/biz/ - Business & Finance

>>11293570
renown coin sellers only buy new bullion from trustworthy source like the mint itself. if they buy anything from a private person they do specific speed of sound test.

>>11293592

Right. But I'm talking about trying to pass them at the places that buy bullion back from the market they sell to.

stop scamming people, theres so many ways to make money without being an asshole you fucking dick

Gold is super dense, only a few other metals would work for this due to weight and sound being off.

>>11293592
>>11293626

So it's primarily beating weight and sound tests. Interesting.

>>11293629
you can beat specific weight test but not the specific speed of sound test because that is unique to the element and chemical bond.

You need a metal like tungsten or something like that, and then you need to bathe it in gold. This will fool 1 in 10 gold buyers.

>>11293644

What about creating a wafer of alloys that is averages out identically to the same weight and speed of sound as what I'm mimicking, then bathe it in the element itself ala >>11293646 in order to copy the luster and physical properties?

>>11293626
its cheap amd easy actually look up tungsten and osmium... both cheap and they averae it out nicely in the rigbt ratio then you fols plate it for chwmical and xray tests.

>>11293644
This.you can beat the weight test, you can beat the sound test, and I forgot to mention conductivity, but you can't beat them all. Gold is really quite unique.

>>11293674
Think theres also electrical conductivity tests to prove if its gold or not

>>11293570
Lol my company makes coin blanks, good luck replicating our work that shit is a very difficult process. I guarantee any coin you try to make will look like shit and be obviously counterfeit.

So a list of tests:

>Visual (luster, design etc)
>Weight
>Speed of Sound
>Conductivity

What if I create alloy wafers that have an average speed of sound and conductivity that mimics gold bullion and coat the wafer in gold? I mean it'll take a lot of research into how conductivity and speed of sound works, but after that point it's just math and craftsmanship.

>>11293734

I mean compared to cracking dollars and euros I'm guessing that it's lower in difficulty and risk.

>>11293739
Don't forget to factor the cost of all this into profit projections. You might lose $

where can i buy some fake gold coins? It would be cool to get some gold plated tungsten coins just for the larp factor.

>>11293938

Up until I start making money. I consider counterfeiting a skill worth investing in though.

>>11293948
Why wouldn't you spend your time learning something practical that won't land you in prison, or tortured by an angry mobster who bought your black market gold? That shit will come back to haunt you.

>>11293739
conductivity is literally stupid as shit, visual also won't work on any quality fake. beating the specific weight test only very high quality fakes can, and nothing can beat the specific speed of sound test. it's not possible. also if you put layer boundaries into your medium the ultrasound test will clearly show them anyhow.

>>11293688
won't work on gold plated.

>>11293618
>he doesnt realize profit is literally scamming people

>>11294014
Hes not selling to mobsters though, hes going to scam Bob the father of 4 out of his life savings who thought buying gold would help secure his assets

>>11293674
>What about creating a wafer of alloys that is averages out identically to the same weight and speed of sound as what I'm mimicking
that works in theory with imaginary metals won't work in real life. these metals have very different specific speed of sound due to their ductility/hardness and density.

nobody found a way to fake pure gold or silver with a mixture of elements it's hard enough to get the density right most fakes can't even do that. most are very obvious blatantly wrong dimensions.

>>11294077
Gold plating gives identical conductivity to a pure gold substance?

>>11294157
obviously

>>11294195
well here is the thing resistance will be the same speed of conduction will be the same. voltage travels on the surface of conductors with near speed of sound, but the electrons crawl compared to that and on the full cross section. so there is an electric test that could expose a plated coin but it's very far from feasible and not even on the same planet as convenient.

>>11294247
*near speed of light
fuck i was talking about sound too much, voltage travels near speed of light.

>>11294014

Adventure.

>>11294066

So you think I can beat visual and weight and that conductivity is stupid. The ultrasonic one is the one you think I can't beat huh? What kind of tech do they use for that for you to say it's uncrackable?

>>11294099

No, I'm selling to the store that's scamming Bob the father of 4 out of his life savings by overcharging him when he buys and sells gold knowing that he'll be at best barely making money saving it over time.

>>11294123

I think it's crackable. If not identical then very similar to it. I could be wrong though.

