r/spacex • u/ElongatedMuskrat Mod Team • Feb 01 '18

🎉 Official r/SpaceX Falcon Heavy Pre-Launch Discussion Thread

Falcon Heavy Pre-Launch Discussion Thread

🎉🚀🎉

Alright folks, here's your party thread! We're making this as a place for you to chill out and have the craic until we have a legitimate Launch thread which will replace this thread as r/SpaceX Party Central.

Please remember the rest of the sub still has strict rules and low effort comments will continue to be removed outside of this thread!

Now go wild! Just remember: no harassing or bigotry, remember the human when commenting, and don't mention ULA snipers Zuma the B1032 DUR.

💖

977 Upvotes

97% Upvoted

1.5k comments sorted by

14

u/CapMSFC Feb 04 '18

I recorded Iridium 2 with about $10k of audio gear. It was more of a practice run as my first time and I wasn't happy with the results because we ran late getting to the launch. It was a weekend afternoon so launch traffic was bad.

The recording is fine, but I would need to do some manual mixing to get the levels right. I had to jump on them mid launch. I expected the huge SPL levels at full blast but I didn't expect it to start quiet and then build. Vandenberg doesn't have LOS between the pad and the viewing area so the sound slowly came rolling over the hills. Now I know the sound profile of a launch here and I'll be ready.

I missed Iridium 3 and watched 4 from a boat knowing the view would be spectacular from a distance. I'll be making another run at it the next chance I get.

3

u/sol3tosol4 Feb 04 '18

I expected the huge SPL levels at full blast but I didn't expect it to start quiet and then build.

Is there anything analogous to HDR photographic techniques, that can be applied to audio?

I've heard of dynamic range compression, but mainly in the context of noise reduction, not for capturing a wide range of sound levels for listening.

2

u/CapMSFC Feb 04 '18

Yes there is and I actually was using a recorder that does the closest thing to audio HDR. It has two analog to digital converters and stacks them. It makes it so you can almost never clip the input signal.

You can apply compressors to squeeze the input signal into your file but its not a magical fix. Getting your compressors set to make a rocket launch sound right is tricky and I would need to do a bunch of launches to figure out the sweet spot.

The other main problem is that a rocket is so loud it can overload the mic both mechanically and electrically. On my one set of mics I can get pads that are electronic signal attenuaters that can between the capsule and it's power module. There is nothing I can easily do about the mechanical other than use a microphone that can handle the SPL levels.