Transferring Cassettes to MP3 or CDR    magicref@lycos.com

Last Update: Oct 2009 Minor editing.

Introduction:

This page provides a step by step procedure for copying audio from a cassette (or any other input, such as an LP record, for that matter) to your computer to be transferred to MP3 format or made into an audio CD. Many car cassette players are being replaced by CD players, and tiny MP3 players like the Apple iPod, the Microsoft Zune, and so forth are also available that are highly portable. This process allows you to take sermons and educational recordings wherever you need them!

This guide has been written for Microsoft Windows based systems, so adjust appropriately if you are using a MAC, Linux, or other operating system.

There are some much more detailed (with graphics) articles on the Web; I've provided some links on the bottom of the page.

As always, be sure to respect copyright laws. If you don't have permission to copy a tape for others, be sure you use the copies only for yourself.

Outline of The Process:

STEP 1: Play the analog cassette, feeding the output of the player into your computer's sound card. This step converts the analog signal into a digital WAV file.

STEP 2: Clean up the file to remove hiss, unwanted sections, long silences, and so forth.

STEP 3: Burn the WAV file to an Audio CD (playable in most car, home, and portable CD players) using your CD burning software that came with your CD writer. There is also free CD burning software available on the Internet.

OR, convert the WAV to MP3 or other compressed audio format. These compressed audio files can be played in your iPod, MP3 player, or burned to CD for use with an MP3 compatible CD Player or most DVD players.

What you need:

1. Good quality cassette tape player with LINE OUT capability. If in a crunch, you can use the headphone output of any tape player, but the quality will suffer.

Note: if you are recording from a record player (turntable), you will have to have a pre-amplifier between the turntable and your computer, as most record players have a very low signal.

Options: You can purchase tape decks and turntables today that have USB outputs. For example, the Korean company BTO makes a tape player that fits in a 5.25" slot in your PC (see http://plusdeck.com/englishsite/index.asp), or a separate stand-alone model (plusdeckEX). You can search the web for turntables with USB outputs.

2. A sound card in your computer with a LINE IN input. Most laptops and PC's have this built in. An alternative to this is to get a USB sound card that has a LINE IN input.

Options: Most built-in sound cards handle 16-bit recordings with sampling rates up to 44.1kHz. Some companies have USB sound cards that provide high-rate digital to analog proceesors that can handle, for example, 24 bit recordings at up to 192kHz sample rates. Examples are M-Audio's Transit and E-MU's 0202 audio interface. Don't worry if you don't know the difference between 16 and 24 bit, you don't need to know this to record your audio!

3. Audio Recording software: You may already have software you can use. Audio recording software often comes with CD Burners and sound cards. Also, there are several freeware and shareware programs available. See the Digital Audio Editors page for information and links to many programs.

Some audio recording programs allow you to record direct to MP3 format. I do not recommend this for tape/LP transfer because you will likely want to perform some editing on the recording before it is finalized. Since MP3 is a lossy format, you will lose music information by opening the MP3, editing it, and saving it again. For tape & LP transfers, you should capture the audio in WAV format.

4. CD Burnger and CD Burning Software: Most modern PCs have a CD-Burner built in, or they can be purchased relatively inTwo top programs are Roxio Easy CD Creator and Nero Ultra Edition. This is only needed if you plan to make an Audio CD for your car or to burn MP3 Audio CDs for play in specialized players or your computer. I you

5. LOTS of hard drive space. A 60 minute audio file will require approximately 600 Megabytes of space, and you want at least double this for processing space. Several gigabytes of free space is best.

Part 1: Recording the Cassette to Hard Disk

1. Connect the tape player to the computer. Use a good quality cassette player for the best sound. Connect the LINE OUT from the tape deck to the LINE IN of your sound card. You may need to visit a local Radio Shack store for an appropriate cable.

2. Set up the computer sound card settings. Start the Volume Control application of Microsoft Windows. It is often in the task bar; if so, simply double click the speaker icon in the task bar. If it isn't there, you can probably find it under: Start Menu: Programs: Accessories: Entertainment: Volume Control, but this may vary depending on specific operating system version.

