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Post Posted:: October 5th, 2017, 7:42 pm 

Joined: October 4th, 2017, 7:00 pm
Posts: 32
https://librivox.org/uploads/tests/lvtestmomo.mp3

This is an mp3 file, recorded in digital format with a Zoom H4n,
then edited in Audacity on a Windows 10 desktop computer.


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Post Posted:: October 7th, 2017, 6:54 am 
LibriVox Admin Team

Joined: March 28th, 2014, 5:57 am
Posts: 8599
Hi Wayne and welcome to the forum

thank you for your one-minute test, which is almost up to Librivox requirements. And the bit that is not, we will iron out together now :D

I found it funny that your title says "now in mono" and then I open the file and it is in stereo nevertheless. Since you are using Audacity, you can tell if a file is in stereo, if you see two windows open one on top of the other, that's stereo. In mono you would only see one window. Strangely enough the bottom window is totally blank, usually there should be the same recording. I suppose you deleted that part maybe ? :hmm: Still that's not enough to make it a mono file.

To convert stereo to mono is very easy in Audacity. Try the following steps:

> open your stereo file
> go to "Tracks" in the upper bar
> select "Stereo Track to Mono" and you will see the bottom window will vanish 8-)

Of course the best thing is to put your initial Audacity setting onto Mono from the start. You can change your settings here:

> go to "Edit" in the upper bar
> select "Preferences"
> select "Devices" in the left column
> and here put the "Channels" to 1 (Mono) and press OK

I think if you do it this way, the settings should stay in Mono for all your recordings.

You also see the small slot between the Microphone and Speaker icon should be set to Mono now. If ever this changes back to Stereo, you can manually toggle it back to Mono again, but I think if you don't fiddle with the Preferences again, it should stay that way.

Could you please change this recording to Mono now, using the steps above and reupload in the same thread ? Then I can have another listen to your file.

thanks, and if you have further questions, don't hesitate to ask :)

Apart from this technical error, there is nothing wrong with your way of reading. You have a fine voice to listen to and are well-paced so the listeners can well follow and process what is narrated. :thumbs: So once we have this Mono problem solved, you are ready to roll.

Sonia


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Post Posted:: October 7th, 2017, 9:42 am 

Joined: October 4th, 2017, 7:00 pm
Posts: 32
https://librivox.org/uploads/tests/lvtestmonoWA.mp3

Hi Sonia, I think I've got the mono thing worked out...
How does this look/sound?

I'm not sure if it makes any difference in sound quality
if I plug my mic into the computer and record directly
into Audacity... or if I record into my Zoom H4n and
then put the SDHC card into my computer and
transfer it to Audacity. I have more control over
the volume input when I use the Zoom. Any thoughts on that?

Thank you for the help.


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Post Posted:: October 7th, 2017, 2:25 pm 
LibriVox Admin Team

Joined: March 28th, 2014, 5:57 am
Posts: 8599
thanks for your second submission. It is indeed in mono now, but the bit rate is still wrong. And to my shame I have to admit, I forgot to tell you about that one before :oops: I was so caught up in explaining the stereo to mono thing that I omitted the variable bitrate, which should be constant.

Well the mono is good now, don't change anything there anymore.

Now to change the bitrate, do the following:

> go to File - Export Audio
> go to Options in the bottom right corner
> select: Bit Rate Mode: Constant / Quality: 128 kbps / Channel Mode: Joint Stereo
> press OK

From now on these settings should stay the same for all your recordings.

Also in this recording, your volume is too loud. It's at 93 dB, while we accept between 86 and 92, with preferred average of 89. Your previous recording was bang in the middle with 89.5.

To reduce volume in Audacity:

> highlight the entire recording
> go to Effect - Amplify
> input -3 (don't forget the minus sign) and press OK
this should reduce the sound to about 90 dB.

Quote:
I'm not sure if it makes any difference in sound quality if I plug my mic into the computer and record directly into Audacity... or if I record into my Zoom H4n and then put the SDHC card into my computer and transfer it to Audacity. I have more control over the volume input when I use the Zoom. Any thoughts on that?

well I am not familiar with the Zoom but whatever works best for you will be acceptable. As long as your technical settings are up to standard now, and the volume within the required limits, it's your choice with what device you get there.

Again, sorry for not telling you about the bitrate immediately, otherwise I'm sure your file would have been ok.

Could you change these settings and reupload one final time please ? I think then you will be all in the clear.

thanks

Sonia


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Post Posted:: October 7th, 2017, 4:44 pm 
LibriVox Admin Team

Joined: April 3rd, 2008, 3:55 am
Posts: 28039
Location: Melbourne,Australia
There are a number of experienced readers who record away from the computer using their Zooms , and I've never heard them complaining about loss of quality. I assume they make corrections using the computer - so I suspect it doesn't cause problems . If you have doubts , post in the help wanted putting Zoom in the heading and I'm sure someone who knows will answer.

Anne

_________________
Our objective is to make all books in the public domain available, for free, in audio format on the internet. - Hugh McGuire.


