Before digital recording, the total number of available tracks onto which one could record was measured in multiples of 24, based on the number of 24-track tape machines being used. In the 2010s, most recording studios now use digital recording equipment, which limits the number of available tracks only on the basis of the mixing console's or computer hardware interface's capacity and the ability of the hardware to cope with processing demands. Analog tape machines are still used by some audiophiles and sound engineers, who believe that digitally recorded audio as sounding too harsh and who believe that tape has a "warmer" sound. The scarcity and age of analog tape machines has increased their value, as does the fact that some audio engineers still believe in recording to analog tape.