Stereo? Point Source Mono!

I was listening to some records engineered by the late great Al Schmidt. Damn, his stuff sounded great at any stage in his career, regardless of the size of the console or the number of tracks.

While listening, I started pondering how he used stereo and panning and that got me thinking about “stereo” as a concept in the studio.

Very often, stereo really isn’t stereo. You might be listening with two speakers, or a pair of headphones, and things might be panned around and all wide sounding, but the reality is, generally, very few things on a recording are actually true stereo. Instead, they are Point Source Mono.

If you stick a microphone on a guitar cabinet and record it to one track, and then play that track back and pan it, oh, 60% to the left, that isn’t stereo. That’s a panned mono track - Point Source Mono panned to the left off center.

If you take two microphones and stick them way up close to two speakers of a guitar cabinet, record each mic to its own track, and then play those two tracks back... and pan them opposite of each other, one to the left one to the right, that is Point Source Mono with two mono point sources. It might sound wider than using one mic and it might approximate stereo, but it is still panned mono—Point Source Mono.

You can even do the AC/DC guitar recording thang, which is to put one mic down the throat of a speaker on the guitar cabinet and then another a few feet away to catch more of the sound of the cabinet in the room, and then record each to its own track and pan them wide on playback and... STILL Point Source Mono! Sounds great, but it’s not true stereo.

So, when is it actually stereo?

It’s actually stereo when you record something with two microphones set-up as a stereo pair, either using a spaced pair arrangement, a coincident pair arrangement (XY, MS), or a near coincident pair arrangement (ORTF). Set up the mics in proper stereo setup, record each to its own track, play them back panned wide and now you have actual stereo. You can also use a dummy head (binaural) if you have one around.

What about stereo keyboard samples? It has two outputs, you run it through two channels. Stereo or not?

Depends. If the samples were made using a stereo mic’ing setup, then it might be. If the samples were recorded as mono tracks and then electronically panned to give the listener the feel of someone playing a piano from low to high, that is again Point Source Mono.... with 88 little point sources.

Does any of this matter?????

Maybe, maybe not. But it’s always nice to know what you’re doing.

Probably 90% of the time when you’re making records you’re working with Point Source Mono sounds. The overall recording might be a stereo experience, but most of the parts of the recording are panned point source mono sources. I admit that this is a bit like knowing the difference between frying and sauté-ing when you’re cooking, but great chefs know the difference; if you want to be a great chef, you should know the difference.

This is not to say you should walk around the studio saying, “Let us record this in glorious Point Source Mono and then pan it wherever we desire in the final mix.” Let’s not do that. But, let’s know the difference.

And let’s know why point source mono is probably better for most of what you’re doing anyway.

Getting something recorded in true stereo to sound good can be hard, and it might not be that useful.

If you stick a crossed pair of mics in front of a singer, a few inches from their mouth and record that, and then play the tracks back panned wide, the first thing you’re going to notice is that the image of the singer is unstable. If the vocalist moves even a tiny bit while close to a stereo pair of microphones, the image is going to jump from speaker to speaker. That will either be cool if it happens every now and again, or distracting as hell if it happens a lot.

The same thing can happen on any instrument or source you record in stereo if you get the microphones close. Of course, you can tighten up the panning up a bit to minimize the jumping... but then you should have just recorded things in mono, right? I suppose a stereo recording that has been tightened might have more perceived... size? Width? Maybe the recording will make the source sound physically bigger? Maybe. You can try it.

Rather than putting the mics up close, what if you pull them back and record?

Unless you’re dealing with something actually wide, like a string ensemble or a drum kit, most instruments are physically narrow and that is how we hear them: basically as a point source. How wide is an acoustic guitar? Two feet? The “stereo” experience of listening to an acoustic guitar is really a mono experience of the sound coming directly out of the guitar, the position of the guitar relative to the right/left of your ears, and the sound bouncing around the room.

A lot of the sound of stereo is the sound of the room, more so as you get further from the sound source. If you have a shitty sounding room and you stick your stereo pair far enough away to get a stable stereo image, then you’re going to be recording shitty room in stereo. Perhaps go close, go mono and add reverb later in the mix. Getting rid of shitty room on a recording is really hard.

Of course, sometimes shitty room sounds are amazing, so remember... often what is cool is what you like.

Most of the time, when you’re using two or more mics to record an instrument, you’re not doing a stereo recording. You’re trying to capture more of the totality of the instrument, or get a certain effect from it. Recording an acoustic guitar with two mics, one near the bridge, the other near the neck where it meets the body isn’t stereo. It's two point source mono recordings of the same instrument from two separate places. Think of it as a recording of the neck and a recording of the bridge. Pan it wide if you want a huge wide guitar. That might be cool. Might be dumb or distracting. Try it! See what you think.

Ditto for sticking two mics into a piano right over the strings near the hammers, or one mic near the hammers and the other further away over some resonant area of the sound board. This isn’t stereo. And if you pan it wide across the speakers it certainly isn’t a true-to-life stereo listening experience unless you normally stick your head in a piano while people play it. Which is dumb and will destroy your ears. But.... it might be awesome in a recording, to have a huge piano eating the listener's head.

A piano recorded ten feet away with a stereo pair, if you’re in a good room, might sound amazing. It also might get swallowed up by everything else in the mix, and you might have a lot of trouble getting it to sit correctly. Again, most of the stereo component is going to be the sound of the room—the piano itself is sort of “wide mono” when you get ten feet out. In mixes, room sounds tend to get masked quite a bit.

Many people put a spaced pair of microphones over a drum kit—this is a very common recording technique. I would argue that this isn’t really true stereo. You’re recording the left half and the right half of the kit—again, two point source mono recordings from two different locations. If you put a coincident pair above the drum kit, then you’re much closer to getting a true stereo recording of the drumset.

I occasionally recorded drummers using an AKG C-24—which is a stereo tube mic—right over their heads as they played. It sounded A LOT like what they were hearing. However, on the speakers, it wasn’t really all that dramatic. When the drummer went around the toms, you could sense the locations of the toms, but they weren’t pinpointed—nowhere near as much as if you panned individual tom mics. It worked well for jazz sessions, less so for metal. Modern drum recording is a mic on everything, down to individual cymbals, and the top and bottom of snares, toms, three mics on the kick, etc. And in the mix that all gets panned around and reassembled into an aural “picture” of the drums. It’s a stereo experience made up of mono sources.

Al Schmidt was, like most engineers who came up through the 60s and analog tape, a minimalist. One thing that I always get from anything recorded by Al Schmidt: you can’t beat the right mic on the right sound source played by the right player.

Speaking of, have a listen to This Masquerade by George Benson. This recording blew my mind when I first heard it as a little kid. It still does. A lot of point source mono to hear. God, this is sexy stuff.