Auto-gain disable function on DXA-5D at DVinfo.net

Marco Leavitt · November 10th, 2009, 03:52 PM

The Beachtek Web site claims that their DXA-5D somehow disables the autogain function on the Canon 5D MKII. Really? How is that possible? Anybody have experience with this thing?

Jerry Porter · November 10th, 2009, 06:28 PM

It sends a 20K hertz signal to the camera (it's inaudible to the human ear) but the camera hears it as a level and it defeats the auto gain controll, but like I said in another post I'm pretty disappionted with the unit as a whole.

Marco Leavitt · November 11th, 2009, 11:04 PM

That's ingenious. Wish they had that during my old GL1 days. I do miss that camera despite it's infernal audio issues.

Jon Fairhurst · November 12th, 2009, 08:47 AM

When testing for my video reviews of 5D2 audio, I found that the Beachtek cuts the 5D2 gain, but not all the way. If you give the camera a hot signal, it will cut to a lower gain level and stay there. (This is a camera thing, rather than a Beachtek thing.)

One problem is that the 5D2 autogain is implemented on the digital side. The analog gain is fixed at +31dB, so the recordings have a lot of hiss no matter what you do externally.

If you really want to control the gain, get Magic Lantern. You can set the analog, digital, and monitor levels as needed. If you provide some clean external gain, the sound quality can be very good.

Check out my six part review of 5D2 audio here:
P3Pictures on Vimeo

November 10th, 2009, 03:52 PM	#1
Marco Leavitt Inner Circle Join Date: Jul 2002 Location: Albany, NY 12210 Posts: 2,652	Auto-gain disable function on DXA-5D The Beachtek Web site claims that their DXA-5D somehow disables the autogain function on the Canon 5D MKII. Really? How is that possible? Anybody have experience with this thing?

November 12th, 2009, 08:47 AM	#4
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	When testing for my video reviews of 5D2 audio, I found that the Beachtek cuts the 5D2 gain, but not all the way. If you give the camera a hot signal, it will cut to a lower gain level and stay there. (This is a camera thing, rather than a Beachtek thing.) One problem is that the 5D2 autogain is implemented on the digital side. The analog gain is fixed at +31dB, so the recordings have a lot of hiss no matter what you do externally. If you really want to control the gain, get Magic Lantern. You can set the analog, digital, and monitor levels as needed. If you provide some clean external gain, the sound quality can be very good. Check out my six part review of 5D2 audio here: P3Pictures on Vimeo __________________ Jon Fairhurst

November 10th, 2009, 06:28 PM	#2
Jerry Porter Major Player Join Date: Aug 2005 Location: Satellite Beach, Fl Posts: 784	It sends a 20K hertz signal to the camera (it's inaudible to the human ear) but the camera hears it as a level and it defeats the auto gain controll, but like I said in another post I'm pretty disappionted with the unit as a whole.

November 11th, 2009, 11:04 PM	#3
Marco Leavitt Inner Circle Join Date: Jul 2002 Location: Albany, NY 12210 Posts: 2,652	That's ingenious. Wish they had that during my old GL1 days. I do miss that camera despite it's infernal audio issues.