Several folks make low tension strings. You don’t have to spend the big $$ on TIs.
Just know they feel a bit different, so you will need to compensate / adjust / get over it.
Smaller gauge strings are a bigger deal for me than low tension strings. I have labella low tension flats on my Rick and I don’t notice a thing different (other than how awesome the Rick is 
)
If I were going to do rounds I would go to Stringjoy and use their tension calculator. I have a set of Stringjoy at home waiting to go on. I love TIs but can’t afford them on everything. SJ are my backup
You can do custom sets with SJ, and ask them questions and they respond pretty quickly
I guess I am lucky; I really love the feel and tension of D’Addario 45-100 light gauge rounds. Excellent strings and inexpensive. The NYXL’s are my favorite bass string so far.
I’ve tried:
flats (on a friend’s bass; hated them)
D’Addario (EXL and NYXL) - my faves
Elixir - not bad
EB Super Slinky - not bad, not my favorite
Warwick Reds - utter garbage
Fender rounds - quite good, but I prefer D’Adsario’s main strings more though
Bass Centre Elites - Excellent but not so in to steel rounds
I feel lucky to be happy with the EXL’s and NYXL’s.
I am quite liking the Ken Smith Burners 40-100 set that are on the Tele-inspired Warmoth build I just bought. They were never on my radar but seem to be lower tension and have a good feel under my fingers.
So, as a rule of thumb, if I got a set of .45-.105 flats, they’d have less tension than my rounds?
It’s the other way around, at least for D’addario strings.
Yeah other way around
Doh. Totally flipped “flats” and “rounds” in my head.
The round string is made of a thin wire wrapped around a core wire. A flat string is made by wrapping a narrow, flattened metal strip around a core. As such, flats generally aren’t as pliable as rounds of the same gauge, so they don’t have an equal amount of give when pressed down.
That said, there are low-tension flats that are designed to not be as resistant to finger pressure as regularly manufactured flats.
I have a question for you wise gurus of the BassBuzz forum…:
Does anyone know whether different strings make any notable difference to the sound that comes through via a piezo pickup on an acoustic?
My Aria came with (I’m 99% certain) D’Addario Phosphor Bronze strings, and I’m curious whether changing them at some point in future would have an impact on the amplified noise, or indeed if it would even have much impact on the acoustic noise, as that’s after all how it’s played most of the time.
Thanks in advance 
Interesting question !!
And I don’t know the answer. Sadly.
My hunch though is yes as everyone seems to like the phosphor bronze strings. May be to reduce brittleness of the piezo? I have nylons tapes on a combo piezo/P bass I have and quite like the results.
Phosphor Bronze strings are the generally preferred strings for acoustic steel string guitars.
In general, piezo pickups will faithfully recreate the sound of an acoustic guitar. If a different type of strings is used on an acoustic guitar (e.g., nylon strings vs PB), the tonal character of what you hear when you play unplugged will be what you will hear when your instrument is amplified, just louder (assuming you don’t add EQ or effects, of course).
As is the case when using different types of strings on any type of guitar, you will definitely hear and feel varying degrees of difference between how each type sounds and plays.
Thanks both of you @John_E and @MikeC
Interesting to know for future and something to investigate in future, though my wallet is nervous about what this may entail…
I also wonder how much low tension strings are marketing and packaging.
The LaBella low tension flats are a lighter gauge, one that isn’t available in their normal flats. Is there a difference other than gauge?
Same question on Rotosound 77 monel flats. Is their a difference between them and the Steve Harris flats other than gauge? SH monel flat wounds (part #SH77) I think are just heavier gauge 77 monel flats.
And I’m suspicious Lower Tension flats are simply lighter guage.
A healthy does of suspicion is duly warranted. 
A $25ish caliper from Amazon will answer the question 
Sometime Soon 
I’m taking my last set of Cobalt rounds off my basses (Stiletto has them) to swap to Stringjoy nickel rounds. I really like the stainless strings on the Reverb Trash Bass though, so I might eventually try a custom stainless set from Skull all the way over in France. Sadly they seem to stop at 34" scale for some stupid ass reason 
I’ve been playing with string choices on my basses in an effort to finesse their sounds to suit my needs and provide some variety.
Warwick Streamer: This is a PJ and I’m really looking for that 80s - 90s rock sound. After some experimentation I’ve settled on Rotosound RS66LD, round stainless. These give me the super zingy sound I’m looking for, dial in some chorus, drop the tuning a half step and it’s pure Guns n Roses territory.
Dingwall: This has a very modern sound and there’s limited choice of strings suitable for the multiscale but I’m sticking with the stainless version of the stock Dingwall strings. If I’m tuning drop D or lower I use the Dingwall as the longer scale keeps everything in check. I may consider going BEAD with this (or I may just buy a 5) but I’ll still stick with the Dingwall strings.
This brings me to the Lakland DJ4: A passive J style bass that I bought for a more traditional type sound. It’s already significantly different sounding to the previous two, but I’m seriously considering going the whole hog and fitting flats on this one.
Is anyone else running flats on a Jazz bass and if so, what have you found to work well? I’d love some suggestions.
TI flats on my Jazz. Best match for it. A little bright at first but settled in to wonderful bell tone in about a month.
Yes indeed! On a few and always LaBella
Me too. You might like this video (I did):
