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

[RickS]

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.

Thanks, it is rather dismal...

Major downgrade from the day when he at least attempted to have anechoic space. Lack of a mic boom almost certainly means some stand reflections. Surprised he can get his gate to 4 msec even. Off axis measurements will be affected by base that extends too far. Clearly shows where his priorities are versus his vast space devoted to speaker demonstration.

 

[Ropeburn]

Thanks, it is rather dismal...

View attachment 533113

Major downgrade from the day when he at least attempted to have anechoic space. Lack of a mic boom almost certainly means some stand reflections. Surprised he can get his gate down to 4 msec even. Off axis measurements will be affected by base that extends too far. Clearly shows where his priorities are versus his vast space devoted to speaker demonstration.

Iirc, he got a rather large area there with plenty of space. Whole barns worth. Very "American" - in the middle of nowhere with no space constraints to speak of.

My educated guess from his talk about the old chamber: too much work, doesn't bother.

 

[Maxim-ICOM]

Thanks, it is rather dismal...

View attachment 533113

Major downgrade from the day when he at least attempted to have anechoic space. Lack of a mic boom almost certainly means some stand reflections. Surprised he can get his gate down to 4 msec even. Off axis measurements will be affected by base that extends too far. Clearly shows where his priorities are versus his vast space devoted to speaker demonstration.

4ms it is enough to see what happens there as on-axis too of-axis if gate set to show only first reflection. Nearest reflecting surfaces are at longer distance and cut from the response.

Gated + nearfield measurements are well-described decades ago, first references are end of 60th :

Measuring Loudspeaker Low-Frequency Response

With the availability of low-cost, PC-based acoustic data acquisition systems, experienced hobbyists can make highly accurate loudspeaker frequency-response measurements without an anechoic chamber. The power of these systems comes at a price. These systems window the time-domain measurement to...

audioxpress.com

https://www.audiomatica.com/wp/wp-content/uploads/Testing-Loudspeakers-at-low-Frequencies-with-CLIO.pdf

Would be great to steer the discussion back toward “Audio Science,” where the focus is on technical aspects and objective analysis, rather than searching for any possible reason to diminish “GR” with Clio and elevate “ASR” with Klippel

 

[RickS]

4ms it is enough to see what happens there as on-axis too of-axis if gate set to show only first reflection. Nearest reflecting surfaces are at longer distance and cut from the response.

Gated + nearfield measurements are well-described decades ago, first references are end of 60th :

Measuring Loudspeaker Low-Frequency Response

With the availability of low-cost, PC-based acoustic data acquisition systems, experienced hobbyists can make highly accurate loudspeaker frequency-response measurements without an anechoic chamber. The power of these systems comes at a price. These systems window the time-domain measurement to...

audioxpress.com

https://www.audiomatica.com/wp/wp-content/uploads/Testing-Loudspeakers-at-low-Frequencies-with-CLIO.pdf

Thanks, but have done plenty of gated measurements in my much more limited space. As mentioned, he has the space to likely do better than 4 msec but chooses not to do so. I also do nearfield measurements that Danny refuses to do.

Would be great to steer the discussion back toward “Audio Science,” where the focus is on technical aspects and objective analysis, rather than searching for any possible reason to diminish “GR” with Clio and elevate “ASR” with Klippel

If you pay closer attention, had already posted that CLIO rig was not Danny's downfall. We have already shown his process shortcomings, just wondered why some of it might be. Notably, he still refuses to value distortion measures while is the only clear metric that showed why he needed to do a v2. Cannot imagine there is much more audible problem than when you overdrive a tweeter to the point of potential failure.

 

[Geert]

4ms it is enough to see what happens

Not to reliably determine if low and mid frequency resonances are audible in a waterfall spectrum, that requires gating times spanning 15 ms to 30 ms. The 4 ms window time smears out resonances across a wider band and might give the impression of a faster decay rate than what is physically happening.

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

If we use a linear extrapolation from the data provided with the 4 ms windowed measurement, we get an T60 decay time for that resonance Danny is focused on of about 9.6ms. (To busy so asked IA to derive that time from -25 dB amplitude at 4 ms, hope it didn't made any errors). That's very short, which means it will be masked. So the resonance won't be audible as 'ringing', as Danny calls it, but it might color the sound if the peak level is high enough and his has sufficient bandwidth. Which brings us back to the remark about the limited window time I made above.

 

[RickS]

Not to reliably determine if low and mid frequency resonances are audible in a waterfall spectrum, that requires gating times spanning 15 ms to 30 ms. The 4 ms window time smears out resonances across a wider band and might give the impression of a faster decay rate than what is physically happening.



If we use a linear extrapolation from the data provided with the 4 ms windowed measurement, we get an T60 decay time for that resonance Danny is focused on of about 9.6ms. (To busy so asked IA to derive that time from -25 dB amplitude at 4 ms, hope it didn't made any errors). That's very short, which means it will be masked. That's also why, as other already explained, the frequency response doesn't show anything alarming. So the resonance won't be audible as 'ringing', as Danny calls it, but it might color the sound if the peak level is high enough and his has sufficient bandwidth. Which brings us back to the remark about the limited window time I made above.

I agree there are too many instances where we need clearer information around audibility than what Danny alleges. Dr. Toole helps define some of it for resonances but looking at graph with manipulated scaling and trying to judge low Q vs higher Q can get subjective...

