Tag: Engineering

Monitor Mixer Controller Foot Pedal

Often times it would be nice to adjust the monitor mix on the fly… but alas, the monitor engineer can’t read minds, and I’ve never seen a on stage talkback microphone just to the monitor engineer. Of course a talkback mic isn’t much help if one is a vocalist either. The end result, levels are pretty much static during an entire song. The only exception being if one works out some type of hand signals with the monitor engineer.

In my situation… I dont have a monitor engineer, and often times its a challenge enough to handle page turns, much less run over to the monitor console to adjust the mix.

One concept… a foot pedal controller to adjust monitor levels.

Some features:

  • foot pedals to increment or decrement individual channel levels
  • highlighted LED bars with user customizable overlays indicate to the user which channel is being adjusted
  • a middle foot pedal which serves to select the appropriate channel to adjust
  • no master volume control on the pedal board, as that is set once at the main amplifier… ideally only individual levels would need tweaking. I may need to rethink this a bit. (its only a software and overlay mod)
  • output is digital only… in keeping with minimally invasive audio, I want to keep multiple audio signals off the stage floor as much as possible. (likely the data will be midi sysex messages to control a midi mixer)
  • a LED bargraph meter to provide feedback as to current level setting

Comments invited

Egads, I need a Monitor Mix

I’ve returned to live performance, albeit on a very small scale. Its been interesting to note how quickly most of the skills came back… but sadly hearing is not one of them. I fully believe hearing issue is not so much the loud music of my younger days, as much as it was a kazillion hours of roaring aircraft engines.

To add insult to injury, the church I play at logistically stacks the deck against me in a huge way. It has a very powerful HVAC system, which seems to reverberate off of the projection screen creating an area of massive standing waves… right where I am located. The end result, while I can hear the low frequencies just fine, ie my bass, other must-hear sounds like the vocalists, and the keyboard are pretty much buried whenever the HVAC system comes on.

Granted, years ago, this would have been just a minor annoyance. Many times back then I ended up in positions, where I could only hear myself and the drummer, and due to a much higher skill level it was no big deal. Well… add in rust, and what once was just annoying, is now frustrating.

So, the solution… easy, just add an extra wedge, and feed the vocal and keyboard mix back to my location. However, like 99% of church gigs, there is no rack of splitters for FOH/monitor mixers, nor a splitter snake, nor is there even a monitor send on the PA, much less any amps/wedges. Thus, what might be a simple deal in a concert setup becomes significantly more difficult where I am currently planted. Obvious super simple solutions like changing my position, and or turning off the HVAC system during services are not very realistic. Its the same deal with spending $2000 for an off the shelf solution (I dont have $100 to spare, much less $2000), to say nothing of the possible integration problems with the existing system.

Being similar issues plagued me years ago, in venues ranging from churches to dance halls… there does seem a need for simple, lost cost, minimally invasive monitoring system. Stay tuned for more.

Pushing the Fader is like Rubbing a Gumby on Concrete

A funny comment as concerns the pot feel on an Alesis 1622… having played with one years ago, yep, that about sums it up too. Sadly, if Alesis had wanted to, they probably could have had premium feel, but instead let economics dictate over good judgment. Of course, not being in the designers chair, it might well have been they didnt have any margin left to improve the feel… but I’m sure it was one of those things that caused many a heated meeting during the design process.

Ultimately though, user experience or not, the unit suffered reliability problems. Granted everyone early on was going egads, this is not going to work, despite the fanfare, and testing they tried to put it through. I remember the cigar ash and beer mixture they poured on one while it was running to dispel user perception of a lack of robustness. The thing is… even mil grade pots are screened today, the technology of screening substrates with resistive material, and getting 50,000 plus life cycles is not unusual, if not even more. Realistically, the technology to do such is not all that new either, so Alesis was likely correct from a tech point of view… but ultimately something did go seriously wrong with their implementation.

Eigenharp key resolution of 1 micron? Hmmmm

I read that the Eigenharp has a resolution of one micron as concerns its key positions. Thats about 8 times smaller than a human blood cell…hmmm, I’m pretty skeptical for a number of reasons. First a disclaimer, that my skepticism is not with the instrument itself, I think they may have really hit on something huge, but its not the one micron thing.

The instruments intrinsic value is not the wippy internal tech stuff, like one micron resolution or otherwise, but that it provides many magnitudes of greater usability as a computer music interface. Light bulbs have been coming on left and right for the last few days, despite having never played with one, nor even seen one other than online. What they have, imho is really a world changer (even if it is not a success, nor widely adopted, the Eigenharp blows far too many paradigms to be ignored no matter what happens). As they mention in the video, the QWERTY keyboard and mouse is for word processing, its not designed for music. It really is insane when one thinks about it a bit… typing and mousing for musical impression? This is why I believe the Eigenharp is a world changer. Thus, onto the issue at hand, one micron resolution.

First of all, no musician on this planet can hold to any level of absolute positioning anywhere ever close. Physiological issues like blood flow pulsation will more than throw a wrench into 1 micron positioning, to say nothing of ambient air flow, or even temperature variations. Notice the key word I used, absolute….

More likely, is a pseudo relative thing. Ie, the Eigenlabs folks created one or more massive absolute dead zones (probably based on semitones) during the initial measurements, such that absolute positioning is not a factor, and then after an initial measurement period, use the high resolution measurement as a delta value for purposes of artistic nuance. Dead zones would still provide capability to start out with a sharp or flat tone if desired, without requiring incredibly precise finger position for intonation if being sharp or flat initially was not the intent of the artist.

This of course assumes they are using technology capable of really resolving 1 micron of resolution. Thats where the second part of hmmm comes in. Magnetic measurements wont cut it, as simply changing position of the instrument will throw off nearly any type of magnetic sensor due to the earths field or surrounding metal or body effects. At least without some incredibly high tech physical or electronic shielding that is.

About the only type of sensing device to have that level of resolution, in a reasonably small package is optical interferometry. In a nutshell, you fire off a laser and have it reflect back on itself, such that an interference pattern is generated. Then, as an object moves, so will the interference pattern, and as such one can detect incredibly small movements, in most cases well under a micron. Philips was working on this some years back with the PL2020, but it appears that parts data went blank, although they still have some marketing stuff available on their website.

Another possibility, is that the 1 micron thing is just marketing hype. For example, if you set maximum XYZ key travel at 0.080″, and digitize it at 12 bits resolution, toss the lsb, and you will find the output has a resolution of 1 micron. Such a sample is likely pretty noisey, drifts like all get out, and is pretty useless, but some marketing guy might have fun with it.

Either way, I find the instrument fascinating… Too bad I dont have a kazillion dollars to get one. About the only thing I might do, is resurrect some of my old notes on wind instrument design. It might be pretty cool to look at such interfaces once again.