Greenwave 2500i AC Filter Review

[MediumRare]

My experience with his amps (I own one) is that the supply is fine. What have you seen?

The comment re the Pass amp was just an example of a device with high distortion. No idea where that distortion is coming from. So it would be interesting if filtering power source noise above 2k would make any difference. But any device with excess distortion above 1k would do.

 

[fpitas]

The comment re the Pass amp was just an example of a device with high distortion. No idea where that distortion is coming from. So it would be interesting if filtering power source noise above 2k would make any difference. But any device with excess distortion above 1k would do.

OK. My J2 is 0.008% THD, maybe it got the good supply (?)

 

[MediumRare]

To prevent a poorly-engineered device from screwing up a nearby properly-engineered device.


This seems to me to be backwards - a mediocre DAC would hide any theoretical power line noise behind its already-high noise floor. A highly-revealing SOA DAC that has very little self-noise should give you the highest chance of measuring noise being introduced from other sources, such as power lines.

No, you do have it backwards. We know Amir’s power source has significant distortion which the D90 already is completely immune to. So we need a device demonstrating problems and we see if this filter has any benefits. That’s what the filter is allegedly used for.

 

[MediumRare]

OK. My J2 is 0.008% THD, maybe it got the good supply (?)

Here’s one that’s not as transparent as yours. https://audiosciencereview.com/forum/index.php?threads/pass-aca-class-a-power-amplifier-review.9741/

 

[fpitas]

Here’s one that’s not as transparent as yours. https://audiosciencereview.com/forum/index.php?threads/pass-aca-class-a-power-amplifier-review.9741/

That's why I "only" paid $2600, vs whatever those huge Pass amps cost

 

[Takaya]

Amazing reviews on Amazon:

'Excellent, works as advertised. Noticed significant change in feel to the house. Tested and confirmed reduced enforcement with emf meter."

"Great product. Noticed a reduction in our electric bill. Not sure if that is a happy byproduct, or if that is just a coincidence. I will be ordering more."

They have large packages of these. Above quotes were from 16 filter pack for $509!!!

Hello AMIR, the "noticed a reduction in our electric bill "is one of the reasons i sent you these filters. How does one even notice this. The filters are quite heavy was another reason i sent them to you. Feel free to bust one of the outlet ones open to see why. I think i read something about shifting the 60 Hz sine wave to accomplish this.

 

[DonR]

Hello AMIR, the "noticed a reduction in our electric bill "is one of the reasons i sent you these filters. How does one even notice this. The filters are quite heavy was another reason i sent them to you. Feel free to bust one of the outlet ones open to see why. I think i read something about shifting the 60 Hz sine wave to accomplish this.

^^^ This... so much this. I suspect we will see a simple Pi network.

 

[lc6]

^^^ This... so much this. I suspect we will see a simple Pi network.

Most likely.
But then how would this network reduce the EMI in the building wiring (per the manufacturer's claim) and not just at the outlet of the device? If that EMI energy is so high as to be hazardous to human health, then, when eliminated, it must be converted to heat and dissipated that way. So the box should get really hot. However, a CLC network (disregarding parasitic resistance) could not do that. It must be some physical miracle, then.

 

[DonR]

Most likely.
But then how would this network reduce the EMI in the building wiring (per the manufacturer's claim) and not just at the outlet of the device? If that EMI energy is so high as to be hazardous to human health, then, when eliminated, it must be converted to heat and dissipated that way. So the box should get really hot. However, a CLC network (disregarding parasitic resistance) could not do that. It must be some physical miracle, then.

Time discrimination through the quantum flux density parameters... duh.

 

[fastfreddy666]

Dirty Electricity doesn't cause autism? Darn It. I was looking for a simple answer to a complicated question. I'm on the spectrum myself.
I consider my autism to be a gift that keeps on giving... Uncertainty is a natural and unavoidable part of life. The only constant is change. Focus on the things you can control.
I'm not overtly religious but I always liked the serenity prayer. "God grant me the serenity to accept the things I cannot change, courage to change the things I can, and the wisdom to know the difference." Can I get an AMEN? God is a historically charged term. Let's call it The Universe or something? Maybe agnosticism? The definition is very important. There's a difference between believing and knowing. If you are agnostic you might believe there's a God but you cannot possibly know or prove the existence of that deity. You can also believe there's no God. But you won't be able to provide evidence for that either. And we circle back to uncertainty. Militant atheists like Dawkins proposed that God is a figment of our imagination. A delusion of biblical proportions. LOL. Nevertheless I also liked Voltaire's idea: if God did not exist, it would be necessary to invent him. The meaning of life. Existentialism, Nihilism. Absurdism. Whatever-ism. We're all on the same boat. Let's have peace?


Annihilation! WOOHOO. O, Well.....

 

[Zippy]

Nowhere on the Greenwave website does the company make any claims their filters improve audio quality.
As far as the health claims, our family definitely noticed a positive difference when placing filters in our home. We used the Greenwave EMI meter
to properly place the filters.
We are very happy and have recommended the product to friends and family.

 

[fpitas]

Thanks for your review, and welcome to ASR!

