I have no way to know. But the magnetic holder has a rubber bottom on it, and the cell phone has a some kind of soft plastic cover through which the other magnet is attached so it doesn't seem like that's much of a problem. Anyway, I just wanted to point out the readings I was getting in that position even sitting on the bridge were much clearer than they were when I was locating it in other places, largely due to my inability to hold it there with anything reasonable. If nothing else the discovery of these magnetic holsters was worth the trip
Original Message:
Sent: 04-03-2024 17:18
From: Jurgen Goering
Subject: ETDs holders and microphones present microphones placement
Question: When the cell phone holder is sitting top of the bridge, how much sound input (or vibrational input) is coming from the direct connection to the bridge?
When I hold a vibrating tuning fork (perhaps comparable to a vibrating string) close to my phone, the tuning app does not really register it. When I touch the stem of the tuning fork to the (soft rubber) case of the phone, the tuner instantly registers the 440 Hz. (Comparable to the phone being mechanically connected to the bridge)
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Jurgen Goering
Original Message:
Sent: 04-03-2024 01:38
From: David Love
Subject: ETDs holders and microphones present microphones placement
Attached below are photos of the magnetic cell phone holder and various placements. The one sitting on top of the bridge in the upper section I found very useful for steadier readings in that section. II don't reposition but when it seems necessary. This is obviously not a replacement for Norsworthy's device, it just came of that discussion and while I was looking for a cell phone holder best suited for this purpose that I discovered that repositioning, in the treble especially, yielded some benefits. I don't usually have any problems lower in the piano. Hopefully you get the idea with the photos below how the phone attached with the bottom of the phone pointing down. Obviously hard to photograph a picture of my own phone, kind of like trying to look at your own face without a mirror. A zen problem.
BTW the magnet is plenty strong to hold the phone not only on these thin struts but on the from of an upright plate as well. Whatever comes of these steady spinner claims, it's a nice way to hold the phone place, a simple (and inexpensive) solution,
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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
Original Message:
Sent: 04-02-2024 11:27
From: Adam Schulte-Bukowinski
Subject: ETDs holders and microphones present microphones placement
Along David's lines, I tried an experiment, but with an external mic I'd forgotten I owned (Dayton Audio iMM-6 calibrated measurement mic) attached to a magnetic flexible gooseneck alligator clamp meant for soldering use, combined with a 3' audio extension cable, so I could move the mic where I wanted while keeping the phone at a convenient viewing location. (I use CyberTuner)
The clamp has a magnetic base and the gooseneck is very firm and holds it position well (after these pictures I added a piece of thin bushing cloth to the base of the clamp to avoid any potential for scratching/marring the plate). I wish the alligatorclamp itself was slightly larger so I could fit the barrel of the mic in the clamp, but it holds the cable firmly.
Setup and use was actually pretty easy. It's easy to position the mic where I want it, and it's easy to swivel the clamp on it's base to move the mic as you tune without having to reposition the clamp itself too often.
It is a little trickier to position in the top capo section to not get in the way of the lever, but it is possible.
Overall, the readouts were much steadier across the keyboard, and especially in the treble, but mic positioning is finickier in the treble to get those clean readouts, and chasing those cleaner readouts does add a little time. I haven't decided if the improvements in readout clarity are worth the tradeoffs yet. It does add a few extra pieces to the kit, and a little extra time in the treble. I don't think I'd want to add anything bulkier than this to my tuning kit, but could see how one could get used to moving a few extra pieces around as you tune, without it slowing you down too much.
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Adam Schulte-Bukowinski, RPT
Piano Technician
Glenn Korff School of Music
University of Nebraska at Lincoln
Original Message:
Sent: 03-30-2024 22:04
From: David Love
Subject: ETDs holders and microphones present microphones placement
Yes that's true. But I thought your device was measuring the string? If not what's the point of going to the trouble to place it where you do?
