# Degrading audio quality on purpose



## gafftaper (Feb 22, 2009)

Hi all, we are using SFX for playback and Audacity for editing at the college. This is our fourth show with that combo. I know there are fancier products out there but I'm finding Audacity easy to work with without any real training. My students also like it. So I keep running into situations where I want to take a modern high quality digital recording and degrade it to sound more appropriate for the time period. I've been running a high pass and low pass filter in Audacity and that does a pretty good job but I would really like to be able to take it a step further and put a little bit of dirtiness and noise into it as well.

Is there a feature of Audacity that I'm missing that will do this? Is there another program that will do this easily... without switching to an entirely different product? Are you yelling at the screen to tell me to not be so cheap and buy a better product than free Audacity that has lot's more effect features? Do it the old fashioned way by playing it through an old crappy speaker? 

Thanks for your thoughts!


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## lieperjp (Feb 22, 2009)

gafftaper said:


> Do it the old fashioned way by playing it through an old crappy speaker?



That's what I do! It's so easy!


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## Eboy87 (Feb 22, 2009)

I did something like this in GarageBand for a friend's school project. He wanted an old 50's PSA film strip sounding voice over, so I just ran it through an amp simulator. I've never really gotten that deep into Audacity (I'm a ProTools kind of guy), but search around for something like that.


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## hsaunier (Feb 22, 2009)

Not sure what effect you are going after. Try recording the sound of a record player at the end of the album. Use audacity to get rid of the needle skip for every revolution, and then loop it. Mix that track in with your re eq'd vocal and vuala. Again, don't know exactly what you're after. Just a brain storm.


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## gafftaper (Feb 22, 2009)

The problem is even with the high pass and low pass what remains is a high quality recording. I've been thinking about messing around with adding in a layer of static in the background as hsaunier has suggested but that still doesn't exactly change the fact that I've got a clean original signal. 

I think I saw an amp simulator plug in for Audacity. I'll give that a try too. 

Perhaps I should just go find myself a crappy old speaker.


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## ishboo (Feb 22, 2009)

I haven't found an easy way to do this in basic Audacity (no plugins) and I've been in this situation before. I've done what you mentioned about adding a layer of static in the background, I've had relative success with this approach, just choose your static wisely.


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## DaveySimps (Feb 22, 2009)

ishboo said:


> choose your static wisely.





If I had a dime for every time I heard that........... 

~Dave


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## lieperjp (Feb 22, 2009)

gafftaper said:


> The problem is even with the high pass and low pass what remains is a high quality recording. I've got a clean original signal.



Perhaps change that. Use an older mic or older recorder to record the sound so as not to get the cleanest record possible?


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## JoeGriffin (Feb 23, 2009)

Quite a lot of it depends on what effect you're going for. Groove noise is a good thing to add if you want to make a record-player sound, but probably not if you're looking for a telephone. Think about what the characteristics of the technology you're trying to replicate actually are: limited frequency range? Tape hiss? Static? Groove noise? Turntable rumble? Tape compression? Radio station broadcast limiting? Small, underpowered speakers? Resonant EQ peaks?

You can do an awful lot with EQ, not just high- and low-pass filters but boosting certain frequencies and cutting others (telephones will often have a boost somewhere around the resonant frequency of the human voice...funny how that works). 

Compression is also a great tool for "aging" a recording--certain compressors (and limiters) are less transparent than others and if you hit them hard they start to distort and filter the sound. 

Then, too, actual distortion is a great tool as well. The amp simulator idea above is a great suggestion, as is the suggestion to send the signal through another speaker and re-record it. In music mixing they call that "re-amping," and in film it's sometimes called "worldizing." Either way, run the signal through an overloaded amp into a cruddy speaker and you'll be well on your way. To something at least...


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## gafftaper (Feb 23, 2009)

Just to clarify, for those unclear of what I am trying to do. My current example is I've got a perfect crystal clear CD recording of an orchestra playing a song... which is supposed to be coming from a 1940's radio. So I need to degrade the quality enough to make it fit the time period. We are going to try adding a layer of static next ("choose your static wisely"). If that doesn't work, I'm off to Value Village to buy a crappy speaker. I'm thinking I might have good results running it all through a mid range driver and the possibility of poking a couple holes in it is in the back of my mind as well.


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## JoeGriffin (Feb 23, 2009)

Thanks for the specifics. For a '40s radio, that's a mono AM broadcast. I'd limit the bandwidth (at that period AM radio topped out at 5kHz, so roll off frequencies above that) and add some compression/limiting, and then try to use EQ to replicate the odd low-mid peak that AM broadcasts all seem to have. As far as static is concerned, I'd keep it kinda light and thin, and maybe fade it in and out so it isn't constant. The speaker idea is a good one, though you probably won't have to put holes in it.


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## BillESC (Feb 23, 2009)

In stead of an "old crappy speaker" you could get one of the new Behringers. That ought to give you exactly what you're looking for.


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## David Ashton (Feb 25, 2009)

you could feed the signal into a cb radio and take the signal off another cb radio, but do not degrade the signal too much as 1940 radios could have a sweet tone, especially lows and mids, but were prone to signal fade.
And don't forget the valve radio took about a minute to warm up.


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## spiwak2005 (Feb 25, 2009)

Does Audacity not accept plug-ins? If it does, here's a great vinyl "modeler" that can be tuned to add noise, dust, scratches, record player year and stereo/mono - iZotope Vinyl - Authentic Lo-Fi Vinyl Simulation for Pro Tools, VST, MAS, Audio Unit, and DirectX audio applications. And it's FREE!!

It appears that Audacity does recognize VST plug-ins so this should work.


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## JoeGriffin (Feb 26, 2009)

Good thought--I had forgotten that plug was free. It's very useful for this sort of stuff.


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## gafftaper (Feb 27, 2009)

spiwak2005 said:


> Does Audacity not accept plug-ins? If it does, here's a great vinyl "modeler" that can be tuned to add noise, dust, scratches, record player year and stereo/mono - iZotope Vinyl - Authentic Lo-Fi Vinyl Simulation for Pro Tools, VST, MAS, Audio Unit, and DirectX audio applications. And it's FREE!!
> 
> It appears that Audacity does recognize VST plug-ins so this should work.



Thanks, That looks like exactly what I'm looking for. I'll give it a try.


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