GR Research Speaker Upgrade Review (Sierra-2EX V2)

[amirm]

Is it true that EMI tests were performed on a cord in a wall with no load?
Or that the xo was tested with incorrect polarity?

Answering second part, I contacted Danny prior to publication of my review. He told me about the woofer possibly being wired wrong. I investigated and it seemed to be the case. So I modified the speaker and measured again. It made almost no difference because the problem is elsewhere. All of this was documented clearly in my text and video reviews which Danny hasn't bothered to read: https://www.audiosciencereview.com/...v123-gr-research-x-voce-speaker-review.49563/

Before the wiring change:

After the wiring change:

I even took a picture of said wiring:

Really disappointed that folks take Danny's claims at face value.

Anyway, on your power cable interference test, remember, Danny's claim is that NO radiation occurs in such an AC cable. That, is false as a matter of physics, and demonstration I showed. And the fact that very same test causes interference in some audiophile cables. To the extent such cables pick up this kind of interference already, what good does it do to try to create a more severe case???

Please note that I am not trying to create an "EMI Test." This is a quick test to see if the screwing geometry these companies use, such as lack of shielding, passes the smell test. And they don't. If someone thinks they magically work better when the radiation is larger, then be my guest.

Also note that this is one of many tests I do. In other cases, I use a transformer which creates a pretty strong field with similar outcomes.

 

[amirm]

So onto the Ringing waterfall exhibits presented by Danny. Any truth to this?

None. As noted, he somehow managed to get different results with his own measurements this time around!

If I decided to do another video, I will show the Klippel generated waterfalls.

 

[RickS]

Thanks dfuller.

That seems reasonable & I don't doubt the fundamental premise that 'power cables don't matter' as much as other things with respect to amplification of source materials at line level.

However, it seems perhaps this was tested with no load to emphasize a point about relative impacts of noise on cable vs. other things. I think there would be a lot more credibility if the unit were plugged in and actively producing music through an amp and speakers, for lay people such as myself, who may not be able to readily understand that there won't be a difference in measurements contrary to the premise.

My own curiosity, though, remains unsatisfied, and I'll have to figure out how to test myself or see if someone else has.

On another topic, addressed to the wider group...

With regard to the induced XO dip used to address ringing. Do we think these were random exhibits produced after the fact or were the waterfall measurements also available in Amir's testing, showing a slightly reduced ringing. Also, curious, as the ringing is not completely eliminated, if the benefit is a better looking graph or real audible differences. Certainly they are measurable, if legitimate and confirmable.

Danny’s hyperbole regarding CSD has been debunked previously and as recently as earlier in this thread…

GR Research Speaker Upgrade Review (Sierra-2EX V2) [Video]

He did no such thing. He *claims* AI said it pulled such quotes out of ASR. But he neither shows the prompt he used, or the response. I repeated his experiment, with exact question he said he asked: "audible effects of electrical shift of phase in speaker's impedance" This is the answer...

www.audiosciencereview.com

 

[sam08861]

Many thanks Amir for the considered and considerate responses!

 

[sam08861]

Loudspeakers are minimum-phase devices. Waterfall diagrams add no new information. Our ears aren't sensitive to ringing, but are to frequency response irregularities (resonances), which are revealed in frequency response measurements. Here is a post by Dr Toole on AVSForum.
View attachment 532965

Many Thanks! Reading up on this now.

 

[sam08861]

Danny’s hyperbole regarding CSD has been debunked previously and as recently as earlier in this thread…

GR Research Speaker Upgrade Review (Sierra-2EX V2) [Video]

He did no such thing. He *claims* AI said it pulled such quotes out of ASR. But he neither shows the prompt he used, or the response. I repeated his experiment, with exact question he said he asked: "audible effects of electrical shift of phase in speaker's impedance" This is the answer...

www.audiosciencereview.com

Thanks RickS,

I agree with these being mostly room related artifacts in practice, at least from my own experience, measuring for room correction on a set of speakers in different environments and even different positions in the same room.

