XL1 hum removal in FCP? at DVinfo.net

Ignacio Rodriguez · January 29th, 2005, 09:39 AM

Hi. I am working on postproduction on a documentary shot mainly with an XL1 (no S). When the camera-mounted mic is used, there is a distinct hum, presumambly coming from the tape transport. I am using Final Cut and have been trying to remove the hum but I can't seem to find the exact frequency. Has anybody experienced this, found the frequency and succesfuully removed it? It shouldn't be difficult, but for some reason I can't seem to get it right. Any suggestions? I have also pposted this question to the FCP board.

Gordon Nicol · May 9th, 2005, 10:18 PM

Ignacio,
Did you ever get an answer about that camera hum?
If you'd like to send me a short sample in aiff format, I could check it out and probably get pretty close to the frequency.

Gordon
gjnicol@swbell.net

Scotch Productions, Inc.,
Dallas

Ignacio Rodriguez · May 9th, 2005, 11:13 PM

Hi Gordon! That is so generous of you! Thanks. However somebody else ended up mixing the audio and seems to have gotten it right. All I needed really was a spectrum analyzer.

Ben Simpson · May 10th, 2005, 07:33 AM

If I remember corectly the XL1 does not have a balanced line in for the mic that it comes with right? Just saying that it may not have ‘tape hiss’ but that it maybe the line.

Ignacio Rodriguez · May 10th, 2005, 08:38 AM

Hi Ben. No it was not that kind of hum. When using long unbalanced audio cables you can get EM hum from AC which is 50 Hz or 60 Hz depending on where you are in the world. The hum we were talking about here seemed to be caused by the XL1's tape mechanism, and I think was somewhere close to 150Hz.

Frank Meek · July 27th, 2005, 12:10 PM

While it seems you have "fixed" the problem, there is a fairly inexpensive solftware app/tool that has helped me in the past with various audio issues. Obviously, you don't want them in the first place...you want "clean," (preferably 16 bit, 48K), audio tracks...but that doesn't always happen.
I imported some SVHS, VHS and Beta SP footage for a docu-instructional piece I did and the audio from some of this was horrible: hum, buzz, crackles and pops. Even after conversion to 16 bit, 48K, the stuff was unacceptable for broadcast. Suggestions from some audio gurus indicated that SoundSoap 2 might help. For $80.US (The standard, non "Pro" package), I ordered it. The interface is simple and it works easily with existing audio programs, BIAS Peak, etc. The "2" version is supposed to work inside FCP, but that hasn't happened for me, yet (frankly, I don't use these apps too much as I work hard on good audio acquisition...so I haven't pursued it). But, the program "saved" the clips in which I needed the audio. Like any after-the-fact-rescue program, it needs to be used carefully to avoid the perils of stripping the sound of "presence" and "body." But, for $80US, it is a valuable application.

Greg Boston · July 27th, 2005, 12:37 PM

Quote:

Originally Posted by Frank Meek

While it seems you have "fixed" the problem, there is a fairly inexpensive solftware app/tool that has helped me in the past with various audio issues. Obviously, you don't want them in the first place...you want "clean," (preferably 16 bit, 48K), audio tracks...but that doesn't always happen.
I imported some SVHS, VHS and Beta SP footage for a docu-instructional piece I did and the audio from some of this was horrible: hum, buzz, crackles and pops. Even after conversion to 16 bit, 48K, the stuff was unacceptable for broadcast. Suggestions from some audio gurus indicated that SoundSoap 2 might help. For $80.US (The standard, non "Pro" package), I ordered it. The interface is simple and it works easily with existing audio programs, BIAS Peak, etc. The "2" version is supposed to work inside FCP, but that hasn't happened for me, yet (frankly, I don't use these apps too much as I work hard on good audio acquisition...so I haven't pursued it). But, the program "saved" the clips in which I needed the audio. Like any after-the-fact-rescue program, it needs to be used carefully to avoid the perils of stripping the sound of "presence" and "body." But, for $80US, it is a valuable application.

Forget that. Just use Audacity. It's a free open source app that can do a great job of removing noise, especially if you have a clean signature of the ambient noise for it to work from. It works on both OSX and Windows. I use this software alot.

If you upgrade to Soundtrack Pro on the Mac, you'll get the same features.

