frankfalbo
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Post by frankfalbo on Mar 18, 2017 21:07:22 GMT -5
What was the moment at time in your life when you concluded that inner-coil comb filtering was a thing? What experiment or piece of information "sealed the deal", for you? That is information that would be useful to me. Well I didn't fall and hit my head and wake up with a flux capacitor drawing. But I can tell you it's post-Duncan, Fluence-era. The Fluence core is extremely revealing in that, by being one full coil per vertical layer, all I can say is that it allows us to see things that are more difficult to see with a wire-wound coil. But it also proved out some theories and demystified some voodoos. With a peak that high for example, there are things we can see in isolation. Like swap Ceramic for Alnico with zero shift in frequency response from coil resonance. Stuff like that. As for what I refer to publicly as phase anomalies within a wire-wound coil, if we remove the effect of the return path from the equation it's loosely tantamount to setting up 3 mics, each behind the other. To a much smaller degree that happens throughout the height of a coil, which I can see layer by layer with a Fluence coil. Bill Lawrence was playing in that field with his microcoils.
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frankfalbo
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Post by frankfalbo on Mar 18, 2017 20:49:32 GMT -5
Frank, string window and Gauss meter comments aside, do any of the commercial pickups/systems you have worked on, incorporate the stated and/or implied results of your R&D involving either direct audibillity of signals in the 5Khz-15KHz+ range, and/or interaction of those frequency components with tube guitar amplifier preamp, intermediate driver/phase inverter, or power amp/speaker stages? I'm only aware of your design input on the Seymour Duncan Zephyr and Fishman Fluence products. Would it be possible in theory to test one or both of these products in some form factor, and be able to verify what you are saying? I'll do what I always do, which is to share anecdotally but I can't give a 360° tour of a multi-year R&D project funded by companies who have earned the right to do so over decades of discovery and fair commerce. (I'm not suggesting that's what YOU are asking, just that it's a common theme) To answer the question directly, Fluence is the most obvious project, in that one thing I've mentioned publicly in the past (without revealing final iteration data) is that the original Fluence core had a resonant peak of 80kHz. I have the full spectrum at my fingertips during the voicing process. I can literally listen to the difference 1dB at 10kHz makes in realtime. Same is true of 16k, et al. Now, if you run a simple plot of a Fluence vintage Strat voice against a 54 Strat pickup they'll be pretty similar. Whether or not subtle differences are meaningful, or whether someone thinks they're not worth spending money is up to the consumer. But they're not imagined or conjured. As far as Zephyrs were concerned, we felt the subtle differences did manifest themselves north of the resonant peak, and in the time alignment/group delay. They will also not provide any chart or plot that verifies it and I do not work for them anymore.
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frankfalbo
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Post by frankfalbo on Mar 18, 2017 18:40:05 GMT -5
"Compound that by the comb filtering associated with one lone pole..." A lone pole piece does not produce comb filtering. It causes an attenuation of the higher harmonics in the string motion as determined by the pattern of string magnetization that it excites, and the component of the resulting flux along the coil axis. Who are you to decide which statements that you make are the ones I consider absurd? That is a rhetorical technique as subtle as Trump on twitter. You avoid answering legitimate questions about what you write, and claim that is because you are a working professional. Then what are you doing here if you cannot actually say anything? I did nothing of the sort. I offered some preemptive clarifications to some things I thought you might have meant. It's not a technique. You're projecting something that doesn't exist (or I didn't intend) on my end. So let's isolate what you quoted. I believe you're using the term comb filtering solely as it relates to the string window; the Tillman article. I'm referring to the comb filtering that occurs within a coil as it relates to the return path, and the proximity of the turns to the strings. If you believe the latter doesn't exist, then I'm powerless in that matter. Comb filtering does very little to the overall dB reading, so an amplitude plot that attempts to show how large the string window is, or establish parameters for how to define the string window, it's not that relevant. But as it relates to the sound associated with it, and the descriptive terms associated with the user experience, it's not that cut and dry.
