Do you think it's more important to have a bass with max clarity (probably comes down to pickup choice, mostly) when using flats vs rounds, or less important. Or the same, I guess. Personally, I would say less important with flats. On the other hand, perhaps one risks too much mud with flats?
Apples and oranges. They just are two different things. I use the same rig and basses for both and get two completely different - and useful - sounds out of them.
So do you think using flats with a muddy pickup, like the mudbucker on a Gibson eb-01 is fine? Or is it better to have a bass and pickups with more clarity (like a fodera with hum buckers). I definitely like more clarity when I use rounds, but think flats tend to sound the same, more or less, no matter what bass you use.
I'm not sure what you mean by "clarity". When I play either live or play to a studio recording, I need the result to be well defined in the mix so that it can be be heard distinctly, just like the other instruments. Also, the bass tone needs to be appropriate for the style of music. Which means my string and pickup choice are just the first part of the signal chain that determines my sound. Preamp and EQ settings are critical to the final sound and those decisions are made based on what the string and pickup combation sounds like. The short answer is, it depends.
I'll put it this way: A jazz pickup like the Nordstrand NP4 definitely has more clarity than a DiMarzio DP123, but is that clarity wasted on flats? Would you even be able to tell?
I'm not a fan of a lot of clarity or a bright sounding bass. I use D'Addario nylon tapewounds for thump. In the past I used D'Addario Chromes for a slightly twanger thump and Labella nylon tapewounds or flats for thud.
So do you think the type of pickup matters when you go for twanger thump or thud? Or do you think a $12 Artec would thump just fine. I think it would.
I do pickup characterizations (think of that as profiling your pickups) and circuit simulations when I build or rewire basses for myself and others. One of the guys I've done quite a few basses for had a bass that he kept flats on. The frequency response of the circuit simulation for what we ended up with was VERY bright - lots of high end. With a set of flats on it, it was just about bright enough for me (but not quite). If I had put rounds on that bass it'd bite my head off. If you want articulation with flats, a bright bass is a good idea. With rounds, too much treble is too much.
That sounds interesting. I don't know if I like turning up the treble on flats. There's not a lot there, usually. But it sounds like you're doing more than that.
Clarity is how detailed the sound is, I suppose. If you used a Neumann microphone on an acoustic guitar you would get more clarity than you would a behringer mic. But would it matter which you used to record hitting a cardboard box? Not as much, I don't think. That's why I'm not sure pickup choice matters as much with flats as opposed to rounds. Or is there more subtlety in the sound of flats than I'm giving credit?
Since pickups act as filters and transducers they do matter but I've found that the strings have the most effect. I'd try different strings before changing pickups. I forgot to mention in my previous post that, before I changed to tapewounds, GHS Precision Flats were my favorite flats for thump and I like their surface texture.
I think EQ is a little more straight forward. There is a ton more you could do EQ wise with rounds than with flats. On a graphic equalizer, you could probably turn the upper half down all the way, and not be able to tell with flats. But could you tell the difference between the $12 Artec pickup and and a $200 Lollar when using flats? Probably, but a lot less so than with rounds. Are there pickups that sound super good with flats, but not so good with rounds?
I have a Gretsch jr jett, and I put labella low tension flats on it. To me the low tension feels like the tension of rounds. It has this sound that is flats, but sorta compressed, and more round like. I dig it. HOWEVER, I do run it into a bass fly rig and play with the eq. For my short scale, bumping up the treble and a tiny bit of mids bring out the clarity quite nicely. this is probably because the short scale is naturally a bit boomy. tldr: You can do it if you tweak your eq enough, but strings do matter.
My fretless P runs TI Jazz flats. I put a Bill Lawrence PU into it because that pickup does a good job preserving the highs and I figured the fretless with flats could benefit from a some added clarity.
I have the total opposite experience. I have different sets of flats and different basses. Each string has it's own vibe, sounds different with picks or fingers and reacts to effects differently. It took me a while and quite a bit of experimentation to figure out which bass got which flats and which bass got which rounds for the tones I was after. One set of flats that works on one did not work on another, as far as what I was trying to achieve. For this project. A different project, I might have to use different flats!
My initial thought is that it's largely contingent upon your tonal goals. Everything else is subservient to that end. I think that your premise is flawed. Good to excellent quality gear with TI's or EB Cobalt Flats have provided me with a subtlety of lower mids, a warmth, and tight roundness which appeals to my ear. Your ear might hate it, or find it immaterial.