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[Tim Barber]

The article is pretty light on specifics, but interesting.

http://www.popsci.com/why-lockheed-martin-is-blasting-orion-crew-capsule-with-noise-from-1500-speakers

[Tim McCulloch]

The article is pretty light on specifics, but interesting.

http://www.popsci.com/why-lockheed-martin-is-blasting-orion-crew-capsule-with-noise-from-1500-speakers

We provided a "bunch of stuff" for an acoustic test, the location and nature of which required I sign an NDA, but this is not that gig.

I suspect that's why the article isn't terribly specific....

[brian maddox]

The article is pretty light on specifics, but interesting.

http://www.popsci.com/why-lockheed-martin-is-blasting-orion-crew-capsule-with-noise-from-1500-speakers

The guys that specialize in this are located right here in my home state of Maryland.  So yes, they do Sound.  In Maryland.  They also work Internationally.

Do you need more clues?  😀

In truth this isn't a secret.  http://msi-dfat.com/  But yeah, it's cool stuff.  Mids and highs are Vertec 4889, but the low end is totally proprietary.  And they've got a TON of it.  Turns out it's actually quite difficult to make 30hz at 145+Db. 😀

[Keith Broughton]

The article is pretty light on specifics, but interesting.

http://www.popsci.com/why-lockheed-martin-is-blasting-orion-crew-capsule-with-noise-from-1500-speakers

So once again,like the "brown note" in Mythbusters, the subs are arranged in a circle.
I'm sure it's loud but would a wall of them all stacked together not create an even better low freq source?
Either way, would not want to be in that capsule...if you dare 

[Stephen Kirby]

From my days in military avionics, I remember strapping things to 20" voice coils and various other things to test them.  There was even a place in SoCal that would load a plucked chicken into a howitzer and fire it at a test unit.

[David Morison]

From my days in military avionics, I remember strapping things to 20" voice coils and various other things to test them.  There was even a place in SoCal that would load a plucked chicken into a howitzer and fire it at a test unit.

I think jet engine manufacturers still do something similar to simulate bird strikes - not sure it's an actual howitzer for them though.

[Chris Hindle]

I think jet engine manufacturers still do something similar to simulate bird strikes - not sure it's an actual howitzer for them though.

it's an Air Cannon. Same idea though.
It's required to certify the engine for use.

[Jeff Lelko]

The details surrounding a launch environment are always quite interesting to study.  Acoustic and vibration concerns to the launch vehicle and payload aside, the ground systems also see some insane conditions during the first 5-10 seconds following a liftoff.  To those that have never seen a launch in person, I highly encourage it - even just once.  Television and Youtube do no justice to watching something leave our planet with your own eyes.

[Craig Leerman]

OK I just got permission to let you guys in on some testing secrets

1.  If they want to do destructive testing they use a Justin Bieber soundtrack

2. For really loud testing they just point Neil Schon's guitar rig at it

3. The old testing guys stopped wearing ear plugs about 5 years ago when it was discovered they could not hear the Bieber tracks (or any tracks really)

4. To ensure the platform is level before testing they position a drummer on it. If the drool comes out of both sides of his mouth the platform is level and ready for testing.

5. During the test, 5 audio guys are present. One conducts the test and the other 4 tell each other how they could have tuned the rig better.

6. There are only 2 testing sessions done per day because audio folks can only count to 2

7. I asked a test engineer named Ivan what SPL level and frequencies they used and he replied "It depends"

8. I asked him about what special testing equipment they used for the "Brown Note" test and he replied "Depends"

9. You used to be able to go online and buy tickets and see a test for yourself but Ticketmaster scalpers have bought them all up, so now you need to look on Craigslist.





 

[Ivan Beaver]

Turns out it's actually quite difficult to make 30hz at 145+Db. 😀

It depends at what distance the measurement is made at.

But it is actually not all that hard.

[ProSoundWeb Community]