I’m not sure I’ve heard anyone cover this topic but I’ve been doing a lot of recording at The Record Shop in Nashville and this always comes across my mind. Every time I use a really expensive tube microphone I notice there is an abundance of low mid frequencies! So much that it makes the vocal muddy and requires a lot of eq and multiband compression. I’m not necessarily saying this is a bad thing, it’s better to have the frequencies there to subtract than try to add something that’s not there…but it could push you to do some mixing moves that you aren’t use to doing. This is where trusting your ears is huge! I record with a Neumann Tlm103 and Neumann U87 all the time and don’t experience an excessive amount of low mids and lows, but when I bring out the tube microphones like the Neumann M149 or Korby tube mic, it’s overwhelming! Tube microphones are known to sound warmer and warmth lives in the low mids so I am not surprised, but when I started using tube mics occasionally I started to be aware of the difference. So when approaching mixing vocals that were recorded with a tube mic, it’s okay if you have to cut more low mids or compress them harder with a multiband compressor or dynamic eq. Not all of us get to use tube mics because they can be expensive but just remember this advice when renting a fancy studio! Comment your thoughts!