>>11293629
You can't beat a sound test. It's physically impossible. I spent a year researching this topic for my RINGS system (resonance induced numerics for gold and silver). Every coin I purchase I do a sound test on.

>>11294390

How do sound tests work, exactly, that you say that they're unbeatable?

>>11293570
Lead core with Nordic Gold (it's a brass alloy) coating, and finally if you can get access to a SEM and gold splatters coater, your forgeries will pass even easier. Good luck anon, fuck those goldbugs over. This post is a larp and not advice, I have never done this

>>11294397
A sound test is based on the frequencies of a given coin. I followed the peer-reviewed research of a French professor at the Bank of France. The frequencies are produced by a combination of geometric, chemical, and transcendental equations. Every metal has a unique vibration, and the vibrations are even more unique depending on the diameter and thickness. If you use a different metal, like tungsten, even though gold and tungsten have the same weight more or less, the frequencies for tungsten will be over twice as high and sound completely different. The audio spectrograph will look vastly different for a real coin vs a fake.

>>11294407
The secret service investigates fake gold, they will fuck you up hardcore if you try that.

>>11293570
jail

>>11294470
Let's face it, most gold coins go in a safe in a safe room in a bunker and will never see the light of day again

>>11294449

Right. But what exactly is being measured in output? An exact frequency as an output against a given frequency as input?

So basically I'd need a wafer that weighs the same and outputs an identical frequency. I mean isn't layers modulating the frequency of the next layer a possibility?

>>11294470

So it is the secret service?

>>11294512
>Right. But what exactly is being measured in output? An exact frequency as an output against a given frequency as input?
You look at a spectrograph of the first three modal frequencies, they will appear as sharp peaks. This is a Gold 20 Franc spectrograph. If it were made of tungsten the spikes would be at points over twice as large on the Hertz scale, it would be painfully obviously even to a complete noob. Plus my spreadsheet automatically generates frequencies for known fakes (like tungsten) as a reference point.

>So basically I'd need a wafer that weighs the same and outputs an identical frequency. I mean isn't layers modulating the frequency of the next layer a possibility?
No, you can layer it all you want, that can't mask the inner metallic composition. The tungsten portion will create a very obvious distortion in the graph.

just buy bitcoin, there's no counterfeit bitcoin, and its obvious when somebody tries to pass a fake as an original (i.e. bitcash).

>>11294512
Honestly OP, if you want to make fake gold, you're wasting your time with coins. Coins are often less than 1oz and very difficult to work with for duplication due to the fine detail, which is why they are made by government mints. Bars on the other hand are super, super easy to fake and hollow out. Plus you can't really do a sound test on it, although they do use ultrasound for bars.

https://www.youtube.com/watch?v=SYXkSTCU9CA

>>11293570
>Hypothetically who enforces this?
Law enforcement, lol?

are you kidding? This would be felony fraud in most places in the USA as you would be trying to defraud someone out of over $500 (most likely) and if you mail it that's felony interstate mail fraud or whatever

>like who enforces laws

>>11294552

I'm going to have to figure out how to fool that thing then. Hypothetically.

Just how common is that form of testing?

>>11294602

Do they really have a harder time testing bars with sound tests?

>government mints

I thought they were private.

>>11294606

The question is which agency.

>>11294397
>How do sound tests work, exactly, that you say that they're unbeatable?

The only thing that would remotely work to fool someone who has ever handled a gold coin before is tungsten, it's the only thing that is as dense as gold that is cheaper than gold.

Sound passes at a different speed though tungsten and gold

>>11294619
>The question is which agency.
with interstate commerce it would be the FBI, otherwise local fraud law enforcement depending on the local crime

does it matter? It's felony fraud and there is very little chance you will get away with it for long, there is no fucking way you could sell $100,000+ of tungsten gold to dealers/whatever without getting caught

>>11294607
>I'm going to have to figure out how to fool that thing then.
The only way to fool it is to go to a different Universe where there's a metal with the same vibration pattern as gold. It's impossible. I'm not joking.

>Just how common is that form of testing?
Sound testing is VERY common, especially at the dealer level. They have some proprietary technology that follows the same equations as my RINGS system. The only people you could fool with that are dumb boomers who only do scratch and weight tests.

>I thought they were private.
Some are.

