
CatsEye 1 minute test [OK]
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- LibriVox Admin Team
- Posts: 15588
- Joined: July 14th, 2008, 4:54 pm
- Location: Nottawasaga Bay, Ontario
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Hello CatsEye, there are a few items to fix in this recording...
the volume is too low at 68.8 dB. You should aim for your waveforms to peak near the 0.5 mark, like this:

You can check your volume using our Checker program - see info at http://wiki.librivox.org/index.php/Checker You will find the volume in decibels on the Information tab. For your information, we look for around 89 dB (87-91 is OK) (all the other tech specs are there also)
There is also a 47 dB background noise level that will increase with amplifying, so you will have to apply some Noise Reduction to the file.
Please experiment with amplifying and Noise Reduction and upload a new file (same filename please).
- the bitrate of 101 kbps and the sample rate of 48000 Hz do not meet our requirements. Files need a bitrate of 128 kbps (constant) and a sample rate of 41000 Hz. These are set when saving/exporting the files as mp3
- the DC offset is -41, this is set near zero with Effects / Normalizing in Audacity.
Please ask if you need help with any of the settings. (the video that Phil linked in your Greetings post and the links below the video will explain how to set up Audacity nicely)
the volume is too low at 68.8 dB. You should aim for your waveforms to peak near the 0.5 mark, like this:

You can check your volume using our Checker program - see info at http://wiki.librivox.org/index.php/Checker You will find the volume in decibels on the Information tab. For your information, we look for around 89 dB (87-91 is OK) (all the other tech specs are there also)
There is also a 47 dB background noise level that will increase with amplifying, so you will have to apply some Noise Reduction to the file.
Please experiment with amplifying and Noise Reduction and upload a new file (same filename please).
- the bitrate of 101 kbps and the sample rate of 48000 Hz do not meet our requirements. Files need a bitrate of 128 kbps (constant) and a sample rate of 41000 Hz. These are set when saving/exporting the files as mp3
- the DC offset is -41, this is set near zero with Effects / Normalizing in Audacity.
Please ask if you need help with any of the settings. (the video that Phil linked in your Greetings post and the links below the video will explain how to set up Audacity nicely)

David Lawrence
* Weekly & Fortnightly Poetry - Check out the Short Works forum for the latest projects!
* Weekly & Fortnightly Poetry - Check out the Short Works forum for the latest projects!
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- LibriVox Admin Team
- Posts: 49134
- Joined: June 15th, 2008, 10:30 pm
- Location: Toronto, ON (but Minnesotan to age 32)
We can give step-by-step instructions if you're using Audacity. Are you?

Bulwer-Lytton novel: The Caxtons
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
-
- LibriVox Admin Team
- Posts: 49134
- Joined: June 15th, 2008, 10:30 pm
- Location: Toronto, ON (but Minnesotan to age 32)
Okay! Looking at the list of issues, I think it's best to direct you to this spot in the Wiki: https://wiki.librivox.org/index.php?title=Audacity_1-2-3#Configure
Work through those steps to take care of the sample rate and bit rate.
For the volume, I think you have to now go into your device control panel in Windows (or OS). For Windows 7, and I assume similar on Win 10:
- Right click your speaker icon in your taskbar (right side by the date/time somewhere).
- Select Recording Devices
- Click on your microphone, then click the Properties button
- Click on the Levels tab and move the mic slider all the way up. You may also need to do some Mic Boost, but don't do it now.
- Click OK.
Now go back to Audacity and record something. As mentioned, get your wave forms to peak around that 0.5 mark.
Regarding the DC offset: it's not too bad, so I wouldn't worry about fixing it. However, if you look at your wave form, the start of it begins above that black base line. You start speaking, and it gradually comes down and goes below the base line, then around about 5 seconds it settles in and stays at the base line. I would suggest starting your mic and watching your wave form, and wait until it settles in at the base line before you start speaking.
For the background noise: you've got a fair amount of low-toned noise which doesn't clean up very well.
First, try turning off any extra nearby equipment that you don't need - printers, fans, fluorescent lights, etc. Make sure your microphone cord is not lying next to any other cords. If you've got a USB microphone, plug it into a port that has nothing plugged in beside it. If you're using a laptop, try running on battery power instead of being plugged in. See if those things help. Try to eliminate as much noise at its source as you can, before it gets to the microphone. Imagine dead silence (totally dead), then listen to your recording area and figure out what is making sounds that your mic is picking up.
If you have a desktop mic, it might be picking up vibrations from the desk. Put a folded towel or piece of foam under the mic stand to absorb these.
--- Whew! It sounds like a lot, but the first few are a set-and-forget thing, so once you fix 'em, they'll stay fixed. The rest take a little finesse and patience. You can do this!
Work through those steps to take care of the sample rate and bit rate.
For the volume, I think you have to now go into your device control panel in Windows (or OS). For Windows 7, and I assume similar on Win 10:
- Right click your speaker icon in your taskbar (right side by the date/time somewhere).
- Select Recording Devices
- Click on your microphone, then click the Properties button
- Click on the Levels tab and move the mic slider all the way up. You may also need to do some Mic Boost, but don't do it now.

