Friday, August 22, 2014

How Low can you Go?

When I told everybody back in June that while our organ console and the wiring between the console and the pipe were getting repairs and new features the sound of our organ would remain the same because we weren't getting any new pipes or anything, it turns out I wasn't entirely correct.

That's all due to a sudden development last week wherein I discovered, in the middle of a conversation with a technician working in the pipe room, that it would indeed be possible to add a spectacular sonic feature to our organ.

The pitch of groups of pipes is given a number based on the length of the lowest pipe for that particular sound. And of course a longer pipe will make a lower sound, so a 2-foot stop will sound very high, and a 16 foot stop very low.

Now a 32-foot stop is really in the basement. It produces a nice grand rumble. And there aren't any such resplendent rumblers on any organs that I know of in Champaign-Urbana, nor are they all that common on pipe organs in general, for one very good reason: the pipes have to be in the neighborhood of 32 feet long!

There isn't any way we at Faith could actually install a rank of 32-foot pipes. For one thing, at today's prices, a single rank of pipes (one sound at one pipe per note; somewhere around 60 pipes) costs upwards of $40,000 (which is about 80% of the cost of our entire project). And for another, where in the heck would we put a bunch of 32-foot long pipes?

A few years ago I read about an interesting way to make it sound as if the organ had a 32-foot stop without actually going to all the trouble and expense of creating one. And I happened to mention that to our organ technician, Trevor, who said that contrary to my dashed hopes, it would in fact be easy to create one on our organ. It's called a Resultant, and here's how it works:

When you play a note, in addition to the note you called into action, there are other, higher pitches that sound as well. They are called overtones (you can read about them here). The first overtone is always an octave above the note played (called the fundamental), and the second is a fifth above that. Now if you combine two existing ranks of pipes together, so that one note plays using one group of pipes and the fifth note above that plays on another group of pipes at the same time, you can fool the ear into thinking that what it is actually hearing are the first two overtones of the octave below that. So without actually playing very very low basement C, you can create the aural illusion that it is there anyway. Pretty sneaky! And since there are no new pipes involved, the cost is small. All that needs to be done is that a new stop knob has to be put in, and also a new wire or two in order to be able to send signals to both ranks at once, and the rest is done courtesy of the new software in the little computer screen that comes with the console which allows all kinds of things to be programmed in.

Trevor tried it out for me by temporarily rewiring the low C. If you felt a slight earth tremor at 3:48 last Wednesday afternoon, that could be why. At that extremely low pitch it almost sounds like a helicopter, and is more vibration than sound. I won't even use it very often. You might well ask why I would want one. To which I have to answer: when I strike the final chord of a grand organ toccata, full organ, with the 32-foot down there to fill everything out, you'll know why. Better yet, you'll really feel it in your bones!

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