Complex sentence: Grey Gull's audio fidelity is generally slightly below average for the era, but pressings are often in cheap shellac which gives them more surface noise and stood up to repeated playing poorly, further degrading the sound quality.
Split into simpler sentences: Grey Gull's audio fidelity is generally slightly below average for the era. Furthermore, pressings are often in cheap shellac which gives them more surface noise and stood up to repeated playing poorly, further degrading the sound quality.