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Generator creating hum? di box fix maybe?
Old 2 weeks ago
  #1
Here for the gear
 

Generator creating hum? di box fix maybe?

Okay so I got a bit of a issue.

I run a PA system and since I can't run it all off one genny I run multiple gennys. I "think" this is causing a hum between whats hooked up between the two.

Generally I have 3x amps +driverack 260 +dbx compressor+limiter on one genny, while having two amps, lights and dj equipment on the other genny.

Now what I "think" is happening is two things:
a)
The difference in power from the two gennys is creating this additional sound/hiss when I connect the driverack 260 from genny 1 to the two amps from genny 2.
b)
The dj equipment and live mixer are both plugged into genny 2 so it could have the same power difference issue between the two gennys causing a issue there too.

Now if a) is the issue, then in theory I could just slap a DI box between genny 1's driverack 260 and genny 2's 2x amps. Or should I use something like a hd400 for that? Either way "something" to either remove the ground or equalize the ground would be helpful here I would think.

Now if b) is the issue, then again in theory if the grounding/power difference is the issue then I could put the driverack on genny 2 with everything else, that way the mixer+driverack260 is on the same line and would possibly eliminate this issue due to that. I would then need to have 3x di boxes or di120 or hd400 or phe400 or something to go between the driverack260 if I moved it to genny 2 since they would be alone now on genny 1.

Either way I have some sort of issue here and I'm damn sure it has something to do with connecting the grounds of both gennys, either through my driverack 260 wiring to amps or by the mixer connecting to the driverack 260 along with everything else that plugs into the mixer.

Now with all that being said I'm not sure if I need a phe400 or di120 or hd400 or any of a half dozen other boxes out there that seem to range anywhere from $30 to $200+. Now if I need 3x channels, spending $600 on 3x lines seems a bit insane by my standards. But at the same time, the cheapest option that has the most features, the di120 is known for adding sound that I know I won't want since I'm trying to eliminate that white noise or light hiss that I think is caused by the two gennys and grounding.

Anyone ever experienced anything like this or have advise of a budget di box or ground lift box that would also not sound like crap?
Old 2 weeks ago
  #2
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JayTee4303's Avatar
1. "Hum" and "additional sound" and "hiss" in your post, should be replaced with "minus XY dB (narrow, medium or broadband) noise, centered at Zz hertz", or whatever accurate, based on what a spectrum analyzer, placed at specified locations in the audio chain, reads out. For starters, hiss and hum are two very different things, and we can't hear what you hear, or even, see your face while you're typing. Engineers quantify.

2. 1 Amp, 1 speaker, 1 cable between them. What do you hear when powered by one genny? Is it quiet? Is it quietER than if powered by the other genny?

What if you power this simpLEST rig via grid mains?

That's where you start.

Add one more piece of gear, then compare. Keep adding till you start to get unwanted noise. Quantify the noise. Stop and FIX THAT before proceeding.

You are on the right track. Noise doesn't usually occur inside one box. It usually occurs when TWO boxes INTERACT via a cable.

:-)
Old 2 weeks ago
  #3
Here for the gear
 

Quote:
Originally Posted by JayTee4303 View Post
1. "Hum" and "additional sound" and "hiss" in your post, should be replaced with "minus XY dB (narrow, medium or broadband) noise, centered at Zz hertz", or whatever accurate, based on what a spectrum analyzer, placed at specified locations in the audio chain, reads out. For starters, hiss and hum are two very different things, and we can't hear what you hear, or even, see your face while you're typing. Engineers quantify.

2. 1 Amp, 1 speaker, 1 cable between them. What do you hear when powered by one genny? Is it quiet? Is it quietER than if powered by the other genny?

What if you power this simpLEST rig via grid mains?

That's where you start.

Add one more piece of gear, then compare. Keep adding till you start to get unwanted noise. Quantify the noise. Stop and FIX THAT before proceeding.

You are on the right track. Noise doesn't usually occur inside one box. It usually occurs when TWO boxes INTERACT via a cable.

:-)
If I had all the time in the world to test everything I wouldn't be here asking questions, I'd be testing and then finding the problem, solving it and moving on with my life.

I am asking questions purely since I do not have the ability to sit down with the system and do a bunch of testing. I have "maybe" a hour between setup and the first act so there leaves little to zero time to be testing or "trying" things. Sometimes we setup 5-10 mins before the first act.

Its alot of work since we're outdoors and need to setup the entire stage, sound system and lighting from scratch every show.

I would farther question if you've actually finished reading what I typed out before responding, since I cannot run the system off one genny without rewiring it, so your suggestion is moot since I do not have the time to re-wire everything to try, then rewire it back in order to use the system.

The sound itself is hard to describe cuz I'll only hear it for a couple seconds when the beat drops or on a quite brakedown in the middle of a track. Something of a hiss or grey noise, something like this:
https://www.youtube.com/watch?v=0iGdLDeyeso&vl=en

After the show everything gets packed up till the next show, I really don't have the ability to do what your asking since again I can't hook everything up off one genny without rewiring everything and I don't have enough time with the system outside of shows to debug things myself, if I did have the additional time with the system, I'd have this figured out already without needing to ask.

I mean with 20+ speaker cabs I really don't have the time to go 1 by 1 to try and solve it the way your suggesting, nor should I have to when I've already stated out what the possible problems could be and what connections I have between the two gennys. How does testing speakers one by one solve the problem of the ground being connected between the two gennys? It doesn't.