>The question is which agency.
FBI and SS usually

>>11294512
>So it is the secret service?
no, well maybe if you were counterfeiting US issue gold coins with face values made by the mint

don't do that, it's a bad idea

>>11294504
kinda like bitcoin. Most are dormant, never traded

>>11294619
>>government mints
>I thought they were private.
wat

how old are you?

>>11294607
>I'm going to have to figure out how to fool that thing then.
Well considering you would be changing the atomic properties of elemental atoms, if you figure out how to do that you won't have to defraud people with fake gold coins as the technology will make you a billionaire in it's own right

>>11294407
>Lead core

>>11294625

See, we're back to the sound thing again. I can make a wafer as the base of a coin or bar made of heavier and lighter materials than gold such that it weighs out what it should compared to an equivalent wafer of gold. That's just math and I can do math.

It's the sound that's a headache.

>>11294659
>>11294673

That's important. If it's the Secret Service then they're specialized in cracking this. If it's the FBI then they don't have an entire staff of people dedicated to this specific thing ready to come after me.

>>11294717
>See, we're back to the sound thing again. I can make a wafer as the base of a coin or bar made of heavier and lighter materials than gold such that it weighs out what it should compared to an equivalent wafer of gold. That's just math and I can do math.
>It's the sound that's a headache.
i think you might be retarded

>>11294717
>See, we're back to the sound thing again. I can make a wafer as the base of a coin or bar made of heavier and lighter materials than gold such that it weighs out what it should compared to an equivalent wafer of gold. That's just math and I can do math.
You can throw in all the different materials you want. You will not be able to replicate the sound of gold. Those metals will have vastly different frequencies.

>>11294670

Sound engineering is a thing though. I just don't know enough about it to do it. Damn, counterfeiting precious metals is hard.

Are bars harder to sound test than coins like the other anon said?

>>11294717
>If it's the FBI then they don't have an entire staff of people dedicated to this specific thing ready to come after me.
yeah those dumb FBI fucks will never catch you with their stupidness and lack of ability to know what gold is or knowledge of how to investigate fraud

go for it

>>11294742
>Sound engineering is a thing though. I just don't know enough about it to do it. Damn, counterfeiting precious metals is hard.
Yes it is a thing, I had to work with a materials engineer just to get the transcendental equations solved for the eigenvalues that correspond to each metals' poisson ratio. That is not for the faint of heart. And no matter how much engineering you do, you can not make another metal or alloy of metals sound like gold. It is a unique fingerprint.

>Are bars harder to sound test than coins like the other anon said?
They don't really sound test bars, they use ultrasound, which is not something the average person has access too. It's also super common for bars to be counterfeited because they are large and easy to work with in a metal shop. Most people hallow them out and fill it with tungsten. Again, DO NOT TRY THAT, YOU WILL GET CAUGHT. Hypothetically speaking.

>>11294783
>They don't really sound test bars, they use ultrasound, which is not something the average person has access too. It's also super common for bars to be counterfeited because they are large and easy to work with in a metal shop. Most people hallow them out and fill it with tungsten. Again, DO NOT TRY THAT, YOU WILL GET CAUGHT. Hypothetically speaking.
I read somewhere that if someone is buying significant amounts of gold bars from an unproven seller it is not uncommon to demand the bars actually be sent to a foundry and melted then recast to prove they are real

you seem to know a lot, is that true or just an overdramatic rumor?

>>11294748

Totally ;)

>>11294783

I mean I kind of want to do it the hard way with bullion. Sounds like it's as follows:

1. Figure out how to produce a wafer that as closely mimics the frequency of gold as possible when subjected to a sound test. The impossible dream, but even as a science project it sounds like fun
2. Make sure it weighs correctly
3. Mass production

Hypothetically pretty cool.

>>11294844
>1. Figure out how to produce a wafer that as closely mimics the frequency of gold as possible when subjected to a sound test.
you just don't know what you are asking

why don't you just ask how to vary the atomic weight

>>11294783
your info is like 5 years old
today simple cheap small devices are used to soundtest bars and or coins that every merchant has or can have easily.

>>11294844
people since the dawn of history have dedicated their lives to recreating or faking gold. You're delusional if you think that you're going to come up with some new brilliant method that nobody else has thought of

>>11294884
>people since the dawn of history have dedicated their lives to recreating or faking gold. You're delusional if you think that you're going to come up with some new brilliant method that nobody else has thought of
basically this, hell Issac Newton tried and failed for years

>>11294862

I know what I'm asking, and I know how complex it is. We're talking about an extremely high level materials engineering problem that might be too complex to even implement even if I find a viable solution, and one that they will inevitably implement a test to foil once they figure out what I'm doing and how I'm hypothetically doing it.

