The RAA project web site offers on-line services for the matching of audio devices, direct comparison and evaluation of devices compatibility. The RAA web site presents 2738 reports of measurements of headphones, musical players, amplifiers, DACs, smartphones, sound cards and other audio devices. The measurements were carried out in our research laboratory, on the hardware-software complex designed by RAA. We are improving the tests and test reports. RAA make tests and reports more understandable to customers and amateurs, not just professionals.
В дБ это будет как -30.6, -24.4 и -20.9 дБ
6% здесь ближе к 9%, а не "посередине".
Кстати, калькулятор процентов в дБ и наоборот
https://reference-audio-analyzer.pro/dbprossent.php