Do you think that mono records, like shellac records, are old news and that real HiFi is only possible with stereo? Don’t worry, you’re not alone. So why the discussion of mono vs. stereo? I invite you on an exciting journey through the past and insights into why mono records definitely have their place.
Mono vs. stereo signals
In general and regardless of records, a mono signal means that there is only one single channel. The left and right ear receive the same signal, which is why the auditory impression is that the music is coming from the center. A single loudspeaker is therefore sufficient to reproduce a mono signal (more on this later).
A stereo signal, on the other hand, consists of two channels. If you will, a separate channel for each ear. The fact that both ears receive slightly different signals can create a spatial hearing impression. Just like in a concert hall, we can assign individual instruments to individual locations on the stage. That’s why HiFi nerds also refer to this effect as the soundstage.
In this article I describe how a stereo record works and how to combine two channels in a single groove. Quick recap: Mono records only modulate in depth (lateral cut) while stereo records modulate in depth and width (lateral and vertical cut).
A trip into the past: How it all began
Don’t worry, we won’t start with the clicks and grunts of Neanderthals. Just this much: The vinyl record as we know it today has been around since the 1940s. At that time, radio stations broadcast music, if at all, via AM. Record players were large pieces of furniture that sat in a corner of the living room. They were supposed to fit well with the interior and, because of their high price, were intended as long-term investments. Think of your refrigerator or washing machine today. In the post-war period, people were grateful to have music in their living rooms. It didn’t bother anyone that both the records and the radio program were mono.
The emergence of HiFi
As technology developed, recording and playback quality also increased. So you could not only listen to music at home, but also in a quality that lived up to the term HiFi. So far everything is still in mono. This development continued into the 1960s, even after the first stereo record came onto the market in 1957. As already mentioned, record players were relatively expensive back then. They simply could not be easily replaced with a younger model like a wife. This meant that stereo records got off to a slow start and only virtually replaced the mono format in the 1970s.
Mono vs. stereo? Both!
It was the exciting decade of the 1960s, when recording and playback quality was already very high, but the stereo format was not yet widespread. Many radio stations still broadcast on AM and therefore mono. Many households stuck with their beloved (and paid for) mono devices. After all, switching to a stereo system didn’t just mean spending on a new stereo device. In addition, the entire arrangement changed because two speakers had to be set up independently of the turntable and amplifier. The studios also reacted cautiously to the stereo format, as they suddenly needed multi-track tape recorders. Of course, artists and producers took this into account. For a long time they continued to master their albums preferably in mono. It was not uncommon for artists to concentrate on the mono version. If there was a stereo version at all, they left this unpleasant (and unfamiliar) job to a technician.
Fake stereo: The enfant terrible
We all know the dark side of the music industry and that in the end it’s all about the money. When the transition to stereo format was practically complete in the 1970s, labels wanted to release older albums in stereo as well. The problem: Many recordings were only available on mono tapes. The solution (then and now): If you can’t make it – Fake it. Applying filters and delays, engineers developed procedures to create two stereo-ish tracks from a single audio track. Although the sound is more reminiscent of a surround simulation than of real stereo, the effect is, let’s say, interesting.
Because the term fake stereo doesn’t necessarily promote sales, labels invented impressive terms like “Duophonic”. You can find an example of an advertising record from that time here. As a German, it makes me particularly proud that German Beer Drinking Music was apparently worth the effort to be released in fake stereo. However, I doubt that the average listener will place an increased value on “the wonder of duophonic sound” after their second Maß.
The compatibility of mono and stereo
When it comes to technology, the question of compatibility naturally arises. Let’s look at each one in turn.
Stereo record with mono cartridge
Since mono records only contain lateral modulation, mono cartridges can normally only sample in a defined manner in this degree of freedom. Modulation of the depth is not provided here, which is why the stylus is mounted very tightly in this degree of freedom. Since a stereo record modulates laterally and in depth, a mono cartridge causes significant damage to stereo records. Conclusion: We should please avoid this combination.
Mono record with stereo cartridge
As described in the article about cartridges, the two coils of a stereo cartridge form a 45° angle to the record surface. Modulating a mono record (purely lateral) results in the same signal on both channels of the stereo cartridge. It is therefore possible to listen to mono records with a stereo cartridge without risking component damage. So much for the good news. A bit of not-so-good news is that the styli of mono and stereo cartridges are designed differently. In detail, they often differ in compliance and the radius of the stylus. Of course, each pair of ears has to decide for themselves to what extent these differences spoil the listening pleasure.
Conclusion “mono vs. stereo”
Although the era of mono records predated stereo records, they do not necessarily have to be outdated technology. The period between 1960 and 1970 in particular produced high-quality mono albums. During this time, many artists and producers focused on mono albums, which is why they can be superior to their possible stereo counterparts. And if you’ve been wondering who the heck spends money on a mono cartridge, you can now certainly answer that question. Collectors who predominantly prefer records from before 1970 can best reproduce the sound as the artists imagined it with a pure mono setup. In the end, as always, it is a very personal question how far you want to go. But hopefully some of the facts mentioned here will help you get your wife to finally approve your investment application.