I have a home built siesmometer. Its wideband. 0.01hz-40hz.. Ultra low frequencies are a really hard engineering issue because of 1/f noise and all sorts of weirdness.. Ive been using a DI-1120 since it came out years back. I just swapped to a 2108-P. The difference has been truly remarkable in the frequency band i am interested in. In fact its been shocking.
The difference is not the 14bit vs 16bit. Its the far lower 1/f noise below 10hz down to 0.01hz.
Where I once just had noise, signals have become extremely obvious. Very clear. Well resolved.
Amazingly this spectrogram used to be noise with almost no signals. Now it has some much stuff it amazing. Note that the top of this chart is 10hz, the bottom of the cart you can see detail of 0.05hz pretty easy.
This FFT also shows a lot of details. Not its in log and note the major tick marks are 0.01 far left, 0.1, 1, 10 ending at 40hz far right.
Im really happy with this upgrade. Yes the 2 additional bits helped also.
So, you really get what you pay for going from the 1120 to the 2108-p. The 2108-P was huge step up. Well worth the price difference.