The stereo image was not made up of fully discrete left and right channels; each channel's signal coming out of the cartridge contained a small amount of the signal from the other channel, with more crosstalk at higher frequencies. High-quality disc cutting equipment was capable of making a master disc with 30–40 dB of stereo separation at 1,000 Hz, but the playback cartridges had lesser performance of about 20 to 30 dB of separation at 1000 Hz, with separation decreasing as frequency increased, such that at 12 kHz the separation was about 10–15 dB. A common modern view is that stereo isolation must be higher than this to achieve a proper stereo soundstage. However, in the 1950s the BBC determined in a series of tests that only 20–25 dB is required for the impression of full stereo separation.
The stereo image was not made up of fully discrete left and right channels; each channel's signal coming out of the cartridge contained a small amount of the signal from the other channel, with more crosstalk at higher frequencies. High-quality disc cutting equipment was capable of making a master disc with 30–40 dB of stereo separation at 1,000 Hz, but the playback cartridges had lesser performance of about 20 to 30 dB of separation at 1000 Hz, with separation decreasing as frequency increased, such that at 12 kHz the separation was about 10–15 dB A common modern view is that stereo isolation must be higher than this to achieve a proper stereo soundstage However, in the 1950s the BBC determined in a series of tests that only 20–25 dB is required for the impression of full stereo separation.