A new approach to point source?

[Heinrich]

The pretty common definition is simply that ...
When that is how the term is used, I'm not sure I see the point (hehe) of trying to come up with a theoretical one that no one will adhere to.

I'll make the point for you. I know, as a theoretical point it has dimension zero, no extent, and so cannot be seen, hence cannot be understood

In ernest, the wording is sloppy, and so missleads people every other day, as we see here in all glory.

A 'point source' in audio babble is an arrangement of speakers that doesn't exhibit a certain problem. What problem?
Hint: it is not general directivity - not.

Sorry for relating that fancy floppy term to actual acoustical (!) properties, and speaking of problems to be solved. Rest assured, no problem.

 

[sigbergaudio]

I'll make the point for you. I know, as a theoretical point it has dimension zero, no extent, and so cannot be seen, hence cannot be understood

In ernest, the wording is sloppy, and so missleads people every other day, as we see here in all glory.

A 'point source' in audio babble is an arrangement of speakers that doesn't exhibit a certain problem. What problem?
Hint: it is not general directivity - not.

Sorry for relating that fancy floppy term to actual acoustical (!) properties, and speaking of problems to be solved. Rest assured, no problem.

If I understand you correctly you would like it to mean a perfect omnidirectional source (all frequencies). This will never be built, so what will we use this term for then? Put it in a drawer?

We could create a new word to mean what point source is commonly used to describe now, but I am not sure we will be succesful in implementinng it.

You say it is misleading people every day, but I don't think most people walk around with your definition for this word, so how is it misleading exactly?

 

[Arindal]

I greatly prefer designs with coaxial drivers, as they give a combination of precise imaging and soundstage that I like a lot.

We should remark that you combine coaxial drivers with a passive cardioid, a technology which is capable of correcting one of the major downsides of conventional coaxial designs, the insufficient directivity index in the midrange´s lower band. I am not aware of any other manufacturer doing that.

With regards to driver arrays I am not a big fan as it it simply to complicated both from a design/engineering perspective and from an assembly / servicing perspective.

Is this really an issue? With P.A. applications, seemingly not, the number of drivers even in compact systems is apparently increasing.

I mean, we are talking about a limited number of drivers in a studio/hi-fi speaker (10 max), in most cases in active concepts with electronic limiter, which is also increasing the power handling and reducing the risk of a defect.

A 'point source' in audio babble is an arrangement of speakers that doesn't exhibit a certain problem. What problem?

If you refer to lobing or vertical interference, it is not such a problem as you are hinting.

And we should not forget that most of conventional coaxial designs are not free from similar effects, they just appear in a circular range, not a single point, and are pushed to higher frequency bands, or different angles respectively. Almost everything in speaker design is a compromise.

 

[Geert]

We could create a new word to mean what point source is

A more practical solution:

• If a sound source is so small in all dimensions when compared to the distance a receiver is located, this can be considered a point source.
• A 'true’ point source radiates sound equally in all directions.

 

[sigbergaudio]

Is this really an issue? With P.A. applications, seemingly not, the number of drivers even in compact systems is apparently increasing.

I mean, we are talking about a limited number of drivers in a studio/hi-fi speaker (10 max), in most cases in active concepts with electronic limiter, which is also increasing the power handling and reducing the risk of a defect.

Depends on who you ask. I currently assemble the speakers myself, I would prefer to not have 10 drivers.

 

[sigbergaudio]

We should remark that you combine coaxial drivers with a passive cardioid, a technology which is capable of correcting one of the major downsides of conventional coaxial designs, the insufficient directivity index in the midrange´s lower band. I am not aware of any other manufacturer doing that.

The non-cardioid SBS.1 is pretty tidy too.

 

[Arindal]

I currently assemble the speakers myself, I would prefer to not have 10 drivers.

I have an idea whom to ask... these I have recently seen at a trade fair.

 

[Heinrich]

If I understand you correctly you would like it to mean a perfect omnidirectional source (all frequencies). This will never be built, so what will we use this term for then? Put it in a drawer?

