TI Jazz flats are actually not
all that low tension. On a 34" scale (per
Thomastik):
- 28.2 pounds for C
- 44.97 pounds for G
- 50.71 pounds for D
- 44.5 pounds for A
- 39.46 pounds for E
- 34.17 pounds for B
For a 4-string, E to G set, that's 179.64 pounds.
A "Custom Medium" set of GHS Precision Flats (45, 60, 80, 105) is,
per GHS, 41.5, 46.5, 44.9, and 41.2 pounds for G, D, A, and E, respectively. That's 174.1 pounds total -- 5.5 pounds
less than the Thomastik set.
A four-string "Medium" set of Precision Flats (45, 65, 85, 105) is 184.6 pounds total (D and A jump up to ~51 pounds tension); 5 pounds more than the TI Flats.
You can look up the tensions for other sets and/or brands, if you wish.
I've used the Precision Flats on three basses (a six string fretted and a five string fretless, neither of which I have anymore, and a four-string Squier P/J I souped-up for a friend) and have the TI Flats on two basses (a five string fretless and a four string Brubaker Brute). On the fretless five, the TIs actually feel pretty taut -- not floppy at all -- and that bass has pretty low action. On the Brute (where they've been for years), they feel good, but a little more flexible/supple. I also have the action a little higher on that bass. I play everything from Motown to Lou Reed to fingerpicked chords to slapping (which they do pretty well, but not fantastically) on that bass with the TIs and have gotten lots of compliments on the tone. They're a great match for that bass. Likewise, on the fretless, nice feel and pitch definition, including on the B, with some growl.
I tried the TIs on another fretless (that I don't have anymore) and on
that bass they felt like noodles*. It was a stark difference. I've tried them on at least one other bass (forget which) with similar results.
For the GHS Flats, I used the "Custom Medium" gauges (though I'm pretty sure that I had to put the set together from individual strings at the time) because they're more balanced in tension between the middle and the outer strings than the regular "Medium" set. Those strings did indeed feel noticeably stiff than the TIs, even though they're a hair less in overall tension.
As has been often said in string threads,
there is a difference between stiffness (or its converse, flexibility) and tension. The TI Jazz Flats are definitely more flexible strings than the GHS Precision Flats.
So why do the TIs feel so different on different basses? I'm not sure. I suspect that it has to do with the stiffness of the wood and the construction of each bass, but I am sure that there are influencing factors of which I'm unaware. I do know that I wouldn't put them on a bass that felt a little "loose" to begin with.
The GHS flats, on the other hand, were just the ticket for tightening up the feel (and beefing up the tone) of a six string that felt a hair on the "loose" side with rounds (though it did better when I put a balanced-tension set of Kallium rounds on there). The sixer with the flats still had some bite but was more supportive in a band mix (better able to drive and give the band a kick in the butt) than it was before. I also liked them on the fretless, where I was never 100% happy with the B-string on that bass with various tapewounds. (On the current fretless, I think they'd be too much/too stiff.) On the Squier P/J, they were the only flats I tried, but they worked really well off the bat so I kept them on.
In general, I'd say that the GHS flats have more thump than the TIs (but not as much as some) and better mids than a lot of flats. I recall them still having good definition in the mix. On the same bass, you could likely get away with a lower setup with the GHS Flats than with the TIs.
The TIs are more supple than most flats (moreso than some rounds) and encourage some subtlety of touch and finger/pick placement. They might benefit from a slightly higher action/different setup on some basses. For me, they haven't had much of a deep thump, but they do have a little more meat to the note and a little more kick at the start than most rounds I can recall playing. They've got more sustain than most flats, good pitch definition, and sweet, singing mids and upper mids (though this will depend on the bass and amp, of course). I've never felt lost in the mix with them. They can sound nice and full but, with the wrong bass or through the wrong rig or with the wrong approach to EQ, I can see them sounding thin and middy.
Chromes I don't have a tone of experience with, though I've played some basses strung up with them. The first time I played them, I liked them -- gave some kick and definition to a student's previously wimpy Ibanez -- but since then, not so much. To my ear, they have a weird ping in the upper mids and there's something about the feel I don't like (that might just be the basses I've tried with them, though), though I get why people dig them -- they are a bright flat that lets you dig in and play fast and hard and won't turn into a wash of thump in a mix. I could see them working well with overdrive. They probably have other positive qualities that I haven't played them long enough to explore.
I've played DR Flats and a few others, but, overall, the TIs and GHS have been my favorites so far. I am not much of a pick player, but I think the GHS would work well for that -- TIs might, depending on the bass and your attack as well as the tone you're going for.
The Cobalt Flats and the lighter LaBella Flats sound interesting for different reasons.
Hope that helps!
*A set of (I think) light Sadowsky flats felt the same way. The undetermined half-rounds that were on that bass when I got it worked great for it, though -- good tension, feel and tone. When I tried swapping those to the Brute, though, they felt and sounded like fence-wire on that bass -- harsh, rough, stiff, and unmusical.
).