I play in a band that uses drop A tuning. That's 55Hz on guitar. That'd make 27.5Hz for a drop tuned 5 string bass?
My question is, am I suppose to be chasing down studio monitors that can reproduce 27.5Hz? Most 8 inch monitors can't do this, so I'm beginning to doubt I'm suppose to find some to begin with...?
There's a difference between having a note or sound that is periodic at a given frequency (viewed in the time domain), and that note or sound having energy at that frequency (when thought of as a 'spectrum' in the frequency domain). It is actually possible to have a sound that is periodic at (say) 27.5 Hz without having any energy at all 27.5 Hz. In most case though, the ear would in many cases still perceive the fundamental frequency of the note - https://en.wikipedia.org/wiki/Missing_fundamental.
This is what is often happening when you listen to bass sounds in music, including bass guitar - the ear is perceiving the upper harmonics and 'working out' the fundamental frequency of the note, the volume of which is often weaker than the second or third harmonic anyway - so you don't necessarily need monitors that will go down to 27.5 Hz to hear notes of that frequency. After all, you can hear a normal 4-string bass (which goes down to 41 Hz) on small systems that may not be able to produce frequencies below 70 or 80 Hz well.
That said, you might want some way to work out how your mix is going to sound on systems that can produce sound down in that low frequency range. This could mean checking your mix on monitors with an extended bass range, or using headphones with decent bass; or you could use a frequency analyser to check how much low bass energy you have. The usual advice is to check your mix on a variety of systems.
This isn't a problem that only comes about due to using an extended range bass - in many cases, the bass drum will be producing sounds with energy down at the bottom end of the frequency spectrum, too. It's not uncommon for the bass drum to be EQ'd to sit below the frequency range of the bass instrument.
The harmonic contribution of the bass guitar is not at 27.5Hz. 27.5Hz is mainly shaking you up. Now there are organ pipes at those pitches with a strong fundamental and few overtones. But they are pretty vague musically without further context. The function of a bass guitar, most particularly an electric one, is different (which explains funk and slap playing styles and the importance of pick choice or not and so on): the harmonics are the important thing, and those are which determine whether or not the mix is transparent or ends up more of a mush.
There is a reason monitors don't reproduce those frequencies: monitors are supposed to be mainly audible to the musicians (and are not usually included in delay line management) and low frequencies are not focusable and contribute little useful information to the musicians since the balance in the low bass spectrum is usually uncontested and contributes almost nothing to the transparency of the mix. It's the harmonics which need to be balanced with the rest of the band.
So your acoustic control would be impaired if you were playing contra bass recorder (an instrument with few overtones). But neither your nor the other player's relative audability would be affected much if you played at double or half the volume because you'd not be competing in their frequency ranges. It would just be bad for figuring out whether you were playing off-pitch.
Bass guitar? Should not be much of a problem.
The purpose of studio monitors is to mix recorded music. While one wants extremely accurate professional studio monitors which reproduce a broad frequency range, one also has to mix music in such a way that it will sound good on the kinds of inexpensive consumer-grade speakers and headphones that consumers have in their homes and cars.
This is why one does not want to mix recordings on a speaker system that would have tons of heavy bass, added on, using massive subwoofers. If you mix in that environment, then when the recordings get listened to by the people that buy your music and play it back on their ordinary home stereo systems, in their cars, or in their iPhone earbuds, they will hear something drastically different than what you intend for them to hear and what you heard in the studio when you did the mix. This is counter-productive.
Back when I was in professional recording studios, in the 1980s and 1990s (home studios of any sort were very rare in those days), they always had a set of expensive stereo monitor speakers with large woofers and prodigious wide frequency response, but they also had one or two other sets of inexpensive monitor speakers with much smaller bass drivers that were there to represent what people used in their homes and cars. The ideal was to create a mix of the recording that would sound good, on average, whether it was played back on any of these different types and grades of monitors.
Although this is outside of my limited experience, I understand that there are now certain mixing and mastering plugins and signal processing devices available that are designed to encode signals into your mix that are capable of creating extra low bass frequencies (perceivable to the listener) that are reproduced when the recording is played back on consumer-grade speakers or headphones. These kinds of products employ "psychoacoustic bass enhancement technology". One example is the MaxxBass plugin by Waves. Its product information says that it "extends perceived bass response by up to 1.5 octaves".
