JChenault
Well-Known Member
I am evaluating the Altman Spectra Cube for a houselight application. Thought it might be interesting to post my observations.
For my application I am planning to use just the 3000K white. What was provided was a RBGA unit.
The physical unit.
- The unit is a 50 watt LED package. 24 LEDs in the head . An attractive compact package.
- No fans at all ( a huge plus in my book)
- There is an accessory holder that they use to put in various diffusion materials. The test unit came with a directional frost to somewhat emulate a PAR oval beam.
- The unit has in and out connections for both data ( 5 pin ) and power ( powercon ) so you can daisy chain easily.
- The yoke is the more or less standard for this class of fixture – IE a split yoke that you can separate if you want to simply place the unit on the floor – or you move them together to put a c-clamp on.
- The fixture seems sturdy case is either steel or aluminum with what appears to be a powder coat. The hole in the yoke for the yoke bolt looks like it will easily take a 1/2 inch bolt.
There are a couple of problems (IMHO) with the packaging however.
- Although the accessory slot looks like any old 6.25 inch accessory would work – it does not. You need an accessory sized for 5 5/8 inch to fit.
- The method for setting modes / personalities and for setting the DMX values is the most arcane and unintuitive that I have ever seen. Read the instructions carefully and don’t lose them.
Dimming modes / personalities.
- The unit will work in 8 or 16 bit modes.
- You can choose to have an intensity channel, or just manipulate the colors directly.
- You can choose to have ‘smoothing’ enabled.
8 bit mode / with intensity channel / no smoothing.
- At the low end, the LED’s fire at a DMX level of about 16. When they fire they are at a very low intensity so there is n0 annoying pop on at the beginning.
- There is a noticeable jitter with any fade slower than 2 or 3 seconds ( for full to off). I would not want to use these on ( say) a cyc with a slow fade or color change where that was all that was happening.
- The response time from dark to full ( IE 0 to 10 in a 0 count) was immediate. IE you could use this as a strobe replacement if you are willing to program the cue into your console.
8 bit mode / intensity channel / smoothing on.
- The jitter was slightly better. It was still there from about 10% to 35%, but not as strongly.
- LEDs switched on at about 16 DMX.
- The response time from dark to full is very fast – almost immediate. I could not use this as a strobe, but it would be fine for lightning.
In both 8 bit modes, the start of the fade down seemed a bit uneven. IE I would start the fade, and I did not see a change for about a tenth of a second, and then it jumped down and started moving.
16 bit mode – no smoothing.
- Fade ups were very smooth just as you would expect. There was just a faint hint of a jitter – but I think that was only because I was looking for it.
- The LED’s started firing earlier, around 54 ( from 0 to 65535 )
- Fade down was also smooth, but after the fixture faded out, there was a flash. IE just before the LED went out, they flashed at a low, but noticeable level. In my test unit this occurred on a fade from full to our in 3 seconds or more.
- The fade up on a 0 count seemed instantaneous to my eye. IE fast enough for a strobe.
16 bit mode – smoothing. ( this was the sweet spot for the unit)
- The fades up and down were flat our smooth. I saw no jitter.
- There was no flash on a slow fade.
- A 0 count cue took about .3 seconds to come up. Not fast enough for a strobe effect.
In summary – a very nice unit if you are are willing to run in 16 bit mode with smoothing. I don’t know if the flash on slow fade outs is a defect in my test unit, or a problem with all of them – but for what I am doing it does not matter. The addressing issues, and the accessory size are going to be a real pain the rear end – but for an inexpensive unit (~746 USD street), it is (IMHO) quite good.
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