acoustics question/not sure how to word it...

[Studiodawg]

I've been recording acoustic guitars & mando with drums live (bass DI'd) upstairs in my barn (studio). The drums are at one end of the room while I have the cardioid mics trying to null the drums, at least somewhat on the guitars and mando...because of the curvature of the barn roof (and lack of treatment on said ceiling), I get a sneaking suspicion that the drum sound is travelling the arch of the Gambrel ceiling and sneaking into the front of the mics. I Googled "barn ceiling shape" and discovered it's called Gambrel, fyi. Do any of you have any experience with Gambrel shaped roofs in relation to live acoustic recording? The good news is that it is thawing out a bit and I'll be moving tracking back to my larger tracking room, the whole first floor, soon.

[I'm Painting Again]

you can draw a diagram and use a ruler to trace the reflection points perhaps to visualize where reflections might be converging..

if you can't treat the reflection spots on roof/walls you can try moving everything around until you find something that works..

taking a look at a gambrel shape it's a good bet you're right about the reflections..seems if the drums are at one end against the part of the roof that's slanted it could be bouncing off those walls/roof and focusing on the opposite end where I'm imagining your acoustic instruments are placed.

you can also try putting packing blankets in a cloud above the drums and build gobos for the perimeter of the drums..that might help..

also using more directional mics than cardioid if they're available..

[JWL]

You'll be able to estimate where the reflections are with geometry, or if you have a ladder and a helper you can use a mirror to find them.

The main thing is to make sure you know where the reflections from each instrument are being aimed, and to keep the mics out of the reflection paths. If that is the shape of the roof then keeping instruments in the center of the room (ie, directly under the flat part of the roof) is probably not helping you.

[floid]

rather than the typical "walk around with drum until it sounds best," you might try some iteration that causes the mic to hear the least.

[Studiodawg]

Oddly, the gobos didn't help at all, nor did a 5-panel Clearsonic "drum wall", so I began thinking that the ceiling was the culprit. We found that a CAD 100 on the mando helped some and the SM7B I'm using on vocals seems to do well. I also think that the drums are reflecting off the acoustic guitar bodies and bouncing into the mics. I'll probably work on ceiling treatment between now and next winter. It was "just an experiment" to see if my mixing room (which is much warmer in the winter) would work for recording- and the answer is yes. It has a nice vibe. The room is treated from a mixer's perspective front, back and floor, but the ceiling and angled sections are showing their weaknesses upon multiple live tracking sessions. If I were to take the drums out of the equation, the room is excellent, but alas- gots to have drums! The bleed is useable. I will likely try to estimate the reflections on the gambrel ceiling. I'll also look at it from the "make sure you know where the reflections from each instrument are being aimed, and to keep the mics out of the reflection paths" point-of-view and maybe tighten patterns on a couple M179 CAD mics to see if that helps. I was also thinking about pointing mics straight down in figure-8 pattern to try to null the drums...thanks for the responses.

[Gregg Juke]

Can you break-up the ceiling effect by hanging some clouds in the room? What about just some blankets or sheets, or anything to cut at least the high end reflections and the "travelling drum pipe" effect. I'm also wondering where/how you placed the gobos, and also where the drums are in the room and in relation to the wall (drum walls and corners "shoot-out" sound imho and definitely benefit from some spot treating).

There's no substitute for really good acoustic treatment, but even the simplest of attempts can help. We used to practice in a very ring-y basement, and just hanging some material did lesson a lot of the "hang time."

GJ

[losthighway]

I find mic'ing acoustic instruments in the same room as a drum set is extremely difficult no matter what the shape of the room is.

One big realization I've shared with trying to get live vocals going in a drum room is having absorption behind the singer the mic is pointed at is often more effective than putting it in front of them.

In other words the null of a cardioid pattern is usually really effective, the leakage comes from the reflections that are bouncing towards the pickup pattern. If you can make what's right in front of the mic more "dead" it can tighten things up a lot.

Also the ridge line of a barn seems to have the tendency of focusing the sound back down towards the center of the room, it's really just another corner. The idea others have mentioned about hanging clouds could probably improve the acoustics of the room in general.