My question is simple; if everything in my first message is taken to be true, then would the a di-box or hd400 or phe400 or di120 or something like that work for solving the grounding issue when connecting the two gennys together?

Assumingly I need to put a ground lift or di box or something inbetween the driverack 260 and the additional amps that are not on the same genny. The real question for me becomes if I need to rewire everything else so that the driverack 260+ mixer+dj equipment is all on the same genny/line, or if putting some sort of di-box or hum destoryer box would solve the issue by putting it inbetween the driverack 260 and the amps.

Again I'm asking about this since those di-boxes can get really expensive, I'd be pretty choked to spend $100 each for 3 channels and it not solve my problem, or spend $40 on two channels and it sound like trash or add an additional sound. Telling me to just test it one by one then "guess" if I need a di by buying one then using it as a test seems like a really bad suggestion to me cuz your basically telling me to buy first then figure out later by seeing if it works by using it.. what I'm saying is I'd like to know if this is actually going to help things before spending hundreds of dollars on something that may not be what I need.

Look at this from my point of view for 2 sec; if I tell this collective that they gota spend hundreds to solve a problem and then it doesnt solve the problem I would be wasting their very limited resources on something that didn't work. Alternatively to spend a day testing this would cost more then just buying the di boxes in order to transport everything, hire roadies ect in order to get it to a spot we could actually test it. Hopefully this explains the issues I'm dealing with a bit better.
Old 2 weeks ago
  #4
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JayTee4303's Avatar
Quote:
Originally Posted by Zoilus View Post
If I had all the time in the world to test everything I wouldn't be here asking questions, I'd be testing and then finding the problem, solving it and moving on with my life.

I am asking questions purely since I do not have the ability to sit down with the system and do a bunch of testing. I have "maybe" a hour between setup and the first act so there leaves little to zero time to be testing or "trying" things. Sometimes we setup 5-10 mins before the first act.

Its alot of work since we're outdoors and need to setup the entire stage, sound system and lighting from scratch every show.

I would farther question if you've actually finished reading what I typed out before responding, since I cannot run the system off one genny without rewiring it, so your suggestion is moot since I do not have the time to re-wire everything to try, then rewire it back in order to use the system.

The sound itself is hard to describe cuz I'll only hear it for a couple seconds when the beat drops or on a quite brakedown in the middle of a track. Something of a hiss or grey noise, something like this:
https://www.youtube.com/watch?v=0iGdLDeyeso&vl=en

After the show everything gets packed up till the next show, I really don't have the ability to do what your asking since again I can't hook everything up off one genny without rewiring everything and I don't have enough time with the system outside of shows to debug things myself, if I did have the additional time with the system, I'd have this figured out already without needing to ask.

I mean with 20+ speaker cabs I really don't have the time to go 1 by 1 to try and solve it the way your suggesting, nor should I have to when I've already stated out what the possible problems could be and what connections I have between the two gennys. How does testing speakers one by one solve the problem of the ground being connected between the two gennys? It doesn't.

My question is simple; if everything in my first message is taken to be true, then would the a di-box or hd400 or phe400 or di120 or something like that work for solving the grounding issue when connecting the two gennys together?

Assumingly I need to put a ground lift or di box or something inbetween the driverack 260 and the additional amps that are not on the same genny. The real question for me becomes if I need to rewire everything else so that the driverack 260+ mixer+dj equipment is all on the same genny/line, or if putting some sort of di-box or hum destoryer box would solve the issue by putting it inbetween the driverack 260 and the amps.

Again I'm asking about this since those di-boxes can get really expensive, I'd be pretty choked to spend $100 each for 3 channels and it not solve my problem, or spend $40 on two channels and it sound like trash or add an additional sound. Telling me to just test it one by one then "guess" if I need a di by buying one then using it as a test seems like a really bad suggestion to me cuz your basically telling me to buy first then figure out later by seeing if it works by using it.. what I'm saying is I'd like to know if this is actually going to help things before spending hundreds of dollars on something that may not be what I need.

Look at this from my point of view for 2 sec; if I tell this collective that they gota spend hundreds to solve a problem and then it doesnt solve the problem I would be wasting their very limited resources on something that didn't work. Alternatively to spend a day testing this would cost more then just buying the di boxes in order to transport everything, hire roadies ect in order to get it to a spot we could actually test it. Hopefully this explains the issues I'm dealing with a bit better.
My approach to noise begins with a 400 I/O studio. Along with sound reinforcement systems using up to 14 loudspeaker enclosures. Not 20, but complex enough. Unless you count wedges. On single and multiple generators.

Then theory. A LOT of it. There's a LOT more I have not studied. Yet.

I am not bypassing your situation. I am giving you an opinion, based on the background just related, that you might as well flip a coin as ask the question you're asking.

Not what you want to hear, but you obviously don't want a lie. The number of variables in your system are nearly infinite. The very first question you HAVE to know... can both gennies, seperately, drive a single amp and speaker quietly?

You can spend a dime, a Franklin or ten grand on other solutions, only to find you have lousy AC outta one or both. And still noise.

It seems strange to me to have that large a system on the road, touring, without pre-testing, or, if not on the road, with no base of operations to perform routine tests and simple maintenence, but... you know what?

You say that's the case, so it is. Period.

It serms strange to me that the tech in charge if such a rig is sweating a hundred buck DI, or really... even considering a hundred buck DI. I have a coupla cheap such DIs, but consider myself lucky that they do a job when needed, cuz the piles I go thru regularly on deployed systems run double that to start, but again... you say its so, so it is.

