Taperssection.com

Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: vwmule on November 07, 2017, 12:13:29 PM

Title: What is going on here?
Post by: vwmule on November 07, 2017, 12:13:29 PM
I recorded Oteil and Friends last night in Silver Spring, Md., outside Washington. Strong performance and the sound was probably the best I've heard at the Fillmore, no doubt helped by venue allowing us to set up DFC rather than off to the side of board as is standard.

Yet listening to the recording reveals some really strange, annoying sound fluctuations. The volume will suddenly increase or decrease, giving a sorta "wavy" feel to certain passages. It's a bear to listen to.

A good example is Bertha: https://archive.org/details/oteil2017-11-06/oteil2017-11-06.vwmule.t14.flac

I cannot figure out what is up.

- Doesn't seem to be a loose cable; I inspected L and R channels and the fluctuation is present in each.
- The recorder settings were not changed, though before the show I upgraded to the latest MixPre firmware.
- I noticed some swaying of the stand when the audience started dancing, but nothing extreme. Could it be phasing? If so, I've never experienced anything like that.
- Could it be the venue PA? I didn't notice it at the show.

I'd appreciate any observations, thoughts you might have.
Title: Re: What is going on here?
Post by: lsd2525 on November 07, 2017, 12:23:05 PM
Paging Gordon. He reported similar issues with his Mix Pre at NMAS the other night. Not sure if he got it sorted out.
Title: Re: What is going on here?
Post by: IMPigpen on November 07, 2017, 12:34:34 PM
I listened to the Bertha from your source and also the AKG C1000 source on archive and it's not a venue/PA issue since it's not present on the other source.  Very weird....
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 12:41:54 PM
Thanks. I was waiting to compare with another source and hadn't seen that one.

You're right; it's not a venue thing.
Title: Re: What is going on here?
Post by: Gutbucket on November 07, 2017, 12:55:53 PM
Hey Alex, I suspect an issue with the Mixpre.  Maybe phantom power fluctuations.  It's not unlike the problem I and other folks were occasionally having a few years back with the Tascam DR-680, generally thought to be related to powering/overheating.  That firmware update is suspect to my way of thinking.

Bummer.  That recording sounds great otherwise.
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 01:12:59 PM
Total bummer (I'm going to have the recording removed but wanted to allow others to inspect). I'll go back to the older firmware, which I had no issues with.

Any other thoughts?
Title: Re: What is going on here?
Post by: dallman on November 07, 2017, 01:36:03 PM
Total bummer (I'm going to have the recording removed but wanted to allow others to inspect). I'll go back to the older firmware, which I had no issues with.

Any other thoughts?
I would contact Sound Devices . They are always actively involved and quick to respond. I am sure they would want to address an issue like this immediately.
Title: Re: What is going on here?
Post by: Gordon on November 07, 2017, 01:40:26 PM
Exact same issues with both mine and jbells the other night! I'm out and about now but can post samples later when I get home. Gotta be firmware. I was thinking maybe channel linking but who knows. Where your channels linked?
Title: Re: What is going on here?
Post by: Gordon on November 07, 2017, 01:42:07 PM
Total bummer (I'm going to have the recording removed but wanted to allow others to inspect). I'll go back to the older firmware, which I had no issues with.

Any other thoughts?

Fwi I painstakingly edited mine and it's not too bad but it took a while!  I sent Paul from SD a pm about it this morning.
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 01:54:43 PM
> Exact same issues with both mine and jbells the other night! I'm out and about now but can post samples later when I get home. Gotta be firmware.

Were you using the latest firmware?

My settings show linked.
Title: Re: What is going on here?
Post by: dallman on November 07, 2017, 01:56:21 PM
Exact same issues with both mine and jbells the other night! I'm out and about now but can post samples later when I get home. Gotta be firmware. I was thinking maybe channel linking but who knows. Where your channels linked?
This could be an (the) issue. I unlinked my channels just before a show because I didn't like the way the meters looked. I was running the new firmware, and had no issues after. That does not prove anything, but it is a possibility unless others having the issue were not linked.
Title: Re: What is going on here?
Post by: willndmb on November 07, 2017, 02:23:37 PM
Are you guys using "proper powering"?
I.e. Green light and not orange
Title: Re: What is going on here?
Post by: rippleish20 on November 07, 2017, 02:30:48 PM
I recorded several shows in the last week and did not have this particular problem (I did have a strange issue one night where is decided it couldnt see my sd card when I hit record but..). I did not upgrade from 1.11 however ...
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 02:35:07 PM
> Are you guys using "proper powering"?

