When I wrote about Tallis's Lamentations of Jeremiah a couple of weeks ago I mentioned that the LP I had was a 1969 "rechanneled for stereo" reissue of a recording originally made in 1955. Rechanneling was a gimmick used for a while in the earlier days of stereo, when purchasers paid a significantly higher price for stereo. As I recall, it was 20-25% higher--I think monaural LPs sold for about $4, stereo for $5. 

Audiophiles really hated rechanneled stereo. And maybe not just audiophiles, if by "audiophile" we mean people with exquisitely sensitive hearing who pay extremely close attention to sound reproduction and have extremely high standards. Also, frequently, rather high incomes, as the equipment needed to satisfy those connoisseurs is generally quite expensive. I didn't know much about that debate, but have always had the impression that the techniques used to split a single recorded track into two channels sometimes produced undesirable effects audible to non-obsessive but attentive listeners. 

Out of curiosity, I decided to test that judgment. I mean test it on myself--I'm certainly willing to believe that the problem is real, as it's been well attested to since the '60s. But is it a problem for me? Do I actually hear those effects? And if so how much do they matter?  

The only way to do that, obviously, is to compare two recordings, one mono and the other a rechanneled version of the first. Before the internet, it wouldn't have been practical for me to do that. Not impossible, but not practical--it would have taken too much trouble to locate and purchase the records. But now we have the wonderful web service Discogs, which is not only a vast storehouse of information (discographies), but a marketplace where used record dealers all over the world can sell ti customers all over the world. I was able to identify a 1972 monaural pressing of the Deller/Tallis recording, with at least half a dozen available to buy.

Just for fun, I picked one in mint condition--meaning unopened, still in the shrink wrap. It was only a couple of dollars more than several in near-mint condition, and still under $10, though shipping charges were as much as the purchase itself. (The seller was Satellite Records in Kalamazoo, Michigan, and I recommend them. Yes, the shipping charge was high, but not unusual for a single LP, and the record was very well packaged, and arrived more quickly than I expected.)

"Mint" and "Near-Mint," by the way, are official or at least conventional terms, with agreed-upon definitions. Descending from there, you have VG+ (Very Good Plus), VG, G, F(air), P(oor). 

If you looked back at the previous post on this (or have a good memory), you'll notice that the cover of this LP is different. The performance was originally released under the Vanguard label, and issued on that label more than once, then later on the Bach Guild label, which was a Vanguard subsidiary. 

So what about the test? Well, I'll state outright that I don't regard it as conclusive. I did hear a difference, but it was not huge, and I don't have either the sensitive hearing or the vocabulary to describe it in any detail. But for what it's worth, here's my impression.

Most TVs and computer monitors have controls for adjusting brightness, contrast, color, and sometimes more esoteric parameters. Many have presets by which you can choose a predefined  combination of these adjustments meant to be optimal for movies, games, sports, and so forth. When you switch these, you may be startled by a fairly dramatic difference in what you see. You may not be able to pinpoint exactly what's changed, at least if you aren't any more interested than I am in trying to figure it out. You may even have trouble deciding whether it's better than the previous setting. But it's obviously different. 

That's what it was like when I listened to the mono version of this LP after listening to the rechanneled stereo version. I certainly had not been conscious that there was anything wrong with the latter. But the mono version seemed more vivid and more present. This is exactly the opposite of what is supposed to happen with mono and stereo: the whole point of stereo is to use two channels to create an illusion of three-dimensional sound, in which not all the components of the sound reach your ears at exactly the same time. (If you want a good explanation, read the Wikipedia article.) You should, if the recording and the equipment are right, have a sense of the sound being produced by something located in the space between the speakers. At best, you should "see" the performers. It's very pleasing when it works properly.

But, as I said, with these two recordings, it was the mono and not the "stereo" one that seemed more  present. The mono one didn't have the three-dimensional quality of real stereo, but it was...and I'm having trouble describing this...more solid. The pseudo-stereo image was spread around and vague. The mono image was actually more, not less, defined. 

I wonder how many rechanneled-for-stereo LPs I have. As I write this it is crossing my mind to find them and replace them, but I'm not going down that rabbit hole. Almost certainly they are things I've listened to three or four times at most in forty or fifty years.

I can't vouch for the attribution, but there's way too much truth in this.