recording. The recording engineer's goal is usually to create a stereo "image" with localization information. When a stereophonic recording is heard through loudspeaker systems (rather than headphones), each ear, of course, hears sound from both speakers. The audio engineer may, and often does, use more than two microphones (sometimes many more) and may mix them down to two tracks in ways that exaggerate the separation of the instruments, in order to compensate for the mixture that occurs when listening via speakers. Descriptions of stereophonic sound tend to stress the ability to localize the position of each instrument in space, but this would only be true in a carefully engineered and installed system, where speaker placement and room acoustics are taken into account. In reality, many playback systems, such as all-in-one boombox units and the like, are incapable of recreating a realistic stereo image. Originally, in the late 1950s and 1960s, stereophonic sound was marketed as seeming "richer" or "fuller-sounding" than monophonic sound, but these sorts of claims were and are highly subjective, and again, dependent on the equipment used to reproduce the sound. In fact, poorly recorded or reproduced stereophonic sound can sound far worse than well done monophonic sound. Nevertheless, many record companies released stereo "demonstration" records to help promote stereo. These records often included instructions for setting up a stereo system, 'balancing' the speakers, and a variety of ambient recordings to show off the stereo effect. When playing back stereo recordings, the best results are obtained by using two identical speakers, in front of and equidistant from the listener, with the listener located on a center line between the two speakers. In effect, an equilateral triangle is formed, with the angle between the two speakers around 60 degrees as seen from the listener's point of view. Many higher quality multichannel (two-channel and beyond) speaker systems, then and now, include detailed instructions specifying the ideal angles and distances between the speakers and the listening position to maximize the effect based on, often extensive, testing of the particular system's design. Vinyl records Although Decca had recorded Ansermet's conducting of Antar in stereo May 1954 it took four years for the first stereo LPs to be sold. In 1958, the first group of mass-produced stereo two-channel vinyl records was issued, by Audio Fidelity in the US and Pye in Britain, using the Westrex "45/45" single-groove system. Whereas the stylus moves horizontally