VINYL INFO
Please refer to the following suggested vinyl side lengths to maximize volume and fidelity and to reduce the risk of poor pressing outcomes:
12″ @33 1/3 RPM:
OPTIMAL – 16 to 20 minutes per side
MAXIMUM – 25 minutes per side
SAFE BET— 35-45 minute record
12″ @45 RPM:
OPTIMAL – 6 to 12 minutes per side
MAXIMUM – 15 minutes per side
SAFE BET— 20-25 minute record
10″ @33 1/3 RPM:
OPTIMAL – 9 minutes per side
MAXIMUM – 14 minutes per side
SAFE BET— 15-20 minute record
10″ @45 RPM:
OPTIMAL – 8 minutes per side
MAXIMUM – 10 minutes per side
SAFE BET— 12-16 minute record
7″ @33 1/3 RPM (not recommended):
OPTIMAL – 5 minutes per side
MAXIMUM – 7 minutes per side
SAFE BET— Drop a song and do 45rpm or do 12”45rpm
7″ @45 RPM:
OPTIMAL – 3 minutes per side
MAXIMUM – 5 minutes per side
SAFE BET— 5-8 minute record
Understand how important sequencing of songs is when compiling a record for vinyl pressing...
All vinyl records are going to sound quieter and thinner as they approach the last song on a side. The reason being, the length of the groove at the outer edge of an LP is 37.7". The length of the groove at the inner edge at the label is 12.7". That is 1/3 the length to transmit the same sonic information.
For a 7" EP the length of the grooves to transmit this information is even shorter, which is why shorter side lengths and 45rpm are strongly recommended. The faster rpm rate basically means that the information etched into the grooves of the record will be less compressed into the short circumference length, although the trade-off is that it shortens the amount of time possible. If you wrap a piece of string around the outside of a record you will have a longer length than if you wrap a piece of string around the center label. You can equate longer length with "high resolution", and shorter length with "low resolution".
The proper way to sequence a record is to place quieter, more dynamic songs as the last song on each side. This is why most classic rock records end with a ballad.