Recording sound...Attn: Toaster

[Floppyman]

Hey Toaster,

A while back you posted about how you recorded the sounds of trains and various aircraft taking off. Have you ever tried to record thunder? I just thought of it the other day. Thunder can be so powerful as to shake an entire house, and it's deep growling sound sure oughta be something than can blow a few speakers. I know it could be very dangerous (for obvious reasons) to try (lightning)...what's your opinion?

[MITotaku]

Wouldn't recording thunder just clip?
I don't know about blowing speakers on playback... unless you had volume up to max.
Maybe I'm not getting the whole concept here...

[Toaster]

Hello there Flopster,
Iv`e recorded many a thing and thunder was one.
While its very possible to record thunder, the problem being is rainfall and hoping your subject noise source is of "usable" amplitude.
I set my DAT recorder to record for the duration of a 90 meter tape using a quasi 3 mike set-up. This was 2 standard mics and one "transducer" of my design.
For the most part, the levels were too low and floor noise was evident.
There were (4) "claps" that were quite close. 2 of the "claps" were well in excess of my set recording levels, 1 clap was almost perfect and one was too distant. The "near perfect" clap was very near ideal recording levels except during the initial "crack" of the nearby lightning. While it slightly oversaturated the recording for a brief instant, the recording came out well.
I would suggest to amature recordists to use the following level setting method outlined below and hope someone could better it for something "special" and rare.

The following assumes a DAT recorder where the levels can be manually set.

1. If available, set your level meters to read "instant" instead of "average".
2. Set the recorder to its fastest speed and highest quality settings.
3. Keep cables short, use fresh batteries.
4. Have an associate count to 30 in a normal speaking voice. It is perferred that the associate me either male or have a lower voice tone.
5. While your associate counts, move to 15 feet away with your mics set to a "typical" arc of 5 feet apart, 5 feet from the ground and clear for about 100 feet in any direction. (ideal is 200 feet+)
6. Set your levels to -30db relative and allowing no peaks beyond this figure.
7. Check the recording. The sound should be clear but quite low. If the equipment/mics are noisey, you will have to use higher settings and risk saturation.
8. Hope for a close (but not too close) event to record.


Another option is to record traffic from an overpass. Find the constant setting that does not need to be reset regardless of vehicle type.
Mark this setting as for "high dynamic".


Be forewarned that reproducing thunder is dangerous to equipment and requires oodles of power to do. Thunder has frequencies that approach "DC" and is very damaging to both loudspeakers and "modest" amplifiers.