FLASH Noise Free 4 X 1 Stereo Switcher with Passive Mixing and MIDI from Uptown Technologies
by Jerry Vigil
This month's Test Drive is on a box mentioned in last month's interview. We wanted to know a little more about this thing called "Flash," so we contacted Uptown Technologies and the brightly colored unit arrived within days. What is Flash? As the labeling on the front panel states, Flash is a "Noise Free, 4 X 1 Stereo Switcher with Passive Mixing and MIDI." At first glance, the unit appears to be nothing more than a simple stereo switching device with four stereo inputs and one stereo output, but Flash is far more than just a four-input, one-output stereo routing switcher.
To begin with, this switcher is absolutely noise free. Many signal routers will give you a pop or a click when you switch from one input to another, but Flash makes the transition as smoothly as a digital edit. Added to this noise free switching is a noise floor of -108dB. That's quiet, folks.
Okay. So you have a box that will let you switch between four different stereo sources, but you can also have more than just one of the inputs going to the output. Flash lets you output all four of these inputs simultaneously, or any two stereo pairs, or any three. So, Flash is also a mixer, a passive mixer to be precise. What is a "passive" mixer? Consoles utilize amps and other circuits that are "active," and signals flow through these circuits on their way to the console output. Flash, on the other hand, has no active circuits in line, and the result is a mixer that can claim a noise floor of -108dB. There is no addition of "console" noise when Flash is used as a mixer. Another characteristic of passive mixing is a drop in audio when the inputs are mixed. The 10dB drop in the output level of Flash when used as a mixer is compensated for by simply increasing the level at your console or wherever you end up sending Flash's output. Four trim pots on the front panel let you adjust your inputs for the proper layering of audio, or you can bypass the trims and set levels at the input source.
Mixing or layering audio through a passive mixer such as Flash offers something else. In the world of audio in the nineties expect to hear more and more about psychoacoustics, the study of audio perception. The manual states that mixing two sounds on a standard console gives you a "mixed" sound, while mixing those same two sounds with Flash results in a "merged" sound. This merged sound is a psychoacoustic effect -- it is a perception. If you mix a voice track with some music on a Pacific Recorders ABX console then do the same mix using Flash, you may be hard pressed to tell the difference. On the other hand, if you're mixing two very pure sounds from two very nice synthesizers, a trained ear may well be able to distinguish the difference. We ran the A/B tests doing a console mix of a voice track on R-DAT with music on CD then mixed again using Flash. Just knowing that the Flash mix was supposed to sound "merged" tended to solicit agreement that it did. It definitely sounded clean. Then again, maybe our levels on the Flash mix were just a little different than our levels on the console mix, and the Flash mix simply seemed better for that reason. If someone were to present a mix done with Flash and ask the listener (who has no knowledge how the audio was mixed) what was unusual about the mix, I doubt the individual would say it sounds "merged" rather than "mixed." (Psychoacoustic effects -- What'll they think of next?) Now, when the day comes when we're all producing for digital radio stations, the high fidelity and psychoacoustic effects of Flash's mixing abilities may be a bigger consideration, but for now, if you're just going to take Joe Bob Store Manager and mix his voice over some music for a spot, you can safely perform your mix on a console without worrying about how the audience is going to perceive Joe Bob in relation to the music under him.