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[Sean Chen]

Hello All,  I'm the drummer/sound guy for our 4 piece band.  I'm using EV SXA180 subs with EV ZLX 12p tops.  The last 2 shows I'm getting a whining noise fro the tops.  I'm using xlr cables from the board to the sub then, high pass out to the tops with an xlr.  2 weeks ago I thought it was just a power issue with the venue but then, it happened again this past weekend.  I tried the normal out from the sub and it reduced the noise some but did not eliminate it.  I also tried a ground lifter plug and that made this worse. Any  thoughts or suggestions for me to try?  Thanks!

If the ground lift made the noise worse, could be a ground loop related issue. Try a different facility. Is everything including mixer and instruments plugged into the mixer off the same power circuit? If not, try putting everything on the same power circuit and see if the noise persists.

If this happens to both tops, it is unlikely caused by a  damage at cable or speaker. It is likely a common cause, as 2 things are unlikely to fail at the same time outside a catastrophic event.

Can you get a recording of the noise? Is it like a white noise, or like a distinctive pitch humm?

[drew gandy]

What did EV say when you called them?

Where's the up-vote button!?! 

[Rick Guyer]

If the ground lift made the noise worse, could be a ground loop related issue. Try a different facility. Is everything including mixer and instruments plugged into the mixer off the same power circuit? If not, try putting everything on the same power circuit and see if the noise persists.

If this happens to both tops, it is unlikely caused by a  damage at cable or speaker. It is likely a common cause, as 2 things are unlikely to fail at the same time outside a catastrophic event.

Can you get a recording of the noise? Is it like a white noise, or like a distinctive pitch humm?

I will try swapping everything around  tonight and see if I can narrow down the cause (speakers, cables, power sources).  If that doesn't help, I'll record the sound.
And ... I have sent an email to EV asking for some guidance.  Thanks for all of the suggestions.  I'll report back my findings.

[Tim McCulloch]

I will try swapping everything around  tonight and see if I can narrow down the cause (speakers, cables, power sources).  If that doesn't help, I'll record the sound.
And ... I have sent an email to EV asking for some guidance.  Thanks for all of the suggestions.  I'll report back my findings.

Not to belabor the point - but I've found when dealing with manufacturers that phone calls are harder for them to ignore.

That said, "whining" noises tend to be digital in nature (anyone who has put a passive DI on top of a DX7 knows what it sounds like).

The most likely suspect - the switch mode PSU in one of the speakers, and the noise is leaking to signal ground, which carries it to the other speakers.  Another - a different source of digital noise, induced into the XLR cables hooking up the speaker system.

There are probably a couple more failure modes but those are the 2 I see most often among multiple brands.  Not saying these are for sure the failure you are experiencing, but they're common possibilities.

Does *every* combination of speaker make the noise?  I suspect just 1 PSU...

[Kevin Conlon]

Hello All,  I'm the drummer/sound guy for our 4 piece band.  I'm using EV SXA180 subs with EV ZLX 12p tops.  The last 2 shows I'm getting a whining noise fro the tops.  I'm using xlr cables from the board to the sub then, high pass out to the tops with an xlr.  2 weeks ago I thought it was just a power issue with the venue but then, it happened again this past weekend.  I tried the normal out from the sub and it reduced the noise some but did not eliminate it.  I also tried a ground lifter plug and that made this worse. Any  thoughts or suggestions for me to try?  Thanks!

Did a country club last week, fund raiser with 100 ppl. Small EV system and a ton of noise. After doing the mute thing and trying other snake channels it was a power problem. Everything on one circuit solved it. Expand to more outlets until the noise came back and stop. Enough power for the gig and no noise. Maybe you can be as lucky? Call EV anyway!

[Tim McCulloch]

Did a country club last week, fund raiser with 100 ppl. Small EV system and a ton of noise. After doing the mute thing and trying other snake channels it was a power problem. Everything on one circuit solved it. Expand to more outlets until the noise came back and stop. Enough power for the gig and no noise. Maybe you can be as lucky? Call EV anyway!

Your experience points to a mis-wired outlet somewhere in the room, and whatever fault condition existed was exacerbated by using an additional circuit.

In the sense the term is most often used, there is almost no such thing as "dirty power" from the utility company.  It can be contaminated by poorly designed, defective or improperly utilized equipment, but it didn't leave the meter that way.

[Ike Zimbel]

I will try swapping everything around  tonight and see if I can narrow down the cause (speakers, cables, power sources).  If that doesn't help, I'll record the sound.
And ... I have sent an email to EV asking for some guidance.  Thanks for all of the suggestions.  I'll report back my findings.

You can also try tightening the jack hardware (usually one or two Phillips screws on the XLR's) on the sub and the speakers. Those little screws are the actual connection point to chassis ground for any noise that is traveling along the shields in the XLR cables. If they are even a little bit loose, the noise just keeps on going right into your amplifier circuit.

[Mike Caldwell]

Do you always use the same XLR cables to connect your cabinets and are you using a legit brand of XLR cables, not the 20 pack special from Ebay.

A lot of you cheap XLR cables have pin 1 tied to the XLR shell. That can cause all sorts of strange problems with some equipment to no problems at all with other equipment.

[drew gandy]

Your experience points to a mis-wired outlet somewhere in the room, and whatever fault condition existed was exacerbated by using an additional circuit.

In the sense the term is most often used, there is almost no such thing as "dirty power" from the utility company.  It can be contaminated by poorly designed, defective or improperly utilized equipment, but it didn't leave the meter that way.

I agree with this but "dirty power" is often confused with the effects of the "conduit transformer".  Google it.  Neil Muncy and Bill Whitlock are some of the names involved in figuring this out because it is an issue for audio gear. 

[Rick Guyer]

Update:  I found that the cables that I used used 1/4" to XLR but not TRS, only TR.  This took care of most of the noise.  These were 50' cables.  I replaced them with XLR cables and used one power source and the sounds was much cleaner.  Thanks for the suggestions and comments.

[ProSoundWeb Community]