With the volume control open, click the Options menu and select Properties. Under "Show the following volume controls", select them all and click OK. In the main volume control window, toggle MUTE to ON for everything except Line In (such as SW Synth, CD Audio, and Microphone). On my laptop, non-muted inputs created a lot of low-level noise that reduced overall recording quality.

3. Start your recording software. Start the software program for recording digital audio such as Audacity. I used to use Steinberg's WaveLab Lite that came with the program Clean!, but have more recently switched to Acon Digital's Acoustica software. Again, see Digital Audio Editors page for other alternatives.

4. Set up the recording software for optimal settings. The exact process will vary depending on your recording software, but in general, you'll want to set up the recording for standard stereo music recording (44.1kHz sample rate, 16 bit). Again, you needn't worry about what these mean if you're not interested! This is the default or only setting available in some of the programs anyway.

Note: current advanced soundcards allow recording at higher bit and sampling rates, such as 24-bit, 96kHz. If you have the hard drive space, sound card support, and the correct software, this approach will allow you to edit your WAV file and bring it back down to 16-bit 44.1kHz later for CD burning with minimal loss in the editing process.

Even if you are recording speech, you can convert the file to mono later. However, if your recording program does not offer WAV file editing features, you may want to select MONO recording at this point to save the need for further processing later.

5. Check the recording levels. Again, the exact process will vary depending on your recording software.

Usually, you will click on a "record preview" button and you will have a chance to preview the volume level of the recording. Start the tape playing, and if you are aware of any particular loud sections, try to play the tape at this section. Most recording software will provide a set of level meters. You want to have the recording as close to "peak" as possible, without going into the red area. If the recording goes into the red, digital "clipping" will occur, which sounds simply awful! Note that this is different than recording to cassette where some red peaks are acceptable.

If the Line In volume control in the Windows Volume Control Panel are at maximum and the sound level is still too low, you will have to increase the volume on the cassette player. This step is pretty crucial to getting a quality recording, so take your time. If you cannot get enough volume with both your player and your sound card volumes set to maximum, then you will either need to get a player with greater power, or get a pre-amplifier that will go between the tape player and the sound card.

6. Rewind the cassette player.

7. When ready, click the Record button in your recording software. Depending on the software, you will have to insert a filename for your file either before or after this step.

You have two options. If you are recording two sides of a tape and have an auto-reverse cassette player, you will only need to record a single audio file. Of course, this file will have a significant blank spot in the middle where the cassette reverses direction, but if you have WAV editing software, you can take care of this later. Alternately, you can record a single side and stop, turn the tape over, and record the 2nd side into a second sound file.

Name the file accordingly, such as EdwardsSermon_SideA.wav.

Now, start your cassette player and wait until the sound starts to make sure the audio level meters in your recording software indicate that the sound is being recorded.

8. Walk away, get a drink and a snack (optional), and wait for the first or both sides of the tape to be played. Note that some software recorders come with timers or "silence" detection so you don't have to hang around during the recording process. Be sure to set the silence detection long enough so that it shuts off at the end of the tape, and not between tracks or while the speaker is pausing for dramatic effect!

9. When the recording is completed, stop the tape player (if needed) and click the STOP button in your recording software. Typically, you will see the graphical representation of your new digital WAV file, though some recorders don't provide a waveform image. You can usually listen to the file by clicking the play button to ensure the process worked correctly. Look for high spots that may represent clipping in the file, and start the process all over if the quality is not what you expected. Note that tape hiss may be able to be removed by specialized recording or cleaning software.

10. Repeat the process for side 2 of the cassette, if necessary.

11. You will now have two large WAV files, each with one side of the cassette (or one large WAV file if you used an auto-reverse player). Use an audio editor program or the tools that came with your recorder software to edit these files to remove the silence at the beginning and end of the file, and to split the file into two if needed. You'll need to read the program instructions for how to do this as each program works a little differently.

Note: If you burn one audio CD from these two files, you will end up with two "tracks" on the resulting CD, each track being one side of the tape. 

Note 2: If you recorded a music tape instead of speech, you'll likely want to split the WAV into individual songs. Some software does this automatically, or you can do it by hand with the sound editing software.