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Post Posted:: October 7th, 2017, 7:17 pm 

Joined: October 4th, 2017, 7:00 pm
Posts: 32
https://librivox.org/uploads/tests/TestAgainWA1.mp3

Another try... Thanks Sonia and Anne.

How do you determine the db level? I have
usually just pumped the level up until it's just
below clipping... without worrying about db.

As for the Zoom recorder, I was thinking it
would be better quality than mic to computer
because the Zoom comes with a great set of mics attached.
Also it has XLR inputs for two mics. But my ears
can't detect a difference between the two methods
of recording, so I guess it's a moot point.


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Post Posted:: October 8th, 2017, 1:29 am 
LibriVox Admin Team

Joined: March 28th, 2014, 5:57 am
Posts: 8599
wsraymond wrote:
https://librivox.org/uploads/tests/TestAgainWA1.mp3

thank you for persisting, Wayne :clap: (and again sorry, as we could have done those two corrections at the first try)

so this third test has both the bitrate and the mono sound correct and the volume is at 87.6 which is quite acceptable. So I will give you this long waited for and well deserved OK on your test and you can finally record "for real", which you were probably itching to do already. :mrgreen:

Quote:
How do you determine the db level? I have usually just pumped the level up until it's just below clipping... without worrying about db.

ah that was my big problem in the beginning as well. But: help is near ! There is a handy little plug-in you can download from this site, which you can put into Audacity. It's called ReplayGain and if you let it run after you have recorded and edited your section, you can let it determine by how many dB you have to amplify or decrease the volume to get to an acceptable average of 89. Now isn't that neat ? 8-) I personally use it with each of my recordings. Your volume will always be acceptable then.

Here is the download process:
Quote:
http://forum.audacityteam.org/download/file.php?id=4668

1. Save the file to your computer - your desktop or somewhere where you can easily find it.
2. Now browse to the folder in which Audacity is installed. (It's probably in C:\Program Files\Audacity) and then open the Plug-Ins folder.
3. Drag the file you saved into the Plug-Ins folder.
4. When next you start up Audacity, you will be able to select the whole recording, then go to Analyze - ReplayGain, and it'll tell you how much to amplify your file to get to about 89 dB.


And since we are at handy programs, here is another one. It's called Checker and this is what we use to check that the technical criteria are all Librivox Standard. So when I told you about the bitrate for example, it's because Checker flagged it as wrong. Same with the volume, it told me it was over 93 dB. I run this program each time I have a finished mp3 file ready to post to Librivox. It is a last-minute check to see if all is as it should be. It's the tool the Prooflistener will use later on to check your file. So you are one step ahead of technical problems if you know them beforehand and can already correct the error before uploading.

You can download it here: http://wiki.librivox.org/index.php/Checker

So now you are well equipped to make your recordings sound great. :)

One final thing I might add, just for completeness sake. Your first recordings had a bit less background noise than your final one just now. It wasn't too disturbing but if you want an even cleaner sound, there is a nice noise-cleaning function in Audacity, which I personally also use every time I record.

One final step-by-step tutorial from me:

> select a small portion of noise at the end of your recording
> go to Effect - Noise Reduction
> first press Get Noise Profile
> then highlight the entire recording
> again Effect - Noise Reduction
> now press OK

You will see the background noise waves will become considerably thinner. This process can be repeated a second time if the noise is too disturbing, but don't overdo it, because applying it too often may result in distortion of sound.

All right, if you wish you can try this function out on your recording and you may repost another test if you wish me to make another comment. But actually you could also test yourself now with the Checker program, because it also tells you the background noise. :) For the moment it showed me some 40 dB of noise, a cleaner sound would stay underneath or around 30 dB.

So I think you learnt about the most common tools and appliances we Librivoxers use on a day-to-day basis. I hope I didn't crush you with the information, but you will see, once you have done the recording/editing/amplifying/cleaning a few times, you won't need my step-by-steps anymore. :D

Now I hope you will have fun on the forum and find an interesting project to contribute to.

Good luck, and if there are still questions, you can either post them in this thread or in the help forum. There are always friendly and capable people around who probably have encountered the same problem already and may know a solution.

see you around :)

Sonia


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Post Posted:: October 8th, 2017, 7:54 am 

Joined: October 4th, 2017, 7:00 pm
Posts: 32
Thanks again, Sonia. I will add those apps.
When I do a real recording, I will turn off the fan
sucking air from my room, and get further
away from my computer... and put the mic
on a tripod. Your help is much appreciated.
--wa


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Post Posted:: October 8th, 2017, 7:57 am 
LibriVox Admin Team

Joined: March 28th, 2014, 5:57 am
Posts: 8599
wsraymond wrote:
When I do a real recording, I will turn off the fan sucking air from my room, and get further away from my computer... and put the mic on a tripod.

:thumbs: absolutely great ideas. Yes it is always better to get to the bottom of the noise source and try to muffle the sound already at the recording stage. Always better than excessive noise cleaning later.

You'll see, you will fiddle around with the sound, volume and noise by and by until you find the method that suits your purposes best. Each recording area is different.

Good luck and have fun !

Sonia


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