hum

We all have our ideas regarding recording! Share your experience.
Forum rules
If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like
Post Reply
stardust2003
Posts: 194
Joined: Sun Dec 26, 2010 3:30 pm
Operating System: Windows 10

hum

Post by stardust2003 » Tue Feb 05, 2013 2:40 pm

Hi,
I was doing some recording... a good clear audio playing thru a music centre from cassette
audio.
Noticed that on the final recording there is a hum which should not be there
Have a listen please... go to post at top of blog
http://bitsandpieces2003.blogspot.co.uk/

kozikowski
Forum Staff
Posts: 69357
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: macOS 10.13 High Sierra

Re: hum

Post by kozikowski » Tue Feb 05, 2013 7:32 pm

You bumped your microphone, cable or recorder and somewhere the protective shield has gone. Even very high-end microphones have a cable with a tightly braided metal mesh just under the rubber coating to protect the tiny, delicate sound signals inside. Yours isn't connected any more -- no longer doing its job.

Unplug and reseat all the connections in the system and see if that helps. Also, you can listen live on headphones and wiggle parts of the sound system and see if the interference comes and goes when you hit a particular part.

The buzz doesn't change over the course of the clip, which usually means it's a cable or terminal equipment and not, for example, a hand-held microphone. There's no clue in the question how you're actually making the recordings, so apply those ideas as needed.

Koz

Trebor
Posts: 9953
Joined: Sat Dec 27, 2008 5:22 pm
Operating System: Windows 8 or 8.1

Re: hum

Post by Trebor » Tue Feb 05, 2013 8:33 pm

It's a recording of the defunct "Richard & Judy" UK TV show.

so the hum could actually be on the (video ?) cassette recording of the TV show,
If that's the case then your only hope is a de-hum plugin for Audacity e.g. ...

http://forum.audacityteam.org/viewtopic ... 907#p79907 [Steve's]

http://forum.audacityteam.org/viewtopic ... 200#p36200 [mine]

Both plugins both remove mains* hum but they add an echoey effect.

[* if it's UK TV its 50Hz fundamental]

stardust2003
Posts: 194
Joined: Sun Dec 26, 2010 3:30 pm
Operating System: Windows 10

Re: hum

Post by stardust2003 » Tue Feb 05, 2013 8:50 pm

no there's no hum on the original recording,
if you listen to the clip the recording of the show ends and for 4 secs the hum goes on.

If I just record with the mic only , recording silence, I get the hum.
I always expect some level of hum, but Im thinking that is a bit too much
I ve tried setting 0.2 input volume and resetting output volume, but no luck so far.
there must be some way of getting rid of it !

Trebor
Posts: 9953
Joined: Sat Dec 27, 2008 5:22 pm
Operating System: Windows 8 or 8.1

Re: hum

Post by Trebor » Tue Feb 05, 2013 9:24 pm

stardust2003 wrote:no there's no hum on the original recording,
if you listen to the clip the recording of the show ends and for 4 secs the hum goes on.

If I just record with the mic only , recording silence, I get the hum.
If you when you switch off the music-centre at the mains, the hum stops, try this method ...

The hum will be less the further you move the microphone from the music-centre. You could do this by attaching headphones to the music-centre, move the headphones as far from the music-centre as possible* then place your microphone close to one of the headphones (probably microphone will have to be almost touching the headphones, like an acoustic coupling).

( * maybe even use headphone extension cable to get further away )

[ BTW you'll probably be breaching copyright if you re-broadcast a TV show, or its soundtrack, on t'internet , even if it is just Richard prattling on, or Judy flashing her norks ... https://www.youtube.com/watch?v=0apAF7GXPz4#t=10s ]

stardust2003
Posts: 194
Joined: Sun Dec 26, 2010 3:30 pm
Operating System: Windows 10

Re: hum

Post by stardust2003 » Tue Feb 05, 2013 9:33 pm

QUOTE
[ BTW you'll probably be breaching copyright if you re-broadcast a TV show, or its soundtrack, on t'internet , even if it is just Richard prattling on, or Judy flashing her norks
END QUOTE

a million forums are full of a million vid clips of celebs from tv and movies, thats a lorra lorra breach of copyrite , dont worry about 15 seconds of audio on some obscure blog !

Trebor
Posts: 9953
Joined: Sat Dec 27, 2008 5:22 pm
Operating System: Windows 8 or 8.1

Re: hum

Post by Trebor » Tue Feb 05, 2013 9:45 pm

It is possible to electrically, (rather than acoustically), transfer the sound from the music-centre to the computer.

If your computer does not have a "line-in" connector socket, a gadget is required which costs £20 - £30 which connects to the computer's USB socket.

https://www.google.co.uk/search?q=digit ... io+cassete
Last edited by Trebor on Tue Feb 05, 2013 9:46 pm, edited 1 time in total.

kozikowski
Forum Staff
Posts: 69357
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: macOS 10.13 High Sierra

Re: hum

Post by kozikowski » Tue Feb 05, 2013 9:46 pm

"What are you suing me for? Those guys on the Audacity Forum said it was OK."

stardust2003
Posts: 194
Joined: Sun Dec 26, 2010 3:30 pm
Operating System: Windows 10

Re: hum

Post by stardust2003 » Tue Feb 05, 2013 10:02 pm

I v'e been using a mic that is a stick on a headphone so its prob pretty recent and
from the computor world.

Just found a logic 3 mic that again looks pretty modern and on its own base.
suddenly no hum, exellent recording quality and when I record silence, hardly any trace of hum.

so it looks like the source of the hum was basically the microphone.... ! a very important ingredient
in this recording game !

Thanks for help, but it looks like Ive got the prob sorted !

While Im here, ... I got a tablet over xmas, is there an android version of audacity ?

stardust2003
Posts: 194
Joined: Sun Dec 26, 2010 3:30 pm
Operating System: Windows 10

Re: hum

Post by stardust2003 » Tue Feb 05, 2013 11:42 pm

check out the quality of the new recording
only about 10 mins
go to top post in blog
http://bitsandpieces2003.blogspot.co.uk/

Post Reply