Sigberg Audio SBS.1 Active Speaker Measurements & Conclusion
The Sigberg Audio SBS.1 was measured in free-air at a height of 7.5 feet at a 1-meter distance from the microphone, and the measurements were gated at an 11-millisecond delay. In this time window, some resolution is lost below 250 Hz and accuracy is completely lost below 110 Hz. Measurements have been smoothed at a 1/24 octave resolution.
The above graph shows the direct-axis frequency response and other curves that describe the SBS.1’s amplitude response in a number of ways. For more information about the meaning of these curves, please refer to our article Understanding Loudspeaker Measurements Part 1. These graphs show an impressively flat response from upper bass all the way up to upper treble. The bass does seem to be slightly elevated, and the upper treble past 10kHz shows a small dip followed by a slight lowering of output starting at 15Khz. Keep in mind that the “Listening Window” graph is more important here than the on-axis response, and it is quite flat over much of the bandwidth shown here. That tweeter is performing beautifully. Directivity is nicely controlled, and there don’t appear to be any major dips or peaks that would make this speaker difficult to equalize. That also means that the SBS.1 will have fairly predictable performance in any normal room, and acoustic treatments aren’t needed to address any flaws of the speaker.
The above graphs depict the speaker’s lateral responses out to 90 degrees in five-degree increments. More information about how to interpret these graphs can be read in this article: Understanding Loudspeaker Review Measurements Part II. Here we get a closer look at the horizontal dispersion of the SBS.1, and we can see that there aren’t any jarring response swings except a little bit in upper treble where it doesn’t really matter. There is a slight sag that occurs just above 3kHz outside of the 40-degree angle; it is a low Q dip, but it is shallow and would only matter as a reflection since no one is going to be directly listening to these speakers at such a far off-axis angle. Overall, we have nicely flat responses over any reasonable angle that anyone is realistically going to be listening to. This speaker will have no tonal shifts over a very wide listening area.
The above polar map graphs show the same information that the preceding graphs do but depict it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude, and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s behavior more easily. For more information about the meaning of these graphs, we again refer the reader to Understanding Loudspeaker Review Measurements Part II.
The solid red color over so much of this graph tells us that the SBS.1 is emitting a constant level of acoustic energy over a wide area and across a wide range of frequencies. This speaker covers a large area with neutral sound with little deviation. The most consistent coverage can be seen to be within a forty-degree angle of the front-facing direction of this speaker, and that will encompass pretty much anywhere anyone is attempting to hear the speakers. Again, we see no major peaks or nulls at off-axis angles. The in-room sound of the SBS.1 might be a bit on the warmer side seeing as how there is more bass at far outer angles. A speaker with such small bass drivers won’t be able to restrict directivity until relatively high frequencies, and that is what we are seeing here where the dispersion doesn’t become a bit more consistently restricted until above 2kHz.
The above graph shows the SBS.1’s speaker’s response behavior along its vertical axis where zero degrees is directly in front of the tweeter, negative degree values are below the tweeter, and positive degree values are above the tweeter. We don’t normally throw in a ‘profile’ view of the vertical responses, but I think it is appropriate for the SBS.1 to show how much it resembles the horizontal axial response- as would be expected. The vertical dispersion is similar although not the same as the horizontal dispersion, so, as was mentioned earlier in this review, these could be used on their side just as well as upright in a vertical orientation. It won’t do much to affect the sound. To reinforce this aspect of the speaker, let’s take a look at a polar map of the vertical dispersion:
In our polar map of the vertical response of SBS.1, we do see better that it isn’t an exact match of horizontal response, but it is not massively different either. This speaker has a wide dispersion on both axes. One difference that we see is some kind of comb-filtering in the upper bass region between 500Hz and 1kHz in the upper half of the vertical axis. I don’t know what to attribute this to except that the shape of the cabinet would be a factor there since it is one of the major things that is asymmetrical on the vertical axis. It is not at all a big deal in practice, and I only mention it as a point of academic curiosity. Nonetheless, you still get a nicely uniform response out to forty degrees much like the horizontal dispersion.