I'm not sure you really understand the significant limitations in the concept of "ground", or how those limitations apply to noise. Ok... you do what you do, you aren't a bellcurve sound guy, and you want an easy, reliable answer to whether a midrange DI groundlift will quiet a noise you dislike so...

Lift the ground and see. Take ten minutes, clip a lead on a well marked cable, plug it in, next show and see.

Binary solution set. Lifting ground between your 360 and an amp will shut it up or it won't. No hundred bucks, just one pair of sidecuts and a spare cable.

Transformeroid Noize Blaster.

NOT a binary solution set. I've had em work when I didn't expect em to, and not work when they "should have." There's more than one, they are wired differently, each may quiet specific issues.

I've seen guys swear by them, brand specific, cuz one worked one time, AND seem guys swear AT them cuz they didn't, one time, and NEITHER set could intelligently discuss back EMF or eddy currents. That means those opinions were based on a single instance of luck.

Good, or bad.

Tell you what.

Find yourself in Indy, hit me up PM, and I'll loan you a pile of such devices, free, even come to your show and help you test em. Nickle says that's as close to "ironclad" as you get from this thread.

One more thing. The complexity of this issue can go the other way too. You can get lucky, with zero theory, or even rationality. Noise is an unpredictable bitch, until you get DEEP into it... but she goes both ways.
Old 2 weeks ago
  #5
Here for the gear
 

Quote:
Originally Posted by JayTee4303 View Post
My approach to noise begins with a 400 I/O studio. Along with sound reinforcement systems using up to 14 loudspeaker enclosures. Not 20, but complex enough. Unless you count wedges. On single and multiple generators.

Then theory. A LOT of it. There's a LOT more I have not studied. Yet.

I am not bypassing your situation. I am giving you an opinion, based on the background just related, that you might as well flip a coin as ask the question you're asking.

Not what you want to hear, but you obviously don't want a lie. The number of variables in your system are nearly infinite. The very first question you HAVE to know... can both gennies, seperately, drive a single amp and speaker quietly?

You can spend a dime, a Franklin or ten grand on other solutions, only to find you have lousy AC outta one or both. And still noise.

It seems strange to me to have that large a system on the road, touring, without pre-testing, or, if not on the road, with no base of operations to perform routine tests and simple maintenence, but... you know what?

You say that's the case, so it is. Period.

It serms strange to me that the tech in charge if such a rig is sweating a hundred buck DI, or really... even considering a hundred buck DI. I have a coupla cheap such DIs, but consider myself lucky that they do a job when needed, cuz the piles I go thru regularly on deployed systems run double that to start, but again... you say its so, so it is.

I'm not sure you really understand the significant limitations in the concept of "ground", or how those limitations apply to noise. Ok... you do what you do, you aren't a bellcurve sound guy, and you want an easy, reliable answer to whether a midrange DI groundlift will quiet a noise you dislike so...

Lift the ground and see. Take ten minutes, clip a lead on a well marked cable, plug it in, next show and see.

Binary solution set. Lifting ground between your 360 and an amp will shut it up or it won't. No hundred bucks, just one pair of sidecuts and a spare cable.

Transformeroid Noize Blaster.

NOT a binary solution set. I've had em work when I didn't expect em to, and not work when they "should have." There's more than one, they are wired differently, each may quiet specific issues.

I've seen guys swear by them, brand specific, cuz one worked one time, AND seem guys swear AT them cuz they didn't, one time, and NEITHER set could intelligently discuss back EMF or eddy currents. That means those opinions were based on a single instance of luck.

Good, or bad.

Tell you what.

Find yourself in Indy, hit me up PM, and I'll loan you a pile of such devices, free, even come to your show and help you test em. Nickle says that's as close to "ironclad" as you get from this thread.

One more thing. The complexity of this issue can go the other way too. You can get lucky, with zero theory, or even rationality. Noise is an unpredictable bitch, until you get DEEP into it... but she goes both ways.
"It serms strange to me that the tech in charge if such a rig is sweating a hundred buck DI, or really... even considering a hundred buck DI."

The whole point of me saying that is I don't want to be spending $300+ on something that won't work.

If it might work in theory then its worth a try.

But your telling me to "flip a coin" to decide if it works?

With respect I get your trying to help but your not.

We're not running a bunch of guitars and band stuff, so its not a regular bit of equipment that we would normally use, we're talking about things from two totally different perspetives, your most likely doing live sound with bands/vocals/guitars, we're doing exclusively EDM, midi controller to live mixer to processing to amp to speakers.

Seems like a fairly simple question to me; ~IF~ the issue is the grounding/power difference from the two gennys and I'm pretty damn sure it is, then what kind of box would solve this kind of issue?

Telling me to guess, or that $100 is too cheap still doesnt address the base question of what I would need in order to solve this situation if this is indeed the case.

Lets say I confirm through a day of testing that this is the case, then what? Do I need a di120 or something like it with a ground lift? Or would a regular di box work for correcting this ground difference/inbalnce? Would I instead be looking for a hum destoryer like a hd400 or phe400 since they are meant to eliminate the hum in situations where the ground/power difference between your laptop and live mixer create a hum or even your guitar and amp head for your stack.

What I'm getting at here is telling me $100 is too cheap doesn't explain what one of the 3 options might work for this situation.

Its not the money thats the problem, its the fact that I'd be buying tools that may not do the job, as a guess. It seems like a bad idea to buy something without knowing if it will correct the issue, if you know what the issue is already then you should be able to know if the tool will correct that issue or not.