We could create a new word to mean what point source is commonly used to describe now, but I am not sure we will be succesful in implementinng it.

You say it is misleading people every day, but I don't think most people walk around with your definition for this word, so how is it misleading exactly?

You're a practioneer. So let's see

I greatly prefer designs with coaxial drivers, as they give a combination of precise imaging and soundstage that ...

Now you only have to explain where this desirable property comes from.

If you refer to lobing or vertical interference, it is not such a problem as you are hinting. ...
And we should not forget that most of conventional coaxial designs are not free from similar effects,...

As I said, you can ignore the problem further on, and walk in circles. And in regard to "most of conventional coaxial designs", well, this is not true. It is especially not true if you take into account, that one might just pick a design that is o/k once such is available, and it is available, and I was talking of those.

So, you say, the issue is ignorable in the first place, and the coax solution is to be dismissed, because there are some other coaxes, that don't do too good. A quite theoretical argument.

Lobing!

 

[PristineSound]

To prevent confusion or to go off on a tangent, for the purpose of audio loudspeaker (or at least for this thread), we will define source point loud speakers as a loud speaker with a singular source of sound radiation at least for upper bass and above frequency range. This inherently implies no to minimal lobing.

Being omnidirectional is NOT part of the definition.

 

[NTK]

The term Dr. Jack Oclee-Brown uses to describe their (KEF's) Uni-Q coax driver is "coincident driver".

Hi Lorenzo, this is somewhat off-topic of this thread so apologies to everyone else.

Yes, that's generally true. With any rotationally symmetric waveguide, response irregularities will tend to be seen worst along the axis of rotation. This is simply caused by the symmetry. For example, say you have some feature of the waveguide that disturbs the HF wave resulting in some reflection or diffraction. This reflected/diffracted sound is loudest on the axis of rotation because sound from then entire feature arrives at precisely the same time and constructively sums. With a coincident driver, like Uni-Q, avoiding such problems is one of the major challenges. We normally recommend listening at least 10 degrees off axis, but there's also no major issue with going further than this because the MF and HF directivity are well matched and the direct response reaching the listener remains smooth. This means that the toe-in can be used to adjust the amount of direct sound versus room sound the listener hears (like a DI control) and it can help to tune the system to the acoustics of the listening room.

All the best,
Jack.

 

[sigbergaudio]

On the topic of his comment; Listening slightly off-axis is a very good way to avoid some of the inherent problems with coaxial drivers. We both have all our speakers tilted slightly (~4 degrees) + design them to be listened off-axis to maximize this effect.

 

[PristineSound]

Depends on who you ask. I currently assemble the speakers myself, I would prefer to not have 10 drivers.

If you take a look at some of the KEF, the mid cone of their coaxial is deeper than most mid drivers. Presumably the geometry was designed to control the directivity as the mid cone of a coaxial serves as the waveguide.

Having said that, do you think designing a proper coaxial driver is technically more challenging than deploying traditional driver configuration with waveguide?

 

[Ninjastar]

Unsurprisingly, Eric at Tekton says that ELAC, Genelec, James Loudspeakers, and Monitor Audio are all "infringing on Tekton Design intellectual property"

 

[PristineSound]

Unsurprisingly, Eric at Tekton says that ELAC, Genelec, James Loudspeakers, and Monitor Audio are all "infringing on Tekton Design intellectual property"

God, why can't this guy just go into his hole and just stay there.

Interestingly, I called this out on my first post, Eric Alexander's claim and patent is this moving mass nonsense, absolutely nothing about point source.

I actually read his patents, it is a web of circular confusing pseudoscience AND his patent does not specifically say anything about arranging the tweeter sized drivers for midrange encircling the tweeter proper. It just states using these tweeter sized drivers for midrange to reduce moving mass. There is absolutely no mention of point source, heck, I'm not even sure if Eric Alexander knows what point source is.


Additionally, only few of his models with these tweeter sized driver arrays as midrange are configured to encircled the tweeter proper. Other models such as Ulfberht has two sets of 7 tweeter array that is all midrange, including the middle tweeter sized driver.