Mine is green, always has been.
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 02:52:03 PM
As it happens, I'm seeing Oteil tomorrow in Baltimore and will run the MP6 with the previous firmware. Will also run mics into Zoom F8.
Title: Re: What is going on here?
Post by: heathen on November 07, 2017, 03:11:09 PM
As it happens, I'm seeing Oteil tomorrow in Baltimore and will run the MP6 with the previous firmware. Will also run mics into Zoom F8.
Can you change the firmware between sets?  It might be very useful to see if you can reproduce the problem.
Title: Re: What is going on here?
Post by: vwmule on November 07, 2017, 03:43:49 PM
Can probably attempt that.
Title: Re: What is going on here?
Post by: Gordon on November 07, 2017, 04:04:56 PM
> Are you guys using "proper powering"?

Mine is green, always has been.

Jbell and I both have green powering.  Both using mp6 with latest firmware and channel linking.  I was running my ak 40's, john his mk41's both on the same stand with a vark bar.

Anyway here's more info.  I too originally thought it was phasing b/c they had the big ass fan cranked and the stand was swaying some!  That said we both always use dpa screens there and I've taped in the same room with the same big ass fan for 13 years without issues.  And there are some spots that are just unnatural sounding dips and burst of gain on both sources.  It almost sounds like an auto gain feature kicking in or something.  As with yours it happens to both channels. Perhaps if there was slight phasing the channel linking feature "messed up" for lack of a better term. I'm just guessing!

I have listened to all of mine and also have John's untracked source.  I can confirm the issue on his source as well but I haven't listened to the whole thing.  There are spots on mine where it appears to happen on his as well but not as drastic.  There are spots on mine in the right channel and on his it's the left.  On my source the majority of it is during crowd noise and stage banter but there are a few spots in the music where it can be heard.

This is only my second outing with the deck.  I taped Holly Bowling a few weeks ago on firmware 1.20 with channel linking and had zero issues.  Taped npr in my office yesterday for 45 minutes without issues but I know that wasn't a great test!


Here are samples.  All are banter and crowd noise and can be heard best on headphones though you should hear it without.

https://soundcloud.com/user-622689380-134447863/sample


This is the waveform in the spot after he says "from Kansas City y'all".  As you see in the left channel there's a slight, sudden burst then drop and burst again.

(https://farm5.staticflickr.com/4470/24378101408_0f8a088e47_z.jpg) (https://flic.kr/p/D9d9ef)sample 1 wave (https://flic.kr/p/D9d9ef) by Gordon Wilson (https://www.flickr.com/photos/gordonlw/), on Flickr

This is the same spot showing both mine and Johns.  I was convinced that the channels swapped but I guess it just effected his different as a few seconds later I can confirm the channels match in both sources.  His is audible there as well but not as bad.

(https://farm5.staticflickr.com/4579/26473466959_a0ec60d25e_z.jpg) (https://flic.kr/p/Gknrpv)Capture1 34mins (https://flic.kr/p/Gknrpv) by Gordon Wilson (https://www.flickr.com/photos/gordonlw/), on Flickr


Here's another random screen shot with a huge drop for a split second.

(https://farm5.staticflickr.com/4530/37538506054_50a06875bb_z.jpg) (https://flic.kr/p/Zc9E2C)wave (https://flic.kr/p/Zc9E2C) by Gordon Wilson (https://www.flickr.com/photos/gordonlw/), on Flickr


Here's a few more samples.

https://soundcloud.com/user-622689380-134447863/sample2

https://soundcloud.com/user-622689380-134447863/sample3

https://soundcloud.com/user-622689380-134447863/sample4
Title: Re: What is going on here?
Post by: Gordon on November 07, 2017, 04:22:57 PM
Exact same issues with both mine and jbells the other night! I'm out and about now but can post samples later when I get home. Gotta be firmware. I was thinking maybe channel linking but who knows. Where your channels linked?
This could be an (the) issue. I unlinked my channels just before a show because I didn't like the way the meters looked. I was running the new firmware, and had no issues after. That does not prove anything, but it is a possibility unless others having the issue were not linked.

That was because you didn't have the balance to center ;)
Title: Re: What is going on here?
Post by: jbell on November 07, 2017, 04:23:13 PM
I'm going back to the previous firmware until this gets sorted out!

Title: Re: What is going on here?
Post by: Gordon on November 07, 2017, 05:37:05 PM
I'm going back to the previous firmware until this gets sorted out!

Done!
Title: Re: What is going on here?
Post by: jbell on November 07, 2017, 05:44:48 PM
Me too!  I also submitted an inquiry to SD

I'm going back to the previous firmware until this gets sorted out!