I mean that's the game. Honestly I should probably be doing science instead, but oh well.

>>11294838
I haven't heard of that but it wouldn't surprise me. I don't know as much about bars as I do coins.

>>11294844
1. Impossible in this Universe
2. Possible
3. Refer back to 1

I'm not sure why you're hung up on coins. There's Chinese websites that sell somewhat convincing replicas of things like Gold Eagles and Maples. But again, the only people who get fooled by that shit are old boomers. Also, keep in mind, that whatever metals you use, they can't be magnetic. So in addition to weight and sound, there's a third thing to take into consideration.

>today simple cheap small devices are used to soundtest bars and or coins that every merchant has or can have easily.
Not good ones.

>>11294907
it's not that its "complex" it's that it's "impossible"

You would be far better off social engineering your way into a foundry or place where they store bars and somehow stealing the gold or getting yourself put in charge of testing the bars and just committing paperwork fraud/not testing incoming bars from your co conspirators or something like that

you might as well ask how to alter the atomic weight of aluminum so you can make it have the density of gold and pass it off...

>>11294928
topkek

>>11294913
>I'm not sure why you're hung up on coins. There's Chinese websites that sell somewhat convincing replicas of things like Gold Eagles and Maples. But again, the only people who get fooled by that shit are old boomers. Also, keep in mind, that whatever metals you use, they can't be magnetic. So in addition to weight and sound, there's a third thing to take into consideration.
it has occurred to me that a way to fuck people over is to fake old pre 1933 gold coins with tungsten then put them in those sealed collector coin holders and sell them to boomers since you can't really test a coin in one of those sealed holders very well

>>11294913
>>11294928

You keep saying it's impossible. I'm going to do some research into how frequencies work. Maybe it is. Maybe it's not. We will see.

>>11294970
>You keep saying it's impossible. I'm going to do some research into how frequencies work
you do that, it should be quite the education on "what atoms are" and "how reality works"

>>11294956
yeah, that same website has tons of PCGS and NGC sealed gold coins lol, that's why bars are easy to go for because they are often sealed and most people would be scared to break the seal

>>11294980
>yeah, that same website has tons of PCGS and NGC sealed gold coins lol, that's why bars are easy to go for because they are often sealed and most people would be scared to break the seal
yeah that's actually a legit good idea

I have seen the good fake tungsten gold coins go for like $400 though, seems like a lot

>>11294970
you can do it, countless other people have been foiled by the laws of physics, but you're different.
You're a fucking italian aren't you? nobody else would be this autistically stubborn

>>11294992
part of that is due to the exterior layer of gold, even fakes have value due to the gold around them, like the bars in that video I linked to earlier

>>11295003
this. D1wniB64 will make those pesky laws of physics his bitch

>>11294980
to add, the reason I would not do this is I would actually feel bad defrauding old people by selling them fake coins over and over again (I assume the only way to really do this is to sell a bunch of single coins at coin shows or in person)

stupid ingrained ethical morality and christian upbringing..

>>11295023

Yep. J-just gotta set that number to zero and then they're your bitch. *belch*

>>11295096
you're italian, right? i know a couple pasta niggers and they are all just like this- they have a stupid idea and then decide to stubbornly insist that it's a good idea or possible or whatever, and when they get proven wrong they have this retarded instinct to just do it regardless

Question: do these sound tests only measure frequency, or also amplitude?

>>11295259
>>11295257
answer the question my spaghetti friend

>>11295257

I'm more of an olive nigger than a pasta nigger.

My thinking though is like this. Let's think of our target frequency of gold as g. Now the sound wave passing through any other metal is going to change the frequency to deviate from g by + or -. With me so far?

So what I need is a wafer that weighs the same as an equivalent amount of gold and has such values of + and - to its frequency that it approximates the frequency of "g" for whatever passes through it.

So I ask again: am I just matching frequency or are there other factors in the test?

>>11295419
It's not just sound passing through, the metal itself is producing the vibration, like ringing a bell.