 

[voodooless]

As far as the health claims, our family definitely noticed a positive difference when placing filters in our home

You mean these:

Where is the evidence for any of this, let alone the evidence that this device makes any significant difference on these things? And no, your anecdote it not evidence. The fact that the wording here is “has been associated with” should be enough of a red flag one would think…

 

[pkane]

Where is the evidence for any of this, let alone the evidence that this device makes any significant difference on these things?

 

[fpitas]

You mean these:
View attachment 313687
Where is the evidence for any of this, let alone the evidence that this device makes any significant difference on these things? And no, your anecdote it not evidence. The fact that the wording here is “has been associated with” should be enough of a red flag one would think…

I'm not which is worse: audio snake oil, or taking advantage of hypochondriacs. Oh well. Caveat emptor, like usual.

 

[GXAlan]

1) No evidence on this specific product.
2) Insufficient evidence to support sensitivity to EMF pollution is a real thing
3) For the money and time spent on EMF shielding it's better for the vast majority of us to spend that money and time on exercise, eating healthy, and taking time to improve mental health instead of focusing on something that is very difficult to control (other than going WiFi and cell-phone free at home and using a deskop and landline).

But strictly from the perspective of a scientist and the belief that we should consider exceptions to the rule, here's a peer reviewed paper which is part of Cell and indexed by PubMed. It is open access (pay to publish) which means it takes no advertisers which has the paradox of being both good/bad.

When something is open access, it could be a predatory journal with no standards. When an open access journal is indexed by PubMed, and affiliated with a flagship journal like Cell, it's not predatory. It means that there is verification of Editorial quality, Publication standards, Content focus, International scope, Publishing frequency, Language, Technical quality

That doesn't mean that the data itself is verified or the test methodology is flawless. You could fabricate all the data like a LARP. There can be errors and mistakes or limitations in the study. But what it means is that the limitations and errors should be discussed in the body of the text. It's good for preliminary data that you need published to get grant funding to do a "real study" with more people.

https://www.cell.com/heliyon/pdf/S2405-8440(22)00709-5.pdf

What it showed was that they took 3 people who claimed EMF sensitivty. Two of them, nothing valid. One test subject, the results were strong enough that they couldn't say it was entirely bogus.

 

[fpitas]

1) No evidence on this specific product.
2) Insufficient evidence to support sensitivity to EMF pollution is a real thing
3) For the money and time spent on EMF shielding it's better for the vast majority of us to spend that money and time on exercise, eating healthy, and taking time to improve mental health instead of focusing on something that is very difficult to control (other than going WiFi and cell-phone free at home and using a deskop and landline).

But strictly from the perspective of a scientist and the belief that we should consider exceptions to the rule, here's a peer reviewed paper which is part of Cell and indexed by PubMed. It is open access (pay to publish) which means it takes no advertisers which has the paradox of being both good/bad.

When something is open access, it could be a predatory journal with no standards. When an open access journal is indexed by PubMed, and affiliated with a flagship journal like Cell, it's not predatory. It means that there is verification of Editorial quality, Publication standards, Content focus, International scope, Publishing frequency, Language, Technical quality

That doesn't mean that the data itself is verified or the test methodology is flawless. You could fabricate all the data like a LARP. There can be errors and mistakes or limitations in the study. But what it means is that the limitations and errors should be discussed in the body of the text. It's good for preliminary data that you need published to get grant funding to do a "real study" with more people.

https://www.cell.com/heliyon/pdf/S2405-8440(22)00709-5.pdf

What it showed was that they took 3 people who claimed EMF sensitivty. Two of them, nothing valid. One test subject, the results were strong enough that they couldn't say it was entirely bogus.

That paper is referencing cell phone frequencies.

 

[GXAlan]

That paper is referencing cell phone frequencies.

I would have called even cell phone/FM frequencies outside the realm of accepted science. But when I go to debunk something, I always do a quick check and I was surprised to see that paper.

At lower frequencies, you see stuff like this:

Electromagnetic frequencies in ELF range (<30 Hz) has negative effects on rodents
https://www.sciencedirect.com/science/article/abs/pii/S0304394008000724
but it actually is restorative/helpful in stroke patients
https://onlinelibrary.wiley.com/doi/abs/10.1002/bem.22055

So is it good or bad? Probably not a straightforward answer. Water can kill you in overdose or in a drowning, but it's also essential for life.

It's pretty obvious that Zippy is not an audiophile and joined specifically to say something good about this product and has the simple conflict of interest of being a customer if not a greater conflict of interest. I use mesh WiFi and 5G in my home, and I'm even typing this on a laptop running on WiFi. This is purely an academic discussion, since, my point from above still stands: Don't spend the money on this unless this is part of your mental health addressing your anxiety in a relatively innocuous way. It's probably better to buy AC line conditioners than ingest random unregulated supplements, etc.

But I'm not here to call Zippy names, or anything like that. What I would say to Zippy, is that suppose you really are the rare person/family who is more sensitive to EMF than the general population. If it's your family, it's not genetic from the standpoint of the unlikelihood that you/your spouse share the rare issue. Relative to the general healthy population, what's your diet like? What's your exercise and physical activity like? What's your overall level of stress and anxiety about other things. AC line conditioning for health reasons is masking the problem even if a problem actually exists.