Certainly this pleads the case for an anechoic chamber at the very least. Even though Danny stated that they built one and have that as an asset, and found little difference, it is a curiosity why GR wouldn't use that as a marketing ploy at the very least or to quell any doubt, even if there's no benefit in their minds.

 

[sam08861]

I even took a picture of said wiring:

That's fantastic! This helps me feel good there weren't potential 2nd order xo related phase inversions. (assuming it's a 2nd order, based on Danny's suggestion there's a 180 degree phase cancellation?)

 

[RickS]

There was some earlier discussion around Danny’s use of CLIO. While it is a usable tool, some of his measurements do call into question how good his actual setup is. Whether if he sets the initial axis properly, has proper speaker and microphone mounting and calibrations are all crucial to making high quality measurements. Anyone who has attempted knows this is not trivial. Notably whether any attempt to establish a baseline and ensure that baseline is repeatable between measurement sessions. This ensures that loose mountings or connections do not cause significant errors. Speaker testing is highly dependent on the test environment.

With all the talk of fans visiting Danny, has anyone discussed or shown pics of his measurement rig?

 

[Everett T]

Everett T said:
As I understand EMI being device originating it's the equipment that would need to be dealt with and wouldn't fluctuate with current, like ground loops.

---
I understand Ampere's law suggests more current = more flux (and therefore higher noise floor, I'm assuming)? so, I think again a slightly different question than this, but certainly appreciate what you're saying.

It's a well known phenomenon (reality) in pro audio (and in my own experience), noise often very often originates from the interplay between power cables and interconnects. This was a problem that was readily apparent, in my own bi-amped system, with a 106db efficient horn.

Cable selection and routing was tremendously helpful in remediating this, as was component selection, particularly at the active crossover and all pre-amplified components in the 'gain chain'. Using properly shielded interconnects and careful routing of power/signal cables is a well established practice for most professional audio guys, so i'm not at all convinced it's trivial.

As an aside, I certainly don't think we need expensive or exotic cables, the inexpensive shielded cables from belden, canare, mogami, etc. work just fine. However, there is significant interference between power supply cable generated noise and interconnects, IME.

I agree with what you're statung, and I wasn't clear regarding the power cords and interconnects. As long as the cables are made correctly and are correct for the application, they shouldn't play a role in improving mains noise or EMI audibly. I'll have to read Amperes law and how it's applied to higher current.

 

[Vergiliusma]

If I decided to do another video, I will show the Klippel generated waterfalls.

Your call, but I wouldn't bother. It's hard to have a "discussion" with someone who doesn't believe in the efficacy/accuracy of the CTA-2034, via the Klippel, and its ability to detect resonances without some representation in the time domain.

 

[Buckeye Amps]

Even though Danny stated that they built one and have that as an asset

What he claims to have built IS NOT a true anechoic chamber, not by a long shot.

 

[amirm]

With all the talk of fans visiting Danny, has anyone discussed or shown pics of his measurement rig?

Yes they have! I post a video by Jay Iyagi where he shows his setup with alligator clips and such outside of the speaker. Speaker is barely lifted from the floor and there are ceilings, etc.

 

[amirm]

Your call, but I wouldn't bother. It's hard to have a "discussion" with someone who doesn't believe in the efficacy/accuracy of the CTA-2034, via the Klippel, and its ability to detect resonances without some representation in the time domain.

My main motivation in doing a video is the general topic of gating. So many published speaker measurements use it that education on that front will be useful to folks. Alas, it is fair bit of work so I have to get motivated to do it.

 

[amirm]

Certainly this pleads the case for an anechoic chamber at the very least. Even though Danny stated that they built one and have that as an asset, and found little difference, it is a curiosity why GR wouldn't use that as a marketing ploy at the very least or to quell any doubt, even if there's no benefit in their minds.

They bought a bunch of foam wedges and stuck them on the wall and expected that to make an anechoic chamber. If it was that easy, folks wouldn't spend a million dollars with specialized companies to build a proper one!

