Thread: Frequencies used by Gemmy 6 channel light show / color organ hacks / tone generation

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Still considering picking up a holiday Gemmy 6 channel light show box--the one that accepts MP3 input. If I create a stereo track with Audacity or some other software, I'm hoping I could split the stereo track, sending control tones to the LEFT side (and route that into the Gemmy) and actual music to the RIGHT side (plugged into an FM transmitter).

I'm guessing a Singing Pumpkin Choir could be put together on the cheap this way. Anyone have specs for the Gemmy? Been searching and haven't found yet found a hack that describes what frequencies to use to activate each of the 6 channels. Also wondering if the gain of each tone matters and how much control you can get over the Gemmy when creating your own "control only" tones track.

I know some will say buy a Light-o-Rama. But I prefer doing effects as inexpensively as possible. Not positive I'd use it for a Singing Pumpkin Choir. But would love to sync lights with music / audio on the cheap.

Also wondering, does the Gemmy respond to changes in volume, e.g. can volume act as a fader? I'm assuming yes because people use them as lightning machines. If so, the unit should be programmable via some sort of physical or soft synthesizer with the left audio track being the tone coding that gets routed to the Gemmy. And the right audio (mono) track being music that can be routed to an FM transmitter. Does this seem plausible? If it's truly a color organ, then this should work, shouldn't it? Unless there's some other circuitry doing something beyond what a plain old color organ does.

Found this one:


And here is an interesting discussion about the unit. Adding it here to "save for later" / for reference:
http://forums.planetchristmas.com/in...s/page__st__60

Still can't find any discussion whatever of programming your own control channel with a synthesizer. I've been looking for a good excuse to buy a virtual analog synthesizer; so this could be a good pairing. Seems bizarre to me that with all the creative Halloween folk out there, no one has already done this--or written about it online. Pretty simple concept assuming the Gemmy behaves as a real-time color organ. I get a kick out of achieving effects in the least expensive way possible so LOR is out for now. Don't really need a hardware synthesizer. I'm sure there are many soft synths or "trackers" out there that would enable be to create a control track synced to music. Hope someone beats me to it. :-)

Just ordered the Gemmy holiday light and sound unit from Front Gate. Hoping to use a free tracker / soft synth to figure out what frequencies its color organ responds to. Thinking also that this puppy could be used as a Pepper's Ghost fader if it also responds to volume. Somewhere on the forums I asked about the cheapest way to automate fading for either a Pepper's Ghost or some sort of scrim effect. The Gemmy may be able to serve that purpose as well. Lots of possibilities for only $50 (on sale).

I'm thinking it might be possible to duplicate the effect in the Haunted Mansion where the portraits change in response to lightning flashes. The portraits seem to use clear fluorescent paint, turning a portrait of a lady into Medusa during flashes of what must be black light. Wouldn't work with actual tube lights due to the delay in turning on. But what about filling all 6 outlets with the largest incandescent black light bulbs one can find?

Now that I've ordered the Gemmy holiday light show and timer, I'm brainstorming all the ways it could be used for both Halloween and Christmas. *If* I can generate my own frequencies / control track and the color organ works well in real-time.

Would wrapping some sort of "purple" filter gel around a regular light also create more black light?

Would love to see what you come up with.I ordered one from fg to got it in last week.It's still in the box.For the price that light show looks great.I am wanting to duel purpose mine to but I really bought it for Christmas.

I've used the Gemmy Light Show for Christmas the past three years and I love it. I don't know anything about the frequency response of the different channels, though.
I'm using my own music piped thru it for the first time this year and it's working great!
The two best recommendations I can make (when using your own songs) is to use Audacity to convert the songs to MONO.
And also burn them to a CD and play them on a CD Boom-box into the Gemmy instead of using an MP3 player.

Thanks H71 and Dave. Will let you know what I come up with.

Originally Posted by mikeerdas

Would wrapping some sort of "purple" filter gel around a regular light also create more black light?

While I can't comment on the Gemmy Light Show. Regarding this specific question: I can say, that for the most part the answer is no. It requires further explanation, as it actually can be done with a light that produces lots of short wave light emission. eg: specific types florescent's, denoted by gaseous content and specific phosphorescent coatings. Also, certain HID lighting types, like Metal Halide, & Mercury Vapor. The latter 2 being quite expensive, and still to factor in that they need have output peaks in at least the middle/upper UV range to be effective. 350-370 nm is the prefered range. Although, up to 450 nm will produce a bit of the UV reactive "glow".


There are two distinctive different types of filters that allow ultraviolet light to pass. The oldest (original), known as Wood's Glass, is not a recommended material except in certain circumstances any longer due to several factors. First, is that it's very, very fragile. Especially where thermal shock/expansion occurs rapidly (read: when the light is switched on). Secondly, it's not very durable against mechanical shocks either. Finally, the last reason is that it's rather prone to a funky type of oxidization with any exposure to humidity/moisture, or CO2.

Even if the above factors are negated, the final nail in the coffin (so to speak), is that with prolonged exposure to UV...it will gradually lose it's transparency to light in the UV spectrum. Hence, it's pretty rare & expensive. Not just from a consumer standpoint, but from a manufacturing one as well. Osram & Phillips still produce these bulb, but they're mostly targeted at the medical & nightclub customer bases. Wildfire's high end lamps use these types of bulbs.


Next, there are UV/Excimer dichroic filters. Available as an enamel coating to commercial sources, I've not seen any available to consumers. Which doesn't necessarily mean it can't be acquired. I've just never seen it, is all. This is what is commonly used for "black lights". The downside of this particular type is that it passes much more of the visible spectrum of light than Wood's Glass. Well into the 550 nm & up, wavelength.


Just as a base of reference, the human eye can detect down to about 390 nm wavelength light. Anything below that, is what we'd prefer. Best thing is to have as a center frequency of approximately 350 nm for a true "black light" effect, even accounting for harmonics/subharmonics.

Long story short: It's a serious pain to delve into, and you are much better off just purchasing UV florescent, or cold cathode bulbs. Instead of trying to modify existing ones.

Originally Posted by DaveintheGrave

I've used the Gemmy Light Show for Christmas the past three years and I love it. I don't know anything about the frequency response of the different channels, though.
I'm using my own music piped thru it for the first time this year and it's working great!
The two best recommendations I can make (when using your own songs) is to use Audacity to convert the songs to MONO.
And also burn them to a CD and play them on a CD Boom-box into the Gemmy instead of using an MP3 player.

So the mp3 issue still exsist from when I bought it the first year it was out?It acted like it had a short in it.