Tekton M-Lore Speaker Review

[ctrl]

Amir's impedance measurement is also flawed and reflects the supplied feet were not used and with no provisions to plug four 1/4 - 20 threaded inserts resulting in him publishing a flawed impedance measurement, flawed distortion measurements, flawed cumulative spectral decay, and lowered bass output in the frequency response measurements due to internal cabinet pressure losses.

Anyway, I hope your video has proper, anechoic, CEA-2034 compliant data with and without said screw holes.

I hope I understood this correctly. In Amir's and Erin's measurements, the focus is on four non-sealed holes (screw holes) in the enclosure with a diameter of 1/4'' and how strongly they have affected the measurements.
@Eric Alexander, the speaker designer of the two speakers, believes that this circumstance renders the measurements completely unusable.

What's the issue?
To understand this, let's first estimate the impact of four holes, each with a diameter of 6mm, in a roughly 30L enclosure with 2cm (0.8'') thickness of material. So, let's consider their behavior as Helmholtz resonators, in this case, a quadruple bass reflex system.

The BR resonance frequency f is roughly calculated as (without port correction term):
f = 154*(portNumbers * portDiameter[cm]^2 / portLength[cm] * cabVolume[L])^0.5
f = 154* (4 * 0.6^2 / 2 * 30)
f = 24 Hz

The resonance frequency of the BR system for the four screw holes in the enclosure realistically lies in the 20Hz range (with port length correction). This means that these openings will hardly have any effect at higher frequencies.

Are port resonances caused by the screw holes a problem?
The fundamental resonance for a double-ended open pipe (our screw hole BR ports) is given by f = c / (2 * PortLength). So, the fundamental resonance for a screw hole is at 344 / 2*0.02 = 8600Hz. Therefore, due to the high frequency, low expected sound pressure level, and strong directional effect of the radiated sound, these do not play a role.

Maximal impact of four screw holes?
To better estimate the range of influence, let's simulate a 30L sealed speaker and then this speaker with the four screw holes under ideal conditions to get a hint of the maximal possible impact under ideal conditions:


Dashed blue line is the FR of the sealed speaker. In black is the simulated four screw hole BR speaker under ideal conditions (red is port FR, blue is cone FR).
So for very low SPL this is the maximal impact.
We can see above 90Hz there is no impact on the frequency response. In real life with normal SPL the impact will be much lower.

So what is the screw hole impact on Amir's Mini-Lore measurement?
Our simulation above shows that the four screw holes act under ideal conditions as four mini BR ports. This shows up in the simulated impedance diagram:

The dashed line shows the impedance FR of the simulated 30L sealed speaker. The black line is the typical double hump of a BR system. So we expect below 20Hz a hump caused by the four screw hole resonators.

Lets see if we can find such an impact in Amir's Mini-Lore Impedance measurement:

Seems that the impact of the four screw holes is not significant - there is nothing to see in this range (see pink rectangular). So if the speaker would be re-measured by Amir (or by Erin the other speaker if cabinet volume is similar) the impact below 90Hz will probably be low and above 90Hz the measurement will probably not change at all. Same goes for distortion, CSD, ...
So, it seems 'screw gate' is more of a storm in a teacup.

If I screwed some things up, let me know.

 

[Newman]

In Amir's and Erin's measurements, the focus is on four non-sealed holes (screw holes) in the enclosure

For this speaker, Alexander primarily focused on the reference axis not being what he specifies, and hence a “much worse” frequency response and step response. He additionally mentions the open holes causing “a flawed impedance measurement, flawed distortion measurements, flawed cumulative spectral decay, and lowered bass output”, and his suspicion that the speaker has been compromised by age.

 

[gnarly]

The one spec on the Tekton site for the Mini-Lore that screamed BS to me...is pain ole sensitivity.
95 dB 1W/1m .....out of a 1" dome and an 8" woof ????? ....on what planet...

Problem i have when I see something so out of whack with even one spec, is it makes everything suspect.

