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Sigberg Audio SBS.1 Active speakers prototype/build thread

abdo123

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Say you have one active subwoofer, and then add another. How many dB will you gain? 6db. Why is that? You gain 3dB by doubling the power (our system now have two identical amps instead of one), and also you now suddenly have two drivers, each moving the same amount of air as our single subwoofer. This means double the amount of air moved = 6dB gain. The result is similar to 4x power one a single subwoofer, assuming it could have coped with that.

So twice the power + twice the number of drivers.


This effect naturally works exactly the same with two active speakers.

I'm still not entirely convinced how you're getting 4x the sound power. isn't the additional energy provided by the additional amplifier is being used used to move the transducer?

Almost every source I have found online says if you have one speaker playing 100dB and another speaker playing at 100dB, their summation (assuming they're perfectly in phase) is 103dB, not 106. I don't understand how an active design changes any of that.

1625579574913.png
 
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sigbergaudio

sigbergaudio

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I'm still not entirely convinced how you're getting 4x the sound power. isn't the additional energy provided by the additional amplifier is being used used to move the transducer?

Almost every source I have found online says if you have one speaker playing 100dB and another speaker playing at 100dB, their summation (assuming they're perfectly in phase) is 103dB, not 106. I don't understand how an active design changes any of that.

View attachment 139449

If you add another speaker, you gain 3dB. I'd you double the power you gain another 3dB. The same thing happens in a passive design.
 
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sigbergaudio

sigbergaudio

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Almost every source I have found online says if you have one speaker playing 100dB and anoth
I'm still not entirely convinced how you're getting 4x the sound power. isn't the additional energy provided by the additional amplifier is being used used to move the transducer?

Almost every source I have found online says if you have one speaker playing 100dB and another speaker playing a
I'm still not entirely convinced how you're getting 4x the sound power. isn't the additional energy provided by the additional amplifier is being used used to move the
Almost every source I have found online says if you have one speaker playing 100dB and another speaker playing at 100dB, their summation (assuming they're perfectly in phase) is 103dB, not 106. I don't understand how an active design changes any of that.
I'm still not entirely convinced how you're getting 4x the sound power. isn't the additional energy provided by the additional amplifier is being used used to move the transducer?

What is not so intuitive, is that if you have a loudspeaker driver, and then add another, identical driver, the efficiency / sensitivity of the loudspeaker actually increases by 3dB. So without increasing the amplifier power, we gain 3dB.

In this instance where we have one active speaker, and then add another, we first get 3dB increase in efficiency by doubling the number of drivers. Then we double the amplifier power, and get 3dB again.

Total gain 6dB.
 

thewas

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In the lower frequency regions where the signals of L R are usually coherent the addition of second loudspeaker gives theoretically 6dB, in reality the sum in most rooms is somewhere between 4-5dB, closer to 6dB at the lower frequencies and closer to 3dB at the higher frequencies (non-coherent addition).
 
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sigbergaudio

sigbergaudio

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In the lower frequency regions where the signals of L R are usually coherent the addition of second loudspeaker gives theoretically 6dB, in reality the sum in most rooms is somewhere between 4-5dB, closer to 6dB at the lower frequencies and closer to 3dB at the higher frequencies (non-coherent addition).

The speaker is only limited in the lower frequencies, which means in practice 6dB increase is possible for the entire spectrum.
 

thewas

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The speaker is only limited in the lower frequencies, which means in practice 6dB increase is possible for the entire spectrum.
Not at the high frequencies where the addition is usually not fully coherent, but anyway you use a 2.5 way design which doubles the output in the bass and there it will be close to 6dB.
 
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sigbergaudio

sigbergaudio

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Not at the high frequencies where the addition is usually not fully coherent, but anyway you use a 2.5 way design which doubles the output in the bass and there it will be close to 6dB.

If the two speakers aren't playing the same signal or you're not symmetrically situated as opposed to the speakers, the signal you hear may not sum perfectly to +6dB at all frequencies, but that doesn't take away from the fact that the speakers have the capacity to reproduce the stated sound levels.

In practice the speakers are able to play way louder in the higher frequencies, since the capacity of a single speaker at higher frequencies are much higher than the stated full frequency capacity.
 
