Freesound Forums
Dare 50 - Man your stations!
Started July 3rd, 2017 · 18 replies · Latest reply by DJCdelaHaye 7 years, 2 months ago
This was the dare I intended to post for July. I got too excited with the results of the previous dare, so I posted a sequel to it...
In any case, I decided I might was well post my intended dare. I will start it now and make it last to end of Aug.
This is a very simple recording dare:
We want the sound of train stations!
Especially if you can get some station announcements in there. That would be great.
Subway stations allowed too.
And, if trains really, really aren't your thing... we will accept recordings of bus stations too - meaning big bus terminals, not bus stops OK!?
Deadline 31 Aug 2017.
NOT a submission!!!
AmbientOnline.org had a "One Sample Dare #50"
In this you where to use a u-bahn sound - if I'm right...
I made this with audacity
https://soundcloud.com/gis_sweden/betweenosd50
Now grab your recorders and get out!
Denver, Colorado
RTD I-25 & Broadway light rail station
A train approaches the platform while ringing its bell, it stops, an announcement plays, then it departs.
Greetings Earthlings. I have a couple of contributions..
#1 http://freesound.org/people/kangaroovindaloo/sounds/398606/
#2 http://freesound.org/people/kangaroovindaloo/sounds/398604/
Have a nice day!
My submission might be a little too old. 
http://freesound.org/people/InspectorJ/sounds/394411/
And have an excellent day as well, kangaroovindaloo!
A little late Alienxxx, but here it is;
https://freesound.org/people/klankbeeld/sounds/398873/
Hello everyone. I am away on holiday so have been less active on Freesound than usual.
A dealayed reply to all that have kindly posted their contributions.
@gis_sweden
You are right: does not count as a submission.
Still was quite interesting to listen to.
@chromakei
really good binaural recording. Thanks for uploading.
@kangaroovindaloo
Greetings back! - Although I am an alien 
Steam train?? - I think you win. Shame the first train whistle clips a bit on the recording.
@InspectorJ
Hmmm... yes... Was actually uploaded to Freesound before the dare started.
But hey, accepted since it is in line with the spirit of the dare
@klankbeeld
Deadline is 31 Aug, not late at all my friend
I recorded the last part of my travel to work, the first day after my vacation. Inside the train my recording equipment (Soundman Digital Recorder DR2) generates a lot of digital noise – more than usual. Interesting. Therefore I upload from when the commuter train stops at Gothenburg central station and the doors open and I walk away from the station.
The digital noise is there all the time but just less audible. In the beginning of the sound file you hear the noise clearly.
Don’t buy this little recorder…! (It has a Sigmatel recording chip.)
In the frequency analysis, and spectral view, I notice peaks at about 800 - 950Hz, 7850 - 8350Hz and 16100-16450Hz. I guess this is part of the digital noise. Tried to EQ this away with spectral edit. This did not improve the sound. The noise has a wider spectrum.
Tried to download the “latest” firmware at www.soundman.de. Had to open command prompt and use unzip to extract the files. What?! But the Firmware downloader does not detect the “device”. I doubt there is a new firmware anyway. The year for this recording, according to the recorder, is 2002…
The recording starts about 07:50 Monday, August 07, 2017
I took 2 seconds from the beginning of this file and used paulstretch. Resulting in a 20second digital noise drone, “DR2 Digital Noise”,
https://freesound.org/people/gis_sweden/sounds/399075/
Had a thought that I could use a file like this to cancel out these frequencies from the other file with an inverted digital noise file… But I cant invert frequencies – off course...
The sound:
https://freesound.org/people/gis_sweden/sounds/399076/
Me again!
Every sound is worth a second chance! I used the failed Dare 50 recording to create this. All it needed was some good company!
Here is the company:
https://freesound.org/people/Corsica_S/sounds/23461/
https://freesound.org/people/DJmastah/sounds/136364/
https://freesound.org/people/Erokia/sounds/398912/
https://freesound.org/people/cormi/sounds/183876/
In the mix I have a bass tone generated in Audacity.
All work done in Audacity.
Here is the result:
https://freesound.org/people/gis_sweden/sounds/399077/
gis_sweden wrote:
I took 2 seconds from the beginning of this file and used paulstretch. Resulting in a 20second digital noise drone, “DR2 Digital Noise”,
https://freesound.org/people/gis_sweden/sounds/399075/
Had a thought that I could use a file like this to cancel out these frequencies from the other file with an inverted digital noise file… But I cant invert frequencies – off course...The sound:
https://freesound.org/people/gis_sweden/sounds/399076/
I don't recommend stretching out sounds and trying to use the stretched version to somehow remove the noise in the original recording.