The above graphs show the SBS.1’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). The SBS.1’s roll-off looks to start at 200Hz, but it rolls off at an extremely gradual 1rst-order slope until 80Hz where it starts to roll off at a 2nd order slope. Typical room gain will shore up the response a bit, but the speaker would sound quite lean on its own without a subwoofer. As the manufacturer says, the SBS.1 needs a subwoofer. Since it uses a sealed cabinet with a traditional sealed roll-off, integration with a sub should be fairly straightforward. I would experiment between 80Hz, 100Hz, and 120Hz crossover points to see what works best in the user’s particular room, however, 100Hz and 120hz crossover frequencies are better used with a multi-sub system so that subwoofer localization doesn’t become a problem.
The Sigberg Audio SBS.1 is a collection of ideas whose time has come in hi-fi audio. On many occasions, audio enthusiasts would wonder aloud, “Why don’t they do this?” for many of the ideas that Sigberg Audio has actually gone ahead and done. Self-powered loudspeaker with one of the highest-performing amplifiers that money can buy? Check. Leave deep bass to subwoofers that are more suited to the task anyway? Check. Using DSP not just for active crossover and response shaping but for a usable onboard equalizer as well? Check. A hi-fi coaxial speaker with a very wide dynamic range? Check. The SBS.1 is as much of a proof of concept as it is a loudspeaker for a sound system.
Before bringing this review to a conclusion, I will briefly go over the strengths and weaknesses of the product under review, and, as usual, I will start with the weaknesses. The Sigberg Audio SBS.1 only has two real weaknesses, but they are inevitable for what Sigberg is attempting to do. The first is, of course, that the SBS.1 does not reproduce deep bass. It is fairly expensive for a loudspeaker that doesn’t reproduce deep bass, but that is by design. If it did have deeper bass extension, it would have to give up dynamic range, and that isn’t a great trade-off in this age where subwoofers are so prevalent. The second weakness is that it is quite expensive. At over $6.5k/pair, a lot of folks are priced out of owning the SBS.1 speakers. That is a shame, but I don’t think these could be available for much less. They are using some of the best components that can be had, and they are assembled in Norway instead of China. There is no way for something like that to be cheap. Shifting the manufacturing to China and using lower quality components could surely knock off a big chunk of the price, but it wouldn’t be as ‘high-end.’ However, it would make the speaker more accessible. Some of the ideas in this design could be executed at a lower price point, although it wouldn’t quite be the same speaker. The SBS.1 speakers are truly nice products, and a mass-manufactured version from Asia would certainly give up some of that ‘niceness.’
At this point, I will mention some features that I wish they had. These aren’t complaints so much as a wish list that could make these a slightly better product. Firstly, an analog output for the digital inputs would be a nice touch and would avoid the need for any external units whatsoever for those who want a simple, complete system. That way you could run a cable directly from the speakers to the subwoofer even from just a TOSLINK or S/PDIF coax input. Users could simply run a digital audio connection straight from their television or computer or any source with a digital audio out, and the SBS.1 plus subwoofer could take care of the rest. Implementing this feature is a bit beyond Sigberg’s control since they source the amps from Hypex, but it would have been neat to see. As it is, there is no way to avoid using an external DAC for a subwoofer if you want to use a source with digital connectivity. The SBS.1 speakers with subwoofer are so close to forming an entire self-contained audio system within a digital signal domain, but doesn’t quite get there, since it cannot throw an analog output to a subwoofer from a digital input signal. This isn’t at all a serious omission, and the vast majority of potential customers will be using the analog inputs. Sigberg tells me that owners who use the digital inputs are uncommon and that most people use the XLR inputs.
Something else that would have been nice to see is the inclusion of some way to control volume on the speakers. Hypex does have available a remote control that has volume adjustment for the plate amp that Sigberg uses, but Sigberg decided not to use it, perhaps because they expected the SBS.1 speakers to be used in systems that will have a volume control. That is a reasonable assumption, however, it would have been nice to have a way to control the volume on the speakers so that they could be used directly with sources that have no gain control.
