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Exact Audio Copy >EAC & LAME Quickstart >


If you want to use Exact Audio Copy for duplicating audio CDs you'll need to configure the gap detection. The gaps - also called pregaps - are the pauses between two tracks. Usually they are 2 seconds long and a CD player will display a negative time during this pause. The gap detection in EAC is able to detect all gap lengths by reading the sub-channel information on the CD. Because this information is not stored on the CD directly retrievable, EAC has to search for the gap positions.

From the EAC menu select Drive Options... or press F10. This opens the Drive options dialog window. On the last tab you'll find the gap detection settings. Remember that you have to do the following instructions once for every drive you wish to use with EAC!

It's important to find the proper gap detection method for your drive. Some drives will return incorrect gaps if the wrong gap detection method is used. There are 3 gap detection methods you can choose from the Gap/Index retrieval method drop down box.

Detection method A
Detection method B
Detection method C

Detection method A is the fastest and Detection method C the slowest. However not all drives function well with the faster detection methods. Note that there's no quality difference between the 3 methods.

The Detection accuracy is the number of times EAC counterchecks the detected gaps. In the Inaccurate mode the gaps will be retrieved only once while the Accurate and Secure modes retrieve the gaps several times to verify the gap positions. It is possible that your drive does lock up when using the more accurate detection accuracy. Thus some experimenting is required.

Set the Gap/Index retrieval method to Detection method A and the Detection accuracy to Secure. Click OK to save the settings.

Testing the gap detection modes:

Insert an audio CD in the drive. After a few moments EAC will list the contents of the CD similar to the screenshot below. If possible use an original CD (not a copy) because some CD writing programs do not copy all indices. Live or mix CDs are also not recommended for the test because those often do not have pre-gaps. I use the CD "Use Your Illusion II" by "Guns N' Roses" in this example. If you have this CD or know a friend who has it's a good idea to use it so you can verify your detected gaps with mine.

Notice the column Gap which says Unknown for every track. That is normal since Exact Audio Copy does not automatically detect the gaps on startup or CD insertion to save time. Gap detection can be a time-consuming process for certain drives.

From the Action menu select Detect Gaps or press F4. A new dialog box Analyzing pops up showing the progress of the gap detection process. A good drive with the correct gap detection mode set should be able to retrieve the gaps in under 2 seconds per track.

If EAC seems to take forever to detect the gaps or the detection process locks up after a few tracks, the detection method you use is probably not optimal for your drive. Press the Cancel button to abort the detection process. Note that it may take up to several minutes before Exact Audio Copy responds and stops the detection. After the process stopped go back to the Drive options dialog window and change the Gap/Index retrieval method to Detection method B. Eject and reload the audio disc in the drive to reset the possibly already found gaps for the CD and redo the gap detection test. If it fails again lower the Gap/Index retrieval method to Detection method C. For most drives you should now have found a suited detection method.

In the rare case that the 3 detection methods all fail you'll have to lower the accuracy of the detection process. Set the Gap/Index retrieval method back to Detection method A and change the Detection accuracy to Accurate. Now do the gap detection test all over again. If EAC still fails to do a correct gap detection lower the Detection accuracy to Inaccurate and repeat the test for method A, B and C. 

If the gap detection went right you should get a screen like shown below. The column Gap now shows the pregaps of each track. The pregaps usually look like a bunch of random times. If you get 0:00:00.00 for every track you should try another CD. If you also get these times on other CDs you'll have to use another detection method as the one you currently use does not give correct results for some reason.

Gap detection is now configured. Exact Audio Copy is now able to create correct CUE sheets required for CD copying.

Help other users:

Determining the correct gap detection method isn't that difficult. Most people should be able to find the right method. However, some can't and therefore an online User Reported Drive Features Database was set up. If you were able to determine your settings you are strongly encouraged to contribute to this database by sending in your settings. See the Help Other Users section for detailed instructions. Even if your drive is already listed in the database you still may send in the information. The more people report their settings for a certain drive the more accurate it becomes.