Sigberg Audio Manta Cardioid active speakers: Full measurements (Spinorama)

[Purité Audio]

They are designed to be used with subs, taking bass duties completely away from the main speakers, the Mantas are awesome.
Keith

 

[SigbergAudio]

Sorry for the noob question
But why do they need subwoofers to be a optimal system? Is it possible to use them without?

To start with your last question, while it is possible to use it without subs, you will essentially get no bass - so that is not advisable at all.


Then to your first question; I guess there are two ways to answer that:

The simple answer is that they are designed to need subwoofers. After hearing that answer, I assume you may still go "But why?", which takes us to the more complicated answer. The idea to this design approach started with our SBS speakers, and the reasoning behind it is explained in detail in these articles: https://www.sigbergaudio.com/pages/var-filosofi and https://www.sigbergaudio.com/blogs/...hnical-choices-behind-the-sigberg-audio-sound

For your convenience I have pasted the relevant parts below:

True full range sound​

You may have experienced the struggle to get speakers and subwoofers to dance to the same rhythm. Sigberg Audio speakers dance around this problem: Our SBS and MANTA speaker systems are designed from the ground up with modular bass units (subwoofers) as an integrated part of the system. This means they behave as a unit and play as one out of the box. Without time consuming setup and experimenting.

This approach allows us to do a number of things differently than other speaker manufacturers. To dramatic effect. Speakers with modular bass units that provides high-end bass like no speaker alone is able to. And when the deepest bass is handled elsewhere, the speakers can have dedicated drivers designed to handle midbass. In short: The systems are 4-way by design, the subwoofer making up the 4th channel for true full range sound.

(...)

Why is midbass so important?​

The 4-way speaker system approach of Sigberg Audio allows for dedicated midbass drivers. But why is midbass so important?

Sometimes called upper bass and/or lower midrange, the frequency range around roughly 100-500hz contains something important: A large part of both male and female voices. As if that wasn't enough, there's an incredible amount of drive, punch and attack in this frequency range. The fundamental of a lot of percussion and rhythm instruments live here.

A second point is that bass is extremely demanding to reproduce. When speakers are never asked to do that, the added capacity and dynamic range is significant. But let's not just cut away the bass. Sigberg Audio speakers feature different drivers (less mass, different suspension, higher sensitivity), specifically designed for midbass duty and with extreme dynamic capacity.


Don't hesitate to follow up with additional questions if any of this is confusing or lacking.

 

[JohnnyNG]

I'd say most speakers compromise midbass to get some bass but they need a sub anyway for real bass, so...

Since a sub is assumed and not an afterthought, the Manta doesn't compromise midbass and efficiency by using bass drivers. I'm a big fan of this approach. Pure Norse genius!

 

[SigbergAudio]

Sorry for the noob question
But why do they need subwoofers to be a optimal system? Is it possible to use them without?

If you are opposed to the concept of subwoofers, we have the Sigberg Audio Saranna. It is essentially the Manta reborn as a 3-way floorstander, and subwoofers built-in. The sound signature and overall performance is very similar. The only exception is the capacity, which is higher in the Manta, as that is one of the main benefits that is unlocked with the 4-way approach.

 

[Satanica]

If you are opposed to the concept of subwoofers, we have the Sigberg Audio Saranna. It is essentially the Manta reborn as a 3-way floorstander, and subwoofers built-in. The sound signature and overall performance is very similar. The only exception is the capacity, which is higher in the Manta, as that is one of the main benefits that is unlocked with the 4-way approach.

Hi, and what if the Saranna is crossed over at (40-80Hz) to suitably adequate subwoofers, would doing this get it closer in "capacity" to the Manta?

 

[SigbergAudio]

Hi, and what if the Saranna is crossed over at (40-80Hz) to suitably adequate subwoofers, would doing this get it closer in "capacity" to the Manta?