Identifying a resonance, determining its root cause and then applying a proper remediation is good engineering. Danny may have identified a resonance but is not disciplined enough to determine the root cause and applies his usual crude hammer (crossover mod) to attempt to remediate. His remediation results in a FR change that is more audible than the resonance he alleges is a major issue. Is another case of ready, fire, aim on Danny's part. What is really rich when he tries to defend his notch filter when it introduces the FR dip that Amir highlights but still tries to rationalize despite the lack of root cause and demonstrated audibility.

 

[sam08861]

I have to wonder how many other speaker designers in practice don't use anechoic chambers.

Anyone know if well respected , but smaller operations who may not have the means of JBL/Harman, etc such as Zu Audio, Linkwitz of Linkwitz-Reily fame or if Andrew Jones used one for his new field coil speaker design?

Certainly there's a very limited number of these spaces with Apple and Microsoft having a good chunk of them, given their financial means, but I suspect for daily analysis 'renting' one of these spaces is problematic.

Any professional speaker designers who have produced commercially available speakers or crossovers care to comment on their spaces and processes for design?

As an aside.. Interesting commentary from Andrew.. https://www.****************/2025/10/measurement-tools-tricking-audiophiles-warns-speaker-designer/ (Yes, the website is AI garbage, but this contains quotes from Andrew, so let's look past that and at the substance please)

 

[sam08861]

Looks like that link above is being weirdly censored, so you'll have to google it. Necessary keywords are present.

 

[Ropeburn]

Looks like that link above is being weirdly censored, so you'll have to google it. Necessary keywords are present.

That site is auto-censored here deliberately and for a reason.

the website is AI garbage

 

[amirm]

Looks like that link above is being weirdly censored, so you'll have to google it. Necessary keywords are present.

We have already had a thread on it.

 

[RickS]

I have to wonder how many other speaker designers in practice don't use anechoic chambers.

Anyone know if well respected , but smaller operations who may not have the means of JBL/Harman, etc such as Zu Audio, Linkwitz of Linkwitz-Reily fame or if Andrew Jones used one for his new field coil speaker design?

Certainly there's a very limited number of these spaces with Apple and Microsoft having a good chunk of them, given their financial means, but I suspect for daily analysis 'renting' one of these spaces is problematic.

Any professional speaker designers who have produced commercially available speakers or crossovers care to comment on their spaces and processes for design?

As an aside.. Interesting commentary from Andrew.. https://www.****************/2025/10/measurement-tools-tricking-audiophiles-warns-speaker-designer/ (Yes, the website is AI garbage, but this contains quotes from Andrew, so let's look past that and at the substance please)

Try using the search function in the upper right and you will find answers to this question and many others. If you do not find, please feel free to send me a DM and will help! 

 

[sam08861]

Try using the search function in the upper right and you will find answers to this question and many others. If you do not find, please feel free to send me a DM and will help! 

Seems a bit evasive, but, sure.

 

[amirm]

Very few companies have anechoic chambers. Some will use outside services. Overall, they represent small minority of Speaker companies.

 

[RickS]

Seems a bit evasive, but, sure.

Only intended to help without cluttering thread. Your call.

 

[Keith_W]

Seems a bit evasive, but, sure.

This is the thread you want. It has been closed. Look at the last page (post 254) and you will understand why that website has been banned from ASR.

 

[Ropeburn]

Very few companies have anechoic chambers. Some will use outside services. Overall, they represent small minority of Speaker companies.

Hm. Would it be valid to say, too many of them live in echoic chambers?

 

[sam08861]

This is the thread you want. It has been closed. Look at the last page (post 254) and you will understand why that website has been banned from ASR.

Thanks, watched the associated video. Lol, seeing cheap audio man being there reminds me of Forrest Gump. Afflicted with bradyphrenia (perhaps like myself), but somehow manages to be present wherever the action is! (sorry, couldn't resist)

Completely understandable that the entirety of the website is banned and I haven't yet read post 254

 

[Vergiliusma]

Would be great to steer the discussion back toward “Audio Science,” where the focus is on technical aspects and objective analysis, rather than searching for any possible reason to diminish “GR” with Clio and elevate “ASR” with Klippel

I think it was the arrogance that rubbed most folks the wrong way. Kind of like a surgeon with the hunting knife telling the one with the scalpel to step aside.

Dave from Ascend Acoustics and Tom from Power Sound Audio both purchased Klippels to refine their designs.

Dennis Murphy from Philharmonic Audio uses quasi-anechoic measurements to good effect, and then submitted a few models for Klippel testing.

The late Jeff Bagby and Charlie Laub created software for the DIY community for speaker design, taking into account things like Z-offset, accurately blending nearfield and farfield responses, and diffraction. REW and VituixCAD can get you there too.

It's not as much about the tools, but higher resolution is better, and making sure what you're measuring is accurate.

 

[xray]

Kind of like a surgeon with the hunting knife telling the one with the scalpel to step aside.

I think you are giving him too much credit comparing him to a surgeon. Maybe a butcher with a cleaver is closer to the truth.

 

[Ropeburn]

I think you are giving him too much credit comparing him to a surgeon. Maybe a butcher with a cleaver is closer to the truth.

Hey now, that's a respectable profession full of people who know what they're doing.