No point in buying something that doesn't correct the balance or remove the ground so its no longer a issue, thats why I'm asking about things before buying them since I do not own any of these, I don't have experience with them, how they work or what they can do anymore then I read online.

From what I can read a di box may fix the line to balance it, however I can't find alot out of forums to support this. I hear the hd400 hum destoryer is great for inbetween a laptop and a live mixer to solve this same kind of issue of two different power sources being connected creating a power inbalance between them, in theory this is the same type of problem I would be experiencing with the two gennys. I think the hd400 or phe400 is what I'm looking for, but again I'm unsure if it is or if I'm looking for a di box that oculd just do this automatically or a di box with a ground lift to prevent the grounds from connecting and causing the problem to start with.

Whole point is if I can prevent the grounds from touching by having a ground lift in theory it should prevent anything from even being a issue.

So a ground lift seems like a good idea.... however reading and watching videos are telling me its a bad idea to remove the ground and that "some" di boxes can fix mixed grounds of different power automatically without the need of a ground lift. Problem is not alot if any of them advertise this, I found one for $200 that is two channels but again buying it would be a guess or a gamble if it would work for the situation of equalizing the ground between two ground lines of different power.

So even if its something else, I'm pretty sure this is a issue, altho extremely minor, the question is what do I do about it. What is the correct tool is more my question since there is 3 different tools to choose from, di with automatic ground equalizing, di with ground lift (di120) and hum destoryer (hd400/phe400) that seems to be built for equalizing ground power between two units.

Where I'm sitting, I don't feel like removing the ground is the best option, but I could be wrong about that since both units are grounded to their respective gennys, it would just be removing the ground from them being connected to each other. Without the ground I could be adding extra artifacts to those chained past the ground removal due to having no ground?

Sure I could buy a cheap ground removal unit or I could do the oldschool pull the ground on a power bar, lots of ghetto solutions I could do. Yes I could prob save myself alot of grief by just running a no ground power bar on those amps but I think thats pretty risky to be running power amps without a ground.

I'm not here looking for ghetto solutions, I'm looking for the right one for this problem, its a very exact problem I just need to know the right tool in order to fix the problem.

You don't go buy a brand new angle grinder first when you need to change your tire, hell even taking an axe or a blow torch to it wouldn't be ideal, it helps starting with the right tool for the right bolt & nut, otherwise your going to have a bad time and might not even get the job done.

I've identified what the only possible issue is, even if its not a issue I'll feel better having it solved so I can move past it, I need to know what tool to use for this ground/power imbalance, I mean its fairly straight forward but di boxes seem to be vague on what they can do aside of turning a unbalanced to balance, technically that could be what I'm looking for since its a imbalance between the lines, so if it corrects that or prevents it from being a issue that could solve things without needing to remove the ground.

Again I just don't have enough experience with these 3 types of boxes to know what one is going to do this properly.... honestly figured asking people would've been smarter then throwing hundreds at this problem, whenever I don't know something I try to talk to someone who might know more about that then I do, since I don't use or have much experience with di boxes, ground lifts and hum destoryers to correct ground imbalance, I figured I'd ask..
Old 2 weeks ago
  #6
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Quote:
Originally Posted by Zoilus View Post
If I had all the time in the world to test everything I wouldn't be here asking questions, I'd be testing and then finding the problem, solving it and moving on with my life.

I am asking questions purely since I do not have the ability to sit down with the system and do a bunch of testing. I have "maybe" a hour between setup and the first act so there leaves little to zero time to be testing or "trying" things. Sometimes we setup 5-10 mins before the first act.
You can't find the time to take care of a potentially dangerous electrical problem! If you can't find the time to trace the problem you should STOP and go do something easy and less dangerous before you kill yourself and/or someone else!

No disrespect to anybody giving advise, but getting advise about this type of thing from random people on the internet is tantamount to doing brain surgery on yourself...the people who work on the stage and the paying public deserves more, a lot more.
Old 2 weeks ago
  #7
Quote:
Originally Posted by Samc View Post
You can't find the time to take care of a potentially dangerous electrical problem! If you can't find the time to trace the problem you should STOP and go do something easy and less dangerous before you kill yourself and/or someone else!

No disrespect to anybody giving advise, but getting advise about this type of thing from random people on the internet is tantamount to doing brain surgery on yourself...the people who work on the stage and the paying public deserves more, a lot more.
I agree!

To the OP...do yourself and others you work with a favor and talk to a real electrician before you try anything more. Improperly done grounding can kill someone.

I had a power problem in my studio. There was about 3 volts AC between my ground and neutral. It cost me about $300 to get it fixed by a licensed journeyman electrician but it was worth it. He diagnosed the problem (a bad neutral in a sub fuse box) and repaired it in one day. For someone who knows what they are doing it is a simple fix, if I had tried to do it on my own it probably would still be a problem.

Don't try and fix this by DIYing it. If someone is killed or injured and it is traced back to a botched repair then you could be liable for damages. Not what you want to happen. A word to the wise. FWIW
Old 2 weeks ago
  #8
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JayTee4303's Avatar
Quote:
Originally Posted by Zoilus View Post
"It serms strange to me that the tech in charge if such a rig is sweating a hundred buck DI, or really... even considering a hundred buck DI."

The whole point of me saying that is I don't want to be spending $300+ on something that won't work.

If it might work in theory then its worth a try.

But your telling me to "flip a coin" to decide if it works?

With respect I get your trying to help but your not.

