Anyone who has ever tried to delve into the world of vinyl records will certainly have come across the terms 33 laps And 45 rpm. These terms – which can create a bit of confusion for neophytes of the genre – indicate the number of revolutions made by the disc in one minute and, consequently, the rotation speedwhich is greater in 45 rpm than in 33 rpm. But why do these differences exist? And how do we recognize the speed of each record? As we will see, these values are not necessarily related to the disk size and can affect the audio quality.
First we need to establish a key concept:increase rotation speed increases the audio quality. This happens because if a disk rotate fasterthen in the same interval of time the needle manages to travel a furrow of greater lengththus reproducing a greater quantity of information. At the same time, however, high speed reduces the amount of music that can be engraved on each side of the record. With this clarified, it is now easy to understand what the difference is between 33 rpm and 45 rpm.
33 laps
The 33 laps (often indicated with the English term 33 RPM) is a format that rotates more slowly, so it has a slightly lower audio quality but, at the same time, it allows you to engrave on each side of the disc a greater amount of music. Precisely for this reason the 33 rpm (or better said, the 33 1/3 RPM) are usually used for larger disks, the so-called “12 inches“: this, especially in the past, allowed us to record an entire album from 40-45 minutes on a single disc. Just to give an example, the album “Thriller” Of Michael Jackson It is recorded on a single vinyl 33 laps for a total duration of 42 minutes and 16 seconds.
In case of longer albums the songs are split into two different discs 33 laps each and, vice versa, it is not impossible to find even smaller discs recorded at this speed.
45 rpm
The 45 rpm (indicated with 45 RPM) on the other hand is a format that rotates at a higher speed and therefore, even though having a superior audio qualityis characterized by a shorter duration. Usually this speed is used for the so-called “singles“, i.e. smaller vinyl records (7 inches) that contain 1 track per side. These are the successors of the discs that were inserted into the jukeboxwhich was intended to play a single song at a time rather than entire albums.
Attention: the association “45 rpm = small record” it is not always true, and there are albums recorded at 45 rpm also on 12 inch discslike Wasting Light of the Foo Fighters. This allows you to have a entire album in higher quality – even if recorded on a usually greater number of discs.
The 78 rpm record
Honorable mention also for the album 78 rpm (more precisely 78.26 RPM), now almost totally fallen into disuse but still worthy of a quick mention. This is a popular format especially at the beginning of the 20th century, when the technology for producing vinyl was not yet mature. In fact, these could not only record a extremely small amount of music but they couldn’t even guarantee high qualitysince microgrooves were not yet in use at the time. Finally, the icing on the cake, they were not even made in vinyl but in other materials, such as the bakelite, which were extremely fragile and heavy. This mix of factors meant that these discs were slowly fallen into disusealthough today there is a niche of enthusiasts and archivists who still preserve some copies.
