Posted: 9/13/2013 6:05:11 PM

From: Italy

Joined: 9/12/2013

Wow Christopher, really interesting! I'm not skilled with do it yourself tutorials... However the sound is really close to what I was thinking about!

Thank you so much for the idea, I'll ask a friend of mine an helping hand and see if he can build it...

Have a nice evening!

Posted: 9/14/2013 1:59:17 AM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

Homemade Cello Sound   

That is, to my ears, a REALLY lovely sound!

But - To me, it doesnt sound so much like a Cello - it sounds more like vocals, complete with (almost) the correct vocal formants... Not saying it doesnt sound like a Cello - but to me it sounds MORE like a human voice.

If this is just a straight theremin played into a rubber bucket, with no effects between theremin and bucket, then it gets a big WOW ! from me... If its a theremin playing via a TM or some other processor and then into a bucket, well its still nice - but not quite so spectacular....

"my not very helpful opinion is that if you want something that sounds like a cello, you can't beat a cello." - GordonC

I share this opinion.. But I do think that the theremin is better suited to controlling the synthesising of violins, cellos, voice and other instruments which are not fixed to musical intervals (are free to move / glide between notes) than most other electronic musical instruments / controllers.


Actually - that sample doesnt sound at all like a Cello IMO!  ;-)

Posted: 9/14/2013 4:24:39 PM

From: Brooklyn,NY

Joined: 12/1/2009

Christopher- I love the sound of your 'Talking Bucket'   Very cool.

What size rubber pail are you using? With a  lid?  You should post some images.   I imagine a lot  of players/ builder will want to build this. I do.


While on the topic of effects, I just want to mention...

A few months ago I picked up a Deluxe Memory Boy (analog delay) by EH.    I  had been invited to perform 'soundtracks' for a bunch of art performances and I needed something to add a bit more psychedelia to my toolbox.  Pleased to say the DMB does thatvery well, and so much more.  In addition to far/ out trippy, this pedal can also dialed down to add some subtle reverb and chorus-type depth for more traditional playing.  

I initially tried the cheaper memory boy.  It has the same basic functions but without as many tunable parameters/ knobs.   I found this pedal alright, but with tap tempo and the ability to add an expression pedal which can control delay, feedback, modulation rate and  depth - the Deluxe is way more useful.  I also found that the Memory boy I tried seemed to lose much of the highend frequencies in the repeats.  Probably not noticeable with a guitar, but not ideal for my theremin.  My deluxe seems to have a much fuller range.

 Pros and those with significant means may want to opt for the Deluxe Memory Man w/ tap tempo.  It uses the same rare/ nos BBD chips found in the classic and much adored Memory Man's- reputed to have  brighter /cleaner repeats vs the slightly darker /murky sound of the memory Boy BBD's.  


Posted: 9/14/2013 6:47:14 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

I have had a look at the spectrum for the Cello Sound  and there are a number of destinct resonant points that fall within the human vocal formant spectrum - most noticable of these are  584Hz@-10db, 815Hz@-17db, 1086Hz@-9db, 1358Hz@-32db. These were the most significant I could identify.

Because the pitch is not constant at any point, it is difficult to be sure of the analysis - These resonant points appear to vary somewhat as the fundamental frequency varies, but I suspect this is an analysis anomaly (it may also be due to distortion effects on the rubber bucket) .. Also, not knowing the excitation waveform charactaristics, it is not possible to where what I am looking at is coming from.

IF there is no pre (or post) processing on the signal, then I suspect that the bucket is "simply" acting as a complex acoustic filter with resonant peaks and spectral distortion giving the lovely vocal effect.

Placing transducers on something like a guitar, in order to modify sound and impart qualities of an acoustic instrument, used to be done quite regularly in studios, in the good old days (pre 1980 I worked in a studio where I was regularly asked to fit transducers to various acoustic instruments for this purpose)  But using a rubber bucket to simulate vocal formants? - Never heard of that being done!

I much prefer this vocal sound to anything I have heard from the TM (or for that matter, any of my analogue formant filters).

Congratulations, Christopher!


Posted: 9/14/2013 9:20:30 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

I find electronic enhancement to be much "easier to control" where by using acoustics you are constrained in how nature wants to behave. It can be very frustrating." - Christopher in this thread

My comments on this thread were because I really liked the sound..  Yes - it would obviously be far more convienient if THAT sound came direct from a theremin or electronic effects unit..

But it didnt! You say it came from a rubber bucket!  ... With this bucket you have managed to create a (IMO) vocal sound which is better than the vocal sounds I have been able to produce using analogue circuitry, and IMO mor pleasant (probably because of the imprecision) than vocal sounds I have heard from the TM or other digital formant filters / modifiers.

IMO, many electronically produced sounds are enhanced by some form of acoustic resonator -

But I have never heard any simple resonator impart such rich vocal qualities (the only resonators I have heard that do this were some experimental resonators at medical school, which were anatomically correct duplicates of the human vocal system - and that was more than 30 years ago, so I really cannot remember how the sounds compare ;-)

Dont be like me! - You have something which sounds amazing - dont go off and try to modify this.. or at least, not until you have photographed it, filmed it, documented it and fully recorded it... Its up to you whether you choose to publish this so that others can benefit..

But I hope that you do!  I do not see "constrained in how nature wants to behave" as a bad thing if one wants something to sound "natural" ... If one wants to create "unnatural" sounds from electronic signals, this is EASY! .. The real challenge is, and always will be, to create the same "constraints" for electronic signals as nature does - And this can be incredibly difficult and complex, because these "constraints" are incredibly complex..