I am at work right now so I have not listened to any of the sounds. But changing the Freesound sample view to 'spectral' I can clearly see some narrow straight lines which match the frequencies you specify.
The best way to minimize these from a recording is to try to find a portion of the recording containing only the unwanted noise and apply Audacity's noise removal algorithm. This will work by telling Audacity that that portion of the recording contains only the noise you want to remove. Audacity will then apply an attenuation of those frequencies across the whole recording (or a selected part of the recording that you specify).
This only applies attenuation (not complete removal). Caution: if the settings are too heavy-handed or applied multiple times, usually this will result in the introduction of artefacts and smearing of transients.
Some experiments for you to try:
Try recording in a very silent environment and see if you get any noise. - example putting the recording under some pillows in a quiet room at night and recording 1-2 minutes.
If the noise is there it is from the electronics themselves. Check if it changes with different recording volumes. - If the noise does not change with level or just increases in intensity with higher recording volume, it is easy to use this recording you just made as a 'noise template' and perform the noise reduction method above on any recording.
Unfortunately, looking at the 'spectral display' of your sound, looks like the noise line at 16100-16450Hz gets stronger with stronger signal. This indicates it is most likely an aliasing artefact.
If the recorder has different sample-rate settings, you can try a higher setting to see if it improves.
Record a test sound. Preferably something with wide spectrum and plenty of high frequencies. - Maybe find a test sample from Freesound, play it multiple times making recordings with the different sample-rate settings.
Then, something you can try (if you are really taking this very seriously) is to use the test sample as the 'noise profile' and apply that to your recorded sounds using the Audacity noise removal algorhitm. That should leave only the aliasing frequencies, so you can study them in more detail (If you do this and post the resulting sounds you will get a geek award!)
"Audacity's noise removal algorithm"
I will try this!
Geek award 
Hmmmm....
Noise reduction and a little bit of spectral editing gives you interesting sounds. Effect applied to my original sound - a part of it. I play a little with the sound and add kangaroovindaloos steam train. Hope it's okay. This is the result:
https://freesound.org/people/gis_sweden/sounds/399115/
Anyway the Soundman Digital Recorder DR2 is - crap - as a recorder of sounds.
When a musician, instrument designer and sound artist crosses the globe from Tasmania to your home town to get you involved in his research project about the life and artistic career of Futurist and pioneer of Noise Art Luigi Russolo, what do you do?
But of course! You ask him, on his way to the next city, to record some ambience at the train station, to submit it for Freesound Dare 50!
...I had planned to use my smartphone for that, but since he has a Zoom H4n, I took that chance
So my gratitude goes to my friend Mat Ward, first of all for involving me in his project (and taking quite a detour for that on his path around Italy) and then for kindly doing this extra work.
Here are the unprocessed recordings,
https://freesound.org/people/copyc4t/sounds/399307/
https://freesound.org/people/copyc4t/sounds/399306/
https://freesound.org/people/copyc4t/sounds/399305/
https://freesound.org/people/copyc4t/sounds/399304/
conveniently packed here:
https://freesound.org/people/copyc4t/packs/22490/
In case you're curious, this is the project's page:
https://matwardhobart.wixsite.com/russoloproject
In the blog section you'll find excerpts of his audio and video recordings, some of which, taken in Pescara, feature yours truly
You wanted a dare. Here's mine; a contact mic recording of Newcastle's Metro subway train taken from directly beneath a section of the Metro Bridge. This was part of a larger installation project which involved recording all of the bridges crossing the Tyne. The left channel is the contact mic. The right channel is an ambient mic. This way, the listener gets to experience the internal resonances whilst being able to hear the external cause.
Gear used was a Zoom F8, DPA 4060 (actually a stereo pair, but here mixed from just a single channel) and a JrF Contact Mic.
DJCdelaHaye wrote:
You wanted a dare. Here's mine; a contact mic recording of Newcastle's Metro subway train taken from directly beneath a section of the Metro Bridge. This was part of a larger installation project which involved recording all of the bridges crossing the Tyne. The left channel is the contact mic. The right channel is an ambient mic. This way, the listener gets to experience the internal resonances whilst being able to hear the external cause.Gear used was a Zoom F8, DPA 4060 (actually a stereo pair, but here mixed from just a single channel) and a JrF Contact Mic.
First prize !
gis_sweden wrote:AlienXXX wrote: First prize !Agree!
The prize is eternal fame ;-0