Sigberg Audio MANTA dual cardioid active speaker development thread

[Developer]

To my experience, these speakers are missing many of the things that drives audio enthusiasts insane. In particular, the full level rear output, and the issues of integration with subwoofers.

 

[Sigberg Audio]

The voicing of the new enclosures are moving along as well, it's starting to sound really good! These are all still in-door measurements at ~0,5m. We'll probably do some new Klippel measurements before summer to get more precise measurements.

The "BBC like" dip is almost gone, and so is the lift above 4khz. Overally pretty flat. It sounds open, balanced and big. Voices are beautiful, and there's plenty of punch in the mid bass as well as zing in the higher frequencies without anything sounding harsh.

Finally the precision and soundstage is ..well, I'd like to say nothing short of breathtaking! In a track like "Hold up, wait a minute" by Zhu, it's awesome to just close your eyes and excitedly wait to hear where in 3D space the next instrument or sound will pop up.

15 degrees / listening axis:

The dispersion is also very even within a realistic listening window (0-45 degrees), and this speaker will sound tonally balanced just about anywhere in front of the speakers. The responses tightens somewhat at 1300hz and 1500hz, but this hasn't been noticable in the listening sessions so far.

0-15-30-45:

Average of 0-15-30-45-60-75-90:

 

[TLS Guy]

The voicing of the new enclosures are moving along as well, it's starting to sound really good! These are all still in-door measurements at ~0,5m. We'll probably do some new Klippel measurements before summer to get more precise measurements.

The "BBC like" dip is almost gone, and so is the lift above 4khz. Overally pretty flat. It sounds open, balanced and big. Voices are beautiful, and there's plenty of punch in the mid bass as well as zing in the higher frequencies without anything sounding harsh.

Finally the precision and soundstage is ..well, I'd like to say nothing short of breathtaking! In a track like "Hold up, wait a minute" by Zhu, it's awesome to just close your eyes and excitedly wait to hear where in 3D space the next instrument or sound will pop up.

15 degrees / listening axis:

The dispersion is also very even within a realistic listening window (0-45 degrees), and this speaker will sound tonally balanced just about anywhere in front of the speakers. The responses tightens somewhat at 1300hz and 1500hz, but this hasn't been noticable in the listening sessions so far.

0-15-30-45:

Average of 0-15-30-45-60-75-90:

Those look to be really encouraging results!

People really need to get used to the concept that amps belong in speakers and NOT receivers. I have been playing with active designs for nearly 50 years now. Active designs solve problems that can not be solved with passive designs, especially in the lower octaves.

 

[Sigberg Audio]

..and to explain a bit about the process: It's of course not just about measurements, listening sessions are a crucial and major part of the development. The speakers go through countless iterations of crossover/DSP configuration, and basically all iterations has one version based on the measurements, and a subsequent variant "By ear".

This means I first tune them based on measurements on- and off-axis (attempting to balance the two), then I listen for a few days and do additional adjustments based on what I hear. Then perhaps something is difficult to get perfect, so I measure again to help understand what the problem is, do some adjustments based on the measurements, and then go back to listening and additional adjustments based on the listening sessions. This way the response is continuously balanced based both on on objective data and real listening impressions over time, and across a broad range of music genres.

 

[TLS Guy]

..and to explain a bit about the process: It's of course not just about measurements, listening sessions are a crucial and major part of the development. The speakers go through countless iterations of crossover/DSP configuration, and basically all iterations has one version based on the measurements, and a subsequent variant "By ear".

This means I first tune them based on measurements on- and off-axis (attempting to balance the two), then I listen for a few days and do additional adjustments based on what I hear. Then perhaps something is difficult to get perfect, so I measure again to help understand what the problem is, do some adjustments based on the measurements, and then go back to listening and additional adjustments based on the listening sessions. This way the response is continuously balanced based both on on objective data and real listening impressions over time, and across a broad range of music genres.

Yes, you must listen critically as well as measure. Loudspeaker design does require a critical memory for the sound of natural instruments. I fully endorse your approach.
One of my mentors, John Wright of TDL, told me once you have a design really close, listen to it for at least three months and don't make changes more often than that.

The way you are going about it, is the best approach.

 

[Sigberg Audio]

Next iteration of baffle ports may end up like this:

Testing currently in progress.

