mixmkr said:
if your close mic'ing the bass amp, which seems to generally be pretty much the norm, couldn't you throw the room out of the equation?
To a degree but the room if not treated properly will effect the sound. Unlike amping a E. Guitar the bass amp needs to be treated with care. Many engineers will place the amp in a "bass traped" room. It's usualy smaller and full of absorbent material. A closet at home that is treated in a similar fashion can be a great place for homers. I tend to prop the amp also on a small stool. That gives it a tighter sound and helps control the low freq's from going wild. I also place it against a wall facing the room making sure the sound can spread out. I stay
clear away from the corner as much as I can for obvious reasons.
The key is the amount of distance between the mic and the amp.
o close and you'll miss out on the low rounded part of the sound.
To far and you'll have the room effect the sound and get a bassy boomy sound cause the higher freq's die out quicker (even before some reach the mic) then the lower, leaving you with a a muddy content. Another consideration is the amp itself. Is it a multiple identical speaker? Does it have multiple speakers covering different freq's? (in which case you you'll have to move the mic back to get the full content.
actually, wouldn't combining the DI with the mic'd input be more the norm?
It depends on how lazy the engineer is

. Life is so much more simple with a decent DI. A crappy DI will do more damage then good. Also a DI is a somewhat impotent as it is missing out on all the richeness
an Amp can provide.
It's really a color issue. Do you need more high freqs and a cleaner sound so you DI or do you want more low and grit so you amp. But even then it isn't so simple. Whats the quality of the bass...it's pickups....the quality of the amp..can you control the crossover... sometimes a good bass with good pickups through a good DI is simply the better path.
Good engineers who do there work will do as you said, combine the two and mix accordingly. The flexability of the 2 tracks is way more important. There are even engineers who add a third mic for ambience.
Homers who decide to try experimenting with a mic should always remember to keep the level always the same no matter what position you put the mic in or the amp. Any change in level will change the sound.
Having said all that. . All things considered including - budget - time - I tend to DI a lot more then Amp. The person who has time to experiment either has a a huge budget or a lot of time on his hands with a patient client.