I have a problem that recurs

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gswitz
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2015/03/26 21:17:00 (permalink)

I have a problem that recurs

Hey!! First, thanks for listening.
 
The first time I bumped into this issue was here...
http://forum.cakewalk.com/m/tm.aspx?m=3103460
 
I was recording at a house where 2 different mics seemed to make a clippish sound on the same channel fed into my Tascam. The wave form seemed normal below zero but limited above zero. I tested the Mics at home and they both worked great when using only those mics.
 
I went out two Sundays ago and recorded 18 tracks for the first time. I was using new equipment too. I was using the RME UCX with an Audient ASP880 and s tascam 2488. I was syncing the RME to the Tascam. 
 
The RME was clock sync'd using the SPIDF to the Tascam.
The Audient was locked to the RME using the Word Clock Cable.
 
Is this a clock sync issue maybe? The last time the problem occurred the RME was locked to tascam, but that was the end of the chain.

This time,
The Mics that had issues included
The MXL Guitar Cube direct to RME UCX PreAmp.
The KM184 to the RME Quad Mic Pre to the RME UCX
Gary's dynamic vocal to the Tascam 2488 (this even writes to a different hard drive!!).
 
Here is a sample...
http://stabilitynetwork.blob.core.windows.net/g-tunes/20150315_Susan_distortionsample.mp3

The Times the various Mics had issues didn't overlap.

In November, the issue only showed up on channel three of the tascam and it happened for two different MXL condenser Mics. This time, it also happened on a dynamic, not one I own. I suppose I should ask to make sure it wasn't a condenser since it would have had phantom power through the Tascam.

The problem tends to show up at louder moments, but it is random. It happened on a couple of quiet moments too.
post edited by gswitz - 2015/03/26 22:58:46

StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
#1

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    gswitz
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    Re: I have a problem that recurs 2015/03/26 22:40:26 (permalink)
    I want to add that the various channels do not have a problem at the same time and I only have issues like this when mobile... away from home... and recording sixteen or more channels while a full band plays. What are the symptoms of not enough power? Do the preamps starve first?

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #2
    Beagle
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    Re: I have a problem that recurs 2015/03/27 08:07:23 (permalink)
    Hi Geoff,
    I've never used devices being sync'd with a clock, that's above my pay grade.  But this particular problem doesn't seem to me like it would be a clock problem.  clock problems are typically gong to cause timing issues, I don't think they can cause amplitude issues, but I could be mistaken.
     
    I had a similar problem (again!) with this situation just recently and it was driving me nuts.  no matter what preamp I used, no matter which microphone I used, my recording in Sonar was limited at -7dB.  I adjusted my MOTU software and increased the gain on the inputs, I made sure my MOTU software's compressor was off.  I tried turning it on even, nothing seemed to stop it from doing this.  and the -7dB limit was distorted as well.
     
    so I rebooted my MOTU and that solved it!  for some reason the MOTU had gotten into some kind of mode where it was not allowing full range output through the firewire bus.
     
    So, first I'd say make sure you reboot your Tascam and RME and it wouldn't hurt to reboot the computer and see if that clears it up.  I think it probably IS a power issue, but not necessarily household (120V) power.  it's likely internal where some component has gotten saturated from a degraded resistor or capacitor and is not operating at full capacity.  rebooting will sometimes get it back in the correct working order, sometimes not.

    http://soundcloud.com/beaglesound/sets/featured-songs-1
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    #3
    gswitz
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    Re: I have a problem that recurs 2015/03/27 08:13:22 (permalink)
    Thanks Beagle! It is so strange it occurred both on the Tascam, which writes it straight to its own hard drive, and from the RME which sends it over USB to the computer. It seems unlikely for the two items which are sync locked but otherwise independent to give evidence of the same problem. Unless the problem is somehow global in nature.

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #4
    gswitz
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    Re: I have a problem that recurs 2015/03/27 08:23:14 (permalink)
    I suppose it is useful to add I used a different laptop in November from the one used last week. In November I used my daughter's, last week I used mine. I have used mine recently with the RME UCX to make a recording at a bar that went fine. It was not sync to other devices that night.
    post edited by gswitz - 2015/03/27 09:20:51

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #5
    Paul P
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    Re: I have a problem that recurs 2015/03/27 13:12:38 (permalink)
     
    There are a lot of variables in your setups.
     
    Have you made some sort of table/grid listing all of them ?
     
    So far it looks like you've used different mics going into different preamps going to different recorders and have had problems in all cases.  There has to be a common denominator somewhere.
     
    Have you looked at the raw tracks in a simple wave editor ?
     
