Sigberg Audio Manta (12" wideband cardioid active speakers) development thread

[Purité Audio]

Then a lot of English loudspeaker developers have done a lot of things wrong.
Of course you can use the resonances, including those of the cabinet, if you know what you are doing and if it improves the sound and the measurements.

The enclosure shouldn’t store energy which could cause audible resonance, the thin walled BBC designs I have heard all had an audible ‘thrum’ to the sound compared to contemporary designs.
Keith

 

[Audionaut]

The enclosure shouldn’t store energy which could cause audible resonance, the thin walled BBC designs I have heard all had an audible ‘thrum’ to the sound

A fundamental question that may be stretching this thread a bit. Sorry Sigberg

It's not my preferred design either and I wouldn't know how to do it, but the Spendor Classic 200 for example also use the cabinet resonances - and they sound quite decent I'd say.

I myself am more anchored in the "German school" around Fink.
Fight the vibrations! Multi-layered, gel absorbers, reinforcements in the cabinet.

 

[Savi]

You understand the question about explaining scientifically.
The enclosure or the box can only change the way the "back wave" of the driver comes to the listener, with holes or without holes in the box.

There are a lot information on Google about enclosure design: shape, material, damping, bracing... For instance look at https://www.somasonus.net/box-construction-methods

 

[LSPhil]

Then a lot of English loudspeaker developers have done a lot of things wrong.
Of course you can use the resonances, including those of the cabinet, if you know what you are doing and if it improves the sound and the measurements.

I think we might be talking past each other a bit. I’m not arguing that any use of cabinet resonances or diffraction control is inherently wrong obviously, if a designer understands the effects, can model them, and the result is objectively better (both subjectively and in measurements), that’s valid engineering.
What I was cautioning against is the romanticizing of cabinet coloration as a deliberate design philosophy, without clear justification in data or listening tests. There’s a difference between controlling resonances and introducing them for “character.”
The point was not to say "resonances = bad, always" but to question when they are introduced without technical rigor or become a substitute for better transducer behavior.
If my wording came off as black-and-white, I’m happy to refine it. This topic deserves a deeper, more nuanced discussion and not sarcasm or dismissiveness.
I’m here to learn, share, and discuss constructively. Let’s try to stay on track.

 

[LSPhil]

There are a lot information on Google about enclosure design: shape, material, damping, bracing... For instance look at https://www.somasonus.net/box-construction-methods

I’d refer everyone to Siegfried Linkwitz’s writings atLinkwitz Lab, especially the sections on cabinet diffraction,panel resonances, and radiation patterns. He shows quite clearly thatthe enclosure does affect sound but only in ways we can and should analyze, control, orminimize, not celebrate as a musical “flavor.”
For instance, Linkwitz explains how diffraction from sharpbaffle edges introduces time-delayed “ripples” infrequency response with predictable comb-filter effects that mustbe managed by rounding edges or optimizing baffle dimensions https://www.linkwitzlab.com/models.htm
He also emphasizes that panel resonances (wherecabinet walls vibrate) can "contribute delayed sound radiation"and smear impulse response — unless the cabinet is made stiff,damped, or braced https://linkwitzlab.com/
Additionally, Linkwitz’s dipole and open-baffle designsexplicitly use controlled radiation patterns(omni bass to forward mid/high directivity) to shape tonalbalance and spatial clarity but crucially, they do this viaphysics driven design, not by introducing uncontrolledresonance . In other words, the goals are clear, measurable,and predictable.
So yes a cabinet does influence sound. But the intentbehind Linkwitz’s work is instructive: minimize unwantedcoloration, diffraction and resonance; use controlledacoustic effects only when they serve a clear, measuredbenefit. That’s engineering, not guesswork or"cabinet character."

 

[sigbergaudio]

I think we might be talking past each other a bit. I’m not arguing that any use of cabinet resonances or diffraction control is inherently wrong obviously, if a designer understands the effects, can model them, and the result is objectively better (both subjectively and in measurements), that’s valid engineering.
What I was cautioning against is the romanticizing of cabinet coloration as a deliberate design philosophy, without clear justification in data or listening tests. There’s a difference between controlling resonances and introducing them for “character.”
The point was not to say "resonances = bad, always" but to question when they are introduced without technical rigor or become a substitute for better transducer behavior.
If my wording came off as black-and-white, I’m happy to refine it. This topic deserves a deeper, more nuanced discussion and not sarcasm or dismissiveness.
I’m here to learn, share, and discuss constructively. Let’s try to stay on track.

