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From: "Gregg B"
Subject: [CB] 64' PVC contra clarinet completed
Date: Fri, 07 Jun 2002 23:56:18 -0500
This 20 year-old contrabassomaniac has finally completed his project desire to cause a contrabass clarinet reed to vibrate down to 4 Hz using PVC tubing!!! This is an idea I've had for several years; I just never bothered to go ahead and bite the bullet to spend the bucks and time until now! First, let me list the materials I used, and then I will go into details about the *instrument*. (No, I haven't put any keywork on it--yet; I would need help on that.).
The mouthpiece is a standard Selmer C* BBb contrabass clarinet mpc. I used 1 1/4" PVC for the tubing, and I used 90 degree elbows for the bends. In order to create 180 degree bends, I joined two 90 degree elbows together with a short segment of PVC. The mouthpiece fits perfectly, down to just below the cork, into a 2" segment of PVC, which is inserted into a 45 degree
elbow. The total length of PVC tubing is 64', which creates 128' tone, since it is cylindrical and uses a reed as an oscillator. I have divided the tubing into sixteen 4' segments, with fifteen bends described above. So, I had to purchase eight 10' PVC tubes, thirty 90 degree elbows, and one 45 degree elbow. The total cost was only about $40. I say * only*, because I had anticipated that the project would be too costly to be practical. Some may consider $40 to be impractical for an experiment, but I considered it to be a very low cost compared to my desire to create this experiment. I bought all of this at Home Depot , and I had them cut each of the 10' segments into two 4' segments, with a 2' segment left over. Since I knew I would need fifteen 2" segments to connect the 90 degree elbows, plus one to fit into the 45 degree elbow, I had them cut two of the remaining 2' segments into 24 2" segments. Of course, I only needed 16, but I let them do the extra 8 just in case. Fortunately, the guy who did all this cutting did it ALL for free! He was very kind. They are technically only supposed to provide only a couple or so cuts for free and then charge 25 cents for each cut after that, but he just said he was helping a customer by doing this for me. The 10' segments were able to be cut using the powerful cutting machine, but the 2' segments that were cut into 2" segments had to be cut using a hacksaw, because it was deemed too dangerous to make those small of cuts using the machine. The hacksaw left rough edges, which I sanded with sandpaper.
I fit each of the elbows together with black grease, so that I can take the elbows apart at will to get different frequencies. Here is the layout of the instrument: The first 4' segment goes down from the mouthpiece; the first 180 degree bend goes back; the 2nd 4' segment goes up; the 2nd bend goes right; the 3rd 4' segment goes down; the 3rd bend goes forward; the 4th 4' segment goes up; the 4th bend goes right; and that completes one cycle of construction, which repeats itself 3 times after that. The result looks
like a huge plastic radiator.
The first 4' segment alone approximates bass clarinet tone, and the tone is very full. Adding the 2nd segment produces the lowest concert B of a contrabass clarinet, and I actually think it sounds BETTER than a contrabass clarinet!! Producing tone below this involves a little trick that I discovered, because the contra mouthpiece was not designed to produce tones below this. Ideally, the mouthpiece, reed, and tube diameter should increase as the length does, but this IS just an experiment!! The trick is that I have to put my tongue on the reed, like saxophonists do for sub-tone. No, it doesn't tickle! You would think that this techinique would muffle the tone, but it doesn't at all, as long as I keep the tongue pressure relatively loose so that the reed can still vibrate freely. If I don't use this techinique for 3 segments on, the reed refuses to vibrate the fundamental pitch. Anyway, 4 segments sounds very Contra-Bombarde-like, and is very impressive, in my opinion. Below this, the volume begins to diminish as I add more and more tubes, because the mouthpiece-and-reed setup was not designed with enough amplitude potential for these low frequencies to be heard very well. In other words, the reed really needs to vibrate back and forth at a greater distance of displacement in order to have a truly successful tone. Of course, the narrow diameter of tubing in relation to the increasing length also surely has something to do with this. I tried something in an effort to compensate for this amplitude problem. I took a contra reed and snapped it in the middle, but not enough to detach the halves; just enough that the reed tip could potentially vibrate with a much larger amplitude (displacement). Unfortunately, when I bend the reed tip down away from the mouthpiece facing and then blow (my tongue still has to loosely touch the reed), the amplitude is increased for only a couple of cycles, and the reed then begins to vibrate its normal amplitude. Even so, it is still fairly audible down to 8 segments of PVC, which is half of the entire instrument (32 feet of tubing which equals 8 Hz ). It is really interesting to feel the reed going back and forth that slowly!! The project is successful even down to the last segment of PVC, which causes the reed to vibrate at only 4 Hz !!! By "successful," I mean that the reed DOES in fact vibrate at this frequency, and I can feel it doing so in my mouth. I can hear it a little bit, too, but in order to truly hear it, you
have to put your ear right up to the opening of the last tube, which is technically the bell of the instrument, thought it isn't bell-shaped. The good thing is that this 16th 4' segment goes up, so the opening is at the top of it. The bad thing is that the whole contraption is about 4' wide, so I have no way of putting my own ear up to the end while I play the mouthpiece. The fun thing is that it's all put together with grease, which means that I can have different numbers of segments at will for different notes.
Well, I hope some of you have enjoyed the idea I have presented, and I hope that I might have inspired some of you to do this yourself! It's really easy, and even if you only use 16' of total tubing (four 4' segments), it's worth it to hear that 16 Hz and to feel the reed vibrating that slowly!!! Of course, this actually produces 32' tone even though it's only 16' of tubing. By the way, with my 64' total tubing, if I remove the mouthpiece and buzz my lips like a brass player into where the mouthpiece fits in, the overtones around the tenor and bass octave are still so close together that I can produce whole and even half steps this low!!
If we ever have a big contrabass list get-together, I will certainly bring my PVC instrument to demonstrate all of this!!!
Thanks for reading this,
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Date: Sat, 08 Jun 2002 07:41:16 -0500
From: Jim Quist
Subject: Re: [CB] 64' PVC contra clarinet completed
> If we ever have a big contrabass list get-together, I will certainly bring
> my PVC instrument to demonstrate all of this!!!
Can you post photos and sound clips and send us a URL?
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