do they really all sound the same?

No. That’s physically impossible. They are not the same. They use different filter structures with different numerical errors. They have different anti-cramping approaches (pre warped filter poles, corrective fir filter, over sampling) and different anti alias filters. Anyone who thinks Oxford eq sounds the same as fabfilter q3 natural phase mode or fabfilter zero latency vs natural phase must have monitoring compromised in impulse and transient response. Anyone who thinks MDWEQ sounds the same as Weiss EQ1 MP or Slick EQ at 44.1 kHz probably has compromised high frequency hearing or monitoring. Some people just don’t believe. When you come up with a test for which it is obvious, they don’t believe you. A blind test becomes pointless then.

A mastering engineer with more YouTube subscribers than album credits out with a contrarian video about plugins. 🥱

This is well worn territory and it always comes with a pile of asterisks. The null test is only useful as absolute proof if you can generate silence, and it never takes into consideration the all-important workflow considerations. His defense of that point that 'people should know how to use eq' is amongst the weakest I've heard. It completely dismisses the value of the UI experience (be it digital or analog), and of smartly-chosen and well-proven musical curves (and their interaction!!) that get the job done quickly. In short, it's the classic viewpoint of someone who's done more reading and thinking about making records than actual making of records.

As a case in point, I'm demoing the new UTA eqs that are much-touted as able to reproduce any classic eq curve in existence. They even come with a 'cheat sheet' of sorts indicating how to set each band to replicate these classic eqs. They're good at that, and Eric does a good job demonstrating that functionality. But this is so far removed from what is the most compelling way to use these things, that it's almost kind of sad. The functionality of these things compels me not to seek to spend an inordinate amount of time trying to replicate old curves of classic eqs (most of which I already own and could summon in an instant if I need them, far more quickly than recreating the curves using the UTA), but to tweak and tinker to discover NEW curves and even phase manipulations that far exceed the capabilities of anything else in my toolkit. And with the UTA eqs, I can do it all very quickly and (after a bit of a learning curve) quite intuitively.

The shape of the filters is not the point of an eq. Nor even is the harmonic content or coloration. It's how these things interact and compel the user to efficiently realize the sounds in their head.

I'm just going to defer to Dave Gamble of DMG Audio and math wiz. He believes firmly that if you match the frequency and phase response of an EQ you have effectively replicated the EQ and all other effects are insignificant (i.e., coloration from inductors, transformers, etc.)

However, as Dan pointed out, it's hard to copy the exact behavior because of phase response differences (e.g., you can have two EQs with identical frequency response but if one is minimum phase and the other is linear phase, they will sound different). Some digital EQs use fancy analog phase compensation.

Matching freq response is easy. The phase should also match.

It is since it's well known scientifically that it's about 1dB for the *average* person but a trained person can hear around 1/2dB difference, and that's with a step in volume.  If it's a gradual change, then neither can discern it easily. 

the uta eq presets reminds me of the kush tweaker analog presets which showed you what it could do vaguely but of course it cannot be them in real world use objects-us-east-1.dream.io/kushfiles/manuals/ANALOG%20PRESETS%20-%20Tweaker.pdf

I love the mdweq because it forces me to be precise and not over eq. There are only 5 filters. You cannot even automate it. The Slick EQs are similar. Some of the coolest sounds I ever made from eqs were made by barely doing anything or playing broad eq filters against each other. Having multiple channels of hardware encourages this. So do multiple instances of cool plugins.

There’s no smoking gun to say what the difference is. However, everyone who brings up these arguments always happen to have a financial motivation they are defending.

Most are in favor of saving themselves money while STILL competing equally against those who have spent a lot of money.

Others simply want to sell thier product, and convincing the buyer that they can have “super mega expensive” for “way cheap”… it’s easy sell. And even better if you can also enroll them as another voice that cheaper = the same as expensive.

This has been going on for 25 years, and probably will continue.

Here’s where the science needs millions to find out the truth:
Nobody understands what exactly induction is. If someone does know, it’s behind a gov Top Secret clearance and they aren’t telling.

When two wires are next to each other, they copy themselves into each other.

When you make a really big wrap, long enough to let sound waves go through, then frequencies are copying and pasting into each other.

What happens when you have 10 magnets with a + charge, and 1 magnet with a - charge? The - charge flips and joins the rest to be +

This has to occur in magnetic fields whenever signal drops below a certain strength.

You have this gigantic magnet, say a low 40Hz peak inducing across a coil, and itty bitty little magnet..15kHz breathe..at the same time.. And that at the peaks of the low waves, some of that high energy will be eaten and transformed into that 40Hz peak. As the wave goes down in strength, that 15kHz can be itself again.

So I listen for what you’d expect, a smoothness, a rounded character, adjustment to transient info, light pseudo ducking/limiting on complex waves, I feel it can strip out some of the nasty unneeded garbage that is neither fundamental nor harmonic, as the magnets should be pulling noise away from being random and organizing into the larger musical wave shapes

wait, what?

Electromagnetism (Emag) is a very well known science.  It's also not quite the same as magnetism.  You have two phenomenon happening in your statements up there..

ALL currents have a field that they generate.  The stronger the current, the stronger the field.  That field can easily be manipulated to our advantage in items like inductors and transformers.  There's plenty of science behind inductor/transformer core and winding materials to get whatever results you require.  It even works in reverse for guitar pickups..  

Then you have electric motors, both DC brushed and DC brushless, and even AC induction motors.  

Then you have antennas, both transmit and receive..  Work by induction.  Metal detectors.. Induction.  Some stoves.. Induction.  Wireless charging pads for your phone.. Induction.

But I digress.

Another thing you discuss is a subset of induction around transformers.  A transformer will have various attributes as well as parasitic components.  The core must convey an amount of the induced Emag field, so the stronger the field, the larger the core must be.  However, the larger the core, the larger the amount of parasitic effects, so the lower the usable bandwidth.  The winding ratios matter because that affects the amount of current being conveyed to the load from the source, but it can cause the core to saturate, which limits the headroom of the transformer, and that causes issues with frequency response such as your 40Hz vs. 15KHz conundrum above (in a very similar way that an opamp might saturate on large signals, which is why opamps generally give you "large signal" characteristics as well as "small signal" characteristics").

We might not know exactly how magnetism works at a fundamental level, but we certainly know how to manipulate magnetic fields to our advantage!