Sure, its a pain having to use a bucket rather than a small circuit board - but, right now, IMO, there is no circuit which produces the sound you have produced.. Or certainly nothing simple or low cost.


ps.. With analogue electronic formant filters, one needs a 'drive' signal containing the required harmonics, and subtractive synthesis is the primary mode of operation - one is also limited by practical matters such as complexity and cost.. a few formants (perhaps 4 for a fixed formant filter down to 2 for a variable formant filter) is all that can be easily implemented. With digital FF's the iput signal can be dynamically modified to apply / create harmonics and formants..

But I suspect that the signal into the bucket was not particularly rich harmonically - that the resonant properties of the bucket allows formant frequencies to be created even when these are not present in the input signal.. I suspect that if you  tap the bucket with a soft mallet, these frequencies will appear..

And I suspect that this allows a harmonically 'soft' signal to be mixed with the bucket resonances, giving that smooth sound and producing the extremely complex and frequency dependent waveform we see on the sample.. The closest I have seen to this is when audio is used to modulate the VFO in a theremin via acoustic coupling.



I have listened to the other samples in this thread , but alas, IMO,  they do not have the vocal qualities of the sample Cello Sound.. those samples sound much more like what I would expect from a theremin played (without any other processing) into a rubber bucket! .. There are some occurences of harmonics at formant frequencies, but the waveform is far less complex, and does not change as dynamically with frequency as the astounding sample presented in this thread does. Also, whilst there are occasional frequencies / harmonics which sound and can be seen to be 'formant like', the quantity and distribution of these does not come close to the sample presented in this thread.

Was a TM or other processor used in the setup that produced the sample presented in this thread? If it was, this is still useful - it sounds much better IMO than raw TM.

Posted: 9/19/2013 8:50:43 PM

From: Italy

Joined: 9/12/2013

So... just to update the topic and recalling that I'm not able in "do it yourself stuff", I've tested a talking machine with my etherwave theremin and I liked so much! I agree with somebody in the forum I've read in other topics that says the effect "pavarotti in a box" should be avoided... so I will not overuse this effect.

Just wondering what happens with a little bit of overdrive-reverb-flanger.

Does anyone have tested the Electro Harmonix Electric Mistress, the Little Big Muff PI or the memory toy?

Thank to everybody for the help!

P.s: I'm really enjoying this forum! I've found so many interesting topics!

Posted: 9/20/2013 12:44:15 AM

From: Brooklyn,NY

Joined: 12/1/2009

Flanger and distortion dont sound too great with theremin, in my opinion... but try them out, you may disagree.   memory toy is a cheaper memory boy with less options(see my comments above)

Posted: 10/23/2013 8:05:34 AM

Joined: 10/23/2013

RS Theremin has posted a few times on other experiments on physical acoustic sound shaping, but still hasn't posted even a photo of the "rubber bucket" apparatus used to produce the Cello Sound clip in this topic.

RS, is there any chance you'll ever clue us in? You were definitely generous enough to post lots of other photos in the other thread, so hopefully this will be a piece of cake.

I'm sure I'm not the only one looking forward to the final unveiling! Cheers!

Posted: 10/23/2013 2:48:15 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Hello Explorer,

I agree there are some strong voices around here but at the end of the day I am sure we could all sit down and have a beer together, if not something to smoke. (-'

Why this post and link disappeared from this thread is beyond me. I am also the most moody!  LOL

My experimenting showed that placing the acoustic effect on a stereo channel and the original sound on the other has some interesting possibilities for fading to right and left channels during a performance. This could be done by playing higher or lower on the Pitch antenna. A third volume control like electrode could be at the base of the Pitch antenna. This approach is subtle enough not interfere with normal theremin performing.

EtherWave Standard = Sound Sample.m3         Natural Acoustic Effects  webpage


Posted: 10/23/2013 7:35:07 PM

Joined: 10/23/2013


I like your use of the Dayton Sound Exciter as a speaker coil to drive a surface/object, and the transducer to then pick up the signal on the other end. I hadn't known that Dayton was making one which ran on batteries, as your QEX19 does. 

So, just a standard

To note a device with similar formants which approach the human voice, I've always liked the Daxophone.

It's a length of wood, clamped at one end to a block containing a transducer pickup, and fretted/"fingered"/stopped by a curved block of wood with either a smooth surface or frets while being bowed at the free end. It has an extremely vocal quality to its sound. More information can be found at http://daxophone.com/ .

It's interesting to see you working with the pieces of wood, and to hear that same quality arising.

I imagine one of the easiest ways of doing this in a portable way would be to install such a clamped board in a sound-dampening box. One would run the Theremin output through one channel of those $20 amps on Amazon, using one of those Dayton 2-for-$20 drivers which have no amp, but instead wires up like a standard speaker, and then run the transducer output through a volume control and then the other channel of the amp and a full-range speaker. That second volume control would allow you to turn down only the final volume without having to fiddle with the output of the Theremin or the amp channel feeding the board/resonator once you have the perfect levels for each.

Maybe even easier would be to use the driver in the middle of a board clamped around the edges, like a big wooden speaker, with a transducer mounted between the driver and the edge. That might be more stable if one were gigging the piece. There's not even a strong reason to use wood, so one could do all kinds of acrylic/plexi/aluminum/etc. experiments.

Neat idea!

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