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Over at http://freesound.iua.upf.edu/samplesViewSingle.php?id=14830 Acclivity calculated the speed of the race-cars that Heigh-hoo recorded, so I thought, cool, let's do the same for http://freesound.iua.upf.edu/samplesViewSingle.php?id=18794 . However, being a geek I couldn't just take the formula and use it. I had to know why Acclivity calculated the speed like that. Soooo, here we are

We assume the source travels at a constant speed, and we assume the source is traveling directly to the listener, not passing by at a distance (this is a 'good enough' simplification):

Doppler frequency correction: http://en.wikipedia.org/wiki/Doppler_effect

source going towards listener (positive speed)
heard_freq_before = source_freq * (1 + speed_towards_listener / speed_of_sound)

source going away from listener (negative speed)
heard_freq_after = source_freq * (1 - speed_towards_listener / speed_of_sound)

-> heard_freq_before / heard_freq_after = (1 + speed_towards_listener / speed_of_sound)/(1 - speed_towards_listener / speed_of_sound)

let's rename some things.

c = speed_of_sound
heard_freq_before = f1
heard_freq_after = f2
speed_towards_listener = v

f1/f2 = (1+v/c)/(1-v/c)

-> f1/f2 * (1-v/c) = 1+v/c
-> f1/f2 - 1 = v/c + f1/f2*v/c
-> f1/f2 - 1 = (1+f1/f2)*v/c
-> v/c = (f1/f2 - 1) / (1 + f1/f2)
-> v = c*(f1-f2)/(f1+f1)

c = 340.29 m/s
f1 in Hz

so...

speed_of_moving_object = 340.29 m/s * (freq_before - freq_after) / (freq_before + freq_after)

( if you want the speed in km/h we need to multiply by 3.6 )

Make sure you only use this formula for objects passing by at close distance, otherwise you will introduce an error...

- bram

hey, youre farts are excellent!

seriously.
It was worth the wait for these judges.

Can't wait to find out who makes it to round two!

hi everyone

im working on the cover of assemblage 23's "disappoint" and i wish to know what synth can i use for this, if anyone can help me please send a mail to inmundizie@hotmail.com

you weren't the only one.

- bram

was i the only one removed from a competition list because of a tagging error?

harri
I understand there *could* be legal issues involved but surely common sense might prevail.

Cool, the sound is now available!

crowd-16.flac

beeeeep bwip chirp chirp

ha that looks just the job.

There is an R2-D2 freeware plugin out there if you really need that sound...

http://www.kvraudio.com/get/723.html

Ah! Judges... It is worth the wait, really.

Thanks Bram, for the effort you put on this!

hi dpm

i have just uploaded a sound that might be helpful it is called blipback. somewhere i probably have the original template for more variations but thats a whole other conversation. see if this is any good first. the file is at the moderation stage as i type././

Bram

strange, flac files should have an extension "flac" and not "fla", mike! But, perhaps cool edit doesn't like longer extensions (quite possibly a left-over from the old win95 days).

Yes, it's a know problem with Cool Edit / Audition -- it is only capable of handling 3 letter file extentions. Why this hasn't been addressed yet is beyond me.

If I recall correctly the original R2D2 sounds were created using EMS synths such as the vcs3 and synthi. I think the key to success if probably using sample-and-hold modules.

http://images.google.com/images?q=ems%20synthi
http://images.google.com/images?q=ems%20vcs3

( the EMS synthesizers all looked sooooooooo amazing, ... )

However, if you know nothing about synths and how to program them (you're going to need a modular synth to pull this off!), it's going to be pretty difficult to get R2D2'ish sounds! Maybe someone who has Native Instruments Reaktor can help you. I think there's some EMS patches lying around that should get you a long way to recreating those superb bleeps.

- bram

Hi everyone.

I'm making a film and I desperately need to mimic the noises that R2-D2 makes. Obviously, I can't use the real noises because they are very much copyrighted.

I have to admit that I don't have a clue where to start. I mean, I know the real thing is all analog synthesiser stuff, but that's certainly beyond me. How can I get my hands on a range of Artoo-ish beeps and chirps, that i could string together to form sentences?

I don't expect to be able to achieve a pitch perfect impersonation of the little guy, but obviously the closer I can get to his trademark beeps and whistles the better.

If anybody out there's got any ideas, or fancies having a crack at it let me know via this forum.

For the first freesound competition, we gathered a heterogenous panel of judges. We wanted to stress the importance of both designed and recorded sounds. Ross Bencina, Richard Devine, Vance Dylan, Garry Garritan, Richard Humpries, Jose Lozano and Xavier Serra all replied to my request to be on the competition panel... Without further ado, meet the judges.

http://freesound.iua.upf.edu/articles.php?id=4

Please post your comments here!

- bram

sweeeeeeeeeeeet

- bram, bobbing his head

adding the "recorded date" I'm not going to do, as it would add an additional field to the "descriptions". However, all files have an "upload" date, which could easily be used. Also, some file formats have in their headers the date of the last edit, or even the recording date (depends on the recorder) which could be used.

However, if anyone ever wanted to use freesound for a scientific study like this, I applaud the usage of date-related tags, or date-related extra descriptions in the description field.

- bram

hehehe,

strange, flac files should have an extension "flac" and not "fla", mike! But, perhaps cool edit doesn't like longer extensions (quite possibly a left-over from the old win95 days).

I'll add the *.fla extension to the applet.

Thanks for noticing yet another small bug

[edit] should be fixed now [/edit]

- bram