But I have not advocated cabinet coloration or introducing resonances, neither is this what is happening with any of our designs, so this discussion is not really relevant in this thread.

 

[sigbergaudio]

I'd like to thank you Keith for demoing the Mantas and D10 subwoofers for me today. I was left speechless by them, I thought the imaging was amazing and it was the first time I've heard so much depth in a speaker alongside to me the pleasant sound quality. I also got a sense of vertical imaging in the center image which I've never experienced before. I was listening to the Streets of Rage soundtrack by Yuzo Koshiro and I heard a symbol sound out of the left speaker which I localised beyond the speaker which was new to me.

In my view the problem I have is that I have to buy a pair .......for music and the left and right for movies.

Thank you for sharing your experience, I am happy to hear that you enjoyed the Manta system! It seems like you have picked up on and are enjoying some of the key characteristics of our systems!

 

[Soniclife]

Would the people following this thread be interested in my personal comparison between the Mantas and Dutch & Dutch 8cs without subwoofers that I also demoed at Purite Audio?

I'm sure a few of us are interested.

 

[Matt_Holland]

A well-designed enclosure should minimize its influence on the driver’s radiation pattern.

Do you mean it’s radiation when in a perfect infinite baffle? And what about controlling directivity? Is that allowed in your world?

 

[LSPhil]

Do you mean it’s radiation when in a perfect infinite baffle? And what about controlling directivity? Is that allowed in your world?

I’m honestly surprised by the almost childlike tone of some of the reactions to my posts, simply because I have a different point of view one that is based on both experience and reflection. Reading some of these replies feels a bit like stepping into Alice in Wonderland where reason and openness take a back seat to ridicule.
Sure, one can do whatever they want in speaker design. But personally, I would never buy a speaker that behaves like a professional PA unit designed for a concert stage rather than for a living room. I like to walk around my space and enjoy music as part of my daily life – not to be confined to a ±3 cm “sweet spot” as if it’s an audiophile hostage situation.
Do you gentlemen still have any room left in your thinking for the possibility that someone might hold a different opinion and have actual reasons for it?
I keep receiving replies along the lines of “you’re wrong, you don’t know anything, give proof.” And I find myself wondering: how old are you, really?

 

[Purité Audio]

‘3cm sweet spot ‘what are you on about? and start your own thread on the suitability or not of professional drivers.
Keith

 

[LSPhil]

‘3cm sweet spot ‘what are you on about? and start your own thread on the suitability or not of professional drivers.
Keith

I’m genuinely wondering why I’m being told to “start my own thread” when my reply was clearly a direct response to Matt_Holland, who addressed me specifically and challenged my point of view. That’s how dialogue works someone says something, someone else responds.
Suggesting that I should leave the discussion just because my perspective doesn't align with the majority here is, frankly, a textbook example of rhetorical deflection. When actual technical arguments run out, it seems the next step is to delegitimize the discussion itself.
I was engaging with the topic as presented not derailing anything, not going off-topic, just offering a dissenting view, backed by reasoning and experience. If that’s unwelcome, maybe the question isn’t about threads, but about how willing we really are to tolerate diverse views in a technical forum.

 

[sigbergaudio]

I’m honestly surprised by the almost childlike tone of some of the reactions to my posts, simply because I have a different point of view one that is based on both experience and reflection. Reading some of these replies feels a bit like stepping into Alice in Wonderland where reason and openness take a back seat to ridicule.

Our development threads are intended for knowledge sharing and information, so if you are here to learn and understand, you are very welcome. With regards to the reaction to your posts, I will comment on that below.

Sure, one can do whatever they want in speaker design. But personally, I would never buy a speaker that behaves like a professional PA unit designed for a concert stage rather than for a living room. I like to walk around my space and enjoy music as part of my daily life – not to be confined to a ±3 cm “sweet spot” as if it’s an audiophile hostage situation.

This is an example of a comment from you, that is likely to get a negative reaction. The reason is that you are not open and curious, rather you are throwing around strawman arguments.

• Our systems do not behave like professional PA units (beyond having very wide dynamic range and low distortion, which is a good thing).
• Our systems are not designed for concert stages, on the contrary they are explicitly designed for living rooms.
• Our systems do not have a +/-3 cm sweetspot, on the contrary both the Manta and the Saranna have a very wide and large soundstage that does not fall apart despite moving out of the sweetspot, unlike most other speakers. the Manta has a very even dispersion +/- 50 degrees, and the cardioid effect doesn't kick until beyond 90 degrees.