Ignacio, your XL1 would benefit greatly from using the Lightwave Systems System Isolater and Mini Mount for the mic. These two items will completely isolate the mic from picking up camera generated noise. The SI will also push your vf forward an inch or two which helps balance the XL-1 on your shoulder.

regards,

-gb-

Frank Meek · July 29th, 2005, 04:13 PM

Well, I have to agree...although I haven't used "Audacity," if its abilities are the same (or better) and it's free... then go with it...I would.
However, I have used both the Lightwave system's add-ons for years and, while I think they are better than nothing, they certainly do not "eliminate" the camera servo/motor noise...only lessen it. The best advice on limiting servo noise is not to use the zoom or curtail its use to "almost never." Zooming is the first (and most obvious) sign of amateur-hour videography. The other is, don't use the on-board mic...or use a "support cage, like the AT 8410a in addition to the LW gear.
And, the transport noise, if objectionable, (and this seems a camera by camera debate...some have little noise, others more), is only "eliminated" by direct to disc storage and slightly modified by these (pricey) Lightwave accessories. But, I do like the SI-Xl1's ability to shift the viewfinder a bit forward for better balance.

January 29th, 2005, 09:39 AM	#1
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	XL1 hum removal in FCP? Hi. I am working on postproduction on a documentary shot mainly with an XL1 (no S). When the camera-mounted mic is used, there is a distinct hum, presumambly coming from the tape transport. I am using Final Cut and have been trying to remove the hum but I can't seem to find the exact frequency. Has anybody experienced this, found the frequency and succesfuully removed it? It shouldn't be difficult, but for some reason I can't seem to get it right. Any suggestions? I have also pposted this question to the FCP board. __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

May 9th, 2005, 10:18 PM	#2
Gordon Nicol Tourist Join Date: May 2005 Posts: 1	Camera Hum Ignacio, Did you ever get an answer about that camera hum? If you'd like to send me a short sample in aiff format, I could check it out and probably get pretty close to the frequency. Gordon gjnicol@swbell.net Scotch Productions, Inc., Dallas

May 9th, 2005, 11:13 PM	#3
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	Hi Gordon! That is so generous of you! Thanks. However somebody else ended up mixing the audio and seems to have gotten it right. All I needed really was a spectrum analyzer. __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

May 10th, 2005, 07:33 AM	#4
Ben Simpson New Boot Join Date: Apr 2005 Location: Northfield MN Posts: 20	If I remember corectly the XL1 does not have a balanced line in for the mic that it comes with right? Just saying that it may not have ‘tape hiss’ but that it maybe the line. __________________ later, Simpson

May 10th, 2005, 08:38 AM	#5
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	Hi Ben. No it was not that kind of hum. When using long unbalanced audio cables you can get EM hum from AC which is 50 Hz or 60 Hz depending on where you are in the world. The hum we were talking about here seemed to be caused by the XL1's tape mechanism, and I think was somewhere close to 150Hz. __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

July 27th, 2005, 12:10 PM	#6
Frank Meek Regular Crew Join Date: May 2004 Location: Jackson, WY/Steamboat CO Posts: 43	another method... While it seems you have "fixed" the problem, there is a fairly inexpensive solftware app/tool that has helped me in the past with various audio issues. Obviously, you don't want them in the first place...you want "clean," (preferably 16 bit, 48K), audio tracks...but that doesn't always happen. I imported some SVHS, VHS and Beta SP footage for a docu-instructional piece I did and the audio from some of this was horrible: hum, buzz, crackles and pops. Even after conversion to 16 bit, 48K, the stuff was unacceptable for broadcast. Suggestions from some audio gurus indicated that SoundSoap 2 might help. For $80.US (The standard, non "Pro" package), I ordered it. The interface is simple and it works easily with existing audio programs, BIAS Peak, etc. The "2" version is supposed to work inside FCP, but that hasn't happened for me, yet (frankly, I don't use these apps too much as I work hard on good audio acquisition...so I haven't pursued it). But, the program "saved" the clips in which I needed the audio. Like any after-the-fact-rescue program, it needs to be used carefully to avoid the perils of stripping the sound of "presence" and "body." But, for $80US, it is a valuable application.

July 29th, 2005, 04:13 PM	#8
Frank Meek Regular Crew Join Date: May 2004 Location: Jackson, WY/Steamboat CO Posts: 43	good news...bad news Well, I have to agree...although I haven't used "Audacity," if its abilities are the same (or better) and it's free... then go with it...I would. However, I have used both the Lightwave system's add-ons for years and, while I think they are better than nothing, they certainly do not "eliminate" the camera servo/motor noise...only lessen it. The best advice on limiting servo noise is not to use the zoom or curtail its use to "almost never." Zooming is the first (and most obvious) sign of amateur-hour videography. The other is, don't use the on-board mic...or use a "support cage, like the AT 8410a in addition to the LW gear. And, the transport noise, if objectionable, (and this seems a camera by camera debate...some have little noise, others more), is only "eliminated" by direct to disc storage and slightly modified by these (pricey) Lightwave accessories. But, I do like the SI-Xl1's ability to shift the viewfinder a bit forward for better balance.