Bad/Dirty Power & Digital Gear?

[gunpointmetal]

Is there any reason to think bad/dirty power would cause feedback issues with digital gear? There are two venues that I end up playing (usually not by choice, but when you only do originals, you gotta take a show sometimes) where I have constant feedback/squeal issues that I never have anywhere else. We've played basements to garages to 1200 cap venues and there are only two places where this issues occurs. It's like my gates aren't set tight enough all of the sudden on presets/patches that I never experience issues with in any other environment. The only consistency between the two places is that the buildings are old, we're on the floor, and power is sourced from two outlets on the same wall. Anyone have a similar issue, or know a reason for it, or what the options are to stop it? 

[spikey]

Dirty power can cause lots of weird stuff. Florissant lights can cause noise and mess with gates too.

[DunedinDragon]

Feedback has nothing to do with electrical power or digital gear.  It's purely an acoustic issue. You can aggravate the situation with effects like compressors and EQ that may cause resonation within an environment and lead to more feedback, but feedback is always caused the same way with the signal being re-fed into the source via mic's or pickups.

Normally you would address such issues by "ringing out" the PA at sound check time to isolate what channels are feeding back and correcting for them.  You do this in each environment because the acoustics are always different.  Without more specific information about the gear you use and how you have things setup, it's hard to guess where your problems are although setting up on the floor, especially a hardwood floor, can cause the sound to be transmitted up through a mic stand and into a mic causing feedback if your amps or speakers are also in contact with the floor.

[spikey]

Two issues- No, feedback doesn't but you said your "noise" gates would mess up (at least I think that's what you meant). Extra dirt on the AC line can cause a set noise gate elsewhere to open. And I had one of those pink noise generators on our PA where we could EQ the room with a special mic before the show and yes that should have "fixed" most of the EQ issues, so I don't know why there is more feedback at the 2 places. Extreme - but do you run line conditioners on your gear? 

[gunpointmetal]

I run Guitar w/Active Pickups ->Helix->EV ZLX monitor with the XLRs going to an IEM mixer and FOH. I don't run a true power conditioner, just the breaker-protected power strips (Furman). I guess excessive line noise could be the issue, as I said, my gates and their usual settings are pretty tight and I literally stand 3' away from two of those ZLX monitors for hours a week at practice at usually higher-than-gig volumes with no feedback issues. I understand how feedback works mechanically, and usually dialing up my gates will remedy this issue the most part (I'll still get little squeaks when muting quickly). I guess maybe the question would be can bad/dirty power raise the noise floor or reduce dynamic range or something in something like the Helix. The squeals are solely coming from my on-stage monitoring AFAIK even when I'm DI'd to the FOH. I didn't even really think of the fluorescent lights. Both places are kinda dive-ish and have lots of those multi-color beer sign lights throughout.

[DunedinDragon]

How deep is the area you're standing in?  It's entirely possible you could be reflecting sound from the wall behind you into a mic which creates a feedback cycle.

[gunpointmetal]

14 minutes ago, DunedinDragon said:

How deep is the area you're standing in?  It's entirely possible you could be reflecting sound from the wall behind you into a mic which creates a feedback cycle.

There's no mic's involved in the feedback. It's only coming from my on-stage monitor, which is only being fed by the Helix.

[HonestOpinion]

On 7/16/2019 at 3:43 PM, gunpointmetal said:

Is there any reason to think bad/dirty power would cause feedback issues with digital gear? There are two venues that I end up playing (usually not by choice, but when you only do originals, you gotta take a show sometimes) where I have constant feedback/squeal issues that I never have anywhere else. We've played basements to garages to 1200 cap venues and there are only two places where this issues occurs. It's like my gates aren't set tight enough all of the sudden on presets/patches that I never experience issues with in any other environment. The only consistency between the two places is that the buildings are old, we're on the floor, and power is sourced from two outlets on the same wall. Anyone have a similar issue, or know a reason for it, or what the options are to stop it? 

 

Sounds to me like something in the physical layout of your equipment in those particular venues is causing your guitar's pickups and monitors to setup a feedback loop, no mics required although they could potentially be involved as well. I would definitely test with the mics muted if possible to see if they are involved. One thing worth trying would just be to reposition your monitors and see if that eliminates the feedback. Your typical setup may not work in those venues.