Crackling noises from SP3

0 Members and 1 Guest are viewing this topic. Read 1313 times.

WillyP

  • Jr. Member
  • Posts: 66
Crackling noises from SP3
« on: 20 Feb 2018, 06:29 pm »
Hi all,

At the beginning of each Blu-ray disc, I can hear crackling noises from my SP3 through my centre speaker, strangely enough also when the power amplifier is in standby modus. I don’t hear them from my other speakers. Not very loud, but it is a bit discomforting. It happens every time after my SP3 (with HDMI 2.0a board) has locked. Any idea what causes these noises and how I can get rid of them?

Kind regards,

Willy

Grit

  • Full Member
  • Posts: 605
  • - Garrett
Re: Crackling noises from SP3
« Reply #1 on: 21 Feb 2018, 04:21 am »
That sounds like what my SP-3 without the HDMI board upgrade has always done (though my amps are always on, and I don't know from which front  speaker/speakers it's coming).

Best I can figure, it happens when the SP-3 switches from dolby digital (or maybe dolby prologic) to DTS-MA. It may also be when going from Dolby digital to Dolby True HD. Essentially, when I put a Bluray in (Oppo 103) and the SP3 switches from whatever the menu audio format (dolby prologic for example) is to the actual movie format (DTS MA), I get a one second or less digital screeching sound. Happens nearly every time.

I believe there are settings on the SP-3 that have to do with HDMI handshaking that might address the issue, but I've never taken the time to try and work it out.

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #2 on: 21 Feb 2018, 11:07 pm »
Hello Garrett,

Thanks for your reply. Your remarks about the relation between the noises and changes in the Dolby signal made me think. What will happen if I change the output signal of my Blu-ray player from Bitstream to LPCM? My Blu-ray player uses relays to mute the outcoming signals when the format changes to prevent disturbing noises. And guess what: no more cracks from the SP3! Until now, that is, so knock on wood.

In theory, an LPCM signal could be more prone to jitter than a Bitstream signal when the HDMI connection is used. I have only watched a few short movies after I changed the output signal so it is too early to tell, but I will possibly find out in the next few weeks if this is true. When there isn't much difference in sound quality I will continue to use the LPCM output of my Blu-ray player. From time to time, the crackling noises from the SP3 are quite loud and these are getting on my nerves a little bit.

Thanks again for your help.

Willy
« Last Edit: 23 Feb 2018, 07:00 pm by WillyP »

artur9

  • Jr. Member
  • Posts: 124
Re: Crackling noises from SP3
« Reply #3 on: 22 Feb 2018, 11:39 am »
In theory, an LPCM signal could be more prone to jitter than a Bitstream signal when the HDMI connection is used.

That's interesting.  A while ago I had changed all the sources to use PCM on the theory that noise generated by decoding in my processor might be having an effect.  I never bothered to A/B or anything just overthinking it.  I had done something similar with my music library and really preferred the sound that way.

I wonder which theoretical effect dominates.

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #4 on: 23 Feb 2018, 06:59 pm »
According to the manual (page 29 and 30), it is recommended to send the audio signal to the SP3 in Bitstream format when HDMI is used. I have read on many occasions that it does not make any difference where the audio signal is decoded, in the player or in the processor, but in theory, the Bitstream signal is unaffected by jitter when transported via HDMI while the LPCM signal is not.

I have seen some more movies in the meantime and, until now I haven't heard one single crack. For me, this is more important than a slight loss in audio quality, so I will keep using the LPCM mode as output from my Blu-ray player.

Willy

Buseto

  • Jr. Member
  • Posts: 46
Re: Crackling noises from SP3
« Reply #5 on: 24 Feb 2018, 08:39 am »
I got ploppings when playing via HDMI.
This is what Stan advised:
'I asked about trying CBL/SAT input because there is a special handling of the HDMI implemented on this particular input, dealing with some TV cable boxes.   The special feature involves recovery after sudden switching between adertisements interruptions (typically PCM 2ch or old Dolby 2 channel format), and high resolution audio play (Dolby True HD or DTS HD Master Audio).     
 
