Experimental wrote: ↑Sun Aug 02, 2020 4:40 pm
Hi Si, thank you for the lengthy response. I agree that single tones are boring, my intention in using them was to get a rough idea of how the ABox reacts with a consistent, repeatable input before I provided it with something more complex.
I emailed your customer services before I made the purchase asking how the output signal is 'mapped' from the input, and was told by Mick that there was no mapping. I stated that my intention was to create an application in order to control the ABox, but with what you've said here, it seems that might be impossible (at least in any meaningful, predictable manner). It would have been nice to have had that information earlier.
You asked about about a number of aspects, from processing to mapping the input to output. The ABox doesn't have any 'mapping' as such as that infers that there is a signal processing relationship to the input and the output. You asked does the ABox 'learn' aspect of the output, again the answer was it does not. You also asked if there would be a difference between a sine wave and a square wave of the same frequency, and the answer given was there should be. The problem with answering a range of questions such as these is there appears to be a number of assumptions. The ABox does not have a signal processor on board, so learning/mapping and such link are all processes that we would associuate with DSP techniques, indeed the 2B does have DSP software on board. The ABox is prediuctable in so much that what it does with a signal today will be the same as what it does with the same signal tomorrow, but systems are highly dependent on aspects out of our control - the subject, electro placement intensities etc etc. In addition the signal produced to generate the sensation is not a sinewave, as a sinewave is highly inefficient in transferring energy and thus sensation.
So the simple answer is we gave you correct information, but given the wiide range of E-Stim sensations possible its impossible for us to cover every eventuality[/quote]
You're right in that I was expecting the ABox to behave like a stereostim device, and the information page for the ABox reinforced that belief. I had considered building my own stereostim, but buying a product designed for the purpose from an established company seemed like a better, safer option, despite the expense.
The questions you asked would not have applied to a classic stereostim device, so it was not clear that was what you where looking for. You didn't ask is this a stereostim box, to which the answer would have been no, but that is not your fault, or ours, we just tried to answer the questions you asked to the best of our ability.
The product page for the ABox says "Select your favourite Stim track, plug in and lie back", so I thought that 'designed' stim tracks would at least be compatible. The files offered here
https://e-stim.info/downloads/audio are exactly that, not music, which again reinforced my belief that the ABox would react appropriately, but it does not. The product page also states that the output is "similar, both in amplitude and frequency [to the audio input]", but this is not true whatsoever - the amplitude of the audio signal is effectively meaningless.
The Amplitude of the audio signal does offer control over the output, that is fundamentally how the ABox works, otherwise all you would feel is a steady output even with no input. Getting the sweet spot where the input is driving the output how you wish is harder, and is very dependent on what levels are set - ie both the input level and the output level - and remember the leds only give an indication of input. Its one of the reasaons we suggest people experiment.
It works with my 'favourite tracks', that does not mean that it will work with all - its a figure of speech. Just because you like a track does not mean that I would, therefor the point is what? Most of the downloaded tracks are not actually single tones either - some are some aren't so that would indicate there is a relationship between the input and output. As to the input and output the answer is yea and no. The output on a scope will not match, the feel will - well in terms of sensation anyway. So higher frequencies will feel different to lower frequencies, higher amplitudes will feel different to lower, but the human body response to frequencies is different to that of the human ear so there is no exact correlation as you might be assuming.
My complaint is not that "the ABox doesn't work with this file", it's that the information in the preceding paragraph, taken from the product page, is completely inaccurate.
There is no detail in the page - its opinion based on our experiences, and that of our customers over time - the ABox has been around since 2006, with many happy users. Put simply the ABox converts sound into sensation, how to qualify the exact effects of that process is impossible when you connect a human up to it. Humans are not pieces of test gear - we vary. What was written is perfectly correct with the undersatanding that every product description in exisitance is based on opinion - otherwise all our cars, based on recent TV adverts) would be setting forests on fire and saving furry animals.
Maybe one of the more experienced users can chime in, but my expectation is that an audio file that produces particular sensations would produce extremely similar sensations at a lower intensity, if the audio volume was lowered. Instead the ABox produces an unrecognisable, unpredictable output. I don't think that is a matter of personal choice or that my expectation is 'different to others'. I would be quite frankly shocked if anybody agrees that my expectation is unusual or unreasonable.
I am an experienced user, I as the first ABox user mainly as I designed it!!. Since intensity is one of the key elements of stimming, it's hard to see how a lower intensity v a higher intensity is not going to give a different sensation. We are not a linear amp, we are complex. As to the output being unrecognisable -I disagree you are comparing two complete different items sound and sensation. I know people who can identify music from the feel of the ABox stimed version, so clearly its not unrecognisable.
I appreciate that you believe that using music as an input is the way that the ABox should be utilised, but if a simple fade out (as in test_mono.mp3 in my previous post) results in a spiking painful output, I'm not going to risk using the ABox with music that has a high variation and dynamic range. Receiving a few random full power pulses as a piece of music that I know well is fading to zero doesn't really sound like my idea of fun, and is absolutely not what I bought the ABox to experience.
The ABox is designed to work with music. The fact it works with some Stim tracks is a bonus, but music is what the ABox was created to work with.
You could always ask support to have a look at the unit, but generally unexpected spikes with audio sources have many causes and are dependent on many factors - electrodes, wires, the subject, the levels being used, the device used to generate the audio, the connections between - all can be a factor.
Your audio file download page even mentions using Audacity to generate specialised tones to drive the unit and that they work "very well", to find out after purchase that I should not be doing so is a little jarring.
Audactity is an option yes, as are many others. Some of the Demo tracks where produced on a KORG synth. but again not every tone or track is going to work for you.
I hope that you can try test_mono.mp3 with an ABox hooked up to an oscilloscope and see if the spikes at 43 seconds occur. I have a feeling from your response (and the previous "50% spike" thread by "Singular", where "Yogi" had the same issue) that if they do, then this behaviour will be considered 'normal'. If so, please post an image of the oscilloscope output so that other potential buyers can make an informed decision on whether or not that is something that they would want, before purchasing the device. If the spikes do not occur, then my ABox must be as faulty as it feels, and I will have to take advantage of the lifetime guarantee and get it repaired/replaced.
You what us to provide you with an oscilloscope trace? really? why? so we can all argue around what is and isn't correct. That is not how we work as a company. As I had said several times before humans are not test instruments, so any trace for 99.99% of people is complete meaningless, confusing and just results in pointless technical discussion which confuses even more people. The ABox has been around since 2006 and has quite a few happy users, so two posts on spiking when there are so many possible causes is not indicative of a defective design. Could it be faulty? possibly. But it is difficult to say without investigation of your unit.
Going back to you last question, the fact the spikes occur at 43 seconds with that specific file would indicate that its the file, not the ABox.... or do all files spike at 43 seconds? Have you tried different locations, levels etc etc? does it always spike at 43 seconds? if you half the file length do the spikes occur at 21ish seconds?
If you feel that you box is spiking them mention it to support and it will be investigated, We are always happy to look into issues, all you need to do it drop support an email and arrange to return the unit.
Si