Although, is a 94dB dynamic range in any way inadequate? Considering the S/N ratio of mic amps, and the S/N ratio of recording venues, what's actually being recorded once one gets down to below about -80dB? Aircon noise, traffic rumble, mic amp and mixing desk noise, not a lot of actual musical value.
That is the study from Fielder which shows that to not be a limitation. I wrote a digest of his research for the playback side in this article:
https://audiosciencereview.com/forum/index.php?threads/dynamic-range-how-quiet-is-quiet.14/
In a nutshell, we need to look at the spectrum of noise. When we do, the SPL noise numbers that we think are too high, turn out to not be the case where our hearing is most sensitive.
Furthermore, we are able to hear noise coming out of speakers or a band playing, well below room noise. The directionality of the noise that way is key, versus diffused one in the environment.
He also examines the limits of microphones, speakers, amplifiers, etc. The paper is quite long, is peer reviewed, and has some 60 references. It is very hard to shoot holes in it.
Here are some sample data from his paper, Dynamic-Range Issues in the Modern Digital Audio Environment*
LOUIS D. FIELDER, AES Fellow
So here we see despite these recording venues having noise floors at low frequencies as high as 45 db, they are all pretty close or beat threshold of hearing. They do so because their noise level is as low at 0 db or even lower at mid-frequencies where we are most sensitive.
This is peak playback levels in same and other venues across larger number and genre of performances:
So we see that peak is above 120 db even for non-amplified music in some cases (black bars). So if we take 0 db for the lowest level and 120 db for highest, we arrive at 120 db dynamic range requirement.
Here we see that threshold of hearing white noise -- the kind created by equipment/channel -- is actually lower than threshold of hearing that is based on detection of tones:
Here is the data on microphones:
On and on. Here is the abstract summarizing it: