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Post by teejay on Jun 25, 2020 18:20:36 GMT -6
Seems like I saw a thread on phase issues a while back, but can't find it so here goes.
Please forgive the "newbie-ness" of this question. I'm experiencing phase issues and am wondering if it is the cabling. I'm using my RME Multiface II and TotalMix as my patchbay to route. I have two preamps, AudioScape Opto, TC Electronics M-One XL, and an AudioScape BUSS Comp connected individually to the inputs/outputs on the Multiface II using XLR-to-1/4" TRS. I route the full chain to my headphone mix for tracking, and am also starting to use some of the individual gear on hardware inserts in Reaper. When I record vocals, I track both Input 1 or 2 (the preamps) and Input 3 (the Opto with minimal compression).
If I route my headphone signal directly from one of the preamps, the phase button needs to be out (not depressed) to hear the correct phase (fullness/bass/focused). However, if I route the signal through the complete hardware chain first, I have to push the phase button in to hear those same sonics. I've tried routing the signal to each separate component in my headphones (pre to opto, pre to verb, pre to BUSS) and they are not consistent. I like having the full chain in my headphone mix when recording so I hear myself in a virtually "finished" feed, but if I want to hear myself phased correctly then the recorded track direct from the pre is phase inverted, while the track from the Opto is correctly phased.
Is it likely my cables are inverting the signal several times along the path? My copy of TotalMix does not have a phase option, and I'm not sure that simply using the phase button in Reaper truly mirrors what a non-inverted recorded signal really sounds like. I know further experimentation is needed, but wondering if I should just invest in some newer/better cables as a starting point. I can't imagine that the RME or the individual components are inverting the signal, but I certainly don't want any hardware inserts to be changing phase when printing. I need the phase to stay consistent and be predictable.
Thanks!
Todd
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Post by Guitar on Jun 25, 2020 18:43:47 GMT -6
If you can test the cables, pin 2 should go to pin 2 on the other end, and pin 3 to pin 3. Pin 1 is ground. If one end is flipped, yeah, there could be a polarity inverse. I would try to test the cables. You can use a multimeter, a cable tester, or a visual inspection if you unscrew the connectors. The internal wires of the cable are usually color coded. The XLR should have pin numbers in tiny font you could spot, or you can reference a stock image. A TRS would be Tip to Tip, ring to ring, and sleeve to sleeve for phase coherence.
Some gear can flip polarity. Not all gear has the "pin 2 positive" standard output. (EDIT: correction from thirdeye)
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Post by popmann on Jun 25, 2020 20:58:56 GMT -6
Analog multing...first Y goes to the ADC and a second Y that goes to the two compressors. Pick ONE to monitor in Totamix while you record the three...since you seems set on recording three vocal tracks. I hope this is just a test of compressors or something.
Take the digital reverb out of the equation. Unless you know some good way to add an aux system to Totalmix on a Multiface….it's what's causing your issues. Or using Totalmix to mult to the compressors. The reverb isn't set 100% wet is it?
Maybe talk about what you're trying to achieve here. And get a multimeter. It's a really fast simple thing to check cable continuity. A Multimeter is overkill for that alone...BUT...you're going to be messing with analog recording kit? You need one.
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Post by svart on Jun 26, 2020 7:20:10 GMT -6
Not your cables most likely. Probably the opto is inverting polarity.
Phase is usually such a misnomer since it implies that the signals are always time-aligned, but since you're routing through an extra piece of gear, the signal is being skewed out of time alignment, so you don't know whether it's simply a polarity issue, or time-skew issue.
I'd bet if you were to start recording on three tracks(preamp 1, preamp 2, opto), input a 1K sinewave, that when you zoomed in on the start of the waveforms in the tracks, they'd be at different points in the cycle on the grid. If it were truly a polarity inversion through one or more of the devices, you'd see that as well, but only if you start/stop the input sine so each track has a defined start point.
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Post by christopher on Jun 26, 2020 15:00:24 GMT -6
Some old stuff like limiters can grab one leg of the + - more than the other. I don’t know if that’s a design flaw, but it just might be a feature..the “least destructive” way to limit for broadcast? I really don’t know how it works.. in digital DAW the + is the max level, negative is just low voltage. Im not sure if analog AC measures peak the same. If so, then yeah they just had to limit the + side and the - could be more natural. Any case, whether it’s correct or broken, if you flip polarity you can hear different amounts of limiting/slope and decide which polarity sounds better.
Is that what’s going on here? For typical phase coherence you can flip phase, line up levels until they null, revert phase.