>>11295476

Right. So we are looking for a composition that produces an average within the testing frequency for gold. An exact match is probably impossible within the confines of testing a coin. A rough match that approximates the signal that's good enough to fool a series of bored counter jockeys watching for obvious deviations toward things like tungsten is all we need.

What I'm talking about sounds crazy, I get that. Even if it worked an extremely deep scratch test or more sophisticated equipment looking for an exact frequency would beat it. What I'm looking to do is imitate just closely enough to pass though.

Hypothetically.

>>11295524
im pretty sure the "reader" device would show a peak at the frequency of material 1 and a peak at the frequency of material 2. In fact i'm 99% sure that's how it works

>>11295558

That could be. The trick to this would be to make the sound waves distort one another and have the reader take the average of the peaks. Which brings us to the physics/engineering problem.

>>11295524
Good luck with that, and you need the weight to be within 2% and no magnetic properties since those are also quick tests that take less than a second.

>>11295583

Right. But once in my hypothetical scenario such a wafer is devised then it's just a question of mass production and distribution. Then our hypothetical character is the Walter White of counterfeiting coins made of precious metals.

>>11295599
i'm loling right now because you have the same exact mannerisms of my stubborn fucking italian friend. He even says "right" when he gets proven wrong and then continues with the idea.
you italians are good guys but it's fucking hilarious seeing the shared traits

>>11294970
>I'm going to do some research into how frequencies work
resonance is not only dependent on the material but also the exact geometry of the object.
but specific speed of sound is only dependent on the material. the exact chemical bonds that pure solid gold has is very specific. it's dependent on temperature and frequency of sound to a degree of course.

>>11295634

I mean it's possible that I'm wrong and that there's no way to spoof a frequency in such a way that it fools a reader. To me though "impossible" usually means "nobody has figured it out yet".

>>11295599
Jesus Christ Marie, they're not rocks, they're minerals!

>>11295664
and you don't think for a moment that people way more educated and smarter with miles better equipment and resources than you have tried before?

>>11295662

I think I have the calculus background needed for the equations once I know how to set them up. The problem is that I don't know enough about the physics of specific speed of sound or the testing mechanism. I can research that. Then it's a matter of getting access to the data. Then rigorous testing.

>>11295709

I'm sure that they have. I almost want to try to break into the Secret Service's files just to find out.

>>11295664
One metal that has frequencies near gold is platinum. There were even counterfeiters in the 19th century who made fake gold coins with a platinum core that could get close to the sound of gold. The problem is now that platinum costs nearly as much as gold, and a few years ago was even higher, so there wouldn't be much of a point.

>>11295735

Right. It's also a question of cost to produce such a wafer.

>>11295724
>I almost want to try to break into the Secret Service's files just to find out.

>>11295815

I mean how far would you go to make sure that your book is accurate?

>>11295096
>>11295840
>rick and morty
>south park
you need to go back to plebbit

>>11295724
>Then rigorous testing.
yeah lots of expensive materials and equipment lots of time lots of trial and error anf the likelihood of success is very remote but go for it!

>>11295858

I was thinking I'd start with computer models and math before moving into the prototyping phase.

>>11295724
>I almost want to try to break into the Secret Service's files just to find out.

Just lmao at this guy. Seriously.
>took calculus, thinks he's some kind of genius now
You're "trying" something beyond your comprehension. Might as well be autistically daydreaming about inventing a super tonic that gives you lazer vision.

Just go to craigslist and sell your gold to some boomers who dont even test it. Have it all nicely packed up with a fake receipt. I read somewhere that a couple of zoomers scammed over 10k per person. They got the bars from AliExpress lmao.

>>11296029
Several people have already told OP this. I think he has a severe case of autism.

>>11294390
Can you share this with us? Looks cool. I have an old silver dollar and love the sound it makes vs modern coins.

>all this hate because I'm thinking about trying something out that they haven't even bothered to think about

I guess this is the process with everything, huh?

>>11295889
wait you think if you mix two metals together their speed of sound somehow averages out or something? like there is an easy formula for this crap? kek...

>>11296951

Not remotely. I'm thinking that it's going to be a complex matter of figuring out how to modulate alter the frequency of signals and that the process of figuring it all out is going to be massively expensive and time consuming.

>>11294407
Top kek

>>11296951
>>11297030

Actually you know what? I think this is a lot simpler than I'm making it. Possibly.