We're not running a bunch of guitars and band stuff, so its not a regular bit of equipment that we would normally use, we're talking about things from two totally different perspetives, your most likely doing live sound with bands/vocals/guitars, we're doing exclusively EDM, midi controller to live mixer to processing to amp to speakers.

Seems like a fairly simple question to me; ~IF~ the issue is the grounding/power difference from the two gennys and I'm pretty damn sure it is, then what kind of box would solve this kind of issue?

Telling me to guess, or that $100 is too cheap still doesnt address the base question of what I would need in order to solve this situation if this is indeed the case.

Lets say I confirm through a day of testing that this is the case, then what? Do I need a di120 or something like it with a ground lift? Or would a regular di box work for correcting this ground difference/inbalnce? Would I instead be looking for a hum destoryer like a hd400 or phe400 since they are meant to eliminate the hum in situations where the ground/power difference between your laptop and live mixer create a hum or even your guitar and amp head for your stack.

What I'm getting at here is telling me $100 is too cheap doesn't explain what one of the 3 options might work for this situation.

Its not the money thats the problem, its the fact that I'd be buying tools that may not do the job, as a guess. It seems like a bad idea to buy something without knowing if it will correct the issue, if you know what the issue is already then you should be able to know if the tool will correct that issue or not.

No point in buying something that doesn't correct the balance or remove the ground so its no longer a issue, thats why I'm asking about things before buying them since I do not own any of these, I don't have experience with them, how they work or what they can do anymore then I read online.

From what I can read a di box may fix the line to balance it, however I can't find alot out of forums to support this. I hear the hd400 hum destoryer is great for inbetween a laptop and a live mixer to solve this same kind of issue of two different power sources being connected creating a power inbalance between them, in theory this is the same type of problem I would be experiencing with the two gennys. I think the hd400 or phe400 is what I'm looking for, but again I'm unsure if it is or if I'm looking for a di box that oculd just do this automatically or a di box with a ground lift to prevent the grounds from connecting and causing the problem to start with.

Whole point is if I can prevent the grounds from touching by having a ground lift in theory it should prevent anything from even being a issue.

So a ground lift seems like a good idea.... however reading and watching videos are telling me its a bad idea to remove the ground and that "some" di boxes can fix mixed grounds of different power automatically without the need of a ground lift. Problem is not alot if any of them advertise this, I found one for $200 that is two channels but again buying it would be a guess or a gamble if it would work for the situation of equalizing the ground between two ground lines of different power.

So even if its something else, I'm pretty sure this is a issue, altho extremely minor, the question is what do I do about it. What is the correct tool is more my question since there is 3 different tools to choose from, di with automatic ground equalizing, di with ground lift (di120) and hum destoryer (hd400/phe400) that seems to be built for equalizing ground power between two units.

Where I'm sitting, I don't feel like removing the ground is the best option, but I could be wrong about that since both units are grounded to their respective gennys, it would just be removing the ground from them being connected to each other. Without the ground I could be adding extra artifacts to those chained past the ground removal due to having no ground?

Sure I could buy a cheap ground removal unit or I could do the oldschool pull the ground on a power bar, lots of ghetto solutions I could do. Yes I could prob save myself alot of grief by just running a no ground power bar on those amps but I think thats pretty risky to be running power amps without a ground.

I'm not here looking for ghetto solutions, I'm looking for the right one for this problem, its a very exact problem I just need to know the right tool in order to fix the problem.

You don't go buy a brand new angle grinder first when you need to change your tire, hell even taking an axe or a blow torch to it wouldn't be ideal, it helps starting with the right tool for the right bolt & nut, otherwise your going to have a bad time and might not even get the job done.

I've identified what the only possible issue is, even if its not a issue I'll feel better having it solved so I can move past it, I need to know what tool to use for this ground/power imbalance, I mean its fairly straight forward but di boxes seem to be vague on what they can do aside of turning a unbalanced to balance, technically that could be what I'm looking for since its a imbalance between the lines, so if it corrects that or prevents it from being a issue that could solve things without needing to remove the ground.

Again I just don't have enough experience with these 3 types of boxes to know what one is going to do this properly.... honestly figured asking people would've been smarter then throwing hundreds at this problem, whenever I don't know something I try to talk to someone who might know more about that then I do, since I don't use or have much experience with di boxes, ground lifts and hum destoryers to correct ground imbalance, I figured I'd ask..
It is a bad idea to throw money at this problem, with your current understanding level of the possibilities that may be contributing to the unwanted signal levels. Most likely, you would spend the money and still have the noise.

One or both generators may be delivering "bad" AC. One or both generators may be delivering beautiful AC... AND creating eddy currents in ANY OTHER piece of gear, OR ANY CABLE IN YOUR SYSTEM.

This may be because of a generator problem, OR a problem with the specific box where the unwanted signal is imposed upon the desired signal, OR BOTH.

Your cellphone or another crew member's cellphone MAY be radiating RF, which is leaking into the protected signal path. ONE piece of gear may be radiating, and another piece, thru a shielding flaw or a tuned cirvuit may be picking it up.

Every single piece of gear, AND every single cable, is a possible suspect, and that is just the tip of a huge iceberg. ANY signal present, from equipment miles away, might be "the problem."

From nature's point of view, this ISN'T a problem. Electrons are behaving as normal, in very, very complex circuits.

NOT... times how many boxes and cables you have.

NOT times how many other boxes and cables are in range.

Those numbers FACTORIAL... because noise is very often due to INTERACTION between multiple items, all of which MAY be working perfectly, just not together, the way you WANT.

THERE IS NO "GROUND."

