio Theory, Setup, and Chat
Gear in this thread - SA-XR55, by PriceGrabber.com

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off