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Post by thirdeye on Jun 26, 2020 20:14:41 GMT -6
If you can test the cables, pin 2 should go to pin 2 on the other end, and pin 3 to pin 3. Pin 1 is ground. If one end is flipped, yeah, there could be a polarity inverse. I would try to test the cables. You can use a multimeter, a cable tester, or a visual inspection if you unscrew the connectors. The internal wires of the cable are usually color coded. The XLR should have pin numbers in tiny font you could spot, or you can reference a stock image. A TRS would be Tip to Tip, ring to ring, and sleeve to sleeve for phase coherence. Some gear can flip polarity. Not all gear has the "pin 3 positive" standard output.I've always thought pin 2 hot was standard??? |
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Post by Ward on Jun 27, 2020 5:30:01 GMT -6
If you can test the cables, pin 2 should go to pin 2 on the other end, and pin 3 to pin 3. Pin 1 is ground. If one end is flipped, yeah, there could be a polarity inverse. I would try to test the cables. You can use a multimeter, a cable tester, or a visual inspection if you unscrew the connectors. The internal wires of the cable are usually color coded. The XLR should have pin numbers in tiny font you could spot, or you can reference a stock image. A TRS would be Tip to Tip, ring to ring, and sleeve to sleeve for phase coherence. Some gear can flip polarity. Not all gear has the "pin 3 positive" standard output.I've always thought pin 2 hot was standard??? It is now, but wasn't always so. It was infuriating in my early days at this to find a lot of the British/European stuff was Pin-3 hot. There's lot of great advice on here! P.S. There's a company that starts with a B and rhymes with Ear-engineer that makes a cable tester that will work well for testing all your pin connections. I would post a link, but that would be profanity. |
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Post by Guitar on Jun 27, 2020 7:36:28 GMT -6
If you can test the cables, pin 2 should go to pin 2 on the other end, and pin 3 to pin 3. Pin 1 is ground. If one end is flipped, yeah, there could be a polarity inverse. I would try to test the cables. You can use a multimeter, a cable tester, or a visual inspection if you unscrew the connectors. The internal wires of the cable are usually color coded. The XLR should have pin numbers in tiny font you could spot, or you can reference a stock image. A TRS would be Tip to Tip, ring to ring, and sleeve to sleeve for phase coherence. Some gear can flip polarity. Not all gear has the "pin 3 positive" standard output.I've always thought pin 2 hot was standard??? Oh shit! I think that's what I meant to say. sorry for goofing. |
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Post by the other mark williams on Jun 28, 2020 10:40:03 GMT -6
I've always thought pin 2 hot was standard??? It is now, but wasn't always so. It was infuriating in my early days at this to find a lot of the British/European stuff was Pin-3 hot. There's lot of great advice on here! P.S. There's a company that starts with a B and rhymes with Ear-engineer that makes a cable tester that will work well for testing all your pin connections. I would post a link, but that would be profanity. Isn't that the direct clone of the E*tech unit that, when people pointed it out on the purple site, they got slapped with a defamation lawsuit by the company you're talking about, Ward? Not that I know any details whatsoever about any of the companies involved, nor do I mean to imply that I even know which companies are currently being discussed. |
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Post by Ward on Jun 29, 2020 0:36:03 GMT -6
It is now, but wasn't always so. It was infuriating in my early days at this to find a lot of the British/European stuff was Pin-3 hot. There's lot of great advice on here! P.S. There's a company that starts with a B and rhymes with Ear-engineer that makes a cable tester that will work well for testing all your pin connections. I would post a link, but that would be profanity. Isn't that the direct clone of the E*tech unit that, when people pointed it out on the purple site, they got slapped with a defamation lawsuit by the company you're talking about, Ward? Not that I know any details whatsoever about any of the companies involved, nor do I mean to imply that I even know which companies are currently being discussed. I believe you have your facts straight! |
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ericn
Temp
Balance Engineer
Posts: 14,921 
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Post by ericn on Jun 29, 2020 8:01:02 GMT -6
By B word cable testers in bulk! They are great then they are useless. They also never seam to be in stock in the US.
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ericn
Temp
Balance Engineer
Posts: 14,921
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Post by ericn on Jun 29, 2020 8:04:00 GMT -6
There really isn’t a standard as far as pin 2 hot, a lot of gear inverts polarity, the best solution is to read manuals and play with your gear.
It’s really simple to correct for anything that reverses polarity at the patchbay.
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Post by Ward on Jun 29, 2020 18:11:22 GMT -6
There really isn’t a standard as far as pin 2 hot, a lot of gear inverts polarity, the best solution is to read manuals and play with your gear. It’s really simple to correct for anything that reverses polarity at the patchbay. But why isn't there? In this day and age? Haven't we all accepted that XLR means 3 pins" X=ground L=live R=return ? I know it's a euphemism, a colloquialism for the three-letter abbreviation, but please accept it? |
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ericn
Temp
Balance Engineer
Posts: 14,921
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Post by ericn on Jun 29, 2020 18:47:14 GMT -6
There really isn’t a standard as far as pin 2 hot, a lot of gear inverts polarity, the best solution is to read manuals and play with your gear. It’s really simple to correct for anything that reverses polarity at the patchbay. But why isn't there? In this day and age? Haven't we all accepted that XLR means 3 pins" X=ground L=live R=return ? I know it's a euphemism, a colloquialism for the three-letter abbreviation, but please accept it? Because there has never been a real standard for XLRS, right down to pin size. As much as some of the political BS that goes into making standards, they sure make life easier. |
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Post by thirdeye on Jun 30, 2020 18:01:40 GMT -6
There really isn’t a standard as far as pin 2 hot, a lot of gear inverts polarity, the best solution is to read manuals and play with your gear. It’s really simple to correct for anything that reverses polarity at the patchbay.A while back, I looked in the manuals of all our gear to see what was not pin 2 hot. The only piece I think I found was my Eventide H3000S. I'm a big fan of wiring multiple polarity reverses, pads, mults, etc into the patchbay. |
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Post by mulmany on Jun 30, 2020 18:38:31 GMT -6
Old dbx units are pin 3 hot.