Done!
Title: Re: What is going on here?
Post by: Paul Isaacs on November 07, 2017, 09:30:58 PM
Just read this thread and listened to the samples.
Very unusual indeed and certainly nothing we've heard or seen so far with the latest firmware.
We'll investigate.
If you haven't already, please contact Nelson or Danny in Tech Support and send them your setup file so that we can try and duplicate.

Paul
Title: Re: What is going on here?
Post by: willndmb on November 07, 2017, 09:55:26 PM
Just read this thread and listened to the samples.
Very unusual indeed and certainly nothing we've heard or seen so far with the latest firmware.
We'll investigate.
If you haven't already, please contact Nelson or Danny in Tech Support and send them your setup file so that we can try and duplicate.

Paul
:clapping:
This is the stuff that adds value to a purchase. There is nothing better then to know someone will help you out if need be. Hats off to Paul and SD
Title: Re: What is going on here?
Post by: dmcculh on November 08, 2017, 08:13:22 AM
I had the same issues at NMA and PGroove last week too after upgrading firmware 1.51. Initially thought it was phasing too, but appears not to be. Was also concerned about my cables/PFAs but hadn't had time to trouble shoot with another recorder/phantom power source to see if it was reproducible. FWIW was running 4V's > NBobs/PFAs > MP6 1.51 with channel gain linked (USB battery powered with green light); happened at two separate venues on two different nights.
Title: Re: What is going on here?
Post by: rocksuitcase on November 08, 2017, 09:33:33 AM
Just read this thread and listened to the samples.
Very unusual indeed and certainly nothing we've heard or seen so far with the latest firmware.
We'll investigate.
If you haven't already, please contact Nelson or Danny in Tech Support and send them your setup file so that we can try and duplicate.

Paul
Paul, ask your engineers to test Phantom powering anomolies, especially after the unit gets warm. Possibly similar to the phantom powering issue with the DR680 mki device (defined as certain mics with large capacity draws and/or too many mics drawing p48 created signal drops or just noise on one or more channels).
Of course, this is probably NOT the issue, but throwing it out there since SD is so good about their customer communication.
Title: Re: What is going on here?
Post by: vwmule on November 09, 2017, 02:13:55 AM
Back from tonight's Oteil and Friends show. I used the older firmware and the recording has none of the issues the last one did.

https://archive.org/details/oteil2017-11-08
Title: Re: What is going on here?
Post by: jbell on November 11, 2017, 03:34:46 PM
I doubt it is P48 power.  It is a bug in the firmware, I haven't had this issue with any firmware, but the 1.51.  It is were P48 then it would have been present in earlier firmware versions. 

Just read this thread and listened to the samples.
Very unusual indeed and certainly nothing we've heard or seen so far with the latest firmware.
We'll investigate.
If you haven't already, please contact Nelson or Danny in Tech Support and send them your setup file so that we can try and duplicate.

Paul
Paul, ask your engineers to test Phantom powering anomolies, especially after the unit gets warm. Possibly similar to the phantom powering issue with the DR680 mki device (defined as certain mics with large capacity draws and/or too many mics drawing p48 created signal drops or just noise on one or more channels).
Of course, this is probably NOT the issue, but throwing it out there since SD is so good about their customer communication.
Title: Re: What is going on here?
Post by: rocksuitcase on November 11, 2017, 06:32:57 PM
I doubt it is P48 power.  It is a bug in the firmware, I haven't had this issue with any firmware, but the 1.51.  It is were P48 then it would have been present in earlier firmware versions. 

Just read this thread and listened to the samples.
Very unusual indeed and certainly nothing we've heard or seen so far with the latest firmware.
We'll investigate.
If you haven't already, please contact Nelson or Danny in Tech Support and send them your setup file so that we can try and duplicate.

Paul
Paul, ask your engineers to test Phantom powering anomolies, especially after the unit gets warm. Possibly similar to the phantom powering issue with the DR680 mki device (defined as certain mics with large capacity draws and/or too many mics drawing p48 created signal drops or just noise on one or more channels).
Of course, this is probably NOT the issue, but throwing it out there since SD is so good about their customer communication.
Good thought process. No one has issues previously,then after a firmware upgrade, diff folks have similar issue. As the thread has progressed I'd now go with your analysis.
Title: Re: What is going on here?
Post by: dallman on November 13, 2017, 11:58:37 AM
Back from tonight's Oteil and Friends show. I used the older firmware and the recording has none of the issues the last one did.

https://archive.org/details/oteil2017-11-08

I rolled the firmware back too as I saw no reason to risk a recording. Fortunately since all the firmware upgrades were on my SD card, it was as easy as pressing a few menu buttons. Hopefully there will be another upgrade soon correcting the flaw. In the meantime I will stick with V 1.20