 

[Sigberg Audio]

Today we're testing to allow the 12" midbass in Manta a bit more wiggle room in the lower frequencies. The cardioid effect is relatively powerful now, but it fades away when the subwoofers take over. Manta rolls off naturally with a -3dB point in-room at around 90hz by design. But I've now changed the tuning so the roll-off is more gradual, allowing the cardioid effect to be present at a slightly lower frequency. The final tuning will of course be designed into presets allowing you to just plug and play if you have both Manta and Sigberg Audio subwoofers.

It sounds promising so far, and gives a slight increase in punch and attack even at moderate listening levels. Especially noticeable in percussion on older rock. "JBL and Klipsch killer!" was the comment of one visitor after a couple of AC/DC tracks. Manta is of course much more than that, but they definitely contribute with an urge to headbang on the right music!

 

[ryanosaur]

How is testing progessing on the redised Baffle Ports for controlling the dispersion of your Coaxial Driver?

 

[Sigberg Audio]

How is testing progessing on the redised Baffle Ports for controlling the dispersion of your Coaxial Driver?

Looking good, frequency response is almost identical as opposed to one, larger opening (biggest deviance around 0,3dB) - and impulse response is also very good, implying no significant reflection/diffraction issues. Theoretically the added edges could add some problems, but it turned out to be of little consequence. Some more testing and listening to do, but the next prototype will probably feature the revised baffle ports.

 

[ryanosaur]

I almost want to hesitate at calling them ports!

In your experiments with this Speaker, have you found that they behave in a resonant manner?

What is the corelation between open surface area and quality Beam Forming or Cardioid effect?

 

[Sigberg Audio]

I almost want to hesitate at calling them ports!

In your experiments with this Speaker, have you found that they behave in a resonant manner?

What is the corelation between open surface area and quality Beam Forming or Cardioid effect?

Not sure what's the correct / proper / best term.

Ports? Vents? Radiators? The purpose of the redesign by the way is two-fold: I think it looks better, and also it's a bit more tamper proof / child proof compared to the much larger area covered / protected only by felt/fabric. So the goal now is to achieve that without any adverse effect on the sound.

Can you expand on what you mean by "behave in a resonant manner" ?

With regards to correlation between open surface area and cardioid effect I don't want to go in full detail. But as an indication, the current prototype has a larger surface area on the ports in the lower (midbass) chamber as opposed to the previous one, and the cardioid effect is now stronger below ~160hz than it was previously. Above 160hz it's largely unchanged.

 

[ryanosaur]

I think it looks better, and also it's a bit more tamper proof / child proof compared to the much larger area covered / protected only by felt/fabric.

I would agree! The render you showed looks very cool!

Can you expand on what you mean by "behave in a resonant manner" ?

I read about perforations in sound treatment panels having an effect on the frequency at which the panel would work best (Master Handbook of Acoustics, 6th ed.). I may be misunderstanding something there (not afraid to say that), but was curious if there was any noted effect as you changed size and shape in the way the Speaker works.

Always grateful for your interaction here! Thank you!!!

 

[Sigberg Audio]

I would agree! The render you showed looks very cool!

I read about perforations in sound treatment panels having an effect on the frequency at which the panel would work best (Master Handbook of Acoustics, 6th ed.). I may be misunderstanding something there (not afraid to say that), but was curious if there was any noted effect as you changed size and shape in the way the Speaker works.

Always grateful for your interaction here! Thank you!!!

The upper chamber is relatively small and braced in two dimensions, and the lower chamber is braced in three dimensions. There's also a significant amount of damping material in both chambers, so there is very little resonance to speak of. Changing the port configuration will slightly change the resonance frequency of the affected panel, but any resonances are damped to the point where it's not of any practical significance.

It would also be easy to assume that the ports themselves cause the cabinet to resonate or peak at certain frequencies, but they do not.

 

[Developer]

There are several potential resonance phenomena that could occur. One is the fundamental Helmholz resonance. We have standing waves, resonances in materials, local resonances due to dimensions etc. For transparency these ports will be way bigger than what would cause any limitations. The Helmholz resonance will be non existing due to damping, dimensions etc. For low frequencies, those ports would be a significant limitation, but for the coaxial, those ports are far bigger than the point where limitations should occur. It is also imporant to note that in acoustic absorbtion panels (I am guessing Mr @ryanosaur read about them in the MHOA?) the relationship between the internal volume of the panel, and the dimensions of the holes, create an effect that was probably described in that part. Anyway, that is the type of effect you do not want in a cardioid speaker. The key to achieve this is to keep loss at the working frequencies dominant in the regions where resonances could potentially occur with the current dimensions. A bit like combining very stiff suspension on a car with super hard shock absorbers, it will never go anywhere near resonating.