Yes it would, at least in the bass. It would still not match the Manta in the midbass (upper bass / lower midrange), but that isn't necessary in almost any real world situation. Also note that I wouldn't cross the subs over too high, as the bass drivers in the Saranna only play up to around 140hz. So to not completely remove their job, I'd cross the subs at 40-60hz.

Stjernholm at Stjernholm reviews, who recently reviewed the Sarannas, has also reviewed the Mantas (review to be published soon). He has had both systems for almost two months.

He tested this exact setup, and crossed over the subs at 60hz. He commented on the fact that the two speakers sound very similar, and when adding the subs as well to the Saranna to match the bass capacity of the Mantas, it was only nuance that separated the two.

Note that most wouldn't need to add subs to the Sarannas for capacity purposes, as they already play very loud on their own.

 

[Audionaut]

The only exception is the capacity, which is higher in the Manta

When you play loud music on the Manta, aren't you pretty close to the tweeter's power handling limit?

It's a 1" silk dome with a small waveguide.

With the Saranna, you have a full-grown compression driver with a diameter of 1.7" / 44 mm with a proper horn and an approximate efficiency of 101 dB/W – the bass and midrange are more likely to break down than the high frequencies to distort.

How does this work with the Manta? I can imagine that the headroom in the high frequencies is rather limited.

 

[SigbergAudio]

When you play loud music on the Manta, aren't you pretty close to the tweeter's power handling limit? It's a 1" silk dome with a small waveguide.

Not at all. 110dB@1m sine sweep outdoors gives less than 1.5% THD @ 5khz.

With the Saranna, you have a full-grown compression driver with a diameter of 1.7" / 44 mm with a proper horn and an approximate efficiency of 101 dB/W – the bass and midrange are more likely to break down than the high frequencies to distort.

How does this work with the Manta? I can imagine that the headroom in the high frequencies is rather limited.

It's makes sense to imagine limited headroom with what feels like a "traditional dome tweeter". But this is a coaxial which mean it's hornloaded / has a waveguide, and also this driver is also both high sensitivity (93.5dB for the tweeter) and can take a lot of power.

Finally it's worth reminding about the fact that the spectral balance of normal music means there's way less energy in the top end than at lower frequencies. So the tweeter doesn't need to handle as much abuse as the drivers handling the lower frequencies.

 

[Audionaut]

also this driver is also both high sensitivity (93.5dB for the tweeter) and can take a lot of power.

Yes, it's good, but since you specified 122 dB for the Manta, I thought I'd ask.

If I understand you correctly in this thread, you only let the 12-inch reproduce the fundamental tone from approximately 100 to 500 hertz, which is a little more than two octaves.
Did you determine the correct ratio for the ventilation openings through experimentation, or could you calculate it now?
I imagine it had be difficult for you to achieve the right balance between the 12-inch cardioid and the 5.5-inch cardioid.

 

[SigbergAudio]

Yes, it's good, but since you specified 122 dB for the Manta, I thought I'd ask.

If I understand you correctly in this thread, you only let the 12-inch reproduce the fundamental tone from approximately 100 to 500 hertz, which is a little more than two octaves.
Did you determine the correct ratio for the ventilation openings through experimentation, or could you calculate it now?
I imagine it had be difficult for you to achieve the right balance between the 12-inch cardioid and the 5.5-inch cardioid.

Energy in music typically falls, I don't know, somewhere between 5-7dB / octave, let's call it 5dB (more as we go higher in frequency). That means if we're at 122dB at 100hz, we're at 117dB at 200hz, 112dB at 400hz, 107dB at 800hz, 102dB at 1600hz, and 97dB at 3200hz. Which means even at 122dB, the tweeter will be at less than 1% THD. All this is average level, and there will of course be transients that is way higher, but it will handle that just fine.

The resistive openings are hard to calculate (I'm sure it's possible), so it was mostly experimentation. It was a combination of several prototypes and also a setup where I could partially open and close all ports to experiment with different variants and measure the effect. Internal stuffing and dampening also matter. I'm sure it could still be perfected even more, but you have to stop at some point.