>>11297098
>I think this is a lot simpler than I'm making it.
lol, the amount of elements is one thing but the cooling process and a lot of things determine the crystalline or metallic or amorf structures within a non-homogenous metal mix. if you know a little bit about metallurgy you would realize this can never be a purely mathematical problem because the experimental legwork is not publicly available for these metals.

steel and it's alloys are much more widely researched but even there there is not enough data to account for everything.

>>11296029
This is why I only buy from dealers

>>11297173

Oh, I get it. Cracking the math with the frequencies and the weight is one thing. The craft of doing it in practice is entirely different. This is going to be a major fucking headache to do but I think it's worth doing if only to satisfy my curiosity.

The thing is that if I can do it once I might be able to do it again. If I can do it again then I might be able to do it en mass. If I can do it en mass, well, then I've got some ideas about a story to write.

watch this

>>11297522
forgot the link
https://www.youtube.com/watch?v=2P1h6uXDACY&t=1s

Does this app work?

>>11294979
Stop dude, you're fucking cracking me up!

>>11294512

>what is actually being measured by a sound test

The subatomic particles that compose the element. When people say it’s UNBEATABLE it’s because it is so conclusive, it relies on such a fundamental property, think of it like “fingerprint” of matter itself, resonance frequencies permeate everything and are unique to every type of matter. So the only way to beat a sound test is to literally arrange protons and electrons into the structure of gold.

>>11298053
the speed of sound is detemined by density and hardness and temperature. if you make something with the exact same density and hardness as gold chances are it will pass the test. but doing so indeed leads to the territory of way too many variables to permutate and not enough data available anyhow to even start modeling.

>>11297951
probably not very well

>>11298147
>the speed of sound is determined by density and hardness and temperature.
also geometric properties as well (diameter & thickness)

>>11298147

Fucking hell anon, you’re confusing the speed of sound with resonance. I suggest you look into resonance and FREQUENCY, not speed, speed could be fooled. Resonant frequencies are determined by FUNDAMENTAL properties of matter and are ever present. Do I need to fucking post a photo of my Chemistry degree? Fucking tired of arguing with boomers who don’t know the difference between frequency and speed.

>>11298223
no geometey doesnt play into sos

>>11298274
>Do I need to fucking post a photo of my Chemistry degree?
after the nonsense you posted i wouldnt belive any photo you provide

>>11297535

See, I could bet that.

>>11298317

He could very well have a chemistry degree and just not realize that he's wrong because creative thinking tends to not be something STEM people are good at.

>>11298294
not the sos itself, but the coins thickness and diameter do alter the frequencies

>>11298337
yes harmonic frequencies are determined by density hardness and geometry.

its just the geometry is not the hardest part by far.

>>11298274
oh yeah this is a good point, I'm referring to the vibration/resonance patterns

>>11298362
I've heard it called sound test and I didn't realize some ppl in this thread were saying "speed" in front of it

>>11298371
specific speed of sound test is today the simplest most reliable and foolproof way to defeat quality insert counterfeits.

>>11298386
I would disagree, I think sound resonance is far superior way.

https://www.researchgate.net/profile/Arnaud_Manas/publication/276297204_The_music_of_gold_Can_gold_counterfeited_coins_be_detected_by_ear/links/5622abb908aed8dd19441378.pdf

>>11298395
its not as foolproof and only works for coins really.

>>11298408
Actually it's more foolproof. And you can do it for bars as well, it's just a different set of equations for rectangular plate vs circular disc.

>>11298417
>Actually it's more foolproof
i see you struggle interpreting that fancy word specific speed of sound requirss a simple 3 steo procedure with a simple portable device a monkey can do and will give consistent repeateable results.

harmonic test with phone apps and by ear are way more error prone and dirty but sure better than nothing and you already have a phone and all.

>>11298443
You can use a real audio spectrograph on a phone, not some shitty verify app. All you do is tap the side of the coin and watch the peaks on the phone, it literally takes 2 seconds flat. Far easier than your little trinket which is not free, but everyone already has a phone ready to go.

>>11298455
>All you do is tap the side of the coin
now you just ruined your own test by holding the coins
its better if you spin the coins freely on the same surface

>>11298502
Read the peer reviewed literature I linked to earlier. You clearly don't know much about resonance testing.