- Click OK.
Now go back to Audacity and record something. As mentioned, get your wave forms to peak around that 0.5 mark.
Regarding the DC offset: it's not too bad, so I wouldn't worry about fixing it. However, if you look at your wave form, the start of it begins above that black base line. You start speaking, and it gradually comes down and goes below the base line, then around about 5 seconds it settles in and stays at the base line. I would suggest starting your mic and watching your wave form, and wait until it settles in at the base line before you start speaking.
For the background noise: you've got a fair amount of low-toned noise which doesn't clean up very well.
First, try turning off any extra nearby equipment that you don't need - printers, fans, fluorescent lights, etc. Make sure your microphone cord is not lying next to any other cords. If you've got a USB microphone, plug it into a port that has nothing plugged in beside it. If you're using a laptop, try running on battery power instead of being plugged in. See if those things help. Try to eliminate as much noise at its source as you can, before it gets to the microphone. Imagine dead silence (totally dead), then listen to your recording area and figure out what is making sounds that your mic is picking up.
If you have a desktop mic, it might be picking up vibrations from the desk. Put a folded towel or piece of foam under the mic stand to absorb these.
--- Whew! It sounds like a lot, but the first few are a set-and-forget thing, so once you fix 'em, they'll stay fixed. The rest take a little finesse and patience. You can do this!
Bulwer-Lytton novel: The Caxtons
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
-
- LibriVox Admin Team
- Posts: 49134
- Joined: June 15th, 2008, 10:30 pm
- Location: Toronto, ON (but Minnesotan to age 32)
Hmm. Sounds like over-cleaning on the noise. Did you do some noise reduction on this? What kind if microphone are you using?
Volume is still a little too low; needs to come up another 6 dB or so.
Try adjusting the volume some more, then upload a test without any noise reduction.
Volume is still a little too low; needs to come up another 6 dB or so.
Try adjusting the volume some more, then upload a test without any noise reduction.
Bulwer-Lytton novel: The Caxtons
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
-
- LibriVox Admin Team
- Posts: 49134
- Joined: June 15th, 2008, 10:30 pm
- Location: Toronto, ON (but Minnesotan to age 32)
Digital mics are usually better.
What was the level of reduction you did? (If you're using Audacity, what was the number for the first slider?)
I suggest uploading a raw file - no noise reduction or other effects - and we'll see what we can do with it to get it to the right settings.
What was the level of reduction you did? (If you're using Audacity, what was the number for the first slider?)
I suggest uploading a raw file - no noise reduction or other effects - and we'll see what we can do with it to get it to the right settings.

Bulwer-Lytton novel: The Caxtons
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
-
- LibriVox Admin Team
- Posts: 49134
- Joined: June 15th, 2008, 10:30 pm
- Location: Toronto, ON (but Minnesotan to age 32)
This sounds a lot better!
All you have to do on this one is amplify it by about 3 dB, and it'll be good to go. But even now it's within the acceptable volume range of 86-92 dB. (It's at 86.6.)
There's a plugin for Audacity that will tell you how much to amplify your recordings, or how far off you are from "ideal" volume. It's called ReplayGain. Instructions for installing and using it are on this page: https://wiki.librivox.org/index.php?title=Measuring_Volume_within_Audacity
So I'm going to mark this off as OK, and you're free to start recording "for real".
Do whatever you did on this recording for future recordings, with maybe the addition of a little amplifying, and you'll be all set!
All you have to do on this one is amplify it by about 3 dB, and it'll be good to go. But even now it's within the acceptable volume range of 86-92 dB. (It's at 86.6.)
There's a plugin for Audacity that will tell you how much to amplify your recordings, or how far off you are from "ideal" volume. It's called ReplayGain. Instructions for installing and using it are on this page: https://wiki.librivox.org/index.php?title=Measuring_Volume_within_Audacity
So I'm going to mark this off as OK, and you're free to start recording "for real".

Bulwer-Lytton novel: The Caxtons
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT
Adventure/Travel: Across Mongolian Plains
Boring works 30-70 minutes long: Insomnia Collection 5
Adult dog stories: Best Dog Stories
Gospel of Matthew: Matthew, YLT