Acetates were originally used for home recording in the days before tape
recorders. They usually used a crystal cutter head that had a frequency
response of about 100hz to about 3khz. The output level was about -2db
below standard reference level. Commercial cutting heads could get from
about 50hz to about 10Khz, and about +6db of level.|
Nowadays with the feedback, moving coil cutterheads, the response jumped to about 20hz to 18Khz, many times reaching 22Khz, and the levels of +10 are possible. Aardvark cuts their plates at +6 as +10 puts way too much risk on the cutterhead. Even at +6, we damage the head about 10 times a year, and that cost from $100 to $1000 for repair depending on the parts damaged and if we can do the work in house. European dance club music runs about +6db, so we are satisfied with those levels.
The wear on an acetate is higher than that of a vinyl pressing. A chipped stylus will rip up an acetate with one play. With the higher levels, the fact that we cut the grooves as deep as possible, and today's playback styluses tracking at much lighter pressures, the acetates of today last much longer than those of the older days. Originally, an acetate of the 1940s was expected to last 5 to 10 plays. This was due to the lower sound levels, and mostly due to the stylus pressure of one ounce, or about 30 grams. Radio stations used acetates for commercials and other "spots" These lasted about 50 plays, due to the fact that they tracked them at about 5 grams. With todays playback styluses, I have had reports from DJs of acetates lasting over 100 plays, and still going.
Read the Aardvark page in full at http://www.aardvarkmastering.com/
for a detailed explanation of the entire mastering and cutting process.