One minute test by Clare [OK]

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Seasidebooks
Posts: 4
Joined: April 1st, 2020, 7:34 am

Post by Seasidebooks » April 4th, 2020, 7:18 am

Hello

This is my one minute test. I have exported it to both Flac and mp3; which is more appropriate for releasing and what bit rate should it be at?

https://librivox.org/uploads/tests/one_minute_test.flac

https://librivox.org/uploads/tests/one_minute_test.mp3

Thanks

Clare

kathrinee
LibriVox Admin Team
Posts: 8442
Joined: May 14th, 2012, 5:09 am
Location: in the sun

Post by kathrinee » April 4th, 2020, 9:41 am

Welcome to LibriVox, Clare, and thank you for the test!

We require recordings to be mp3, so thank you for uploading in that format.

Two things to fix:

There is some background hum. You can either click Effects in Audacity > Notch filter and enter the Frequency 121, or use the Noise Reduction tool. Select a few seconds of background noise only (no speech) and click Effect | Noise Reduction | Get Profile. Then select the whole recording (Ctrl+A), click Effect | Noise Reduction again, and use settings:

Noise Reduction: 10 dB
Sensitivity: 6
Frequency smoothing (bands) 6

and click OK.


The bit rate should be 128 kbps and the bit rate should be constant. You fix this when you export the recording.
So, click Export > Export as MP3. In the lower half of the new window you see "Format Options". You want to first click Bit Rate Mode: Constant. Then, for Quality select 128 kbps from the drop-down menu and for Channel Mode: Joint Stereo.

Please have a go at reducing the background hum and fixing the bit rate, then save, upload and post again in this thread. You're doing well! :thumbs:
Kathrine

Seasidebooks
Posts: 4
Joined: April 1st, 2020, 7:34 am

Post by Seasidebooks » April 7th, 2020, 9:43 am

Hi Kathrinee

I have familiarised myself with Audacity and redone the test with your suggestions.

https://librivox.org/uploads/tests/One_minute_test_redone.mp3

Amplify 2.5
Notch filter 121
Noise reduction 10,6,6
Bit rate 128

I recorded in mono. The channel mode is also in mono (I read somewhere that it should be mono).

However, in your post, you wrote that the channel mode should be joint stereo.

The recording below is all the above with the channel mode changed to stereo at the end. Is this correct?

https://librivox.org/uploads/tests/One_minute_test_redone_jointstereo.mp3

thanks

Clare :D

kathrinee
LibriVox Admin Team
Posts: 8442
Joined: May 14th, 2012, 5:09 am
Location: in the sun

Post by kathrinee » April 8th, 2020, 12:29 pm

Thank you for the new tests! Excellent question about the joint stereo. :hmm: Both your new tests have the right tech specs. When I record I have the Joint Stereo checked. I'll check in with some of the other volunteers to hear what they do. :) But, since both your versions have the right bit rate, I think either works.
ETA: This is what another very experienced volunteer had to say about the seeing on Channels
Mine is "joint stereo". I don't think it matters. I do think that some people, if they haven't set their recording to be in mono, can use "Force export to mono" to make it mono at this point, but this wasn't always an option, and actually setting the recording to be in mono from the start makes the most sense.
The volume in both the new tests are a bit soft. We aim for 89dB and accept 87-91dB. The new tests are 80dB and 82 dB respectively. You should aim for your wave forms (not the plosive spikes ;)) to peak near the 0.5 mark, like this:
Image You can increase the input volume a bit (in Audacity, there is a slider button next to the microphone symbol, or maybe on your microphone or in your OS), or you can amplify the recording in Audacity like this: Select the whole recording. Click Effect > Amplify and use the setting Amplification 10. Please make sure to NOT check the box where it says Allow clipping. After amplifying you might need to pass through the noise reduction again.

Please have a go at making the recording louder, save, upload and post again in this thread. I look forward to hearing you again! :thumbs:
Kathrine

Seasidebooks
Posts: 4
Joined: April 1st, 2020, 7:34 am

Post by Seasidebooks » April 15th, 2020, 10:11 am

Hi Katherine

I've been doing more Audacity learning but not sure I have quite found the solution to my quiet recording. Perhaps my microphone is not good enough. Anyway, here are two more recordings that I would be pleased to have your feedback on.

The first is the suggestions you made last time, except that I can't amplify by 10 as then I need to 'manage'. The highest is 6.5 which is this one:

https://librivox.org/uploads/tests/One_minute_test_some_amplification.mp3

The next one is the same as above with added normalisation at -2.

https://librivox.org/uploads/tests/One_minute_test_some_amplification_normalisation.mp3

Thanks

Clare

kathrinee
LibriVox Admin Team
Posts: 8442
Joined: May 14th, 2012, 5:09 am
Location: in the sun

Post by kathrinee » April 16th, 2020, 12:57 pm

Thank you for your work and persistence, Clare!

These test are both louder, and that is good! :clap: I think the microphone is perfectly adequate (I know that many of us have to fiddle around with amplification in order to get to the right volume).

The second of the tests (where you used normalization) is within the right volume range, so it is PL OK, and you can start claiming a section or two in the Readers Wanted forums. However, please don't let the volume drop any lower.

If you'd like to check your own volume you might consider downloading the little app Checker. It was developed by the spouse of a LibriVox volunteer, and I find it super handy. Here is a link to a page where you can read more about if you'd like https://wiki.librivox.org/index.php?title=Checker

If I read you correctly, you amplified the tests as much as Audacity would let you. That is puzzling to me, because when I open the test on my computer, Audacity lets me amplify either of them a few more dB. :hmm: Anyway, you are good to start recording. If you'd like to keep exploring volume, you can post again in this thread, or in the Need help? Got advice? forum.

Have fun! And do let us know if you have any questions!
Kathrine

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