CDRLabs.com

The reason I ask, is because in CD Speed 1.0, Quality Test and scandisc test reported errors
when I start the test while the disc hasn't spinned up yet.

But when I made sure CD is spinning first before starting the tests, then no errors.

Any explanations for this? Thanks.

Many drives will do this. The motor is applying maximum acceleration, trying to get the disc spinning at full speed, and this introduces some vibration and instability in the RPMs, making it more difficult for the laser to track accurately and causing a few errors. It is not something to be concerned about and does not reflect badly on either the quality of the drive or the media (although some drives and media do a little better than others during this transition period).

So, to answer your question, yes you should spin up the CD before beginning the quality test, and doing so gives you a more accurate and "fair" assessment of the disc quality.

cfitz