If you want to get serious replies, you have to stop throwing around false information like this. You are just assuming all sorts of things without knowing anything about the system you are referring to. It is completely okay to not know, but then you have to lead with curiosity, not negative and false arguments.

Do you gentlemen still have any room left in your thinking for the possibility that someone might hold a different opinion and have actual reasons for it?
I keep receiving replies along the lines of “you’re wrong, you don’t know anything, give proof.” And I find myself wondering: how old are you, really?

You should seek to inform yourself before forming an opinion.

 

[Everett T]

I’m genuinely wondering why I’m being told to “start my own thread” when my reply was clearly a direct response to Matt_Holland, who addressed me specifically and challenged my point of view. That’s how dialogue works someone says something, someone else responds.
Suggesting that I should leave the discussion just because my perspective doesn't align with the majority here is, frankly, a textbook example of rhetorical deflection. When actual technical arguments run out, it seems the next step is to delegitimize the discussion itself.
I was engaging with the topic as presented not derailing anything, not going off-topic, just offering a dissenting view, backed by reasoning and experience. If that’s unwelcome, maybe the question isn’t about threads, but about how willing we really are to tolerate diverse views in a technical forum.

You're wondering why? Seriously start another thread and don't highjack a manufacturers...jeez this has gone on long enough to create a sperate thread that includes all of your scientific knowledge.

 

[kyuu]

If that’s unwelcome, maybe the question isn’t about threads, but about how willing we really are to tolerate diverse views in a technical forum.

Well one, this isn't your thread. It's pretty rude to keep crapping all over Sigberg's development thread with contrary nonsense. Two, a technical forum should be more concerned about what is technically correct than entertaining "diverse" views, whatever that means in this context.

I keep receiving replies along the lines of “you’re wrong, you don’t know anything, give proof.” And I find myself wondering: how old are you, really?

Perhaps you should stop and consider the possibility that you might be wrong, rather than resorting to irrelevant things like people's ages.

 

[Matt_Holland]

I’m honestly surprised by the almost childlike tone of some of the reactions to my posts, simply because I have a different point of view one that is based on both experience and reflection. Reading some of these replies feels a bit like stepping into Alice in Wonderland where reason and openness take a back seat to ridicule.
Sure, one can do whatever they want in speaker design. But personally, I would never buy a speaker that behaves like a professional PA unit designed for a concert stage rather than for a living room. I like to walk around my space and enjoy music as part of my daily life – not to be confined to a ±3 cm “sweet spot” as if it’s an audiophile hostage situation.
Do you gentlemen still have any room left in your thinking for the possibility that someone might hold a different opinion and have actual reasons for it?
I keep receiving replies along the lines of “you’re wrong, you don’t know anything, give proof.” And I find myself wondering: how old are you, really?

I would be interested to hear your thoughts on my question?

As to the tone, I have interpreted your tone (not saying it is the tone, just how I have interpreted it) as quite aggressive, argumentative and a touch arrogant.

Tone aside, your opinions about PA drivers being unsuitable for high fidelity systems is interesting, but I see no evidence presented, longer than anecdotal.

The most common difference between PA drivers and hifi drivers is size. The former requiring larger surface areas to deliver the required SPLs, which then makes them aesthetically unsuitable for many domestic applications. I have no idea how you would design a driver so that it did not perform optimally until it was driven with a certain voltage level. This would suggest a large non-linearity in the transducer. But this is what I think you are saying is the case? If so then I would have thought that we could look at drive unit measurements and data and see evidence for non-linearities. I’m confident that the drivers in the @sigbergaudio products are very linear, delivering consistent and excellent fidelity at a wide range of input levels.

If a speaker system sounds better when played very loud then I think the most likely reason for that is that it has been tuned with a frequency response that suits high SPL from the point of view of how our hearing works (equal loudness contours). At lower SPLs such a system may be judged as not having enough bass.

 

[LSPhil]

I would be interested to hear your thoughts on my question?

As to the tone, I have interpreted your tone (not saying it is the tone, just how I have interpreted it) as quite aggressive, argumentative and a touch arrogant.

Tone aside, your opinions about PA drivers being unsuitable for high fidelity systems is interesting, but I see no evidence presented, longer than anecdotal.

The most common difference between PA drivers and hifi drivers is size. The former requiring larger surface areas to deliver the required SPLs, which then makes them aesthetically unsuitable for many domestic applications. I have no idea how you would design a driver so that it did not perform optimally until it was driven with a certain voltage level. This would suggest a large non-linearity in the transducer. But this is what I think you are saying is the case? If so then I would have thought that we could look at drive unit measurements and data and see evidence for non-linearities. I’m confident that the drivers in the @sigbergaudio products are very linear, delivering consistent and excellent fidelity at a wide range of input levels.