    Eliminate as much as you can from your setup.  Have you tried to reproduce the problem with a simpler setup ?  You may have to set up everything again as it was, see that the output is wrong, then remove or swap things until the problem goes away.
     
     
     

    Sonar Platinum [2017.10], Win7U x64 sp1, Xeon E5-1620 3.6 GHz, Asus P9X79WS, 16 GB ECC, 128gb SSD, HD7950, Mackie Blackjack
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    gswitz
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    Re: I have a problem that recurs 2015/03/27 14:05:49 (permalink)
    Paul P
    Have you looked at the raw tracks in a simple wave editor ?


    Yes. I used Wave Shop and it was the same.

    All off my stuff works great in simpler setups. I use the Mics regularly. I've made recordings for decades. The problem only happens when running tons of gear and then erratically.

    I'm starting to think I need a battery supported power supply.

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #7
    Paul P
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    Re: I have a problem that recurs 2015/03/27 14:18:13 (permalink)
     
    I can't see you making progress with this if you can't reconstruct a setup that causes problems.
    It could be anything, and probably something you don't expect.
     

    Sonar Platinum [2017.10], Win7U x64 sp1, Xeon E5-1620 3.6 GHz, Asus P9X79WS, 16 GB ECC, 128gb SSD, HD7950, Mackie Blackjack
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    gswitz
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    Re: I have a problem that recurs 2015/03/27 18:39:12 (permalink)
    Thanks for your help, Paul. I'm thinking it's power supply in the house. Garages are often rated to 30 Amps but living rooms can be as low as 15. My gear alone pulls 6 (laptop - 2, tascam 2488 -2, RME UCX, Quad Mic Pre, DBX Compressor and Audient 880 - 2). With all the amps, pedal boards, and the Bose Tower, it's possible we were just pushing the limits on the living room.
     
    My 'studio' is on my garage circuit (I'm in a room over the garage) so I've got 30 to play with here and that's why I don't have issues here. Most of the time when I do gigs, I'm recording Acoustic stuff where 8 channels does the trick and this takes me down probably below 4 Amps. It's hard to say what pushes it over and why.
     
    It's also just a guess. I'm presuming that the pre-amps are like the environmental frogs that start getting sick before anything else shows an issue. I'm not really sure this should be the case.
     
    Again, Thanks for all the help I've gotten on this. I'm totally bummed, because, of course, when I haul my gear across town to make an 18 track recording I REALLY want it to come out!!

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #9
    gswitz
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    Re: I have a problem that recurs 2015/03/27 19:12:27 (permalink)

     
    This image shows that the guitar cube mic really can't handle volumes. I was using my Fender 4x10 DeVille and the SM57 handled it fine but the Guitar Cube couldn't handle it at all.
     
    Now with the guitar at 3, the Guitar Cube did ok.
     
    I next recorded a Shure SM86 condenser to compare with the guitar cube. The Shure did fine, the guitar cube did not.
     
    I flipped the channels the mics were plugged into and the same result, the Guitar Cube was a problem.
    post edited by gswitz - 2015/03/27 19:31:14

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #10
    Paul P
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    Re: I have a problem that recurs 2015/03/27 22:05:01 (permalink)
     
    I was hunting around for a reason a mic's output could be more towards one polarity than the other and came up with two possibilities.  One is if a circuit is clipping one side of the waveform (like a diode clipper) the other is a natural occurance as mentioned in this SOS article :
     
    "The other element involved in this is that many acoustic sources inherently have a 'positive air pressure bias' because of the way the sound is generated. To talk or sing, we have to breathe out, and to play a trumpet, we have to blow air through the tubing. So, in these examples, there is inherently more energy available for the compression side of the sound wave than there is for the rarefaction side, and that can also contribute to an asymmetrical waveform."
     
    Maybe your mic being close to your amp gets it into this situation, especially when loud ?.  It shouldn't be a problem if the signal half isn't short because it's clipped but rather the other side is tall because it's being blown on by the speaker cone (hopefully not too much so that it causes clipping on that side further down the line).  I can't tell from your pictures if your waveform is clipped on the Cube at guitar=10 or if it's just lopsided.  What do the peaks look like ?
     
    Does this only happen when micing a guitar cab ?
     
    I don't know what the effects on you gear would be if you approach 15a draw on your household circuit.  If the living room in question is normal, it's outlets are probably on the same circuit as outlets in adjacent rooms, like a dining room or entrance.  So there could be even more things plugged into your circuit.  You have a total of about 1500w to work with on a single 15a circuit so you could add up your equipment and see how you're doing.
     
