It is a toy that is sold by implying that you have not figured out how to set levels when you are recording or use the trim levels in your DAW after you have recorded and want to play back.
I think it's a social experiment that is designed to see how many people lack the self confidence to understand that they already know how to record a track and will part with $5 just because...
It also seems to be a social experiment designed to see how many people will line up to save money by spending $5.
The company states that
"Usually the manufacturer of converters set the +4 dBu (the "sweet spot" and what is usually shown as "0" on VU meters) to -18dBFS after the conversion," They said "usually" so it is close enough to a true statement to seem agreeable even though it is not necessarily accurate.
Then the company says
"so if the meters of your DAW reads -3dbFS while you record, you are actually driving the input stage of your converters to +15VU," Which is so far from true that I'm calling it bull hooey.
VU meters have ballistics which behave entirely different from a Peak Program Meter (hint, the waveform drawings in your DAW are peak program drawings)
The only way to figure out what the VU levels are in the digital domain of your DAW is to use a digital VU meter.
The Hornet product appears to be a digital VU meter but it is important to remember that a VU meter has to be calibrated to something unit to have meaning. As has been suggested, most people in the audio "profession" calibrate 0VU to +4dBU. +4dBU refers to an actual voltage level at the analog input or output: 1.23vAC RMS produced with the steady tone of a, usually 1kHz, sine wave.
Most people in the audio enthusiast category listen to music on systems where 0VU meters, if they still existed on today's enthusiast equipment, would be calibrated to -10dBV which is 0.316vAC. I mention this because the Realtek and other onboard gear in laptops and all purpose desktop sound cards are "music enthusiast" products.
What this means is that any digital "VU" meter you use in your pro audio DAW is meaningless when interfacing with the analog signals in your pro audio studio system unless you have calibrated your DAW's analog inputs and outputs.
In other words, VU meters in DAWs have little to do with anything going on inside the DAW and primarily serve as a reference to the analog connections. Properly calibrated VU meters in a DAW can serve to help maintain consistency with your mix room monitoring and maintain consistency in your digital to analog transfers. You know, like when you are burning a cassette to take out to the car for a listen. ;-)
VU meters that are only referenced to digital dBFS can be useful as crude loudness meters but that is an entirely different context than the stated purpose of preventing analog overload during the recording process.
Now, let us get back to the subject of ballistics. The claim that -3dBFS peaks equals 15VU is ridiculous. VU meters don't read peaks. VU meters ignore peaks. Peaks sneak by VU meters. VU meters are based on a combination of RMS measuring and a sort of latency action and they are meant to more or less compare to how we hear loudness. There is no sensible way to say that -3dBFS peaks equals 15VU when you are referring to actual musical content.
Furthermore, if your analog inputs don't have any VU meters on the analog side then it is near impossible to say that -3dBFS peaks equate to 15VU because you have to have a VU meter on the analog inputs before you have any "units" (that need to be calibrated to something like a dBU or dBV) to measure the volume of.
To summarize, VU meters can be very useful before the DAW to get an idea of what you are sending the DAW. VU meters can be very useful in the DAW to get an idea what you sending to your speakers or your analog tape decks. VU meters can be useful after your DAW to get an idea about the what your sending your speakers and tape decks.
What am I getting at? I am suggesting that people should ask them selves
"why do I care about VU levels in my DAW when I am recording analog to digital?", and then I think people should ask them selves
"was I making really nasty distorted sounding recordings all the this time?" You see, Hornets premise that
"Every A/D converter from the cheapest one to the most expensive has an analog front-end before the actual conversion takes place. Since analog must obey to the law of physics there is just a certain amount of current that you can pass without having distortion in the signal. Usually the manufacturer of converters set the +4 dBu (the "sweet spot" and what is usually shown as "0" on VU meters) to -18dBFS after the conversion, so if the meters of your DAW reads -3dbFS while you record, you are actually driving the input stage of your converters to +15VU, that is A LOT of current flowing through your electronics." Is based on two fallacies. First they imply that the sweet spot is at +4dBU when in practice the sweet spot is a wide, and practical range of voltage levels, (which in the case of "enthusiast" grade gear is no where near +4dBU) and second they speak of concerns about
"a lot of current" while referencing a system based on voltage levels. Yes, voltage and current is related but ADC systems measure voltage not current and you can rest assured that they can handle adequate voltage or your recording would sound gnarly and nasty.
Do your recordings sound gnarly and nasty? Be honest!
The Realtek in you laptop may only be able to see +8dBU before it get's overloaded (and that is fine because they are actually calibrated to -10dBV rather than +4dBU) while the ADC in your music store gear I/O box may be able to see up to +24dBU before it gets gnarly. It wouldn't hurt to find out by making some tests, but you can just figure it out by ear too.
Rest assured, if it get's gnarly and nasty you are going to notice it. If it get's nasty and gnarly you know what to do; turn something down.
You don't need to spend $5 on scareware to figure out if you have not figured out how to set your recording levels especially when it's 99% percent likely that you already know exactly when you have or have not set your recording levels correctly.
Finally, the auto gain function on the playback feature may seem useful to some people.
OK, I'll try to be gentle; If you can not look at you waveform or the meter that is already in your DAW and figure out that you shouldn't blast the next stage into the "red" then maybe you do need an auto gain feature. Just remember, you can not actually blow out anything that has been recorded below 0dBFS unless you turn it up so it tries to go OVER 0dBFS. Don't do that. Done.
The only thing an autogain function is going to do is fix some glaringly obvious mistake you have just made. Imagine how easy it is to just notice your mistake and fix it with the controls that you already have. In other words you can only hit 0dBFS overs in your effects dsp if you misuse the gain level your DAW after the content has been digitized. You don't need autogain unless you routinely turn stuff up without knowing what you are doing. We all do it now and then but very few of us do it over, and over, and over again without figuring out how not too. Don't settle for being one of the few... figure it out.
There I said it. :-S
wishing everyone...
all the best,
mike