sounds for cinema: which is it the smallest form factor stereo mic configuration I can use using diy omni to avoid phase cancellation problems in the theatre?

[Dan Wake]

Hi, which is it the smallest form factor stereo mic configuration I can use using diy omni mics to avoid phase cancellation problems in the theatre? I want to mount 2 diy omni mics in my Rycote blimp, but I need a suggestion about the stereo configuration (mics placement) focused on avoiding phase cancellation in theatres.
Thx for you attention!

[Olle Sjostrom]

Well there’s really only one way you can mount them, and that’s the AB way, ie one capsule at each end of the rycot. Pointing away from each other.. might still be a bit tight, but could work.

 

i’ve used two Røde NT5s in a a røde  blimp a few times, but in the ORTF config, since the nt5s are cardioid. Worked,  no cancellation but also not very small. 
 

Line Audio has the CM4 which are super tiny and dirt cheap, I think they have an Omni mic as well, not sure… 

 

the smallest form factor is obviously using high grade lavs, like the dpa  4060. With xlr connectors they sound good enough, I’ve recorded tons of ambiances with lavs just mounted on a backpack. 

[Dan Wake]

2 hours ago, Olle Sjostrom said:

Well there’s really only one way you can mount them, and that’s the AB way, ie one capsule at each end of the rycot. Pointing away from each other.. might still be a bit tight, but could work.

 

i’ve used two Røde NT5s in a a røde  blimp a few times, but in the ORTF config, since the nt5s are cardioid. Worked,  no cancellation but also not very small. 
 

Line Audio has the CM4 which are super tiny and dirt cheap, I think they have an Omni mic as well, not sure… 

 

the smallest form factor is obviously using high grade lavs, like the dpa  4060. With xlr connectors they sound good enough, I’ve recorded tons of ambiances with lavs just mounted on a backpack. 

Thx for help Olle, which is it the shortest AB length in between 2 omni capsules to avoid phase issues for cinema? 
would using cardioids capsules instead than omni capsules change anything about the minimum length in between the 2 mics? 

[Olle Sjostrom]

Honestly, I have no idea about minimum distance, I’ve only ever used my ears to determine those things. I think it varies with the rooms and reflections and also the size of the mics and diaphragm.

 

I’ve used the formula “at least a mic length apart” for both configurations. But again, it varies. You could also put something in between the mics, like a piece of padding, like a disc, to elleviate some issues.
 

with the lavs, I have only ever used them mounted on a backpack with maybe 20-30cm between the mics, and the backpack serves as that disc I mentioned earlier

[Dan Wake]

2 hours ago, Olle Sjostrom said:

Honestly, I have no idea about minimum distance, I’ve only ever used my ears to determine those things. I think it varies with the rooms and reflections and also the size of the mics and diaphragm.

 

I’ve used the formula “at least a mic length apart” for both configurations. But again, it varies. You could also put something in between the mics, like a piece of padding, like a disc, to elleviate some issues.
 

with the lavs, I have only ever used them mounted on a backpack with maybe 20-30cm between the mics, and the backpack serves as that disc I mentioned earlier

Thx Olle, yeah I had the same idea about disks. Anyway my worry about phase issues in theatres is strong if I need to follow my ears during recordings that's why I'm looking for more conventional ways before trying new routes: I don't have the right equipment to check for issues in post. Maybe I can find some users on this forum who mix films in a true theatre room that would be willing to listen my field recording from my diy project?

[DavidEarleChorowski]

Not too sure of the specific application but dpa 4060's could definitely be a great option