Hi Thorbjørn,
why exactly did you move the two woofers from the front to the back at this stage of development?
Development had been well advanced, and third-party tests had been very positive.
Besides, it doesn’t just have advantages.
So why? What was your Idea at this Point and what were you unhappy with?
It was one aesthetic/design perspective, and one functional perspective.
From a design perspective, it just looked too much like any other floorstander to me, and I knew the performance would not be like any other floorstander, so I needed some way to make it catch the eye and attention. At the same time there was certainly mixed reception for this change in my usual group of people I consult with. Some found the speaker to look "weird" with only one driver in front. But at least it was different (I am aware it is not unique, but a less typical configuration). I like different.
The second reason is connected to the fact that if you look at it from the main Sigberg philosophy of a 4-way system with dedicated bass units, this entire project was a compromise from the start. So from a conventional point of view, the Saranna is a normal 3-way floorstander, while our other systems is a bit strange. In my book it's the other way around. Our other 4-way systems are the default and go to approach for best possible sound. And it's the Saranna with its integrated 3-way approach that is strange.
So this entire project was an exercise in minimizing the negative consequences of "settling" for a 3-way solution. One of the required changes was moving to a different and larger coaxial driver, so that I got more capacity in the midbass, since I no longer have a dedicated midbass driver. The other was to find a way to get the sound as similar as possible to a perfectly integrated, 4-way system with dedicated subwoofers. One way of doing that was to use as powerful bass drivers as possible that would still fit on the baffle. The second was to go for a ported enclosure (the first in the line-up, since both existing subwoofers are sealed). The third was to figure out how to minimize bass issues despite having the drivers locked to the main speaker cabinets. So by moving the drivers to the rear, and also separating them vertically, with one driver and the port very close to the floor, and finally tuning the speakers to handle being very close to the wall, I get a similar effect as with the Inkognito subwoofers: The bass drivers get very close to one or even two of the room boundaries (wall+floor), which reduces the number of modes that are excited (the Allison effect).
The result is that the Sarannas are way less boomy than a typical speaker, even when placed close to the wall. I played a EDM track at ~100dB at the last Hifi show we visited (in a 20m^2 hotel room), and a guy in the audience commented "How on earth are you able to get that clean, tight and loud bass?" - This is how.