I am not sure what @Sigberg Audio has put inside that chamber, or exactly how big it is, but it should not take much damping material to knock all resonances out in that region. I would assume it is plenty, and then some more for good measure.

 

[Sigberg Audio]

I don't think I've written much about WHY we're building the Manta, and obviously there are a number of reasons why that came to be. But I was reminded of one of the reasons yesterday, after setting up the Sigberg Audio SBS.1 speakers in order to test the new Antimode X2.

One of the reasons behind building the Manta is simply attention. Not just attention around Manta itself, but in the form of brand awareness, and the other products as well. When you first see the SBS.1 speakers, I can understand how some will think "boring bookshelf speaker". This is in some part intentional, they were designed to be minimalist. To allow you to put two speakers and a subwoofer in a living room and get big sound without a lot of visual impact. But due to their small size and neutral looks, they're easy to underestimate. When you fail to understand the massive difference in dynamic capability in a 2.5-way speaker designed to play with a subwoofer as opposed to the traditional 2-way speaker it resembles. They look similar, but it's just a different league alltogether.

But as a new manufacturer who builds a somewhat anonymous product, it's easy to be underestimated. That's why the idea came to make a speaker that was "over the top" in more ways than one. Something with very high sound quality, unique solutions, striking design and with a midbass capacity beyond belief. So the opposite of the SBS.1 speakers then? Not really.

Because now we've arrived at the fact that I was reminded of when I set up the SBS.1 speakers again in our demo room yesterday: The fact that you get A LOT of the performance from the Manta in SBS.1! The tonality, the sound, and sound quality is immediately recognizable. The coax driver is the same, the design criteria and design goals are largely similar. The focus on mid bass capacity is present in both models. To quote James in the Audioholics review, the SBS.1 sounds terrific!

I obviously hope a lot of people will purchase the Manta when it is released. But I also hope there will be a trickle down effect. That some people will find that they can't afford the Manta, or want something with a design that is less ..loud. And due to the Manta, the SBS.1 will be harder to pass by or underestimate. People will no longer look at the SBS.1 and think "boring bookshelf", they will think "Hey, isn't that the manufacturer that makes the Manta? I want to know more!"

Time will show how it all pans out!

 

[everettT]

I don't think I've written much about WHY we're building the Manta, and obviously there are a number of reasons why that came to be. But I was reminded of one of the reasons yesterday, after setting up the Sigberg Audio SBS.1 speakers in order to test the new Antimode X2.

One of the reasons behind building the Manta is simply attention. Not just attention around Manta itself, but in the form of brand awareness, and the other products as well. When you first see the SBS.1 speakers, I can understand how some will think "boring bookshelf speaker". This is in some part intentional, they were designed to be minimalist. To allow you to put two speakers and a subwoofer in a living room and get big sound without a lot of visual impact. But due to their small size and neutral looks, they're easy to underestimate. When you fail to understand the massive difference in dynamic capability in a 2.5-way speaker designed to play with a subwoofer as opposed to the traditional 2-way speaker it resembles. They look similar, but it's just a different league alltogether.

But as a new manufacturer who builds a somewhat anonymous product, it's easy to be underestimated. That's why the idea came to make a speaker that was "over the top" in more ways than one. Something with very high sound quality, unique solutions, striking design and with a midbass capacity beyond belief. So the opposite of the SBS.1 speakers then? Not really.

Because now we've arrived at the fact that I was reminded of when I set up the SBS.1 speakers again in our demo room yesterday: The fact that you get A LOT of the performance from the Manta in SBS.1! The tonality, the sound, and sound quality is immediately recognizable. The coax driver is the same, the design criteria and design goals are largely similar. The focus on mid bass capacity is present in both models. To quote James in the Audioholics review, the SBS.1 sounds terrific!

I obviously hope a lot of people will purchase the Manta when it is released. But I also hope there will be a trickle down effect. That some people will find that they can't afford the Manta, or want something with a design that is less ..loud. And due to the Manta, the SBS.1 will be harder to pass by or underestimate. People will no longer look at the SBS.1 and think "boring bookshelf", they will think "Hey, isn't that the manufacturer that makes the Manta? I want to know more!"

