my speakers hum

Because you are trying to play music to songs they don't know the words to.... Badum dum! :)

Sorry.

Can you describe the speakers that do hum? Are they particularly efficient? or powered?

Usually it's your cable TV or a connection to a PC.  Try disconnecting it, if any, and see if the problem continues. If so, I have a solution for you. :)

Best,

Erik

Unless your speakers are self-powered, they can't create their own hum.   

the speakers are audio physic tempo. no tv. no computer connection.

Are your current speakers(the hummers), more sensitive than your previous speakers?

Bill

Let me get this straight, you're complaining about a hummer?

I agree Bill above--you probably some type of ground loop and your current (no pun intended) speakers may be more sensitive and letting you hear the resultant hum.  Does the hum level stay constant with volume or does it increase with volume?  Have you tried various grounding schemes like trying ground wires between equipment and grounding to a common point like a screw on an AC outlet?

i have tried different outlets. i have not grounded to a specific point. i don't know about sensitivity between the pairs. the hum is only heard when nothing is playing.

Temporary float the ground on your amp PC with a cheater plug. If the hum goes away it's a ground loop. It could just be your cables too. If your IC's are unshielded and you've been moving gear around, unplugging cables, you might just be picking up noise. Pull out your cables and reconnect everything and keep cables clear from each other as best as possible. Keep your PC's clear from your SC's as well.

Is it possible that these speakers have been wired accidentally in reverse polarity? And I mean, internally or externally by yourself? Try flipping the Positive/Negative Poles around on the speaker cables.

Another option you can play with would be to try varing the speaker cable length between the Amp and Speaker and see if the noise goes away.

@eniac26

Wouldn't make a difference at the speaker end. :)

Best,

Erik

@erik_squires

How do you figure that?

Its certainly not the speaker making noise on its own. There is an Amp and speaker wire connecting everything together is there not?

The speaker wire is the conduit to allow the noise to pass thru to the speaker.

The OP said that other speakers didnt have such issues on the same equipment so I dont see the point in tracking down power line related Ghosts in this case. If speaker A is hooked up to the system and there is no noise but on the other hand if speaker B is connected and there is noise how do you figure unhooking your cable box or computer is going to fix the problem? Could be that the amp,speaker, wire combo is not playing well together.

I've been down this road myself in the past fighting a similar issue. The things I've written in my previous post come from direct experience.

I would suggest that you take a step back and look at the issue from 10,000ft first and think of all pieces in the chain and how they work together. Then start laser focusing in on certain areas, one at a time, until you narrow down the culprit.

@eniac26

I think there may be a misunderstanding. If you are telling me you have a passive speaker, then there’s absolutely no way that swapping the speaker terminals would create or negate hum.

If I misread what I was responding to, I’m sorry.

If you have a passive speaker, and swapping the speaker terminals and it causes any hum to come or go, you have got a very very odd speaker with a metal connection to ground which should never have occurred.

This may not be true if your speaker itself has a connection to the wall AC, in that case all sorts of such interactions may occur if not properly paid attention to.  This could be from an active speaker, an electrostat or the Focal's with the EM voice coils and outboard power supply.  Now hum can become very rare, but not impossible.

Best,


Erik

OP:

Get a digital V meter, something that reads down to 1V or less. Should be around $20.

Connect it to your speakers while you hear the humming. Measure the AC V.

Change speakers. Repeat.

I think you’ll find that the AC V is the same. If so, this means you are just hearing the
difference in speaker efficiency.

Here’s a good meter with a 400mV range that would be perfect.

http://amzn.to/2bISae5

By the way, this works because almost all meters are sensitive to 120Hz or lower, which is usually where power supply and ground loop hum lives.

Best,


Erik