The benefit, I found, was mostly in the high treble where readings are not stable, typically. I set the mic pointing to the speaking length in close proximity to the soundboard and bridge. I'm sure the mic is picking up the pressure waves from the SB but with, perhaps less interference from other sources.
With respect to Geoff's comment I think phase cancellation would not be a problem with mics in such close proximity similar to stereo mic techniques in recording. But yes, new phones have three mics and there doesn't appear to be a way to turn individual ones off.
Anyway, it was more of an observation than a scientific research project. However the magnetic phone holder I found to be the perfect solution for what I was looking for. I don't want this to turn into an infomercial for any particular product. The last thing I'm looking for is to carry around more "stuff"
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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
Original Message:
Sent: 03-30-2024 16:47
From: Steven Norsworthy
Subject: ETDs holders and microphones present microphones placement
It takes the movement of air to produce sound. Putting a mic close to the string does nothing, since the string is moving very little air and producing very little sound itself. The string is the source of all vibrations and sound we hear, but itself is not producing the sound. There is nothing lost detecting the exact vibration of the source, but there is a lot to loose detecting the eigenmodes on the soundboard. The string has more than one mode, and these modes are often close in frequency and amplitude. A string usually produces the 'dominant' string mode over the lesser one, however, the soundboard will often resonate either mode more than the other depending on 'listening' position of the mic or the ear. This explains why we get mic position variances as much as 1-2 cents as has previously been shown with experimental data captures. Therefore, tweaking a mic position cannot be a solution that works across the whole range.
Steve
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Steven Norsworthy
Cardiff By The Sea CA
(619) 964-0101
Original Message:
Sent: 03-29-2024 00:02
From: David Love
Subject: ETDs holders and microphones present microphones placement
My recent search for an ETD holder, coupled with discussions on piano tuning, led me to consider the following. There has been much discussion about microphone placement using ETDs connected to cell phones or similar devices. Inspired by recent conversations about Pianosens, it occurred to me that it's not just microphone placement but also proximity to the string that matters. In my search for a cell phone holder to use at the piano, I found that magnetic holders typically used for gym workouts are well-suited for this purpose. (see link below--only $20)
The cast-iron plate of the piano responds to magnets (of course) and with iphones, at least, will hold onto the phone as well, The cell phone holder, like the one pictured below, can be easily attached to various parts of the plate including the top of the struts. This allows for the cell phone to be oriented in such a way that the microphone points directly at the strings and can be set in close proximity. Keep in mind that the different cell phones have both different numbers of mics and different locations. For example the iphone 14, which I use has 3 located front, back and on the bottom of the phone. The iphone 15 has two at the bottom plus one front and back.
Using the magnet mount you can orient the mic very close to the string (I focused on the mic at the bottom of the phone). The piano struts allow this easily and the magnetic holder allows you to move the microphone incrementally during tuning. By orienting the microphone this way, especially in the extremes, I found the indicator much more stable, In the high treble I set the holder on the plate behind the bridge and pointed the bottom of the phone where the mic is located directly, and as close to the speaking length as possible (the magnet will easily attach to the hitch pins). With this holder you can point the mic straight down onto the strings from the strut bringing it as close to the speaking length as you want.
While this solution may not be as advanced as the high technology Pianosens offers, I found it significantly improved the readings in the difficult, extremes of the piano,
There are several magnetized holders available online at retailers like Amazon. These are magnetized both to hold the phone and to attach to the surface where you mount the phone. The magnets are covered in some kind of soft silicone or rubber and so won't damage the plate. I would have taken a picture of the placement of my phone on the piano, but as you might imagine, I needed the phone to do that. If you'd like pictures, I can set something up and show you where I'm placing it.
Amazon.com: Gym Mate Magnetic iPhone Mount Holder. Attaches magnetically to Metal Surface. Shoot Hands-Free Videos While Working Out. Compatible with MagSafe on iPhones 12/13/14/15. Stable & Secure : Cell Phones & Accessories
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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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