Ambience in Multi-Overdub-Sessions

James Hardiman

Fabian Köhler Posted the following question:

In your opinion,
Does it make sense to record with 2 ambient mics/ main mics when it comes to sessions with multiple overdubs? I tried so with a single omni-microfone of good quality (Neuman 183) in what i considder a room with ‘good accoustics’. Results where good and open sounds on single instruments (summing with the close up mics), but when it came to mix the signals, summing the ambient-mic traces resulted in a confused, ‘spacy’ sound- so i had to replace natural ambience with a convulsion-reverb plugin- but like to use natural ambience of the room i prepared as registration studio next time, as it sounds much better to me (at least on single instuments).
For you, does it make sense- with the same ambience microfone position? Does the overall ‘openness’ of a mix benefit of this summed overdub-ambience-traces (which, in every case, summ even background noises etc.)?
I thank you for your attencion,

Fabian Köhler

Dear Fabian: 

Good question.

I would definitely prefer a pair of ambience mikes, not  a single mono ambience mike. Did you test the overdubbing situation with the stereo pair of ambience mikes or just the mono mike? If you only did the mono mike you probably did not get great sounding results.

I assume in the mix you have full control over the direct and ambient mix level for each overdub.

Still, depending on the early reflection and reverberant character of the room, you may run into cumulative resonances when you add the ambience mikes in for each overdub. There is no yes or no answer to your question… you have to listen to the mix and decide what the consequences of mixing in these multiple ambient mikes could be. It could multiply the bad aspects (resonances) of the room. That sound fine with one recording, but not so good with multiple overdubs. 

So, yes, it is possible that the artificial approach may work better, because you can tune the reverb to the specific mix you are making with the specific instruments and create a perfectly complementary artificial room.

But there also can be problems with a convolution reverb as it does not create depth as well as real ambience mikes or the best algorithmic verbs. For this kind of thing artificially done, I prefer a combination of the hardware Bricasti Reverb with UAD’s Ocean Way. Or, TC’s VSS4. And/or sometimes, Leapwing Stage One. You’re making esthetic and musical decisions, so there is no guaranteed single formula.

Best wishes,