Time will show how it all pans out!

The more in this market segment the faster it grows both financially and scientifically.

Have you considered a DIY offering after the initial release, something similar that drives community buzz?

 

[Sigberg Audio]

The more in this market segment the faster it grows both financially and scientifically.

Have you considered a DIY offering after the initial release, something similar that drives community buzz?

There are no plans for a DIY / kit offering at this time.

 

[TLS Guy]

I don't think I've written much about WHY we're building the Manta, and obviously there are a number of reasons why that came to be. But I was reminded of one of the reasons yesterday, after setting up the Sigberg Audio SBS.1 speakers in order to test the new Antimode X2.

One of the reasons behind building the Manta is simply attention. Not just attention around Manta itself, but in the form of brand awareness, and the other products as well. When you first see the SBS.1 speakers, I can understand how some will think "boring bookshelf speaker". This is in some part intentional, they were designed to be minimalist. To allow you to put two speakers and a subwoofer in a living room and get big sound without a lot of visual impact. But due to their small size and neutral looks, they're easy to underestimate. When you fail to understand the massive difference in dynamic capability in a 2.5-way speaker designed to play with a subwoofer as opposed to the traditional 2-way speaker it resembles. They look similar, but it's just a different league alltogether.

But as a new manufacturer who builds a somewhat anonymous product, it's easy to be underestimated. That's why the idea came to make a speaker that was "over the top" in more ways than one. Something with very high sound quality, unique solutions, striking design and with a midbass capacity beyond belief. So the opposite of the SBS.1 speakers then? Not really.

Because now we've arrived at the fact that I was reminded of when I set up the SBS.1 speakers again in our demo room yesterday: The fact that you get A LOT of the performance from the Manta in SBS.1! The tonality, the sound, and sound quality is immediately recognizable. The coax driver is the same, the design criteria and design goals are largely similar. The focus on mid bass capacity is present in both models. To quote James in the Audioholics review, the SBS.1 sounds terrific!

I obviously hope a lot of people will purchase the Manta when it is released. But I also hope there will be a trickle down effect. That some people will find that they can't afford the Manta, or want something with a design that is less ..loud. And due to the Manta, the SBS.1 will be harder to pass by or underestimate. People will no longer look at the SBS.1 and think "boring bookshelf", they will think "Hey, isn't that the manufacturer that makes the Manta? I want to know more!"

Time will show how it all pans out!

I agree with all the points you make. Speaker design is in need of a good shake up and rethink. I think you and I are aware how unfit for purpose almost all current offerings really are.

The reason you can get away with it, is the rise of the pop culture, where no one really has a clue what it is supposed to sound like. In the first place most studio monitors are awful. I am yet to visit a studio where I could live with the speakers they are using. I have never been in an ATC designed studio, but I have heard good things about those.

On the other hand those who attend live orchestral, choral chamber and solo concerts no darn well what it is supposed to sound like. I really don't think you can evaluate speakers except from recordings of natural instruments and the human voice. That is why the pursuit of high fidelity was driven from the classical market, and I think now it is fast swinging back in that direction. The reason is that more orchestra and other groups are embracing AV, and can now enjoy concerts across vast distances and be able to repeat the experience. The BPO who are the leader, now have over three million subscribers. The BBC in the UK produce fine audio in audio only and increasing AV offerings. This is building up demand for improved audio. I think cost is the the biggest barrier, but also as you say, speaker size and appearance.

Now looking at test data is helpful in choosing a speaker. However, it is not like the electronics where that is pretty much the whole story.

A speaker that measures badly, will not sound good. However, a speaker that measures well, may not sound good. The reason is that current measurements do not tell the whole story, so a good deal of experience and intuition is required to produce a really good speaker.

You comment about mid bass power response is well taken. I have commented about that often. Lack of it is not going to show in current standard measurements.
However this is absolutely crucial. I have always intuitively realized this, as the foundation of the orchestra is the bass strings. So the deficient speaker will undergo significant dynamic compression in the forte passages, and produce excessive string over body, as well as the brass showing excess lip over bell. This latter totally limits the impact of the performance. So designers really do stupid things like cross to a mid at 250Hz. A design like that is "dead in the water" no matter how well it measures on current measurements.

