D'Addario · Chromes Flatwound Bass · 45-65-80-100

D'Addario ECB81 (45-65-80-100) in Drop C (bass) on a 34"–37" multiscale scale

45-100 Regular Light, Long Scale, XL Chromes Bass Strings on a bass with a 34"–37" multiscale scale, tuned to Drop C (bass) (F2 C2 G1 C1), pulls 153.5 lb69.6 kg683 N in total and 38.4 lb17.41 kg171 N per string on average. That is a loose feel for a bass. The set is uneven (spread 14.5%). String 4 (C1) deviates most: −22% from the set average.

Total tension: 153.5 lb69.6 kg683 N
Average per string: 38.4 lb17.41 kg171 N
Feel: loose; medium ≈ 43.6 lb19.78 kg194 N per string; Set your own preferred feel
Balance: uneven; spread 14.5%

Tension per string

The bronze dashed line is the medium-feel target: the average per-string tension of a 45-105 set on a 34" scale in E standard (bass) (43.6 lb19.78 kg194 N). Loose and tight are measured against it.Line thickness follows the string gauge; textured lines are wound strings. Hover, tap or tab to a string for details.

#	Note	Hz	Gauge	Item	Type	Length	Tension	vs avg
1	F2	87.3	.045	CB045	flatwound	34"	37.3 lb16.93 kg166 N	−3%
2	C2	65.4	.065	CB065	flatwound	35"	45.4 lb20.58 kg202 N	+18%
3	G1	49.0	.080	CB080	flatwound	36"	40.7 lb18.46 kg181 N	+6%
4	C1	32.7	.100	CB100	flatwound	37"	30.1 lb13.65 kg134 N	−22%
Total							153.5 lb69.6 kg683 N

Open in the calculator

Multiscale (fanned frets): string lengths change linearly from 34" (treble) to 37" (bass).

Similar sets in Drop C (bass), 34"–37" multiscale

Set	Gauges	Avg per string	Total	Feel	Balance
D'Addario EXL165	45-65-85-105	35.8 lb16.25 kg159 N	143.3 lb65.0 kg637 N	loose	uneven
Elixir 14077	45-65-85-105	37.5 lb17.02 kg167 N	150.1 lb68.1 kg668 N	loose	uneven
Elixir 14087	45-65-85-105	37.5 lb17.02 kg167 N	150.1 lb68.1 kg668 N	loose	uneven
ECB81 (this page)	45-65-80-100	38.4 lb17.41 kg171 N	153.5 lb69.6 kg683 N	loose	uneven
Elixir 14702	50-70-85-105	38.4 lb17.44 kg171 N	153.8 lb69.7 kg684 N	loose	uneven
D'Addario EXL160	50-70-85-105	38.9 lb17.64 kg173 N	155.5 lb70.6 kg692 N	loose	uneven

Best match for a medium feel in Drop C (bass), 34"–37" multiscale

Ranked by how close every string is to 43.6 lb19.78 kg194 N (lower deviation is better).

D'Addario ECB81 45-65-80-100 deviation 17.5%, average 38.4 lb17.41 kg171 N, uneven
Elixir 14102 50-70-85-105 deviation 17.7%, average 41.3 lb18.75 kg184 N, uneven; same gauges: 14702
D'Addario EXL160 50-70-85-105 deviation 18.6%, average 38.9 lb17.64 kg173 N, uneven

More for the ECB81

Other tunings on 34"–37" multiscale: E standard (bass), Drop D (bass), Eb standard (bass), D standard (bass), C standard (bass)

Drop C (bass) on other scales: 35"

About these numbers

Tension is calculated, not measured: T = μ · (2 · L · f)², where μ is the string's mass per unit length (unit weight), L the vibrating length (scale) and f the pitch (A4 = 440 Hz, equal temperament). kg means kilogram-force: 1 kg ≈ 9.81 N ≈ 2.205 lb.

How a set feels also depends on the guitar's setup: action height, break angle over the nut and saddle, string length behind the nut and bridge, and your playing style. Plain strings feel stiffer than wound strings at the same tension. Use these figures to compare sets, not as an absolute measure of feel.

Sources

D'Addario product page, tension chart for ECB81 (2026-10-31): unit weights derived from the published tensions, cross-checked across sets.