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frankfalbo
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Post by frankfalbo on Mar 18, 2017 17:40:24 GMT -5
John, "kills me" is a figure of speech. Ascribe the minimum drama to it possible. The ad hominem attacks flow over from here to other forums, as do the incomplete and inaccurate conclusions reached when the parameters of the experiment can not and will not reveal differences that we in the pickup business have proven to be there. The result is not only the character of decent people being called into question, but valid and repeatable user experiences as well.
I'm here in the event that I might be able to lead horses to water. If you prefer it remain an echo chamber just say the word and I'll show myself the door.
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frankfalbo
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Post by frankfalbo on Mar 18, 2017 17:25:35 GMT -5
Please isolate the absurd claims so I can try to clarify them for you. If one absurd claim is that a narrow Q boost at 16kHz into a guitar cabinet is audible, it's not absurd, just so it. If one absurd claim is that a less than 1dB shift above 5 or even 10k is audible through many typical real-world guitar rigs, it's not absurd, it's a real life occurrence.
So if I tell you something like this, and you are open to accepting it, then it alters the conclusions you might otherwise draw from an experiment that supposedly predicts that an incremental change in string window, so long as the total is less than 1" is having "no discernible impact" on the user experience of the final product.
I am telling you things that, if contemplated, could make an experiment more productive; more accurate.
If youre thinking my comments about the gauss meter are ridicule or belittling they are not. No part of this is me condescending to someone lacking the tools I've had the luxury of benefitting from. Rather, I'm trying to point out why something I say exists, might not look like it exists.
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frankfalbo
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Post by frankfalbo on Mar 18, 2017 13:04:30 GMT -5
Look, we all know where this is headed. I work for companies and I'm not posting graphs or screen shots, or going down too many rabbit holes with you guys. There are uninformed and downright false claims made in the name of science emanating from these kinds of homebrew experiments, and dismissive unbelief in other areas. You run these flawed experiments and then sprint to the nearest pickup forums to blast your newfound knowledge as if it's canon.
It's killing me to watch some of you take this hobby of yours and turn it into a crusade. It's like I'm watching a kid first learn what salt and pepper taste like, and then they proceed to describe everything as "salty" or "peppery" to the entire world...until they learn about garlic.
You pick and choose what you will listen to, such as an article by a dealer that says 5k+ doesn't matter in a guitar speaker, but you refuse to consider return path issues because the gauss meter zeros out at some point. Well, zero isn't zero on that meter. That meter is a bull in a china shop for what you're trying to determine. No, it's a bull in a dollhouse. It's Godzilla.
If you think 5k is a cutoff, stick a 31-band EQ in the effects loop of your Mesa Triple Rectifier and boost 16kHz and see what freaking happens. Does nothing happen? Is the cabinet deaf to 16k? Map out the Q of the 16k fader and see how low it goes.
The FACT is, I work with pickup technology where I can literally touch a button during the R&D process and toggle <1dB at 10kHz and everyone in the room hears the difference, and has an opinion about it. Of course It does different things with different amps, but for example I can pinpoint the exact moment on a Marshall where it goes from ear candy, to crashing the preamp. Yet some of you want to take what I'm saying as a lie, or as "unproven" because you're not on my R&D team and you didn't see it for yourself?
I've done the string window studies. There are flaws in what you're going to conclude from this. You can either keep going and ignore what I'm trying to tell you, post up counterpoints to every one of my points, or consider them.
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frankfalbo
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Post by frankfalbo on Mar 17, 2017 22:06:25 GMT -5
Then why doesn't every guitar amp and/or pedal begin with a 5K brick wall filter? Or 10K even? If those frequencies are meaningless why are they allowed? If you ignore 5-25kHz your conclusions suffer. If you promulgate it you're guilty of the same misleading propaganda the likes of which you've accused the marketing charlatans and profiteers.
As for the return path, that meter isn't going to tell you anything about it.
