Sometimes in specific conditions such as some early mornings, the day after having strained my voice, or having a mild cold, I can reach unusually low vocal ranges. Looking around, there is very little information about how (if at all), one can access this potential under normal conditions through training or preparation as there seems to be very few resources online on singing that specifically target bass singers.
So, how can I access these extra low ranges when I actually need them?
The following is more specific to myself to provide a concrete example of what I mean:
I am 25 years old and have been a bass singer ever since my early teenage years, and since about 16 years of age would be considered a "Basso Profondo" according to the wikipedia definition. On most days, I produce a strong C2 without issue, and I commonly have access to a range down to A2 (albeit most often without any considerable volume). In the situations described above, I produce strong, clear notes in the region of A2, and have sometimes even reached as far as a clear Eb1 (the day after a choir practice weekend where my voice felt really strained the night before). Often during long sessions of practice, I feel strained and are unable to access my normal range of down to C2, but once the strain passes is when I usually have the deepest voice.