With those nitpicks out of the way, let’s talk about the SBS.1’s strengths. Firstly, the sound quality is outstanding. With a nicely flat response on and off-axis, this is a fairly accurate loudspeaker. The heavy emphasis on point source emanation gives it remarkable imaging ability, as well as a flexibility that most other speakers in this segment do not have. The dynamic range was also exceptional, and again, well beyond what almost any other similarly sized speaker can hope for. With such a wide dispersion on all axes as well as a wide dynamic range, these would be a great choice for high-mounted surround speakers in an upscale home theater, although such good speakers would be overkill for surround duty. Even so, an entire surround sound system composed of SBS.1s would be an absolutely killer setup, although when you hear what they can do in a simple 2.1 system, you will not miss the center speaker or surrounds at all. The bottom line for these speakers is that they do not have any significant shortcomings in their sound at all, so long as a subwoofer is used. When used with a subwoofer, they can sound much larger than their size would suggest.
Next to their sound quality is their build quality. As we discussed before, the SBS.1 speakers are built with some of the highest-performing components available. That turns them into an expensive speaker, but the quality can be seen and felt inside and out. It is a classy loudspeaker that looks high-end without being flashy or gaudy.
Another major advantage of the SBS.1s is their versatility. Since they are not large speakers, they can fit into places that others cannot. I have used them on my desktop PC system, and they sound fabulous there (I am listening to them as I type this). Their point source emphasis means that you can use them at close proximities without any degradation to the sound. Their sealed design makes boundary gain less of a concern, so you can place them nearer to surfaces without the acoustic penalties that other speakers would face. While any speaker benefits from stand-off distances from room surfaces, the SBS.1s are not as affected by suboptimal placement, at least in low frequencies. As we mentioned before, this makes them great candidates for surround speakers. What is more, their connectivity options enable them to be used in a wide range of setups. Balanced XLR and unbalanced RCA allow them to be used with both pro-audio and consumer audio analog connections, while AES and S/PDIF coax/TOSLINK digital inputs likewise allow them to be used with both pro-audio and consumer audio digital connections. These could easily be used as studio monitors, and the 9-band parametric equalizer could be used to deal with speaker boundary interference response effects (SBIR effects), something that plagues many pro-audio setups but something they are not equipped to deal with. In this light, they are like a hi-fi Swiss Army knife.
While the flexibility of all their possible uses may make them sound like a speaker best suited for certain circumstances, the truth is that they would be a great choice as a more typical 2.1 hi-fi setup as well. The SBS.1 speakers are a great choice for those who want a big sound without a big sound system. Their design maximizes the performance that can come out of such a modest size. Sigberg’s subwoofers have the same design philosophy for that product category as well. As a 2.1 system, they can deliver a dynamic, meticulous, lifelike sound from speakers that do not have a major physical presence at all. As a reviewer, I do look forward to the larger loudspeakers since they usually have a fuller and less-compromised sound than smaller speakers, but the SBS.1s do not have me pining for those larger systems at all. I do think that after I have to return these speakers to make room for other review units I will be pining for the SBS.1s.
The Score Card
The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:
Performance × Price Factor/Value = Rating
Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.
Audioholics Rating Scale
- — Excellent
- — Very Good
- — Good
- — Fair
- — Poor
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Recent Forum Posts:
BoredSysAdmin, post: 1557181, member: 28046He is referring to the movie I watched for the review.
Lost, you are
Pat D, post: 1557166, member: 3087
Hercule Poirot is French speaking but his nationality is Belgian!
At first I want to repeat the fact that the 15 degrees angle has been the focus with regards to smoothness, and is the angle that most will be listening to. The total difference of the average level in 150-400hz area and the dip in the 2-4khz is indeed almost 4dB. But bear in mind that still translates to less than +/-2dB. And as explained earlier in the thread, the 2-4khz dip is intentional voicing to get the right total energy in this area when combining on-axis and off-axis response.
With regards to the midbass bump: During testing of these speakers across a number of rooms, we saw a trend of slight dips in this area, meaning this slight (1-2dB) bump actually helped give a more neutral in-room response, and also what gave the most natural timbre during listening sessions. If you have a look in some “share your in-room response” threads, you'll also likely notice that weak energy in the 100-300hz area is actually quite common (not just with these speakers), often due to reflections / SBIR effects.
TL;DR: This is intentional voicing in order to give the most natural and neutral combined response in-room.
Sigberg Audio, post: 1556126, member: 92130I am sure the Loudspeakers area is fine for that.
What part of the forum would I put that, typically?