When converting an electrical signal to mechanical motion, there is an inconvenient fact: the lower the frequency, the higher the excursion of the moving part for a given signal level. This is important in several fields, particularly with LPs. The grooves of an LP would wobble very widely if the bass frequencies were cut in direct proportion to the signal. The playing time would, consequently, be very short and turntables would have a great deal of difficulty in holding their styli in place within the groove. So before LPs are cut, the signal is subjected to RIAA equalization. This reduces the bass by an enormous amount (-17dB at 50 Hertz), and increases the treble equally hugely (+13dB at 10,000 Hertz). A circuit built into the phono preamplifier of the playback equipment reverses this EQ, boosting the bass back to its proper level and handily cutting the treble. This last has the welcome effect of substantially reducing the hiss produced by the scraping of the stylus within the groove. Note: old-style ceramic cartridges did not require this second step of reversing the EQ because their frequency response characteristics roughly approximated this anyway.