Help recording lectures to CD-Rs?

It all depends on how exactly you put the information on the disc.

For your purposes here, there are basically two ways to store the media on the disc, which mean formatting the disc in one of two ways:

1) as data disc

2) as a media disc

 

Again for your purposes, the only difference between the two is compatability with your player.  A media disc will be formatted like any normal CD and will play in virtually any player.  This is where you run into the limit of maybe 20 songs or less.  As a data disc, you can store up to ~644MB worth of mp3, which is closer to 200+ songs.  The catch is, most CD players will not be able to read the data on this disc.

If you have a special (aka non-standard) stereo/CD player in your car, you may have the option to play this disc.  If not, then you're stuck with the media format.  So to answer your question, no, there isn't a "certain type" of CD that is capable of holding more data, it's basically just a matter of how you format it, and whether or not your player is sophisticated enough to be able to read it.

That's kind of the price you pay for using dated technology.

Obviously the better option is using a digital audio device that will allow you to store mp3 files (e.g. an iPod).  Of course the default way to listen to this is through headphones (or if your player is more advanced, a built-in speaker).  Of course the quality isn't very good this way, especially if you're in a car with road noise...and also if you want more than one person to be able to hear it.

So the main two ways to get the audio of your mp3 player to play from your car speakers are

1) an auxiliary jack

2) an AM and/or FM transmitter

Ideally, your car comes equipped with an auxiliary jack that will allow you to simply connect your audio device directly to your car speaker system.  This basically means you'll never need to use CDs again.  Hopefully your car has one.  If not, it can be added, but it's not exactly like flipping on the kitchen light.

If you don't have a jack and don't want to put one in (or install a new stereo that has one), your other option is a transmitter.  This is a device that will attempt to transmit the audio from your device over the radio spectrum, and allow you to pick it up by tuning to the proper frequency on your radio dial.

Here is a very small one, that also has a USB port which allows you to also charge your audio device (assuming it has USB connectivity)...i.e., it's also a car charger.

The only draw back to a cheaper one like this is, you are limited in your radio frequency choices.  This particular one, for example, will only allow you to choose from 4 different frequencies.  If you happen to be in an area that is broadcasting on those frequencies, odds are their signal will be strong enough to interfere with yours, and your listening experience will be less than satisfactory.  If you're willing to spend more, you can get more advanced models that allow you a much greater range and power...but you pay for it.

 

The set up for audio listening in a car, starting with best is:

1) mp3 player with noise-cancelling headphones

2) mp3 player with auxillery connection to your car stereo

3) stereo with ability to play data CDs

4) Standard CD player

5) mp3 player with regular headphones

6) mp3 player with built-in speaker

7) phone speaker

 

Tues. 12/07/03 13:23 EDT
.post #198

ThatOldGuy:

I want to make a playlist of lectures I could play in the car on the way to work.

Okay. Assuming these lectures currently reside as files on your computer's hard drive, tell us what the format of these files is: .wav, or .mp3?

ThatOldGuy:

Which number is the actual limit: the MB capacity or the time duration?

They're both limits, actually.

If you burn .wav files to your CD-R (i.e. create an "audio" disc), your burning software will likely provide an indication of how many minutes in total the files you want to burn amount to.

If you burn .mp3 files (i.e. create a "data" disc), your burning software will likely provide an indication of how many megabytes in total the files you want to burn amount to.

ThatOldGuy:

I have two lectures that, together, are 00:73:38 in duration but take up only 20 MB on the CD-R.

This suggests to me that the lectures reside on your computer's hard drive as .mp3 files. mp3 encoding "compresses" .wav files so that, while it sounds very close to the original, the file size is about one-tenth of what it originally was.

Edit:

Wasn't paying attention. You just told us that the files reside, not on your computer's hard drive, but on a CD-R. Great. Proceed as follows:

So now, you should determine if your car's CD player has the ability to also play mp3 files burned to this "data disc." Pop it into your player (turn the volume down to zero beforehand, just in case), and see what happens.

If "yes," then "Bob's your uncle."
If "no," then "decode" the .mp3 files back to .wav files, then burn the disc as an "audio" disc.

Decoding .mp3 to .wav is no big deal. It's just a matter of using something like LAME and running it on your .mp3 files. I can elaborate if you're interested in learning about this.

ThatOldGuy:

Is there a way to compress .mp3 files (so that I can add more than just two unrelated lectures) ...

Yes, you can use a "codec" such as LAME to "transcode" (transform the .mp3 file from one encoding rate to a different encoding rate), but the sound quality will suffer. For spoken audio, this might be no big deal.

ThatOldGuy:

... or is there a certain type of CD that is capable of containing more data?

You might still be able to buy 90 minute CD-Rs, and even 99 minute CD-Rs. But if you are burning mp3 files, you'll be able to squeeze roughly 800 minutes of "audio" onto an 80 minute CD-R, so looking for these larger-capacity discs might not be worth the effort.

Thanks a million John James. I hadn't considered the audio jack (guess what I'm getting today ).

John James:

The set up for audio listening in a car, starting with best is:

1) mp3 player with noise-cancelling headphones

2) mp3 player with auxillery connection to your car stereo

3) stereo with ability to play data CDs

4) Standard CD player

5) mp3 player with regular headphones

6) mp3 player with built-in speaker

7) phone speaker

Well, this is subjective (but I'm glad to know that I've done what you consider the worst of the available options in the past hahaha. Using the phone speaker was decent, but could have been louder).