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ericn
Temp
Balance Engineer
Posts: 14,921
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Post by ericn on Jun 30, 2020 20:01:06 GMT -6
There really isn’t a standard as far as pin 2 hot, a lot of gear inverts polarity, the best solution is to read manuals and play with your gear. It’s really simple to correct for anything that reverses polarity at the patchbay.A while back, I looked in the manuals of all our gear to see what was not pin 2 hot. The only piece I think I found was my Eventide H3000S. I'm a big fan of wiring multiple polarity reverses, pads, mults, etc into the patchbay. It’s not always just about what pin is hot, some designs simply invert phase ( only thing that comes to mind is QSC amps) so you have to read carefully & test in case they left it out of the manual. It’s really a bitch when it’s an unbalanced piece that dose it. |
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Post by teejay on Jun 30, 2020 22:49:04 GMT -6
Appreciate all of the insights, suggestions, and conversation. Have to admit that some of this is just over my head, but I'll do my best to understand and apply it to see if I can resolve the issue.
And just to clarify, I'm recording two tracks: The preamp, and the opto. On mixdown I'll insert the opto for more compression on vox and the BUSS Comp on the two buss.
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Post by Ward on Jul 1, 2020 8:04:40 GMT -6
Old dbx units are pin 3 hot. It's hit or miss with old RCA preamps also, innit? but if they're pin-3 hot on the way in, and pin-3 hot on the way out, it makes little difference. Topic for another day: unbalanced inserts and how much you hate them, and why you should. Or not? |
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Post by Guitar on Jul 1, 2020 9:48:36 GMT -6
Some of the recent behringer Klark Teknik gear is pin 3 "hot" also.
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Post by Ward on Jul 2, 2020 4:58:48 GMT -6
Some of the recent behringer Klark Teknik gear is pin 3 "hot" also. I guess in an attempt to reproduce a reasonable facsimile of the circuit as cheaply as possible, the engineers didn't bother to change that aspect of the circuit. I have a pair of their EQP clones . . . that sit in the 'unused rack' next to the console where no AC or snakes go. They sound pretty good, just don't need them. I should sell them. |
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Post by mulmany on Jul 4, 2020 19:04:05 GMT -6
Seems like I saw a thread on phase issues a while back, but can't find it so here goes. Please forgive the "newbie-ness" of this question. I'm experiencing phase issues and am wondering if it is the cabling. I'm using my RME Multiface II and TotalMix as my patchbay to route. I have two preamps, AudioScape Opto, TC Electronics M-One XL, and an AudioScape BUSS Comp connected individually to the inputs/outputs on the Multiface II using XLR-to-1/4" TRS. I route the full chain to my headphone mix for tracking, and am also starting to use some of the individual gear on hardware inserts in Reaper. When I record vocals, I track both Input 1 or 2 (the preamps) and Input 3 (the Opto with minimal compression). If I route my headphone signal directly from one of the preamps, the phase button needs to be out (not depressed) to hear the correct phase (fullness/bass/focused). However, if I route the signal through the complete hardware chain first, I have to push the phase button in to hear those same sonics. I've tried routing the signal to each separate component in my headphones (pre to opto, pre to verb, pre to BUSS) and they are not consistent. I like having the full chain in my headphone mix when recording so I hear myself in a virtually "finished" feed, but if I want to hear myself phased correctly then the recorded track direct from the pre is phase inverted, while the track from the Opto is correctly phased. Is it likely my cables are inverting the signal several times along the path? My copy of TotalMix does not have a phase option, and I'm not sure that simply using the phase button in Reaper truly mirrors what a non-inverted recorded signal really sounds like. I know further experimentation is needed, but wondering if I should just invest in some newer/better cables as a starting point. I can't imagine that the RME or the individual components are inverting the signal, but I certainly don't want any hardware inserts to be changing phase when printing. I need the phase to stay consistent and be predictable. Thanks! Todd Todd, kept meaning to say... buy a Galaxy Cricket/polarity checker. Great little tool for testing this stuff. Use it for mics, preamps, speakers, rack gear, and the whole recording chain. |
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