12. Digital Audio Processing. Your recording may have loud tape hiss, hum, or other unacceptable noise. Also, it is often difficult to acheive the prime volume level without clipping. 

Some software comes with "cleaning" tools to remove tape hiss, hum, or click & pops from recording LPs. You may want to experiment with these tools to see if you like the results. In some cases they can distort the voice/music to an unacceptable level and these tools must be used with care. Refer to the instructions with your software.

One reader reported that the cleaning tools he worked with often seemed to raise overall volume levels to unacceptable limits that introduced clipping. He recommended lowering the overall volume of your WAV file to -6dB before doing any sound processing. Usually this is accomplished by "selecting" all of the audio file

Many recording programs allow you to normalize your recording to maximize the volume levels. This should be done after your cleaning. I usually normalize the level to -0.5dB (just a little below 0).

13. You now have several choices, depending on your end goals.

The WAV format is very useful for editing, and preserves the original quality of the recording. The WAV format can be directly burned to a CD-R using CD writing software that came with your CD Burner. However, the WAV format takes up a lot of hard drive space, so you usually won't want to keep the original WAV files on your computer. You can:

a. Burn the WAV file(s) to a CD-ROM using a CD Burner/Writer. The CD Writer will come with software to do this, or there are many commercial, shareware, and free programs available. The resulting CD will be an audio CD that can be listened to in most modern CD players and DVD players. You will only be able to fit 60-70 minutes of audio on a single CD, however. If your sermon or album is longer than this, you will have to split it into smaller chunks using the software.

Once the CD is written, you can delete the WAV file if you like. You can always use CD-Audio extraction software (CD ripper) to recover the audio in WAV format if you need it later. Of course, if the CD is damaged, the file is lost.

b. Convert the WAV file to a compressed format such as MP3. MP3 files take up much less space, and there are many players available that allow you to play these files directly. Since MP3 files generally range from 3-20Megs each, you can fit many such files on a 700Megabyte CD, and portable MP3 players are widely available that can hold 64-128Megabytes worth of files. There are now several alternative formats that can be played on various portable players such as AAC (m4p) for iPod, Windows Media Audio (WMA), and Ogg Vorbis (Ogg). Be sure your player is compatible with the format you choose!

c. A third option I won't go into in this paper is to convert the WAV files into a lossless file format such as Free Lossless Audio Codec (FLAC). These formats compress WAV files by 1/2 or greater without any loss to the audio quality. If you want to keep an archive of your WAV files but would like to conserve your use of hard drive space, one of these formats may be ideal. Be sure to keep archive copies of the FLAC software for use in the future.

d. A combination of these is probably best: burn an Audio CD for use in your car, make some MP3s for your portable media player, and convert to FLAC for storage of the master files on your hard drive or DVD backup storage.

Final Thoughts

There are too many options for working with WAV files to be covered here. I just leave you with the following tips and comments.

1. Be sure to check the Digital Audio Editors page for links to WAV editors and related tools

2. If you wish to keep WAV format files, note that a MONO WAV file takes up 1/2 the space of a Stereo file. However, if you are recording to Audio CD, 60 minutes is still 60 minutes, whether the source WAV is in MONO or Stereo. You can't fit twice the number of mono files on an audio CD. Also, some WAV editors only work with 16-bit Stereo WAV format.

3. If you are converting a speech WAV file to MP3, I would suggest using a 56kbps bitrate, resampling to 22Khz sample rate, and converting to mono. This will make fairly small files yet retain decent sound quality. As long as you don't delete the orignal WAV, you can experiment with your MP3 encoder program to test various settings and the resulting quality.

4. My process for processing the WAV files include:

Recording one WAV file from an autoreverse cassette
Using Steinberg's WaveLab Lite (or Acon's Acoustica) to save side A as a separate file from Side B.
Use WaveLab lite to truncate beginning and ending silence or noise
Use WaveLab lite to "normalize" each WAV file (often side A and side B of a tape have different volume levels) to -0.5dB.
Use DART CD-Recorder 4.1 to elminate Hiss when necessary.




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