I don't care if each gennie has one... or 50 ground rods, driven in a fixed grid. There WILL BE MULTIPLE PATHS between them, with DIFFERENT POTENTIALS, and therefore DIFFERENT CURRENT FLOWS.

ANY... two paths between point A and B... MIGHT LEAK A FEW ELECTRONS, AND THOSE MIGHT GET COUPLED TO AUDIO.

Read this:

https://www.google.com/url?sa=t&sour...xEKHG6wyLu48-C

I have to go to work. I fix problems. Not by wishing them fixed, but by realistic assessment, approximation, then roll up your sleeves, hurt your head thinking, sweating, risking fingers...work.

YOU... need to go to work. Your current approach will ONLY solve your problem if you basically "win the lottery."

Your current approach to resolving noise issues assumes the availability of magic. There IS NO silver bullet on this one.

Get busy.
Old 2 weeks ago
  #9
Gear Maniac
 

sounds like a grounding problem
Old 2 weeks ago
  #10
Lives for gear
 

Quote:
Originally Posted by 1jordyzzz View Post
sounds like a grounding problem
my feeling too, but as Jay Tee rightly points out, there are so many variables involved that some (competent) person is going to have to take the time and get to work figuring it all out...or get lucky.
Old 1 week ago
  #11
Here for the gear
 

Quote:
Originally Posted by JayTee4303 View Post
It is a bad idea to throw money at this problem, with your current understanding level of the possibilities that may be contributing to the unwanted signal levels. Most likely, you would spend the money and still have the noise.

One or both generators may be delivering "bad" AC. One or both generators may be delivering beautiful AC... AND creating eddy currents in ANY OTHER piece of gear, OR ANY CABLE IN YOUR SYSTEM.

This may be because of a generator problem, OR a problem with the specific box where the unwanted signal is imposed upon the desired signal, OR BOTH.

Your cellphone or another crew member's cellphone MAY be radiating RF, which is leaking into the protected signal path. ONE piece of gear may be radiating, and another piece, thru a shielding flaw or a tuned cirvuit may be picking it up.

Every single piece of gear, AND every single cable, is a possible suspect, and that is just the tip of a huge iceberg. ANY signal present, from equipment miles away, might be "the problem."

From nature's point of view, this ISN'T a problem. Electrons are behaving as normal, in very, very complex circuits.

NOT... times how many boxes and cables you have.

NOT times how many other boxes and cables are in range.

Those numbers FACTORIAL... because noise is very often due to INTERACTION between multiple items, all of which MAY be working perfectly, just not together, the way you WANT.

THERE IS NO "GROUND."

I don't care if each gennie has one... or 50 ground rods, driven in a fixed grid. There WILL BE MULTIPLE PATHS between them, with DIFFERENT POTENTIALS, and therefore DIFFERENT CURRENT FLOWS.

ANY... two paths between point A and B... MIGHT LEAK A FEW ELECTRONS, AND THOSE MIGHT GET COUPLED TO AUDIO.

Read this:

https://www.google.com/url?sa=t&sour...xEKHG6wyLu48-C

I have to go to work. I fix problems. Not by wishing them fixed, but by realistic assessment, approximation, then roll up your sleeves, hurt your head thinking, sweating, risking fingers...work.

YOU... need to go to work. Your current approach will ONLY solve your problem if you basically "win the lottery."

Your current approach to resolving noise issues assumes the availability of magic. There IS NO silver bullet on this one.

Get busy.
Can you point out where I ever asked you to solve my sound systems problems?

Thats not what I'm even remotely asking.

I'm asking about HARDWARE.

I'm asking about the differences between bits of HARDWARE that I don't use, and thus, I don't know what one to buy in order to test that may or may not solve the problem, again throwing money at the problem is beyond stupid.

Lets save you a whole lot of ****ing time bitching and moaning; my gennys are not the problem; their connection to each other may be.

The question is NOT "HOW" the problem is coming to be.

The question is "IF" that is the problem (the two gennys connecting via ground) will a di box work to correct this issue?

Again I'm talking about HARDWARE since they are very ****ing vague about what it can do and the claims are very different depending on the company or model.

Listing off a dozen different "oh it could be this, so your ********" doesn't explain to me any of the differences between any of these HARDWARE TOOLS that could be used to attempt to solve this problem.

Again, a "di box" is vague as hell as to what the HARDWARE ACTUALLY DOES. Whats the difference between a di box and a hum/noise eliminator and a di120 with a dozen different options? Will they all solve a hypothetical problem between two grounds?

Again thats what I'm asking; what will solve the hypothetical issue of the two grounds being the issue? Will plugging a di box between the two lines solve this power imbalance between the two grounds? Or will a hum/noize eliminator do that? Or will I need something with a ground lift switch that doesn't really solve the problem so much as removing it from being a problem?

I read MANY DIFFERENT THINGS ABOUT THIS TYPE OF HARDWARE. Some companies claim their di will automatically fix things like having power imbalance between the ground of the two lines your connecting it between, where others make no such claims.

The hum/noize eliminator doesn't actually explain what it does for any version I've seen.

The di120 would at least in theory solve the problem, however it would eliminate the ground instead of fix the power imbalance between the two lines, so this is NOT the solution I want since its not a fix but rather a bandaid or short term solution.

I'm again not asking you to explain grounding.

I'm asking you to explain di boxes and hum/noize eliminators to see if they are honest options that would work over just simply removing the ground.

I need to know if this tool is worth buying, again no point in buying it if it doesn't solve the power imbalance between the two lines.