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frankfalbo
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Post by frankfalbo on Mar 17, 2017 19:33:04 GMT -5
Why are you considering 5kHz a significant benchmark? Two reasons, 1) many, maybe most guitar speakers have a response curve that drops off around 5kHz 2) not many pickups have a resonant peak that allows for much transfer of sound above 5kHz. Filter'trons are the only ones I know of. Most Strat type pickups attenuate between 3.5kHz and 4.5kHz, and PAFs between 2kHz and 3kHz, as a result of inductance values that are typical to those models. That's where you lose me. Pickups are won and lost between 5k-25k. Between 5 and 15 especially. Treating it like it's marginalized because it's 3/6/12/24/48dB is ignorant of the gain chain. Even frequencies above 20kHz will alias down into the audible frequency range under gain.
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frankfalbo
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Post by frankfalbo on Mar 17, 2017 16:12:15 GMT -5
Why are you considering 5kHz a significant benchmark?
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frankfalbo
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Post by frankfalbo on Mar 17, 2017 13:09:02 GMT -5
I don't think this rules out tonal consequences of proximity, but it does appear that it takes any credit away from comb filtering. Why would you reach that conclusion? Also it sounds like you only use the term comb filtering as it relates to the string window, from the string itself. The other comb filtering opportunities are in the return path, and other shifted relationships between the flux and the coil, within the coil. DB and frequency response charts aren't granular enough to show that. Also FYI it might be more effective with the other pickups removed. They're providing baseline magnetism that is sort of a magnetic noise floor in your experiment. That could be affecting your numbers at the increased distances. Remove the pickups, degauss the strings, repeat. Or to establish the other baseline just remove the pole from your test pickup and check the dB to approximate the minimum contribution from those existing pickups' magnets. .
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frankfalbo
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Post by frankfalbo on Mar 16, 2017 18:55:37 GMT -5
Not with that meter.
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frankfalbo
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Post by frankfalbo on Mar 16, 2017 16:27:04 GMT -5
I understand that string bending is imperfect because it's receives an assist form the neighboring pole piece. hence the need for a test with a single pole piece.. The variable you're missing is that it's not just an assist. It's a null. Let's pretend we're referring to flat poles, no stagger. The assist is vertical by focusing the field, but depending on how close the pickup is to the strings, you're coming in and out of a null. With the pickup far from the strings you have a smeared convolution. Come closer and you'll have 6 focused, concentrated zones with convolution in between, some overlap. Closer still and you'll find the null/dead zone. None of which you'll see during this first rudimentary look. Compound that by the comb filtering associated with one lone pole, mid-coil, generating non-standard audio into the coil in association with its return path. My point is, you won't have a clean number on the amplitude delta across the lateral axis because it's height dependent and altered by neighboring poles. Drive it with a tine like a Fender Rhodes if you want to get a 3 dimensional dB plot.
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frankfalbo
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Post by frankfalbo on Mar 16, 2017 14:40:02 GMT -5
Antigua is preparing to measure treble-to-bass window, possibly as it relates to drop off when bending between poles, by using only one pole piece in a coil. You don't see the problem with that? One pole, with its own unaltered return path and productive coil body on either side of it?
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frankfalbo
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Post by frankfalbo on Mar 16, 2017 13:15:00 GMT -5
One pole is meaningless and will have a phase altering return path within the coil along the treble-to-bass axis. When neighboring, like-oriented poles are flanking it (for the center 4 strings) or it is against the coil edge with only one neighboring pole, the like orientation imparts rejection at the top, completely changing the shape of the field both at the string, as well as the return path. Beveled pole pieces splay the field as well, but while that affects the return path along the string axis, it exacerbates the rejection and focusing betweeen the poles. Depending on how close the pickup is, beveled magnets may have an increased, or a decreased window delta.
Also with regard to -10dB, a measley 2:1 compression Or clipping ratio knocks that down to -5dB. Rarely is guitar played through a totally linear signal path, sometimes clipping under 90dB of gain or more. This doesn't change the physical string window, but it does compress the information present, tantamount to lowering the Q.
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