     

    Sonar Platinum [2017.10], Win7U x64 sp1, Xeon E5-1620 3.6 GHz, Asus P9X79WS, 16 GB ECC, 128gb SSD, HD7950, Mackie Blackjack
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    gswitz
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    Re: I have a problem that recurs 2015/03/27 22:23:16 (permalink)
    Yeah, I think the equipment approached the limit. In the future, I think I'm going to get something like this...
    http://www.amazon.com/CyberPower-CP1500AVRLCD-Intelligent-1500VA-Mini-Tower/dp/B000FBK3QK/ref=sr_1_2?ie=UTF8&qid=1427508815&sr=8-2&keywords=battery+ups+line+conditioner
     
    Additionally, someone at MXL is helping me review the Mic - images of waveforms etc.
     
    *** MXL is AWESOME ***
    I'm totally surprised a human is reviewing this!!
     
    It's a fair question about the Mic'ing of the cab. It's just an Amp. A 4x10. I put the Mix right in front of it to record it tonight. I did the same on the 2x12 when I recorded 2 weeks ago.
     
    But the face of the Mic wasn't any closer to the speaker than the SM57 was or the Shure SM86. Both of those recorded the high volumes fine.
     
    Is it possible this is a Mic positioning problem? It's too late in my neighborhood to give it a try now, but I will tomorrow. I'll try moving the mic back and away and see if that fixes things.

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #12
    Paul P
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    Re: I have a problem that recurs 2015/03/27 22:41:19 (permalink)
     
    http://www.cyberpowersystems.com/products/ups-systems/intelligent-lcd-ups/CP1500AVRLCD.html
     
    I don't think this can help with an overloaded circuit.  It has a capacity of 900w for three minutes.  I think it's only meant to keep a computer alive long enough to shut it down gracefully in the case of a power outage or during a very short interruption.
     
    If you're drawing too much from the circuit, the only solution is to bring in another circuit.  You could use a 12ga extension from another room, like from a kitchen counter outlet which are normally on separate circuits.  But then you'll risk creating a ground loop by having two different grounds for your setup and having equipment on separate circuits jointed by audio cables (if that happens, you can lift the ground on one end of the audio cable, not the equipment supply ground).
     
     
     
    post edited by Paul P - 2015/03/27 22:49:50

    Sonar Platinum [2017.10], Win7U x64 sp1, Xeon E5-1620 3.6 GHz, Asus P9X79WS, 16 GB ECC, 128gb SSD, HD7950, Mackie Blackjack
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    gswitz
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    Re: I have a problem that recurs 2015/04/03 10:12:06 (permalink)
    @Paul P
    Thanks so much for this tips. I tested the Mic a yard away from the Amp and it still clips the top of the wave form, starting at around 85dB using my phone dB meter. The amp is pretty loud, but not screaming. The room is pretty quiet. Other Mics like SM86 never has this (it's a condenser and it was right up to the grill of the amp).
     
    I've pretty much decided I can't use the mic in the future which is too bad. It's only been used a few times and it just isn't worthy. As far as I can tell this problem is isolated to just this Mic.
     
    There is some other intermittent issue that may be related to power supply (which is the clip I gave at the beginning of this post).
     
    Anyone want to buy a MXL Guitar Cube?
    post edited by gswitz - 2015/04/03 22:58:47

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #14
    Paul P
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    Re: I have a problem that recurs 2015/04/03 13:20:38 (permalink)
     
    I just came across this thread dealing with a MXL Drum Cube Pro :
    Strange Waveform from MXL Drum Cube Pro
     
    Look at this snare hit :
     

     
    Looks familiar !  There's something pretty weird about these mics. They can't take high level in one direction.
     
    If you like the sound of the mic, maybe you could still use it for quieter stuff.
     

    Sonar Platinum [2017.10], Win7U x64 sp1, Xeon E5-1620 3.6 GHz, Asus P9X79WS, 16 GB ECC, 128gb SSD, HD7950, Mackie Blackjack
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    gswitz
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    Re: I have a problem that recurs 2015/04/03 14:16:06 (permalink)
    I contacted Marshall through this link...
    http://www.mxlmics.com/support/contact.php
     
    And one of their people has let me know that the Mic should still be under warranty and that this is not expected behavior. It looks like they are going to honor the warranty.
    post edited by gswitz - 2015/04/03 22:57:30

    StudioCat > I use Windows 10 and Sonar Platinum. I have a touch screen.
    I make some videos. This one shows how to do a physical loopback on the RME UCX to get many more equalizer nodes.
    #16
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