 

[dfuller]

I hope I understood this correctly. In Amir's and Erin's measurements, the focus is on four non-sealed holes (screw holes) in the enclosure with a diameter of 1/4'' and how strongly they have affected the measurements.
@Eric Alexander, the speaker designer of the two speakers, believes that this circumstance renders the measurements completely unusable.

What's the issue?
To understand this, let's first estimate the impact of four holes, each with a diameter of 6mm, in a roughly 30L enclosure with 2cm (0.8'') thickness of material. So, let's consider their behavior as Helmholtz resonators, in this case, a quadruple bass reflex system.

The BR resonance frequency f is roughly calculated as (without port correction term):
f = 154*(portNumbers * portDiameter[cm]^2 / portLength[cm] * cabVolume[L])^0.5
f = 154* (4 * 0.6^2 / 2 * 30)
f = 24 Hz

The resonance frequency of the BR system for the four screw holes in the enclosure realistically lies in the 20Hz range (with port length correction). This means that these openings will hardly have any effect at higher frequencies.

Are port resonances caused by the screw holes a problem?
The fundamental resonance for a double-ended open pipe (our screw hole BR ports) is given by f = c / (2 * PortLength). So, the fundamental resonance for a screw hole is at 344 / 2*0.02 = 8600Hz. Therefore, due to the high frequency, low expected sound pressure level, and strong directional effect of the radiated sound, these do not play a role.

Maximal impact of four screw holes?
To better estimate the range of influence, let's simulate a 30L sealed speaker and then this speaker with the four screw holes under ideal conditions to get a hint of the maximal possible impact under ideal conditions:

View attachment 362989
Dashed blue line is the FR of the sealed speaker. In black is the simulated four screw hole BR speaker under ideal conditions (red is port FR, blue is cone FR).
So for very low SPL this is the maximal impact.
We can see above 90Hz there is no impact on the frequency response. In real life with normal SPL the impact will be much lower.

So what is the screw hole impact on Amir's Mini-Lore measurement?
Our simulation above shows that the four screw holes act under ideal conditions as four mini BR ports. This shows up in the simulated impedance diagram:
View attachment 362990
The dashed line shows the impedance FR of the simulated 30L sealed speaker. The black line is the typical double hump of a BR system. So we expect below 20Hz a hump caused by the four screw hole resonators.

Lets see if we can find such an impact in Amir's Mini-Lore Impedance measurement:
View attachment 362991
Seems that the impact of the four screw holes is not significant - there is nothing to see in this range (see pink rectangular). So if the speaker would be re-measured by Amir (or by Erin the other speaker if cabinet volume is similar) the impact below 90Hz will probably be low and above 90Hz the measurement will probably not change at all. Same goes for distortion, CSD, ...
So, it seems 'screw gate' is more of a storm in a teacup.

If I screwed some things up, let me know.

In other words, this is a total non-issue, and Eric should be ashamed of himself for suggesting that it could make such a huge difference.

 

[thewas]

To better estimate the range of influence, let's simulate a 30L sealed speaker and then this speaker with the four screw holes under ideal conditions to get a hint of the maximal possible impact under ideal conditions:


Dashed blue line is the FR of the sealed speaker. In black is the simulated four screw hole BR speaker under ideal conditions (red is port FR, blue is cone FR).

Although like you say from the measurements of Amir rather unlikely it would have been funny if those little BR ports would even help it to a deeper and smoother bass response. In this in the future I wouldn't be surprised of claims that the holes and screws play the role of the ports and bungs that some loudspeakers are sold with to adapt the port behaviour to the desired room and placement and were part of the engineering.

 

[olieb]

In other words, this is a total non-issue, and Eric should be ashamed of himself for suggesting that it could make such a huge difference.

This was to be expected already from eyeballing but thanks to @ctrl for the thorough investigation.