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sigbergaudio

sigbergaudio

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I guess we haven't shared an anechoic / outdoor measurement with subwoofer before. There's something going on around 1khz here, likely reflections from something. Anyway, as the measurements show, we're +3/-6dB from 22-22,000hz. Indoors you'll obviously have room gain, making this a true full range system, typically playing flat to 20hz.

The subwoofer is a Sigberg Audio 10D with it's built-in SBS.1 preset enabled, resulting in a pretty perfect crossover integration. All you have to do is adjust subwoofer volume based on taste and room gain.


1629027897071-png.741142


And a closeup of 20-500hz (not the same measurement as above)
1629028316882.png


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sigbergaudio

sigbergaudio

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sigbergaudio

sigbergaudio

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So these work out at USD$6500 pr? Plus a subwoofer or two needed?

For export (sales to anywhere but Norway), they will be sold ex VAT, which works out to roughly 5200USD / pair. Then any local VAT will apply during import, which will vary depending on your country.

And yes, you will need subwoofer(s) as well.
 
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sigbergaudio

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A different way to look at it is to look at the price for the full system.

It's all modular, so you can do 7300USD ex vat for SBS.1 + our smallest subwoofer, all the way to 9950USD ex vat for SBS.1 + two of our 10D subwoofers.

For that price you get a modular, powered, true full range system where every single driver is individually powered by Hypex power amps.
 
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sigbergaudio

sigbergaudio

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Finalizing some measurements, turns out I've been a bit sloppy with the distance when measuring off-axis (further away when moving more off-axis so that the highend roll-off was higher in the graph than in reality. There are a few artifacts below 500hz here because my measuring situation isn't perfect, so there's some EQ there to hide reflections. In reality it's basically flat (+/-1dB) from 100-500hz.

New, more precise measurements show it's pretty darn good from 0-30.

0-15 is almost identical:
1629624231149.png


Avg 0-30:

1629624121516.png
 
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sigbergaudio

sigbergaudio

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The first review of both SBS.1 and the 10D subwoofers (collective test of SBS.1 speakers paired with two 10D subwoofers) is out. Norwegian only, but here are a few bits of the article translated to Norwegian. :) The review was in the Norwegian hifi magazine "Stereopluss"

"This is sound at a high, international level!"

"The bass is deep and controlled. It's also fast and detailed, without becoming too anemic or sterile. Yet it is the vanishing act of SBS.1 that impresses me the most. They do exactly what some small speakers are extremely good at, which is to disappear, leaving just the music. There's no audible footprint, yet they fill the living room with sound. There's depth, width and an excellent holographic quality. It's extremely precise, and the placement of musicians and singers in width and depth is excellent(..)"

"Sigberg Audio SBS.1 and 10D is living proof that you don't need large speakers get a large and powerful sound. The ability of SBS.1 to seemingly vanish is simply magic, and with the ability to tailor the sound through the onboard DSP, amazing musical experiences are possible even in difficult rooms.(..)"

1630611555858.png
 
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sigbergaudio

sigbergaudio

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We've now published the article "Designing a loudspeaker: The SBS.1 story" on our website. Hopefully it might prove interesting to anyone interested in loudspeaker design in general, and/or the choices made with this speaker specifically. :) Happy to receive feedback about information that may be missing, then I'll consider expanding the article further.

 
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sigbergaudio

sigbergaudio

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Hi @sigbergaudio

Do you have the current/latest directivity plots? Both vertical and horizontal

The plan was do a new, full set of measurements now that everything is finalized, but this needs to be done outdoors, and the weather is troublesome as we're well into the wet and rainy fall here in Norway.

But this listening window shared earlier (pasted below) is still quite accurate (though measures even better now). As I'm sure you know, the listening window curve is an average of horizontal responses at +/- 10, 20, and 30 degrees on the horizontal axis, and +/- 10 degrees on the vertical axis

Looking at this, the bump at ~600hz is a reflection/measurement anomaly (it's essentially ruler flat there). It's now also more even and flat between 10-20khz, and the very slight lift from 3-4khz and up is more even and gradual. Otherwise the big picture is relatively similar.

index.php



The more recently shared average of 0-30 average will probably not be very different from a full listening window average. The dispersion horizontal and vertical is very similar.
index.php
 
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