Removing echo

Jon Fairhurst · October 6th, 2013, 11:13 PM

Seth, it's even worse at low frequencies than that plot suggests. This plot below is more representative (though not quite accurate across the whole range.)

At high frequencies, there is a tight lobe, and many smaller lobes off-axis that can cause comb filtering.

At mid frequencies, the pattern is wider and smoother. You can get a rear lobe too. (For whatever reason, this plot doesn't show the high and mid rear lobes to be as strong as they often are.)

At lower frequencies, the lobe gets wider. This is the real culprit. If you don't have bass traps in the room, the reverberation can pollute the sound with a heavy, underwater feel.

At even lower frequencies, the mic becomes omni-directional, which would be represented with a circle.

I've got a 36 ft x 36 ft barn that we shoot in. We added moving blankets, which remove the high frequency reflections, but not the lows. It sounds okay in there to the naked ear. By adding the blankets, hand claps even sound decent. But with a shotgun, the low frequency reverb is terrible. The poor-man's way of solving it is to EQ out the lows in post, but you still hear the "echo" and the voices become thin. The better solution, of course, is a hypercardioid mic, placed as close as possible.

This plot (follow the link), from the Sennheiser MKE400, shows the stronger rear lobes that can occur, even with very short shotguns...
http://d1c86o3nm55du5.cloudfront.net...l/235994_a.jpg
.
.

Jody Arnott · October 7th, 2013, 07:37 PM

Alrighty. Well I tried the Izotope RX3 Advanced demo, and it got rid of the echo completely. Unfortunately when I go to render the effect in Avid MC, it spits out a whole bunch of errors and crashes.

I was going to try Dyvision Reverb Remover but I don't run Windows.

Does anyone else know of any other software that might help?

Thanks in advanmce.

Josh Bass · October 8th, 2013, 06:19 AM

I see I'm too late, but I was going to suggest the plugin Unveil by Zynaptiq. Works with many different programs, and they have a free demo. I think it runs 300 or so (so same as Izotope?). It works. It's amazing.

Jody Arnott · October 8th, 2013, 09:45 PM

Quote:

Originally Posted by Josh Bass

I see I'm too late, but I was going to suggest the plugin Unveil by Zynaptiq. Works with many different programs, and they have a free demo. I think it runs 300 or so (so same as Izotope?). It works. It's amazing.

Not too late! I'll give it a try. Thanks.

October 6th, 2013, 11:13 PM	#16
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Re: Removing echo Seth, it's even worse at low frequencies than that plot suggests. This plot below is more representative (though not quite accurate across the whole range.) At high frequencies, there is a tight lobe, and many smaller lobes off-axis that can cause comb filtering. At mid frequencies, the pattern is wider and smoother. You can get a rear lobe too. (For whatever reason, this plot doesn't show the high and mid rear lobes to be as strong as they often are.) At lower frequencies, the lobe gets wider. This is the real culprit. If you don't have bass traps in the room, the reverberation can pollute the sound with a heavy, underwater feel. At even lower frequencies, the mic becomes omni-directional, which would be represented with a circle. I've got a 36 ft x 36 ft barn that we shoot in. We added moving blankets, which remove the high frequency reflections, but not the lows. It sounds okay in there to the naked ear. By adding the blankets, hand claps even sound decent. But with a shotgun, the low frequency reverb is terrible. The poor-man's way of solving it is to EQ out the lows in post, but you still hear the "echo" and the voices become thin. The better solution, of course, is a hypercardioid mic, placed as close as possible. This plot (follow the link), from the Sennheiser MKE400, shows the stronger rear lobes that can occur, even with very short shotguns... http://d1c86o3nm55du5.cloudfront.net...l/235994_a.jpg . . Attached Thumbnails __________________ Jon Fairhurst

October 7th, 2013, 07:37 PM	#17
Jody Arnott Major Player Join Date: Mar 2012 Location: Hamilton, New Zealand Posts: 747	Re: Removing echo Alrighty. Well I tried the Izotope RX3 Advanced demo, and it got rid of the echo completely. Unfortunately when I go to render the effect in Avid MC, it spits out a whole bunch of errors and crashes. I was going to try Dyvision Reverb Remover but I don't run Windows. Does anyone else know of any other software that might help? Thanks in advanmce.

October 8th, 2013, 06:19 AM	#18
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Re: Removing echo I see I'm too late, but I was going to suggest the plugin Unveil by Zynaptiq. Works with many different programs, and they have a free demo. I think it runs 300 or so (so same as Izotope?). It works. It's amazing. __________________ The Bass' camerawork The Bass on IMDB