@Purité Audio asked me a question privately, but while typing out the answer I realized it was a quite an interesting question highlighting some design differences of all our speakers, so I decided to answer here instead.
The question was basically if I heard any difference in tonality between the old and new coax. And if so, to what degree did I think this was due to differences in driver size, baffle width or other things. In the same context Keith also said he had previously noticed a "thinner" sound in one speaker versus another (other brands), and had pondered the reason.
First of all, as a general observation, "thinner" can mean many things. It's hard to know exactly what people mean with regards to frequency range when they describe sound. Even when talking about bass quality I can sometimes hear two people discuss and get confused, because one person is focusing on pretty deep bass, maybe 30-50hz, while the other talk about say 80-150hz, and they think they are talking about the same thing.
That aside, I would say that the tonality between the Saranna and the current speakers that use the "old" coax is pretty similar. One obvious reason for that is that I have tuned all the speakers, and I'm pretty conscious of how both the midbass and the midrange "should" sound (in my opinion) with regards to tonality, fullness and sense of body to the sound.
I think with the Manta one will find the midrange and male vocals and stuff like that to sound fuller and deeper than with the SBS.1, but the difference is quite subtle. They're tuned to have the same tonality, and while as 12" will of course deliver more effortlessly and perhaps also to some extent sound fuller, I think there are some sighted bias at play as well when you sit and look at the Manta compared to the SBS.1.
Keith also mention baffle size, and that can perhaps have a bigger impact than the driver itself, since the wider baffle will give more directivity / sound radiating forwards toward the listener in the lower midrange than with a more narrow baffle.
In this regard the Saranna floorstander is somewhere in between. The SBS.1 is just 19cm wide, while the Saranna is 26cm, and the Manta is 36cm. Also, both the Manta and the Saranna have the cardioid as well that contribute to the same (more energy towards the listener in the lower mids).
There's also a pretty big difference in design here, if I am correct in assuming the "thinness" is a midrange / lower midrange aspect perhaps pretty low in frequency. Both the SBS.1 and the Manta has help from a dedicated midrange driver. So in those designs it's not only the coax that is contributing in this frequency range. In the SBS.1 both the coax and the midrange play down to 90hz, while with the Manta you have a dedicated 12" from 600hz and down. With the Saranna you have significantly larger coax, but it has to do all the work by itself all the way down to ~150hz, so that extra real estate is needed.
So in summary, I think there is plenty of punchy and meaty sound in the Saranna. I can't imagine anyone describing the sound as "thin", in the same way as I doubt the SBS or the Manta would be described as such. The reason is that with all three designs there are explicit focus on enough capacity and energy in the upper bass / lower mids.
But how this is achieved is, perhaps interestingly, different in all three speakers.