 

[SigbergAudio]

Perhaps not always communicated very clearly, but included in the price of any of our speaker systems is also extensive support to get it properly set up if you would like that.

Currently I'm assisting a customer in Milan, Italy remotely with his Manta system in a dedicated listening room. At the moment we are experimenting with acoustic panels to even out the decay. He started out with wooden slats with a thin felt behind it on all walls, which dampened very well above 800hz, but not so much below, so the result is a bit uneven.

After the first round of thicker absorbtion panels it's already much more even, with a reduction of almost 100ms in the lower midrange. The next step is to add absorption material behind the 102" screen on the front wall. Note that the current placement of the panels is temporary while experimenting, they will be mounted properly.

Just wooden panel slats on the wall, very low, almost too low reverb above 800hz, but then rising towards the lower end:

Added 6 absorption panels:

 

[SigbergAudio]

The response is starting to look promising too. He has a somewhat tricky room in the bass region. But we’re not far from within +/-3dB when we look at the in-room slope (between the two red lines here), which must be considered a pretty tidy response. There’s no EQ applied above 100Hz here.

 

[Kravi4ka]

I am really fascinated by your work, at least I imagine that is what it's supposed to be like in 2025. With 35 years of audio obsession and crazy speakerbuilding DIY( I have tried almost all possible topologies except the Keele CBT, dozens oof speakers) I had a revelation when I read the "JBL M2 Audiolense Digital Crossovers w/Subs" and the book by Mitch Barnett "Accurate sound reproduction using DSP". All those years that I have swiped tubes, changed tweeters, cables, cable lifters and all that was just trying to fix the unfixable.

I see the Manta as a true high end speaker, one that is also very beautiful in its own way while being a very sophisticated acoustical system, not just a box with drivers. But your last post is the one that is invaluable, I do hope more people will realize what you are saying... Basically you will make a home system indistinguishable from a professional environment in a studio where only true reproduction of music is what matters yet looks like your wife will still keep you in

 

[SigbergAudio]

@Kravi4ka Thank you for your kind words, much appreciated!

 

[songOVERsound]

Always good to see speaker makers get involved with acoustics and especially looking at an even decay time - something that people are finally catching on to. I'm curious how you implemented a sub here and how you aligned it. That's your inkognito below the left speaker?

 

[SigbergAudio]

Always good to see speaker makers get involved with acoustics and especially looking at an even decay time - something that people are finally catching on to. I'm curious how you implemented a sub here and how you aligned it. That's your inkognito below the left speaker?

The subwoofers are part of the system with the Mantas, it's a 4-way system by design (the sub making up the 4th way).

So this particular system has one Inkognito per channel that is connected directly to each Manta via XLR pass-through. The crossover is set when you get the system, so all that is done with regards to integration is to adjust gain, and if necessary adjust EQ for room integration.

 

[SigbergAudio]

The sub response after some additional adjustments in EQ and placement is not perfect (difficult room), but around +/-3dB and sounds tight and punchy according to the customer.

 

[MLDT]

Hello! I am the lucky and proud owner of the Mantas/Inkognitos system above and let me tell you it does sound already very very good indeed, better then anything I owned or experienced in the previous 25y.
I think I would be preaching the choir here, about Thorbjørn's attention to details and scientific approach when developing his speakers but what I must say what I am even more impressed with is the amount of time and effort and care he is putting in AFTER the sale to really dial in the system and make it sound as good as it can and must. Could perhaps sound obvious/due, but let me tell you it really isn't and something to definitively factor in when considering a Hi-Fi system at this price point: the value for money doesn't only come from the extremely high audio quality of the system itself, but in this case also by all the time and advise you get from the manufacturer itself to really dial everything in!

 

[Pearljam5000]

How low to they go without the subs?

 

[SigbergAudio]

How low to they go without the subs?

-3dB at around 90hz.