From our tests i do remember that TEAC can do up to 40x DAE. something is wrong either with your disc or your system
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In testing it will do 40x dae
Setting speed to: 40.0 times (7056 kBytes / Second)
Result: 18.7 times (3307 kBytes / Second)
Range: 00:00:00 - 05:00:00 -> 20,0 times (3528 KBytes / second)
Range: 32:38:73 - 37:38:73 -> 33,3 times (5880 KBytes / second)
Range: 65:17:72 - 70:17:72 -> 42,8 times (7560 KBytes / second)
Nero cd Speed
Start = 18.2
End = 40.17
but for reason, if i copy with Nero, feurio or clonecd it falls back to 8 speed.
As far as i understand the TEAC only supports 40x, 8x and 4x read speeds, so if it can't reach 40x it falls back to 8x.
So i hope in a new firmware upgrade they will ad 16x, 24x and 32x read speeds.