Double Bass Laser Interferometer pickup?

[Matthew Tucker]

Does anyone here know whether anyone has had any success in using lasers as a basis for a musical instrument pickup?

I would have thought that a small laser interferometer would be able to detect the slightest movements in a soundboard and turn that into very pure audio signals. But I can't find any reference to it on the WWW.

 

[Bob Branstetter]

Does anyone here know whether anyone has had any success in using lasers as a basis for a musical instrument pickup?

I would have thought that a small laser interferometer would be able to detect the slightest movements in a soundboard and turn that into very pure audio signals. But I can't find any reference to it on the WWW.

Marty Paglione talked about this and other technical subjects on a Invalid Link Removed. He is of the opinion that laser and optical pickups are years away because musical instrument pickup companies must wait for the technology to trickle down from the military or telecomunication companies since no musical company has the resources or market potential to do the research on thier own. He says it will be 5 to 10 years at the earliest before we will see anything like lasers or optical pickups for sale to the end user. The podcast is well worth listening to just for good practical information about pickups and mics.

 

[drurb]

Does anyone here know whether anyone has had any success in using lasers as a basis for a musical instrument pickup?

I would have thought that a small laser interferometer would be able to detect the slightest movements in a soundboard and turn that into very pure audio signals. But I can't find any reference to it on the WWW.

The ones currently available are reported to be too "hot-sounding."

 

[Touch]

Ron Hoag has the original patent on an optical pickup. He did this in the late 60's.

Invalid Link Removed

These folks have been offering one for some time. Not clear if their technology is different than Ron's.

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I believe that both of these techniques use a cheapo red or infrared LED and a basic silicon detector. The string is in the light path. When the string is plucked it will move back and forth to create a time-varying signal. Add an opamp and you've got a pickup.

 

[fdeck]

No drilling required.

Amusingly, I work with Fourier Transform Infrared spectrometers, which are based on a laser interferometer. One learns the hard way that an inadequate mechanical design turns it into a very expensive acoustical transducer!

 

[Matthew Tucker]

interesting. Both the above systems were using an interrupted light beam across the strings. I was thinking about interferometry picking up movement of the soundboard.

I suppose there'd be the problem of keeping the laser fixed in relation to the soundboard. Perhaps such a system could be installed INSIDE the top, measuring movement between the back and soundboard?

 

[Jazzin']

Seems like the ultimate pickup for any electric or semi-electric stringed instrument.

 

[Bob Branstetter]

I suppose there'd be the problem of keeping the laser fixed in relation to the soundboard. Perhaps such a system could be installed INSIDE the top, measuring movement between the back and soundboard?

An interesting idea, but I think it would suffer the same problem that all current pickups face. The body and cavity vibration modes are very complex and occur at many different locations within the instrument at the same same time. Any pickup that "sees" or "hears" only one spot or one small area will only reproduce the vibrations that occur at that one particular spot and can not possibly accurately represent the vibrations of the whole. You can get an idea of just how complex the vibration patterns and locations are by looking at some of the Chladni mode patterns shown in this article. (I picked this site because it is from a University in your part of the world )

 

[seamonkey]

Interesting topic.
There's another slant on this. Using essentially a pickup that only gets the strings.

Singers have been using reverbs for ages to simulate rooms and chambers. Well the bass body is a chamber. With walls that resonate. There's been a lot of work going on lately with convolution reverb. It takes an impulse response, which may be several sweeps of a space, then lets you send any signal through it, convolve it, to recreate the original space.

Fishman has a line of new convolution pedals. I'm hoping to see more products in this area.

Sure - it's one of those technology points that gets a comment like "It'll never sound the same as just a good mic". I don't know, it will probably sound better than any raw pickup with going raw to an amp.

 

[Randy Ward]

The laser pickup idea reminds me of an interview where Mingus was describing what a bass pickup would be like in the future. About something being able to sense the whole bass.

Just to sidestep the laser PU for a moment (which is Very intriguing)

Interesting topic.
There's another slant on this. Using essentially a pickup that only gets the strings.

Singers have been using reverbs for ages to simulate rooms and chambers. Well the bass body is a chamber. With walls that resonate. There's been a lot of work going on lately with convolution reverb. It takes an impulse response, which may be several sweeps of a space, then lets you send any signal through it, convolve it, to recreate the original space.

Fishman has a line of new convolution pedals. I'm hoping to see more products in this area.

Sure - it's one of those technology points that gets a comment like "It'll never sound the same as just a good mic". I don't know, it will probably sound better than any raw pickup with going raw to an amp.

Seamonkey

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http://www.acousticfingerstyle.com/FishmanAuraPedals.htm

Are these like a modeling device?
Like the LINE 6 and Roland stuff or is it something new?
I couldn't anything very technical on what it does.

 

[seamonkey]

Are these like a modeling device?
Like the LINE 6 and Roland stuff or is it something new?
I couldn't anything very technical on what it does.

They are little embedded single space convolution processors. aka "Convolution reverbs"
http://en.wikipedia.org/wiki/Convolution_reverb

Software convolution reverbs are very popular and you can find sites filled with "Impulse Responses" of rooms, spaces, instruments that you can load into them.

Fishman has done a good job in making the technology practical.

 

[Randy Ward]

Fishman has done a good job in making the technology practical.

Thanks for the link.
Starting to understand
So is it thought that they (Fishman) will apply this technology to a 'pedal' for double bass? Maybe several like they did with guitar pedal.
CARVED
HYBRID
PLYWOOD
ALUMINUM
FIBERGLASS

 

[seamonkey]

My fingers are crossed for a Reso-phonic pedal.

By the time these pedals gets to bass, I bet they have several bodies in the same pedal.

Here's another example of just software:
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They actually created the sample library using a body-less violin and convolution of real violin bodies.
You can play your cheap violin through it to get a good violin sound:
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Garritan Stadivari also uses convolution.

I expect eventually that just any cheap pickup will be working fine for bass. Even a LED laser shining by the strings. The bass bodies derived through convolution. This would include your own favorite bass by creating an impulse from a mic, in an ideal room. Then for live use a pickup to recreate the natural sound through convolution.

 

[Randy Ward]

You can play your cheap violin through it to get a good violin sound:
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QUOTE]
Thanks seamonky;
I sent the live violin link to an electric violinist I work with and she is fairly speechless:
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And will probably look to it.

Is the Garritan Stadivari a sampled library?
http://emusician.com/libraries/emusic_garritan_stradivari_solo_violin/

I am sure the convolution stuff has been covered somewhere on TB but I couldn't find it.

Although I think I am a traditionalist more or less I find this technology fascinating. I would see it as a problem solver for loud live stuff. Probably like everyone I feel like if I can get an amplified sound that is natural live it is easier to play what I hear and want.

Just a side note:
I played electric bass for a short while with Delmar Brown.
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He wanted me to play six string bass but wanted it to sound like 'an old fender' . Harder than it sounds. the only thing that finally worked was the Roland V-Bass thing which is a modeler.