I built my first DAW in 2002. I have always used WaveLab. That has excellent metering and shows where the power is instant to instant right across the audio spectrum. This is about the best instruction I know of in telling you where you need to place you power resources when designing a speaker.

I continue to harp on this and will. That is the way my speakers are designed.

This is one of my active dual TL speakers. So the two 7.5" mids are assisted by the top 10" driver in that crucial mid and actually upper bass range. Both those 10" drivers handle the deep bass. The BSC compensation is continuously variable for optimal room/position alignment.

The results are actually astonishing. Quite a number of experienced engineers have hear these speakers now, and are astounded at the realism of the reproduction.

So I have good reason to suspect your approach is successful. Now amp power is cheap, and with the advent of DSP, it makes sealed design more practical. I can see why you cut the main speakers off around 90 Hz, otherwise the power boost required would have caused dynamic compression. That puts the cross to the sub into the critical range, as so will require that the speakers and sub be designed as integral units. In addition the sub will need placing in close time alignment with the speakers.

I wish you every success and think you concepts and instincts are absolutely valid. They coincide exactly with mine.

I do think you might reconsider the DIY route. In the early days of British Audio, DIY was strongly encouraged by Gilbert Briggs of Wharfedale and Raymond Cooke founder of KEF especially. Fostering this really does help to drive the market. It generates a lot of enthusiasm, and is worth more then most advertising budgets.
I have long lamented the lack of interest in DIY from the industry. Those days gone by were fun times.

 

[Sigberg Audio]

So I have good reason to suspect your approach is successful. Now amp power is cheap, and with the advent of DSP, it makes sealed design more practical. I can see why you cut the main speakers off around 90 Hz, otherwise the power boost required would have caused dynamic compression. That puts the cross to the sub into the critical range, as so will require that the speakers and sub be designed as integral units. In addition the sub will need placing in close time alignment with the speakers.

I wish you every success and think you concepts and instincts are absolutely valid. They coincide exactly with mine.

I do think you might reconsider the DIY route. In the early days of British Audio, DIY was strongly encouraged by Gilbert Briggs of Wharfedale and Raymond Cooke founder of KEF especially. Fostering this really does help to drive the market. It generates a lot of enthusiasm, and is worth more then most advertising budgets.
I have long lamented the lack of interest in DIY from the industry. Those days gone by were fun times.

I genuinely appreciate all your kind words and support!

With regards to the DIY route, I'm not explicitly against it, but I have a number of concerns:

1) Is there a real market? Even a DIY approach will be relatively expensive given the cost of the components
2) If people are to design the cabinet from drawings alone, will they be able to succeed, and if not, will they wrongly assume the speakers are bad?
3) If a flat packed cabinet is to be included, there will still be significant cost involved in manufacturing and shipping, especially world wide shipping.

I'd be happy to hear your reflections on what a successful DIY offering would like.

 

[ryanosaur]

I genuinely appreciate all your kind words and support!

With regards to the DIY route, I'm not explicitly against it, but I have a number of concerns:

1) Is there a real market? Even a DIY approach will be relatively expensive given the cost of the components
2) If people are to design the cabinet from drawings alone, will they be able to succeed, and if not, will they wrongly assume the speakers are bad?
3) If a flat packed cabinet is to be included, there will still be significant cost involved in manufacturing and shipping, especially world wide shipping.

I'd be happy to hear your reflections on what a successful DIY offering would like.

To this last point I would say that a well thought out diagram for a build with easy to understand measurements and even a cut sheet would suffice. Perhaps even offering it as an additional file for cnc production would be nice.
There are companies and shops that offer those services.
Regardless I get and understand your concern.
Speaking with a boutique manufacturer here in the US, he had said he was warned early about doing kits because you will inevitably be inundated with questions about everything.
On the other hand, there are also several companies that have seemingly perfected the flat pack approach for diy construction. GSG Audio is s great example of one such company.
Again, it all comes down to the plans and having an experienced builder do either a video or write out the set up properly.

Some people don’t mind the cost… people build Troels Gravesons kits and those are not inexpensive, or beginner level! Perusing Madisound and Meniscus will show you some other kits on the market here as well.

it would be an intriguing option. One American boutique designer who is sadly no longer with us offered his designs in kit form as well as finished Speakers. You would have to use the way back machine to see his stuff at this point, but Rick Craig and Selah Audio had som cool stuff that had also reviews pretty well.