Please focus on that point before responding with anger, I am not looking for you to explain things I already know

I am looking to have something I don't know explained; how exactly a hum/noise eliminator works (what is it doing) and if a di box would solve the issue of the ground power imbalance. "in theory" since a di box would balance a unbalanced line, thats its whole point, my question is if that process would balance the ground between them so that the power imbalance was fixed or not a issue. I read that the way it goes through the coils "could" do this depending on what company you buy from, so again the question becomes what they are actually doing and if they will solve a power imbalance issue, again in theory it would BUT I DONT OWN ONE so I can't test one without BUYING ONE. So to waste money on something I'm not clear could even "in theory" do the job seems like a waste.. thats why I figured asking someone may be a good idea.. never expected this much hostility over asking about HARDWARE TOOLS, I never expected this much confusion about my question to the point where you avoided addressing any of my question about what these HARDWARE DI BOXES can actually do or the DIFFERENCES BETWEEN THESE HARDWARE BOXES when some are "di boxes" and others are hum/noize eliminators, i don't quite get what the difference is or what they are actually doing, what problem this tool is supposed to solve in the technical sense since "hum/noize" is pretty vague as to what it actually does to stop those effects, what is the cause its correcting? does that make sense?
Old 1 week ago
  #12
Here for the gear
 

Quote:
Originally Posted by 1jordyzzz View Post
sounds like a grounding problem
Yup 100% a grounding problem.

Question is what tools fixes this?

Lets say hypothetically its the connection between the two gennys when the grounds connect from the driverack 260 and the amps from the other genny.

Would be a good place to start at least being the #1 most likely thing if everything else is perfectly fine.

The question becomes than "IF" that is the issue, what is the correct tool to solve that exact issue?

Will a di box fix it due to it being designed to turn a unbalanced line into a balanced line? I read after going through the coil "some" models can correct ground power imbalances between the two lines its hooked between... However its not "advertised" as that for any di boxes I can find aside of one extremely high end and expensive company.

The next question becomes with the hum/noise destoryer's like the phe400 or hd400, are they just doing the same thing the di box is or are they doing something different? Its unclear what exactly they do in order to correct a hum/noise so I'm unsure if it will solve the ground power imbalance issue.

Now what I "KNOW" will solve it is having a ground lift on those amps or ground switch between the two lines connecting them like a di120 or something with a ground switch to remove the ground but that again doesn't solve the problem, it just removes it from being a problem in the short term, I'd rather have it solved as a problem for the long term since its not safe to be running amps full bore without grounding imo.

So the question here is not what the grounding problem is.

The question is if its the grounding power imbalance between them, what is the right hardware tool to solve that exact issue? And what exactly does a hum/noise eliminator do that a di box doesnt?

Quote:
Originally Posted by Samc View Post
my feeling too, but as Jay Tee rightly points out, there are so many variables involved that some (competent) person is going to have to take the time and get to work figuring it all out...or get lucky.
Seems fairly straight forward to me mate, I need to know what hardware eliminates ground power imbalances between two lines.

I also need to know what a hum/noise destoryer does that a di box doesn't, not what it solves, but what it physically is doing, whats the cause it corrects? di box is more straight forward it balances a unbalanced line, in theory a high end one could work, but I DO NOT OWN ONE cuz I don't work with bands, so I have NO IDEA if I need to spend $400 for a high end one or if a lower end one would do the same job, I don't know if this is a standard thing that hardware tool solves or not since they are not advertised for this use.
Old 1 week ago
  #13
Lives for gear
 
JayTee4303's Avatar
Quote:
Originally Posted by Zoilus View Post
Can you point out where I ever asked you to solve my sound systems problems?

Thats not what I'm even remotely asking.

I'm asking about HARDWARE.

I'm asking about the differences between bits of HARDWARE that I don't use, and thus, I don't know what one to buy in order to test that may or may not solve the problem, again throwing money at the problem is beyond stupid.

Lets save you a whole lot of ****ing time bitching and moaning; my gennys are not the problem; their connection to each other may be.

The question is NOT "HOW" the problem is coming to be.

The question is "IF" that is the problem (the two gennys connecting via ground) will a di box work to correct this issue?

Again I'm talking about HARDWARE since they are very ****ing vague about what it can do and the claims are very different depending on the company or model.

Listing off a dozen different "oh it could be this, so your ********" doesn't explain to me any of the differences between any of these HARDWARE TOOLS that could be used to attempt to solve this problem.

Again, a "di box" is vague as hell as to what the HARDWARE ACTUALLY DOES. Whats the difference between a di box and a hum/noise eliminator and a di120 with a dozen different options? Will they all solve a hypothetical problem between two grounds?

Again thats what I'm asking; what will solve the hypothetical issue of the two grounds being the issue? Will plugging a di box between the two lines solve this power imbalance between the two grounds? Or will a hum/noize eliminator do that? Or will I need something with a ground lift switch that doesn't really solve the problem so much as removing it from being a problem?

I read MANY DIFFERENT THINGS ABOUT THIS TYPE OF HARDWARE. Some companies claim their di will automatically fix things like having power imbalance between the ground of the two lines your connecting it between, where others make no such claims.

The hum/noize eliminator doesn't actually explain what it does for any version I've seen.

The di120 would at least in theory solve the problem, however it would eliminate the ground instead of fix the power imbalance between the two lines, so this is NOT the solution I want since its not a fix but rather a bandaid or short term solution.

I'm again not asking you to explain grounding.

I'm asking you to explain di boxes and hum/noize eliminators to see if they are honest options that would work over just simply removing the ground.

