Improving audio quality on a WAV file

[kevtim]

Hi

I'm new to audacity. I have to admit I have never used any kind of sound program before so this is all new to me and I need some help.

I recently recorded audio on a portable device (wav file) at a wedding to supplement a video. The sound quality is good but extremely quiet! I basically need to boost the sound or improve it in various ways. Now I downloaded audacity 1.2.5 (intel) and imported the wav file.

I now need to select a section of the audio file i am going to use, improve/boost the sound (possibly reduce hiss aso) on it and simply export it back onto my desktop so as I can import it into Final cut Express and synch the audio with the video.

Any help anyone could offer would be much appreciated!

Thanks
Kevin

[kozikowski]

Step one, stop using Audacity 1.2. 1.2 is not supported on newer Macs. Get Audacity 1.3.12 from here.

http://audacityteam.org/download/beta_mac

You can leave the old Audacity installed.

Change Audacity preferences to 48000, 16-bit, Stereo from 44100, 32-bit, Stereo. Restart Audacity to make sure the settings stick. 48000 is the video sound standard.

Open the work. Do a simple change: Effect > Amplify > OK.

Is it loud enough now? This is where you find the noise level is way too high. One step at a time.

Koz

[kevtim]

Hi Koz, firstly thanks for the help!

I reset the preferences and then restarted (it stuck).

I imported the audio (Edit>import>audio) then selected my audio clip, then Effect>Amplify. Both Amplification and New Peak Amplification was set at 0.0. I applied the effect but the sound has been affected only slightly (it is slightly louder but not really noticeable)? I reloaded the audio twice and it had the same effect both times?

Some additional info that might help. The audio track is about 50 minutes long and as far as I know is recorded at 44.1kHz (although I have no clue what this means).

Once again thanks!
Kev

[kozikowski]

Amplify just changes the overall loudness until the highest sound in the show hit the top. If the show is already that loud, then nothing happens.

44100.

Now it gets messy. 44100 is the technical standard for a Music CD. 48000 is the standard for television sound. Normally it doesn't make any difference, but sometimes it does and we warn people all the time to convert everything to one standard before you start editing.

Digital systems need to hack sound up into little pieces to assign numbers and values to each piece. Music CDs do it forty-four thousand one hundred times a second. Television systems do it a slightly higher and better forty-eight thousand times a second. It's those little hacked up fragments (or their numbers) that get manipulated when Audacity does production or filtering or effects on your show.

You can open the show in Audacity and make sure the lower left little window says 48000. If not, change it. When you export your music files, they should slide right into your video editor no trouble. Do a very short piece all the way through (a minute) to make sure you're not going to get any nasty surprises.

"How come the music is speeding up in the show....?" "The editor says Format Not Supported."
"Unable to open sound files."

Koz

[kevtim]

Ah that would explain why amplify didn't make it much louder. There is a sound spike where the bride and groom kiss as the audience claps.

I exported it as 16 bit PCM (default setting) and opened it in itunes because from my movie editor you have to import audio tracks from your itunes library. It all worked and there seems to be no problems (no speeding up). However I can't try and synch it to my footage exactly as yet because I'm waiting for Final Cut Express 4 to come through the post. imovie 09 degrades DV footage on import so I had to upgrade to a program that would import the footage to the best possible quality.

However I assume it should be fine, at least it sound fine. What's the next step matey?

Kev

[kozikowski]

Assuming the sound isn't actually broken, you can apply Chris's Compressor...

Chris's Compressor
http://pdf23ds.net/software/dynamic-compressor/

That one really does take the show bit by bit and changes the levels so everything comes out even.

It's not so easy to capture live events....

Koz

[kevtim]

Please forgive my ignorance for the following...

What do you mean by broken sound? I tried downloading the standalone version but it wouldn't work. There is the Audacity plug in but it says it running on the audacity 1.2.6, does that mean i need that version to use the plug in? At the moment I have 1.2.5 and 1.3.12.

Is there no other was to boost the volume in audacity? Turning up the gain and output level slider seems to make it louder? Or is doing that bad? Sorry this must be frustrating for you, I really haven't used any kind of sound programs before.

Thanks
Kev

[steve]

There is the Audacity plug in but it says it running on the audacity 1.2.6, does that mean i need that version to use the plug in?

It will run in Audacity 1.3.12

At the moment I have 1.2.5 and 1.3.12.

1.2.5 is ancient and no-longer supported. Stick with the 1.3.12 version.

Turning up the gain and output level slider seems to make it louder?

I'm not sure exactly which slider you mean.
If you mean the "Output Volume Slider" in the Mixer Toolbar, then yes, by all means turn that up. This slider does not affect the actual recorded audio, it just makes Audacity play louder.

[kozikowski]

If the applause in the show is already at the overload point, you really need to get Chris working, or struggle with the Audacity compressions tools. You need tools that affect different parts of the show differently and that puts you in the dynamic compressor world. A simple slider volume change isn't going to do it.

You can do this with painful editing. Drag-Select the portion with the loud applause in it and reduce it, then select the whole show and bring it up.

You're not in the Simple Show world any more. You need to start using actual post production editing.

Koz