Thread by @t_serror

This week, I was tasked by Sound Supervisor Nicolas Becker to figure a way to record "heavy metal rattling" to feed the soundtrack for a film taking place on a container ship.

Prepare your best Sound Of Metal jokes, this is a #sounddesign & #fieldrecording thread.

1/18

Nicolas had designed a bunch of low/sub textures to evocate/sonify the ship's 100 000 CV motor (Yeah, 100kCV).
This brought the "heavy/oppressing" character of the motor to the soundtrack, but lacked the close-up detail of "stuff on the boat reacting to the motor's energy".
2/18

So I came up with a simple idea : feeding the motor's textures through some transducer stuck to the metal to record the "organic" reaction.

A drummer friend of mine had told me about "buttkickers" : basically "solid speakers" that shake a drummer's seat with sub.
3/18

And that's what can be seen on the first video : the buttkicker clamped to a crowd barrier, tied against a container to make it rattle.
Buttkicker was fed textures from the film's sound track.
(Sound is C414 then xfades to Contact Mic).
4/18

From there, it was a matter of playing with the toy:
- find sweetspot for maximal rattling
- tighten/loosen coupling between the transducer and the sheet (too tight = too bassy)
(Notice the Professional 100%-Cotton® Dampener to lessen some of the unpleasant transients).
5/18

Also brought a smaller transducer for some higher-pitched tones.

6/

The field recording session was all fun and games, but too short to my taste, and we also wanted to experiment in a more controlled environment - aka a studio.
Luckily, I walked by a school whose Central Heating System was being replaced.
I snagged two 1.5x2m metal sheets.
7/18

And there it all started again:
Here, two sheets rattle against each other.
Notice the black tape. Akin to what it'd do to a snare drum, it helped contain the low "wobble" from the sheet (which we didn't need in our case). Left hand's pressure further fine tunes it.
8/18

Being in a studio, we were able to literally "reamp" the sound design session through the transducer and re-record it in perfect sync.
This was because the recs are thus organically tied to the underlying sound design.
Especially when it comes to fades & Co.:
9/18

It's wildly different to "fade in a high intensity rattle" and to cut a "increasingly intense rattle".
Reamping the actual session allowed us to be consistent with the latter.
10/18

Another crucial point : we recorded in a music studio. This was deliberate.
1st of all, working in #postproduction, I've always learnt tons by working with music folks (and, truly, people from any other industry) and their specific skillsets/know-hows and practices.
11/18

Additionally, it allowed us to work with gear rarely found in post studios.
Our setup there included :
- a C800 tube microphone
- five DPA 4006 in a 5.0 setup
- a DPA 4041 pair
- a stack of high end preamps.

12/18

I'm not a huge mic/preamp geek.
However, I had 2 main takeaways from this experience :
a) The tube mic. brought in a ton of energy while not being aggressive (which very well complemented the more natural/transparent sounding 4006 array, especially as a center channel).
13/18

b) These preamps allowed us to sometime overdrive without ever worrying about digital clipping. And the occasional/controled saturation from the preamps enhances the perceived energy of our metal rattling.
(Of course, sat/distortion could be added in post, but I do believe
14/18

there is creative value in finding/recording the "right" sound on the spot).

Here are some other tidbits from this session :
15/18

We also poked wholes into the metal sheets to screw in nuts & bolts for some more detailed rattling.
(Drilling holes into 3mm thick steel required more lubricant than we expected....)
Tweaking the output volume & cutoff controlled how many/which bolts were resonating
16/18

And that's about it. I guess there'd still be a lot to say about this session, so I may add stuff in the future.
May also put up a short soundcloud "summary" at some point of our most interesting clips.
It was an incredibly fun and inspiring session to carry out!
17/18

Finally, a massive shoutout to @timprebble, who's _Sub Rattler_ blogpost (musicofsound.co.nz/blog/repost-su…) was a crucial inspiration.
@TONSTURM also deserve a big up for their _Tremor_ sound library (tonsturm.com/soundpacks/tre…), another inspiring source !
18/18