In general optical drives have become being so cheap, that noone cares about quality. Unfortunately even the better hardware is of a really poor quality.
The error-correction-argotithms of DVD-drives can "repair" many errors, but most burned media are moreless defective, when it's just burned.
Reducing speed significantly improves quality. If the recommended write-speed is 16x use 8x or even less instead. (It's still faster than trying to burn non-playing disks again and again.)
Standalone-player often have trouble with burned media and with some "read-protected" disks (so called copy-protected - you can't copy what you can't read
).
A good approach is testing with different media types -RW or +-R and testing disks from different manufacturers.
Some player are trying to find the second Layer of a DL-disk and can't find one on a CD-R or single-layer DVD+-R.
Test yourself or google the name of your player for supported/working media (manufacturer).
If disks play at least sometimes reducing write-speed should be good alredy.
Disks, which are readable in certain DVD-drives only, indicate bad quality.
Disks that don't play in some players indicate problems in the combination of Player and Disk.