Recording a Tbolt at extremely close range...Suggestions?

[ver tum]

I know this sounds like a crazy idea,but if I can get permission to get up on the roof of the UofL Reynolds Building on test day, I want to record the roof mounted Thunderbolt there from possibly as close as two or three feet away. I may even want to stick a mic inside the horn if the horn doesn't have a screen. I've been wanting to do something crazy like this for a while now, but I have some important concerns before I do it. Hearing protection isn't a problem, since I have loads of earplugs and a pair of acoostic ear muffs. What I'm concerned about is that the excessive sound pressure may damage one of my expensive mics. I'm also concerned about how much wind may come out of the horn when that thing is running. I've heard of debris coming out of those things sometimes. Any ideas or suggestions?

[FedTB]

Your ambition is commendable, but sticking a microphone inside the horn of the activated T-Bolt will probably cause the sound to be so distorted on playback that it wouldn't be pleasant to listen to. If you're concerned about ruining an expensive microphone then I would suggest not doing it.

There are several videos on YouTube of T-Bolts, and myself and many others enjoy them the way they've been recorded....at a distance that sounds normal, and for the most part, from what I've seen, not distorted.

I think it would be pretty cool to videotape a T-Bolt from the close distance that you desire to do, but again, the sound would probably be very distorted.

[guitarguy1985]

What mics do you have? Some dynamic microphones can take quite a beating, the SM57 or 58 for instance. I wouldn't even try it with an expensive mic, especially a condenser one. I've accidentally damaged mics just by putting them in front of a cranked guitar amp, and that's nothing compared to an air raid siren.

[ver tum]

In addition to my two SM58's, I have an Audiotechnica AT8220 powered stereo mic, and a Sony ECMMS957 powered stereo mic. I never thought of using my 58's for this purpose, but it sounds like it could work. Both My AT8220 and my ECMMs957 are able to take the sound pressure from the band's cranked up PA from about 6 feet away, and with the recorder on the lowest gain setting, there's little to no distortion, and I still have a bit of room for volume before I get clipping at the recorder. I'm using a Yamaha Pocketrak C4 recorder.

[guitarguy1985]

Assuming 6dB per halving of the distance, I'd expect a Thunderbolt to be pushing 150dB somewhere between 5 or 6 feet on axis with the horn. Supposedly the SM58 can handle up to 180dB. Unless an attenuator is used, the recorder will probably clip well before that.

[ver tum]

Assuming 6dB per halving of the distance, I'd expect a Thunderbolt to be pushing 150dB somewhere between 5 or 6 feet on axis with the horn. Supposedly the SM58 can handle up to 180dB. Unless an attenuator is used, the recorder will probably clip well before that.

I just remembered that I can also use my Zoom R16 recorder, because it can run on batteries. It would probably be easier to do that anyway, because it has XLR jacks for 8 out of the 16 tracks, and I can connect both of my 58's to it. The Zoom has attenuators for each track, but I'm not sure how much attenuation to give it, or whether I'll need to use my external attenuator. The good thing about the Zoom is that I can record up to 8 tracks at the same time, so I may be able to use another 58 or similar mic to also get a recording from inside the horn. I can take the Pocketrak and the AT8220 and put them on the other side of the roof if it's at least 100 feet away, or I can just let Loukycheckinin record something else with them, since he'll likely be recording as well.

For the recording inside the horn, I really would appreciate it if a TBolt owner could please tell me if I'm going to have a problem with wind in there. I want to put the mic in the outer end of the horn, furthest away from the chopper.

[holler]

A pretty good amount of air under force comes out of the horn. Remember all 250 CFM at 6PSI comes out of the horn.

Thought about putting the mic on the back of the chopper tube behind the horn?

[ver tum]

A pretty good amount of air under force comes out of the horn. Remember all 250 CFM at 6PSI comes out of the horn.

Thought about putting the mic on the back of the chopper tube behind the horn?

I haven't thought about that, but I don't know how it's going to stay on there when this thing possibly rotates at 8 RPM's. I guess I could put the mic on the stand and put it on top of the horn and point it towards the back. I may be able to use my Pocketrak and my AT8220 then, since the sound pressure should be lower. I currently have the recorder in a case mounted on the base of the weighted mic stand that the AT8220 is on, so I wouldn't have to worry about renting a wireless mic like I would with the Zoom. I've tested that stand on a pretty steep slant, and it didn't even act like it wanted to slide off. Do you have any idea what the sound pressure is like about a foot above the middle of the horn with the mic pointed towards the back?

[woodyrr]

I must be missing something really obvious. How do you plan to put a mic inside the Thunderbolt horn unless a battery powered recorder goes in there too? Does this Thunderbolt not rotate? Help me out with the visual here!

I think it is an intriguing idea, but I was just looking across the room at one of my SM57s and I'm thinking that I wouldn't be all that keen on duct taping it inside a thunderbolt horn.

[countypoletop]

I have been 20 feet under a thunderbolt on a ladder and ran it up just for a test (3-5 seconds). The viberations, force, and extreme sound was tremendious. If I do it again I will get on the ground. 100 feet at 120+ decibels- I would stay away from from the beast no matter what ear protection I had. I would suggest staying on the ground and stand directly under the siren then move closer until your eyes and eardrums start to pop out of your head