 

[Muddywaters]

https://www.facebook.com/AlleghenyExcavating/photos/a.515729451797204/683632621673552

The Law of Holes

Law of holes - Wikipedia

en.m.wikipedia.org

Free advice for Alexander the inGrate

 

[haraldo]

IMHO, only one thing to say, this kind of bullying from Eric Alexander is something we never should have around here .... to me Tekton Design is a dead company!

 

[IAtaman]

Watched both of the videos published to understand Tekton's perspective, this is what I make of it:

Guy finds a niche selling non-offending speakers to audiophiles.
Business is good for years, until one day, people measure his speakers and find out that they are actually not very good.
Infuriated by declining sales figures, and incapable of swallowing the humble pill or making a technical case, he lashes out and threatens the reviewers with litigation.
It turns out, he does not even know what litigation means.

Moral of the story : if you are in the business of selling engineering products, you better know what you are doing really well, or be humble. Ideally both.

People feel bad for the guy; a small business trying to make a living. I can relate to that. To a certain degree. The homeopathy guru used to be able to make a living curing people. Now we all go to the hospital, and the Guru has lost his business and your health is better for it. Don't be sad for the guru - be thankful for the modern medicine.

There is one area I can relate to however : if someone who has a large audience and access, reviews your product, rather incompetently, and says negative things about it, what discourse does the manufacturers have to affect the public opinion? What is it that you can do to get your side of the story heard? In the case of ASR, the forums are open to everyone and the manufacturers can share their thoughts and insights with everyone, and if done properly, it is usually welcomed. But that is not true for all reviewers is it? In this instance Tekton is the bully maybe, but I can see how manufacturers can be bullied by reviewers as well.

 

[DLS79]

1. I sincerely believe Eric Alexander is a bully, most likely a bully for the majority of his life. He most likely haven't face many people stood up to his bullying ways, which explains why he thought his bluff of legal actions would have worked.
2. What has developed was a rude awakening for Eric Alexander and people like him, Eric Alexander likely have never dealt with such a crisis and retaliation, I believed he is humbled, very very humbled to say the least. I also believe people like Eric do need to be humbled through one way or another for the public's sake; in this case for the consumers' sake.

The first thing that came to mind when i read this!

 

[dasdoing]

Huh? Speaker dispersion does not change the slightest just because the 0 degree reference point has been moved.

yea, was a mistake. but that wasn't my main point

The crossover is at 3kHz and does not seem to be very broken. At 2.5kHz the mid-woofer seems to have a bump... and is not very linear overall either.

the time alignment is crucial in a cross-over. there seems to be cancelation on the tweeter axis.

Now, on a sidenote: if the woofer is the correct height, was this mentioned in the manual?

 

[Doodski]

Watched both of the videos published to understand Tekton's perspective, this is what I make of it:

Guy finds a niche selling non-offending speakers to audiophiles.
Business is good for years, until one day, people measure his speakers and find out that they are actually not very good.
Infuriated by declining sales figures, and incapable of swallowing the humble pill or making a technical case, he lashes out and threatens the reviewers with litigation.
It turns out, he does not even know what litigation means.

Moral of the story : if you are in the business of selling engineering products, you better know what you are doing really well, or be you be humble. Ideally both.

People feel bad for the guy; a small business trying to make a living. I can relate to that. To a certain degree. The homeopathy guru used to be able to make a living curing people. Now we all go to the hospital, and the Guru has lost his business and your health is better for it. Don't be sad for the guru - be thankful for the modern medicine.

He apparently set himself up for this. He must have known that one day his colored speakers would be scrutinized like many others have been. Maybe the crowd that likes colored speakers has simply grown out of that and that's why he has reduced sales? Nobody's fault other then his own I think.

 

[DLS79]

Now, on a sidenote: if the woofer is the correct height, was this mentioned in the manual?

As far as I can tell none of his speakers come with a manual. Even his most expensive models. None of the product pages mention a manual and the website doesn't have a download section.

take a look at his most expensive model $14,000 USD for a pair minimum.

