other technical issues are involved, for simplicity:
Faster Speeds yield more physical material to record the content.
Tape: 3-3/4; 71/2; 15; 30 ips, each increase in speed yields twice the magnetic material to record the same amount of content, i.e. a violin note.
Tape: 1/4" tape: 4 track is 4 skinny tracks (less magnetic material). 1/4" tape 2 track has tracks twice the width of 4 tracks, thus twice the magnetic material to capture content.
1/2" tape; 1" wide tape, combined with the faster speeds: both factors combine to increase the magnetic material which increases recorded fidelity..
Physical Mechanisms: i.e. Cassettes, 1-7/8 ips (originally for dictation): the mechanism’s precision needs to progressively increase. Cassette speed and tape width stayed the same, it was the mechanism improvements (and cartridge improvements) that yielded acceptable suitability for music, along with improvements in the tapes formulation/material’s ability to more faithfully record and retain the content. Eventually 4 skinny tracks were successfully squished onto the same 1/8" width tape and same playback 1-7/8 IPS record/playback speed. Amazing.
8 track cartridges: take one apart, what a piece of crap. Originally made for commercials, discard when that commercial was kaput.
R2R machines: speeds involved, mechanism for 30 ips is no joke.
Back to 45rpm, likewise: it gives more material via it’s faster speed to capture the same content. Thus less content per lp side.
As for ’wider grooves’, that isn’t involved that I know of, 45rpm goes to the same phono stage/processing, and the same stylus tip is involved
think about RIAA equalization, which is what allows LP (long play). The Bass signal is ’electronically cut’ during recording to reduce the width of the bass grooves (thus more skinny grooves, thus more content per side), and the electronic cut is reversed via RIAA equalization, the bass is electronically boosted (back to it’s original pre-cut signal strength). Highs are electronically boosted, then RIAA electronically cuts the signal back to it’s original pre-boosted signal strength.
Now, bass and highs, properly restored, the signal is LINE LEVEL, (1 volt in the pre-stereo days), the amplifiers ready to receive AT LEAST 1 volt and boost LINE LEVEL signals. Pre-Amp’s Volume Controls allow more or less of the line level signal strength to get to the amp.
Original Ceramic Cartridges signal strength were stronger, and could go into any AUX input. My Vintage McIntosh Preamp has two phono inputs: one Phono Low (current MM cartridge signal strength); the other Phono High, to receive the higher signal a ceramic cartridge produces.
Modern content, like CDs output, i.e. their Line Level can be more, much more than 1 volt.
