Karaoke Forums

Need to pick you audio techs minds.
I have Mackie SRM 450s as my mains(active).
I am getting a slight (on and off) static from the horn of one of them (only one of them and only from the horn).
In efforts to narrow it down I have first unhooked the xlr cable (still present) - left xlr unconnected for further diagnosis.
All components are plugged into the same power source. I tried moving to a different outlet-still within the same power source (still present)
I tried a different power cord into the same power source (still present) I tried both the original and the sustitute power cord into a different power source (still present)
It is a very slight static that is lost as soon as music is played but it still bothers me knowing it is there.
After the above trouble shooting I am stumped.
Any ideas?
Is it time to take it in for professional diagnosis and repair?

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Music speaks to the heart in ways words cannot express.

When you say static, are you talking kind of a "white noise" or hissing (like TV tuned to a non-existent station) or is it more of a "crackling" type static? To former would be a noise floor issue that could just be inherent to the amplifier/crossover circuit. Other than being a little annoying to you, probably not much to worry about. If it's more of a crackling type then it's likely a more serious electrical issue, again likely from the amplifier or crossover circuit (which I believe are on the same board in that model). That's probably more of something I would be having checked out.

Have you tried turning the input level up and down? What happens with the noise then? Does it go away if you turn it all the way down? Are these newer and you're noticing this or have you had these cabs for a while and this is a new behavior you can say for sure was not occurring before?

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DJ Tony
Let It Rip Karaoke

Both speakers, and I believe all active speakers, exhibit some white noise if listened to carefully This white noise does increase a little when the input level is turned all the way up.(which is not where the level is set - only turned way up for this test)
The speaker in question also has a slight crackling type noise but it is only present on occasion and is intermittent when it is present. When I just checked it the crackling noise was not present. Could it be picking up this noise due to other electrical appliances in the house possibly on the same circuit and running at the time the noise was present? the reason I ask is the dishwasher upstairs was running at the time earlier when the noise was present and when I went to check the speaker a few minutes ago the noise was no longer present - and the dishwasher was finished running. Now i am not sure wether the dishwasher is on the same circuit or not...something I will look into tomorrow.

This cabs are several years old and yes I have experienced this intermittent crackling on other occasions.

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Music speaks to the heart in ways words cannot express.

Yes, AC Power issues can do all sorts of crazy things with amplifiers and just about all other components in your signal chain. This is why the first lesson I ever teach any newbie is about making sure mains power is sufficient and clean. It would not surprise me in the least to find out that a intermittent phenomenon such as this was the result of noise on the line. This is where a true power conditioner/regulator can be invaluable.

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DJ Tony
Let It Rip Karaoke

Checked again in the quiet of the morning this morning, no appliances running, etc. the crackling noise was not present. I am begining to think it is indeed an AC power issue. Thank you Tony, for your posts.

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Music speaks to the heart in ways words cannot express.