I need to know if this tool is worth buying, again no point in buying it if it doesn't solve the power imbalance between the two lines.

Please focus on that point before responding with anger, I am not looking for you to explain things I already know

I am looking to have something I don't know explained; how exactly a hum/noise eliminator works (what is it doing) and if a di box would solve the issue of the ground power imbalance. "in theory" since a di box would balance a unbalanced line, thats its whole point, my question is if that process would balance the ground between them so that the power imbalance was fixed or not a issue. I read that the way it goes through the coils "could" do this depending on what company you buy from, so again the question becomes what they are actually doing and if they will solve a power imbalance issue, again in theory it would BUT I DONT OWN ONE so I can't test one without BUYING ONE. So to waste money on something I'm not clear could even "in theory" do the job seems like a waste.. thats why I figured asking someone may be a good idea.. never expected this much hostility over asking about HARDWARE TOOLS, I never expected this much confusion about my question to the point where you avoided addressing any of my question about what these HARDWARE DI BOXES can actually do or the DIFFERENCES BETWEEN THESE HARDWARE BOXES when some are "di boxes" and others are hum/noize eliminators, i don't quite get what the difference is or what they are actually doing, what problem this tool is supposed to solve in the technical sense since "hum/noize" is pretty vague as to what it actually does to stop those effects, what is the cause its correcting? does that make sense?
Believe it or not, we're getting somewhere here.

You can study up on specific devices as well as I can, and you will find that descriptions are often vague.

I call this "snake oil"... to a degree. As in "buy our box, it fixes everything, by magic!"

It us good you understand that there are near-infinite many ways that unwanted signal can become coupled with desired signal, to create "noise."

So, if we assume that you DO find out what each device specifically does, (possible, but unlikely, short of dismantling them, and studying the circuitry) and you don't know how or why YOUR unwanted signal is getting coupled, you probably STILL won't know if THIS "fix" resolves THAT issue or not.

One, pretty much standard, noise "fix", is a simple ground lift. No need to pay any money to see if it works. Clip the ground on an XLR, plug in, and listen. This is not a "ghetto fix." It is a better solution than applying a ground lift PLUS other solutions that may muddy the water, and it's free.

You can filter the summed signal and POSSIBLY remove or reduce unwanted signal. In order to choose an effective filter, you have to know the frequency and amplitude of the unwanted signal.

You can run it thru a transformer, to isolate this equipment from that equipment, but if you don't which two boxes are interacting to couple the unwanted signal to desired signal, you don't know where to place the transformer.

Chokes. Bootleg grounds. Etc etc.

All are guesswork, without knowlege of the noise specifics, and without testing, there's so many different possible probs, that any one fix is very unlikely to work.

Here's a car. It makes a funny noise. Should you change the wheel bearings, or the alternator belt, or the muffler?

There ARE some very simple tests you can run, each might take SECONDS, and done right, could ELIMINATE HALF of the myriad possibilities... but...


You have to understand noise, and the various possible solutions, and the various possible causes, to apply these tests.

A "ghetto ground lift" is one. Running one source, amp, and speaker, off one gennie, then the other, is another.

Breaking the audio chain near the middle, testing each half seperately, might eliminate half of the possibilities, but to do that, you'd have to have the system in the correct config AND know where to plug in your headphones.

I'm asking you to tell me what frequency(s) the noise is, and whether it comes from the front half or back half of the car, and instead of answering, you're repeating the question, "wheel bearings, alternator belt, or muffler?"

In this PDF file:

https://www.google.com/url?sa=t&sour...fiVFfR0tfkLQir

...there is a very simple plug, that you build or buy and insert, which tells you "problem is here" or "problem is downstream" or "problem is upstream" from the point you insert it.

Five seconds.

Once you isolate the issue, you can END IT.

The devices you mention are band-aids. They attempt to UNDO, something that shouldn't happen to begin with.

They often fail to remove the problem, or only partially resolve it, and they can ADD NEW PROBLEMS.

You are trying to shortcut a solution. You risk safety, you risk expensive equipment, you risk your employers trust doing so.

There's an easier and safer way.

Abandon the idea of a magic fix.
Old 1 week ago
  #14
Gear Nut
 

Man, this thred is crazy!

I read through it last night at 2am so I might have missed some stuff.

Hopefully someone with proper knowledge is setting the genys up.

the VERY BEST advice given to you was to test things out, and through order of elimination find out, what the sources/combo of equipment is/are the problems.'

You shot that down in ignorance.

1. What mixer are you using
2. What input into the amp are you going into (line or Mic)? some midline mixers have a built in 20db pad on line.
3. Does you mixer have a pad are you using it?
a. What gain level are you using on the main input channel/s
b. Do you have an EQ section on main channel you can engage/disengage.
c. Have you set up your DBX dsp to make sure its right?


4. When the problem happens have you put on headphones/earbus and monitored the singal at the mixer to see if the hum is happenin at the mixer or after the mixer.

5. Do you have a lot of speaker/signal cables that are coiled?
6. Do you know that long sections of coiled cables can pick up interference that show up as hum/noise some times.

7. Have you read up on your generators manual to make sure they are being used in the proper manner?

I've run into problems in the past where Furman power conditioners were actuallty ADDING noise to the system.

At the very least.

1. Get a pro in there to make sure your genys are being run in a safe manner?
2. Start with making sure your signals gain stage is right.
3. Find out if the hum shows up at the mixer monitoring via headphones or after from mixer to speakers.
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