CBL/SAT input treats every PCM multichannel at 192k samples/s as a case of mis-detection of one of the high resolution streams (Dolby THD or DTSHDMA) and forces the system to reset detection which prevents loss-of sync noise.   Other inputs like DVD, DVR etc do not do that and allow PCM multichannel at 192k as is.   Until now, this problem was reported only with some cable TV decoder boxes, but it is possible that the same on the fly stream changes are now encoded in the newer blue ray disks.  We have to keep an eye on it.  For the time being if you find that CBL/SAT fixes this issue, please let us know so that we will implement a parameter allowing this to be enable for other inputs.   Note that the side effect is that (in 2015.04b) it will not allow you to play multichannel PCM 7.1 sources at 192k from CBL/SAT.'
Since then I use for HDMI the CBL/SAT input.

Grit

  • Full Member
  • Posts: 605
  • - Garrett
Re: Crackling noises from SP3
« Reply #6 on: 24 Feb 2018, 07:25 pm »
I've had this problem with my Oppo BDP-103D and with my Oppo BDP-83 for ever. It's always when watching bluray discs. They start with menus and ads and previews at the beginning. When the actual movie starts, there's always a brief, high-pitched digital static/screech sound. Once the SP3 locks into DTS MA (or Dolby True HD), the problem goes away.

Occasionally, if I skip back and start playing again, it will do the same thing.

I would LOVE that option on a per-input basis. I emailed Stan and James about it in the past and was never able to resolve it (though I never had the time to dedicate several days in a row of trouble shooting).

Please please please! It's one of the only frustrations I have with the SP3, and if Bryston can fix it in a firmware upgrade, that'd be AMAZING!

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #7 on: 24 Feb 2018, 07:47 pm »
@Buseto,

That is an interesting option. Unfortunately, not easy to realise now for me, because all my electronic gear is placed within a lowboard and to change the input I have to dismantle everything. If Stan could fix it via a firmware update, that would be wonderful. Does the fix work for LPCM signals only or also for Bitstream signals?

@Garrett,

My Primare Blu-ray player is built on an Oppo transport mechanism and when I change Bitstream to LPCM in the Audio Format Setup of the Setup Menu the pops and crackles are gone.

Only thing is, theoretically there could be a difference in sound quality between the Bitstream and LPCM options but I have not had the time to check this out.

HTH

Willy



Buseto

  • Jr. Member
  • Posts: 46
Re: Crackling noises from SP3
« Reply #8 on: 25 Feb 2018, 09:12 am »
@
Does the fix work for LPCM signals only or also for Bitstream signals?

I don't know. As the distortion could be so hard I was afraid for my speakers and wan't experiment here.

Grit

  • Full Member
  • Posts: 605
  • - Garrett
Re: Crackling noises from SP3
« Reply #9 on: 26 Feb 2018, 06:35 am »
It's an incredibly unpleasant sound. I literally apologize to my family every time we watch a bluray. But I don't usually have the volume up too high, so while very unpleasant to hear, it probably isn't in danger of damaging the speakers. At higher volumes, perhaps?

BigGeek

  • Jr. Member
  • Posts: 44
Re: Crackling noises from SP3
« Reply #10 on: 26 Feb 2018, 07:59 am »
I've had this problem with my Oppo BDP-103D and with my Oppo BDP-83 for ever. It's always when watching bluray discs. They start with menus and ads and previews at the beginning. When the actual movie starts, there's always a brief, high-pitched digital static/screech sound. Once the SP3 locks into DTS MA (or Dolby True HD), the problem goes away.

Occasionally, if I skip back and start playing again, it will do the same thing.

I would LOVE that option on a per-input basis. I emailed Stan and James about it in the past and was never able to resolve it (though I never had the time to dedicate several days in a row of trouble shooting).

Please please please! It's one of the only frustrations I have with the SP3, and if Bryston can fix it in a firmware upgrade, that'd be AMAZING!


Ditto with my Oppo 203. Nearly every Blu-ray disc has the screech through my SP3 (DVD input).

dminches

Re: Crackling noises from SP3
« Reply #11 on: 26 Feb 2018, 12:38 pm »
Ditto with my Oppo 203. Nearly every Blu-ray disc has the screech through my SP3 (DVD input).

Do you have the upgraded HDMI (4k) board?
 

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #12 on: 6 Mar 2018, 06:33 pm »
Here's hoping that James, Mike or Stan has some recommendations for us to get rid of the annoying noise that is coming from the SP3 at the beginning of each Blu-ray.

