I feel I have gained the ninth dan on my black belt of geek-dom. I now have a working laser harp. The final parts arrived from Croatia last week, and to be honest, this is the clever bit of the harp that makes it all work. I haven’t built a laser harp, merely assembled components, a bit like when you build a PC.
The laser, I have covered before is a 400mw, 532nm with beam 3mm wide. This was sourced from a company in Germany. The brains of the outfit is the laser harp controller which came from a company in Croatia called Prolight. This does all he clever stuff including controlling the laser’s beam into a number of ‘strings’, and sensing when a beam has been broken. It then sends a message via midi to any compatible device.
So far I’m triggering sounds on a Roland D10 from the mid 1980’s, but I have decided that a piece of software called ‘Sample Tank’ will form the voice for my harp.
The next stage is to map all the notes I require for each piece to Sample Tank so I can load up the correct patch with just a few clicks. There are a few issues in getting the harp and Sample Tank to talk to each other, but it should be reasonably easy to fix this. I’d also like to run Sample Tank from my net book which seems to have developed a problem with its sound card which is another thing to fix.
I’ve also attched a pedal for quick selection of midi banks and discoverd that some sort of dispersant (like that produced by a smoke machine) is essential to make the harp respond.
Here’s a video of the harp in Alpha testing from a few nights ago.
This is a recording of the Sonata Pian e Forte by Giovanni Gabrieli as played by Eltham Brass, students at Eltham College in London. It was made in one take to conform with the GCSE requirements.
enjoy…
Laser Harp
So I’ve decided to build my own laser harp. I thought I’d blog a bit about it to share what I’ve found out so far.
You may have seen the laser harp at a Jean Michel Jarre concert as far back as 1986 although the great man was actually using one a few years before this and I have heard stories of instruments dating back to the 1970’s.
The instrument usually consists of a number of beams which emanate from the stage floor and continue into infinity (or the venue ceiling, which ever comes first). The beams are usually produced by one laser which splits into a dozen or so beams or strings. The performer simply places his or her hand over a beam which then triggers a midi note on a nearby synth.
Its quite a cumbersome way of producing sound, with limited pitches available, a polyphony of just two notes (unless you have more hands available), and with no expression, except for the very latest instruments which can control modulation.
Still, undetered I have set about the project.
My plan was to first source a laser which has been far from easy. A regular laser that you find in your DVD player or even a laser pointer you may use in presentation at work is simply not powerful enough to produce a strong enough beam. I had to find a class 3 laser which is the least powerful that can be used and the basis of most laser harps. I quickly found out that 300mw was the very least that is needed, but that also the choice of colour is also of great importance.
Lasers come in different colours and are named after the wavelength of the light they produce. From around 405nm (like the ones found in blu ray players) which are blue to 650mn which show red, the best that the human eye is suited to is 532nm which show green. Sadly, and I guess for this reason, these are also the most expensive.
The next problem is controlling the laser. The beams needs to be split into 8, 9. 10 or 12 strings, one for each note. There appear to be two protocols for controlling lasers, DMX512 and ILDA (International Laser Display Association). Cautious as I am I opted for one that had both.
So, just arrived from Germany is my new 400mw, 532nm IDLA and DMX compatible laser. Yay!
It produces a really strong beam which I’m very happy with although it looks like I’m going to need some sort of dispersant to get a really good machine. This brings me on to the subject of Rayleigh Scattering and fog machines versus hazers, but that is for another day.
I also need an analogue to digital converter and some software to control the beam which is the next step, but for now I’ll leave you with some patterns which are built in to my laser which I’ll upload to this site.
more to follow…
This is an unreleased version of ‘Place Your Hands’ recorded by ‘WonderBrass’ back in summer 2010. WonderBrass is the brass group of the James Allen’s Girls School in Dulwich. The group made a studio CD entitled ‘Out Of Sorts’, which is available on iTunes and this track was from a suggested sister project which never happened, ‘Sort Of Live’. The track was written and originally performed by Reef.