If a speaker system sounds better when played very loud then I think the most likely reason for that is that it has been tuned with a frequency response that suits high SPL from the point of view of how our hearing works (equal loudness contours). At lower SPLs such a system may be judged as not having enough bass.

Thank you very much for your detailed response. I appreciate that we’re diving deep, even if we have different perspectives.
Regarding the specific case:
The woofer we’re discussing has a fairly heavy diaphragm (around 50 g), and to reach about 80 dB(A), it operates at approximately 33 mW in my estimation, its inertia is already critically high. In my own listening comparison for example, Visaton PAW35 paired with an Isophon PSM120 midrange driver and an Audax tweeter the weakness of the PAW25 was always clearly audible; it just had that typical PA background sound.
From my point of view, the manufacturer wanted to develop a system with narrower dispersion characteristics, specifically tailored for room radiation. However, that would require a correspondingly large midrange driver, which in turn brings disadvantages such as high inertia and volume.
The claim that a customer needs 120 dB seems unnecessary to me – hardly anyone listens at such levels for extended periods. It’s more of a byproduct of large PA midwoofers.
I therefore find the pricing (e.g. €16,000 for two speakers) questionable in relation to the audio performance, especially since there are proven alternatives on the market – for example, from Canton or other reputable manufacturers.
Of course, that’s just my opinion – but I think it’s worth taking a critical look when it comes to such sums and promises of quality.

 

[sigbergaudio]

Thank you very much for your detailed response. I appreciate that we’re diving deep, even if we have different perspectives.
Regarding the specific case:
The woofer we’re discussing has a fairly heavy diaphragm (around 50 g), and to reach about 80 dB(A), it operates at approximately 33 mW in my estimation, its inertia is already critically high. In my own listening comparison for example, Visaton PAW35 paired with an Isophon PSM120 midrange driver and an Audax tweeter the weakness of the PAW25 was always clearly audible; it just had that typical PA background sound.

The 12" driver in the Manta has a dedicated 250W amplifier channel and the driver sensitivity is over 96dB, so power and moving the driver is not exactly a problem. The sound from these drivers are effortless and immediate even at low volume. You have some kind of inherent bias to this type of driver or size apparently, so I am not going to convince you over this forum I am sure. I can only hope you are in a position to listen to them at some point.

From my point of view, the manufacturer wanted to develop a system with narrower dispersion characteristics, specifically tailored for room radiation. However, that would require a correspondingly large midrange driver, which in turn brings disadvantages such as high inertia and volume.

Not really, we have done the same with the 8" in the Saranna. Normally you get some of this effect through a wide baffle, but here it is done via the passive cardioid design. The disadvantages you assume in this design does not exist.

The claim that a customer needs 120 dB seems unnecessary to me

Strawman, no one has claimed this.

 

[Matt_Holland]

it just had that typical PA background sound.

Sorry, I don’t know what you mean by this.

I suspect your criticisms are simply based on the frequency response you heard, more specifically a lack of bass output relative to midrange. This imbalance would somewhat correct itself when played at very high SPL due to our hearing being more sensitive to bass at higher SPL. Those factors could easily lead one to conclude that a driver only sounds good when played loud.

I demonstrated the K-array Pinnacle KR802 system to a client last week and after playing at a fairly high SPL I turned the system down so we could chat more easily. The client then commented that they were equally impressed at how dynamic and detailed the system sounded at low level. The 18” drivers in the bass modules reproduce approximately 30Hz-150Hz.

 

[MKR]

Sorry, I don’t know what you mean by this.

I suspect your criticisms are simply based on the frequency response you heard, more specifically a lack of bass output relative to midrange. This imbalance would somewhat correct itself when played at very high SPL due to our hearing being more sensitive to bass at higher SPL. Those factors could easily lead one to conclude that a driver only sounds good when played loud.

I demonstrated the K-array Pinnacle KR802 system to a client last week and after playing at a fairly high SPL I turned the system down so we could chat more easily. The client then commented that they were equally impressed at how dynamic and detailed the system sounded at low level. The 18” drivers in the bass modules reproduce approximately 30Hz-150Hz.

No intent to derail thread topic at hand, but just to mention … Was unaware of this K-array design. Very interesting, thanks for the link @Matt_Holland