Tuesday, May 19, 2009

Recording in the field

Depending on what and where you are recording in the field, correct microphone placement can mean the difference between a mediocre low volume "whoop" and a highly defined, well formed "whoop".

Of course, that’s if you are in an area where you have potential activity. Many days have come and gone with nothing being recorded. Well, nothing except dead air. Not to worry, patience sometimes pays off.

Here are some tips that I will share to help optimize your recording strategies.

Take a moment to observe the topography of the area where you intend to record. Topography is important because of the potential introduction of echo's & reverberations, not to mention the possibility (yet less likely) introduction of Doppler Effect artifacts from something that is moving at a high rate of speed.

Steep inclinations that surround your microphone setup can distort your recordings because of the echo and reverberation that may be present. "Multipath" echo can also cause a loss in audio quality because whatever it is that you are recording is moving, thus projecting the sound in various directions.

Hard surfaces such as rock faces and cliffs are far more likely to reflect sounds than surfaces that are matted with sound absorbing material such as moss, thick grass, dead & decaying leaves. However, hard surfaces can also carry sounds much further. This brings up a good point; Use the local surroundings as a reflector or concentrator if you wish to pickup weak sounds. Parabolic and shotgun mic's work very well as a directional setup but it would be sad to have a sound come from the opposite direction of your collector and of course, not be able to record it.  So picture this setup; This is ultimately how you get the best of both worlds; Having a highly sensitive parabolic or shotgun mic assembly recording the sounds in from of it, but at the end is a rock face or some sort of structure that could potentially reflect the sounds made behind the dish into the collector, therefore, although it would be lower in volume you would still have a chance to record the sound, plus you have the chance to record whatever is between the rock face and your collector.


  Sometimes the stupidest things occur and when you find out what you did, it's too late to correct the problem. I remember I left a recorder out one evening and when I retrieved it a few hours later, I kept hearing this soft thump. For the life of me I couldn’t figure out what it was until I put 2 +2 together and realized that it was the cord of the mic banging against the tripod that I was using at the time. The wind was blowing just enough to occasionally lift the cord and bang it against the leg. I use Velcro straps now and it works quite well.

 That brings up another point - the tripod. Don't trust that thing to sit still if you have a parabolic of any considerable weight or size on there while there is a breeze. It will topple. There are some good tripods that will sit still but if you are like me and on a budget, take some twine and some tent pegs, fasten the twine half way up the tripod legs, above one of the collapsing leg knuckles so that the twine does not slide down, then fasten the other end to the tent peg that you have driven into the ground on an angle facing away from the tripod. This will ensure that the tripod sits still. You can also consider using a sand bag; Tie one end of the twine to the bottom of the middle of the tripod and tie the other end to the sandbag which is placed on the ground in the centre of the tripod.

 Here is something else that you should consider; Microphones are sensitive pieces of equipment. Like an ear drum, the fine pieces of material that make up a typical microphone element such as a condenser mike can be damaged by shock but also by a little know problem – Moisture.

 If you make that 3+ hour trip up north in the middle of summer and you have the air conditioner blasting away to keep your interior cool, that’s great, but taking that mic out of that cool cabin and you might introduce condensation. The easiest ways around this – put the stuff in your trunk or keep the equipment in an insulated case.

 Moisture can also be introduced as the sun set’s and dew starts to form. This is why it’s important not to have your microphone exposed to the hot sun for any substantial period of time. The heat can also affect the frequency response characteristics of the microphone because expansion and contraction will cause variations of size of the actual element.

 Believe it or not, insects might find the time to visit your mic setup and leave you with some baffling recordings.  Such was the case of a friend of mine who thought that someone had visited his mic and played with it, rubbing the actual microphone with a finger or something similar but in fact, it was a caterpillar that took a stroll across the surface. There are several ways to prevent this, suspended screening, etc. I thought it would be worthy to mention.

 Experimentation is the key when it comes to recording the great outdoors. And don’t be discouraged if you come away with several hours of dead air.  It’s all part of the process.

J.

 

No comments:

Post a Comment