Willy

James Tanner

  • Facilitator
  • Posts: 16924
  • The Demo is Everything!
    • http://www.bryston.com
Re: Crackling noises from SP3
« Reply #13 on: 6 Mar 2018, 06:52 pm »
Here's hoping that James, Mike or Stan has some recommendations for us to get rid of the annoying noise that is coming from the SP3 at the beginning of each Blu-ray.

Willy

Hi Willy

Please email Stan - I do not have the issue with my BluRays at home or at the factory - so not sure what is happening in your setup.

james

BSMSPEMBA

  • Jr. Member
  • Posts: 56
Re: Crackling noises from SP3
« Reply #14 on: 19 Mar 2018, 04:45 pm »
Hi Willy

Please email Stan - I do not have the issue with my BluRays at home or at the factory - so not sure what is happening in your setup.

james

I have the same issue, but it is not every time.  My theory is that it is caused when the BR disk switches codecs.  For example, if the previews are in Dolby Digital, but the main movie is in DTS Master HD, the SP3 needs to relock.  When that happens, the pop or screeching sound is produced. 

The problem is better now than it used to be in earlier versions of the firmware.  However, it still happens frequently enough to be worrisome that it will damage a driver on my speakers.  Think what improved it a few versions ago is that a short mute was introduced in the firmware, when the codec changes.  However, I think the mute only happens when there is a gap between the two codecs.  Where I notice the issue the most is with my HTPC.  If I am watching streaming video with Dolby Digital then switch straight to Dolby Digital+, I get the screech.  On the other hand, if I switch from the HTCP to a DVR, there is a break in the sent codec, so no screech.

Hope this additional info from a different owner helps.

Grit

  • Full Member
  • Posts: 605
  • - Garrett
Re: Crackling noises from SP3
« Reply #15 on: 20 Mar 2018, 06:20 am »
Yeah, that's exactly what I have. I hope they introduce some kinda firmware fix.

BSMSPEMBA

  • Jr. Member
  • Posts: 56
Re: Crackling noises from SP3
« Reply #16 on: 20 Mar 2018, 03:02 pm »
Yeah, that's exactly what I have. I hope they introduce some kinda firmware fix.

In my experience, James, Stan, and the entire Bryston team are highly focused on customer service and very responsive.

Have you reached out to Stan to describe the issue, so he can see if there is a viable fix via a firmware update?

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #17 on: 20 Mar 2018, 07:15 pm »
With my Blu-ray player, the noises disappear if I change the output format for the HDMI port from Bitstream to LPCM.

Stan has given me a possible solution for the problem but I have not had the time to try it out. I don't think Stan will mind if I share his suggestion with you.

<< One of the decoding options that affect the locking to the digital stream is:
 
SOURCE SETUP-->OTHER-->HDMI PCM 192 ENABLE/DISABLE
 
Enable is the default, disabling it will prevent playing multichannel LPCM at 192k rate on that source but it will make locking into high resolution Dolby and DTS formats much faster because 192k LPCM and high resolution Dolby and DTS use the same clocks and could be mixed up.
 
Even with “disable” it will still play 2 ch 192k PCM and it will not affect 176k and lower sample rates. >>

Hope this helps.

Willy

BSMSPEMBA

  • Jr. Member
  • Posts: 56
Re: Crackling noises from SP3
« Reply #18 on: 20 Mar 2018, 08:45 pm »
With my Blu-ray player, the noises disappear if I change the output format for the HDMI port from Bitstream to LPCM.

I think the reason the noise stops when you switch from bitstream to LPCM is because the SP3 is not relocking different codecs.  The BR player is always sending a LPCM signal.

Preferably, the lock/noise issue will have a solution when in bitstream.

WillyP

  • Jr. Member
  • Posts: 66
Re: Crackling noises from SP3
« Reply #19 on: 20 Mar 2018, 09:47 pm »
That looks like a reasonable explanation.

Probably it is still too early to draw conclusions but I have played two Blu-rays now with the setting that was recommended by Stan and I haven't heard the dreaded cracks. Of course, I have changed LPCM back to Bitstream for the HDMI output port of the Blu-ray player, before these short tests.

The coming week I will play all my Blu-rays with this setting and I will post the results here.

Willy