Room tone in 5.1 projects at DVinfo.net

Jos Svendsen · May 18th, 2005, 02:21 PM

I am doing a audio mix for a 5.1 project in Vegas 6. I have been a nice boy and recorded some room tone. But i did it using the stereo mic on my XL1s.

All primary sound has been recorded with an Azden shotgun, and are nice and clear. I have a singer and a guitarist in the front channels, but when i try to add room tone it begins to sound stange.

Well - I can not identify the problem. I have tried one channel, the sum of both channels, stereo with and without inverting phase. I have tried to pan it in the center, 3/4 back and all back. It just sounds "unnatural".

If I switch to stereo using the monitor function in Vegas all is fine.

So - what did I do wrong?

Douglas Spotted Eagle · May 18th, 2005, 02:27 PM

You've likely got phase and/or comb issues happening in there. You trying to mix the room tone to the forward mix as well? Center mix? If they're from the same source but mic'd at different locations, it may well be you've got a mix of issues causing cancelation at a variety of points.
Can you better describe the recording setup, and when/how you acquired room tone?

Jos Svendsen · May 30th, 2005, 02:28 AM

Pyhh - now I am back again. Projects that you do for free tend to be very on and off.

My sound set op was as follows:

I Azden SGM-1 connected to a XL1s as backup

The two perfomers on a low stage had normal stage mics.

I've gotten a cd of the performance from the kind sound person. This is my primary sound, the sound from the Xl1s is used for audience reactions

When the event was over I had a flash of inspiration and recorded five minutes of room tone using the XL1s standard mic, as the Azen was packed away. This was recorded in the empty room with the mic placed in the middle of the room.

Just to get more experience I decided to do the project in 5.1. I have placed the performers in front in the sound mix. And the audience in the middle - center between front and back. So far so good, but not very "roomy". It ends up in a sort of 2.2D - not 3D. I want the it to sound like you are sitting in a room. So i started to use my room tone, and no matter where I place it in the mix, it sounds strange. A little out of the world-ish.

I think the suggestion that is phase problems might be right. I'll try to find some bits from the camera soundtrack and use them as toom tone.

Any way - I think that I have learned that you have to use the same mic for room tone and normal recording.

But I would be very delighted if someone could explain the proper way to record and use room tone in a 5.1 project.

Hmmmm. While I am sitting and typing this. I wonder if I am doing this right. I want the mix to be 3D. So I concluded that mixing in something that sound like a room might be the way to do it. Maybe I should use reverb to get a 3D effect? Create an audiobus only for the back channels with a little reverb and feed it with the signal from the camera?

TIA (Thanks in advance)

May 18th, 2005, 02:21 PM	#1
Jos Svendsen Major Player Join Date: Mar 2004 Location: Copenhagen, Denmark Posts: 221	Room tone in 5.1 projects I am doing a audio mix for a 5.1 project in Vegas 6. I have been a nice boy and recorded some room tone. But i did it using the stereo mic on my XL1s. All primary sound has been recorded with an Azden shotgun, and are nice and clear. I have a singer and a guitarist in the front channels, but when i try to add room tone it begins to sound stange. Well - I can not identify the problem. I have tried one channel, the sum of both channels, stereo with and without inverting phase. I have tried to pan it in the center, 3/4 back and all back. It just sounds "unnatural". If I switch to stereo using the monitor function in Vegas all is fine. So - what did I do wrong?

May 18th, 2005, 02:27 PM	#2
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	You've likely got phase and/or comb issues happening in there. You trying to mix the room tone to the forward mix as well? Center mix? If they're from the same source but mic'd at different locations, it may well be you've got a mix of issues causing cancelation at a variety of points. Can you better describe the recording setup, and when/how you acquired room tone? __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

May 30th, 2005, 02:28 AM	#3
Jos Svendsen Major Player Join Date: Mar 2004 Location: Copenhagen, Denmark Posts: 221	Pyhh - now I am back again. Projects that you do for free tend to be very on and off. My sound set op was as follows: I Azden SGM-1 connected to a XL1s as backup The two perfomers on a low stage had normal stage mics. I've gotten a cd of the performance from the kind sound person. This is my primary sound, the sound from the Xl1s is used for audience reactions When the event was over I had a flash of inspiration and recorded five minutes of room tone using the XL1s standard mic, as the Azen was packed away. This was recorded in the empty room with the mic placed in the middle of the room. Just to get more experience I decided to do the project in 5.1. I have placed the performers in front in the sound mix. And the audience in the middle - center between front and back. So far so good, but not very "roomy". It ends up in a sort of 2.2D - not 3D. I want the it to sound like you are sitting in a room. So i started to use my room tone, and no matter where I place it in the mix, it sounds strange. A little out of the world-ish. I think the suggestion that is phase problems might be right. I'll try to find some bits from the camera soundtrack and use them as toom tone. Any way - I think that I have learned that you have to use the same mic for room tone and normal recording. But I would be very delighted if someone could explain the proper way to record and use room tone in a 5.1 project. Hmmmm. While I am sitting and typing this. I wonder if I am doing this right. I want the mix to be 3D. So I concluded that mixing in something that sound like a room might be the way to do it. Maybe I should use reverb to get a 3D effect? Create an audiobus only for the back channels with a little reverb and feed it with the signal from the camera? TIA (Thanks in advance)