Flattening the room response 329 that a broad consensus of recording personnel considered excellent were pitifully few. Many people in the industry knew a good deal about what the problems were, but a lack of knowledge about how to solve them, together with estab- lished practices such as the presence of tall metal racks and the use of rather `industrial' furniture in general, delayed significant progress. What is more, domestic high fidelity systems were not in widespread use, so even many of the bad control rooms were still capable of quality-control monitoring way ahead of what could be heard in the vast majority of homes. The pressure to improve control-room acoustics was still largely driven by the people in the industry who knew that they could do better. What a recording sounded like on the average radio was already an important factor, at least for popular music recording, so the small loudspeakers provided on or in the mixing consoles were used to make a crude comparison. Nevertheless, the general trend in the industry was to try to advance, and to make better recordings. 12.1 Electronic correction concerns By the mid 1970s, the majority of top studios around the world were using monitor equalisation to try to achieve a more standardised frequency response at the listening position. This was almost invariably done by means of putting pink noise into each loudspeaker system in turn, and adjusting graphic equalisers to give the desired response at the listening position (usually flat, with