It might be for all intents and purposes an obsolete music format in the age of 6-channel digital music downloads, but are mono music recordings nonetheless still a utilitarian tool for discerning audiophiles?
By: Ringo Bones
From the perspective of today’s de rigueur discrete 6-channel digital surround sound, it is quite sobering to reflect on the historical origins of loudspeaker positioning for optimum two-channel stereo presentation. Around the dawn of the Golden Age of Stereo in 1956, F.H. Brittain and D.M. Leakey wrote articles in the Wireless World magazine on the subject, entitled Two Channel Stereophonic Sound Systems. Stereo – as in two-channel stereophonic sound – in the home wasn’t a common and practical reality until way into 1958, yet messrs Brittain and Leakey laid down basic principles that are still being followed slavishly until today. Well, back in the mid 1990s, Brittain and Leakey’s method were followed by the then newly recruited generation of hi-fi enthusiasts / audiophiles without them even actually knowing who Brittain and Leakey were or the two loudspeaker positioning method that they developed.
Know them by name or not, there are still veteran audiophiles out there who are not using the “tried and tested” Brittain and Leakey arrangement. Brittain and Leakey’s tried and tested method does have a number of advantages – principally in the creation of a solid narrow image when both left and right speakers are fed with an identical mono signal. This is of crucial importance when it comes to creating a wide, stable, precise left-center-right two-channel stereo soundstage.
If your speakers are optimally set up, you should hear a narrow center image when a mono signal – or a monophonic music recording – is played. Generally, this will only be achieved if the speakers are angled – or toed in – so their axes cross at an imaginary point in or in front of the main listening area, thus the importance of the toe-in of hi-fi loudspeakers in your listening room.
With speakers flat against a wall and pointing straight down the room, an arrangement often employed in British homes – and typical in cramped apartment block type dwellings in Singapore and Hong Kong resident audiophiles – you won’t be able to achieve a narrow center image with mono recordings, but effectively create a “double mono” effect. As a result, stereo soundstaging will be less pinpoint precise than it could be, resulting with a vague center placement and poor “spread” between left / right channels.
Whether it is wholly desirable to achieve a narrow center image with two speakers is a moot point, as live sound is never so precise. But a narrow center image does ensure that you hear exactly how a recording was actually miked and mixed stereophonically, by allowing one’s home hi-fi speaker set up to recreate the subtle shifts of amplitude and phase that our ears use to locate sounds.
Try this experiment; With a mono music recording or a mono radio broadcast (this can be often found in the AM radio band) – or if your FM only tuner has one – switch it into mono mode to convert what was once stereophonic FM broadcasts into instant mono. Using such methods, listen to how narrow your phantom center image sounds. You should hear a thin narrow central line of sound and not be aware of the two spaced loudspeakers – only an image between them. But be careful though as some recorded musical instruments – and even certain singers’ voices – can sound quite timbrrally different when converted into mono. A good example is Gloria Estefan – her voice sounds wholly different in mono when compared side-by-side with her full-blown stereo recordings.
If you don’t get a clear impression of a center image, check for correct speaker phasing then angle each enclosure in or out until the center image snaps into strong focus. If possible, alter the distance between your listening seat and the speakers, moving closer or further away to see what happens.
A narrow center image with two-speaker mono will not necessarily result in a more pleasing overall sound, but things should be more precise – imaging wise. And this should allow you to hear the music exactly as it was recorded – in your listening room and in your own home.