Monitor Audio and Elac are big companies, they have proper process to go to market, so their legal department already did their due diligence on patent infringing risks, and likely read Erik Alexander's Peter Pan patents and determined there is no risk for the reasons I stated above.

I think Eric is having his lawyers talk to Monitor Audio and Elac's lawyers to try to figure out if they can gets some royalty. But he knows he's going against behemoth companies.

 

[PristineSound]

So you also noticed Eric made no mention to Perlisten "infringing" on his patents? That's because Perlisten was awarded their own patent on their DPC array.

Take a read of Perlisten's patent, full of science:

US20240381024A1 - Directivity pattern control waveguide for a speaker, and speaker including a directivity pattern control waveguide - Google Patents

A directivity pattern control (DPC) waveguide for a speaker is disclosed. The DPC waveguide comprises a body and first, second, and third drivers secured to the body. The body comprises a substantially planar portion having a planar surface, a waveguide portion having a waveguide surface...

patents.google.com

Take a read of Tekton's patent, full of pseudoscience:

US9247339B2 - Loudspeaker design - Google Patents

Improved speakers are better able to accurately reproduce sound through the use of low-mass transducers.

patents.google.com

This guy Erik Alexander is already making so much money from all the audio fools around the world, he can retire today and go into his hole and be just fine, but man, his existence is a pain in everyone's ass.

EDIT: updated link.

 

[Arindal]

Eric at Tekton says that ELAC, Genelec, James Loudspeakers, and Monitor Audio are all "infringing on Tekton Design intellectual property"

That must be a really really funny guy:

Monacor Raduno. Published not later than 2011 (Tekton´s patent seemingly was filed in 2014)

Maybe we all get it wrong and his patent is about maximizing lobing and interference problems with positioning domes that far away from each other.

 

[PristineSound]

That must be a really really funny guy:

View attachment 454433

Monaco Raduno. Published not later than 2011 (Tekton´s patent seemingly was filed in 2014)

Maybe we all get it wrong and his patent is about maximizing lobing and interference problems with positioning domes that far away from each other.

I'm sure Elac, Monitor Audio and Genelec knew this history and the nature of Tekton's patent before they decided that it would be no legal risks in producing these products.

That guy Eric Alexander is persona non grata anywhere.

 

[sigbergaudio]

It actually measures surprisingily even on-axis in the frequency range I assume those arrays operate.

Tekton Moab Be loudspeaker

All photos by Rogier van Bakel. Compositing by David Evett. For Christmas in 2020, a friend sent me a gift: a coffee mug decorated with a one-out-of-five-stars rating for the annus horribilis the world had just been through. The caption on the ceramic read, "VERY BAD WOULD NOT RECOMMEND."

www.stereophile.com

 

[Heinrich]

Maybe we all get it wrong and his patent is about maximizing lobing and interference problems with positioning domes that far away from each other.

Lol, maybe. With a not too bad reasoning, actually. Hifi stereo guy sits right center in stereo triangle, speakers directed at his ears by centi degrees, height adjusted by a cushion under his butt, etc. Direct sound is as good as stereophile measures it. Who cares, and if, by what reason, that the indirect sound is full of fine granular interferences? The decorrelation of off-axis sound is even beneficial, maybe.

I did such for a guitar speaker as to improve directivity, but didn‘t get rid of wide range waviness.

 

[dasdoing]

Vertical reflections "are not a serious matter," as "they don't cause any shifts during the vertical plan. . .any image shifts. . .can cause timbre shifts.

Historically, many audiophiles favored a sound that "excited the room," prioritizing a sense of spaciousness and immersion from reflections. However, the community's preferences are now dividing, with a growing segment valuing a clearer, more precise sonic image.

This shift makes me wonder why there aren't more loudspeakers designed specifically for one-seat listening. By restricting both horizontal and vertical dispersion, such speakers could solve numerous problems for listeners who want to hear the recording itself, not the room's influence.