What Is Causing This Noise?

[soundchaser59]

I record my guitar cab with an SM7b. But tonight I noticed a strange noise in the phones, and I isolated it to the SM7b channel. Even if I turn the guitar amp off, I still hear this noise. There are no effects on, just SM7b into the (Emu 1616m pci) mic input, straight to Sonar. I put a Heil mic in front of the guitar speaker as a test and it did not pick up anything, so I know this noise is coming thru only on the SM7b channel. I have not done anything else to isolate it, but wonder if anybody has heard anything like this before?

If I sit there just listening, this noise happens roughly once every minute. The interval is not consistent, sometimes a minute, sometimes a bit longer, sometimes 30 seconds or so, etc....and it sounds slightly different every time it happens, sometimes shorter, sometimes a bit longer, usually just once but sometimes twice or three times in a few seconds, etc.....

There are no motors or anything like that in the house. I have no idea. This just started tonight and last night.

http://www.soundchasermusic.net/demos/whatisit.mp3

Any ideas? It isn't very loud, but it does get recorded......
Almost sounds like a bug like a small moth trapped inside the SM7b capsule....

[Curt]

If you have a cell phone in the house, turn it off and try recording again.

[soundchaser59]

Haven't heard that one yet, but I'll try it......the person with the phone will be gone all day tomorrow.

[alotawatts]

http://www.google.com/search?hl=en&q...h&aq=f&oq=&aqi=

[soundchaser59]

The person with the cell phone left and the noise continued. I switched the mic cables left and right, but the noise continued to be in the left input. I put the phones into the mic preamp and there was no noise at all.

So I knew the noise was not coming from the mic or the mic pre. It had to start at the Emu dock.

You guys talking about wireless stuff got me to looking more closely at what is going on in my studio. Since my Sonar machine is in the basement but I need to authorize software, etc., I use the wireless connection to my router upstairs.

The 1616 dock has two mic inputs on it. A couple days ago I changed my wireless configuration and I set the computer's little 3 inch tall wireless antenna on top of the Emu dock, directly above the left mic input. Didn't give it a second thought. Then I remembered that the wireless connection will periodically (probably about every 60 seconds) "talk to the router" to make sure it is still there and the key code is still valid.

So, by watching this little systray icon.....


I noticed that the noise in the left input only happened when the green "network communication" light comes on in the systray icon. I waited for it to happen again, and as soon as I moved the little antenna away from the dock, the noise disappeared.

Whoda thunk it? Your hints about wireless EMI set me up to figger this one out! So THANKS people!!

[bigroy]

We were doing an offsite sale a few years ago and someone brought a wireless phone to use outside. They sat it next to our wireless router and for two days we thought we were having IP problems, when all the time the two were too close to each other. Live and learn.

We used to do a live remote at a beach club in Terre Haute (I know, it sounds absurd) and the local station used a remote transmitter that looked like R2D2 on steriods. Long story short, every time they turned it on to broadcast the first 10 minutes of our set, it absolutely shut down our Vox Continental Organ. Just a bit of history.....this was back in 1968 or so.

Another glass of merlot please...

[rob2001]

Originally Posted by bigroy

We were doing an offsite sale a few years ago and someone brought a wireless phone to use outside. They sat it next to our wireless router and for two days we thought we were having IP problems, when all the time the two were too close to each other. Live and learn.

We used to do a live remote at a beach club in Terre Haute (I know, it sounds absurd) and the local station used a remote transmitter that looked like R2D2 on steriods. Long story short, every time they turned it on to broadcast the first 10 minutes of our set, it absolutely shut down our Vox Continental Organ. Just a bit of history.....this was back in 1968 or so.

Another glass of merlot please...

WOW!! This is something I have to look into. I've recently been having strange noise from the bass players channel. I mic the amp and also run a direct line from a XLR out on the amp. Never had troubles before. No that you mention this, the bass player recently got a new phone AND a company phone he has to keep with him....and he sets them on top of his amp........could be the problem. I never would have thought it.

[soundchaser59]

Maybe the manufacturers of those phones aren't as FCC Compliant as their little labels like to claim....