1812 Model V12

tektondesign.com

this is all the information he provides.

• 4-way design
• Single 18″ subwoofer capsule
• 12 6.5″ mid frequency transducers
• 12 1″ high frequency transducers
• 1 compression bullet super tweeter
• H 71″ x W 23″ x D 26″ 300lbs
• Sensitivity 104dB 1W @ 1m
• 140dB maximum output each
• 4 Ohm Impedance
• Frequency response 20Hz – 30kHz
• Power handling – 2500 Watts
• Manufactured in the USA

Manufactures who sell significantly cheaper speakers provide far more information than this, almost to the point of information overload.
for example Neumann KH 120 II

click on Data & Diagrams

Then view the download section for the model.

https://www.neumann.com/en-gb/file-finder/?productName=KH+120+II

 

[Doodski]

take a look at his most expensive model $14,000 USD for a pair minimum.

1812 Model V12

tektondesign.com

Wow!

• Sensitivity 104dB 1W @ 1m
• 140dB maximum output each

 

[gnarly]

If I screwed some things up, let me know.

I'm not about to say anything's screwed up...pretty cool analysis considering the 4 holes as little Helmholtz resonators.

I've built a number of DIY ported boxes, subs and mid bass. They all go through a prototype stage where I screw them together as tight as I can, to take them out on the driveway and measure. Only screwed together because port size and length often need adjustments, requiring disassembly/reassembly. But screwed together tightly; and if any joint looks suspect I put a bead of silicone on it.

When proto is over and time to build final version, box gets glued together and silicone put in all panel joints.

Point of all this is....I've learned how getting final box tight, makes the port response behave much closer to simulated predictions.
It's often a bit amazing how the transfer function moves in the right direction, compared to the proto stages when I thought the box was already tight enough.

So that's why I posting here...to explain and ask..
Do your sims take the 'leaky box' into effect, as well as the small resonators effect?

 

[Sokel]

Some of you may not like how this drama unfolded. I won't comment on it's development nor reveal my personal sentiments on the right or wrong of how things developed (at least not at this moment). But I will say this:

1. I sincerely believe Eric Alexander is a bully, most likely a bully for the majority of his life. He most likely haven't face many people stood up to his bullying ways, which explains why he thought his bluff of legal actions would have worked.
2. What has developed was a rude awakening for Eric Alexander and people like him, Eric Alexander likely have never dealt with such a crisis and retaliation, I believed he is humbled, very very humbled to say the least. I also believe people like Eric do need to be humbled through one way or another for the public's sake; in this case for the consumers' sake.
3. Rest assure, the next manufacturer who even considers bullying the little guys, will reconsider. And that is probably the outcome we all would want whether we like or dislike how this drama unfolded. I also think many will agree that the ultimate end result is the best for honest reviewers with integrity and for consumers alike.

I will stick to the FACT that this is a technical review and as such has it's rules.
See @ctrl 's post that follows for example?That has a place.
That's why we are in ASR.

And another,no guy is "little" and if we wanted drama we would read some gossip trash news.
I'm done with this thread.

 

[dfuller]

Yes there is. Amirm made a statement that the NFS is something that any serioust manufacturer has to use. I disagree on that.

Nobody has said that. But actually taking measurements during the design phase is pretty crucial... be that gated+nearfield stitch, anechoic, NFS, whatever. If you're dialing by ear only, then just say that.

 

[Everett T]

This isn't helping.. posted at AH this morning

 

[Berlin]

Person A asks person B to measure his/her used loudspeaker. Person B publishes the results and explains exactly how the measurements were taken. Nobody knows how old the speaker is or what has happened to it over the years. However, the manufacturer of the speaker complains about person B, but is obviously not interested in solving the problem.

This reminds me of traditions from the Middle Ages where the bearers of bad news were killed...

 

[DLS79]

This isn't helping.. posted at AH this morning

It would be hilarious if @amirm sued him for continued defamation attacks!