Here is what he showed in his video:

No way, no how those short wedges were effective below a few hundred hertz. Yet he claimed it was good enough down to 40 Hz. Even the large anechoic chamber at Harman loses its anechoic nature below 80 Hz and needs calibration. No wonder then that when he compared his measurements in that room vs his gated one, he didn't see much difference.

He really doesn't have proper foundation in acoustics science.

 

[amirm]

Here is actual data point. He said they bought Auralex wedges. Here is the thickest they sell which is 4 inches deep:

Looks pretty much like what they bought. Here is their certified test data:

Alpha or absorption coefficient needs to be 1.0 for total absorption. As you see above, it doesn't get to that point until 300 Hz! At 160 Hz, it only provides 1/3 absorption with the rest reflected back. Company doesn't even test below 100 Hz!

 

[Buckeye Amps]

Here is actual data point. He said they bought Auralex wedges. Here is the thickest they sell which is 4 inches deep:

Looks pretty much like what they bought. Here is their certified test data:

Alpha or absorption coefficient needs to be 1.0 or total absorption. As you see above, it doesn't get to that point until 300 Hz! At 160 Hz, it only provides 1/3 absorption with the rest reflected back. Company doesn't even test below 100 Hz!

I said this before, but the similarities between him and Stockton Rush (OceanGate) is hilarious.

Danny - Behold, my anechoic chamber that doesn't even come close to industry accepted standards but what does the industry know anyways?
Stockton - Behold, my carbon fiber sub that doesn't even come close to the industry certification standards but what does the industry know anyways?

 

[dfuller]

Loudspeakers are minimum-phase devices.

Well... Mostly. You can have bad designs with excess phase rotation from crossovers.

Waterfall diagrams add no new information. Our ears aren't sensitive to ringing, but are to frequency response irregularities (resonances), which are revealed in frequency response measurements

This isn't strictly true. They can reveal things like baffle reflections that don't show up readily on a FR graph but can definitely have an audible effect.

 

[Vergiliusma]

This isn't strictly true. They can reveal things like baffle reflections that don't show up readily on a FR graph but can definitely have an audible effect.

It'll still be there in the Spin. Toole calls it acoustical interference, which are anomalies over a more narrow range of angles, as opposed to resonances which are present in all the curves--large angular range.

 

[MAB]

I said this before, but the similarities between him and Stockton Rush (OceanGate) is hilarious.

Danny - Behold, my anechoic chamber that doesn't even come close to industry accepted standards but what does the industry know anyways?
Stockton - Behold, my carbon fiber sub that doesn't even come close to the industry certification standards but what does the industry know anyways?

If bad sound reproduction was harmful we would all be dead.

 

[Haskil]

They bought a bunch of foam wedges and stuck them on the wall and expected that to make an anechoic chamber. If it was that easy, folks wouldn't spend a million dollars with specialized companies to build a proper one!

Here is what he showed in his video:

View attachment 533029

No way, no how those short wedges were effective below a few hundred hertz. Yet he claimed it was good enough down to 40 Hz. Even the large anechoic chamber at Harman loses its anechoic nature below 80 Hz and needs calibration. No wonder then that when he compared his measurements in that room vs his gated one, he didn't see much difference.

He really doesn't have proper foundation in acoustics science.

Mise en service de la chambre sourde des Etablissements Cabasse — Forum Cabasse

www.forumcabasse.org

Kergonan — Forum Cabasse

www.forumcabasse.org

Cabasse

Situé en Bretagne dans l'ouest de la France, le Cabasse Acoustic Center se compose notamment d'une chambre anéchoïque conçue sur mesure. Cette chambre sourde de 500m3 est indispensable à la...

www.facebook.com

Notre Histoire - Cabasse

Notre Histoire - Cabasse

www.cabasse.com

A real anéchoic chamber. The greatest in Europe at the begining of sixties... Poor Ritchie....