Bajo quinto string tension
A bajo quinto is the low end of a norteño or conjunto band, and its strings show it: ten wound phosphor bronze strings from .026 to .078, tuned A D G C F with octave pairs on the two lowest courses. The calculator starts with D'Addario's EJ85 bajo quinto set on a 648 mm (25.5″) scale and shows the tension of every string and of the set.
Tension of the D'Addario EJ85 bajo quinto set
Standard tuning A D G C F at 648 mm, calculated with the unit weights of D'Addario's chart; D'Addario publishes 269.1 lb (122.1 kg) for the set.
| String | Note | Gauge | kg | lb |
|---|---|---|---|---|
| 1 | F3 | .026w | 12.7 | 28.0 |
| 2 | F3 | .026w | 12.7 | 28.0 |
| 3 | C3 | .036w | 14.0 | 30.9 |
| 4 | C3 | .036w | 14.0 | 30.9 |
| 5 | G2 | .046w | 12.8 | 28.1 |
| 6 | G2 | .046w | 12.8 | 28.1 |
| 7 | D3 | .030w | 12.3 | 27.1 |
| 8 | D2 | .062w | 12.8 | 28.2 |
| 9 | A2 | .036w | 9.9 | 21.9 |
| 10 | A1 | .078w | 10.7 | 23.7 |
How to use it
- The instrument, the standard tuning and the EJ85 set are already selected; the scale is 648 mm. Change it if your bajo is shorter or longer.
- Pick lb, kg or N. The chart shows every string, and the total appears under the table.
- Choose String by string to change a gauge right in the table, or pick another set in Compare with.
Help and explanations
D'Addario publishes 269.1 lb (122.1 kg) for the full set, more than one and a half times a steel-string acoustic strung with 12s. Swap a gauge in String by string to see what a lighter or heavier string does before you buy it.
Where the numbers come from
Tension follows D'Addario's formula, T = UW × (2 × L × F)² ÷ 386.4, with the unit weight of each string, the scale in inches and the frequency of the note. The bajo quinto is pitched low: the first course is F3 (174.61 Hz), an octave below the F on a guitar's 1st string, which is why even the thinnest string is a wound .026.
D'Addario's EJ85 tension table gives 27.9 lb for each .026 on F3, 30.2 lb for the .036 pair on C3 and 27.2 lb for the .046 pair on G2. On 648 mm the calculator reads 0.4 to 4.1% higher on every string, 275.1 lb in total; at about 641 mm the two agree, so the published table was most likely figured on a slightly shorter scale. The .046 and the .078 are not in the unit-weight chart: their weight is interpolated and marked with ≈.
The octave pairs
On the 4th course a .030 tuned to D3 pairs with a .062 on D2; on the 5th course a .036 on A2 pairs with the .078 on A1. In D'Addario's table the thin octave string pulls a little less than the thick one on the 4th course (26.7 against 27.1 lb) and the low A carries 23.3 lb against 21.4 lb for its octave, so the two strings of a pair feel almost even under the pick.
If you go to a lighter set, check the neck. A drop of 30 or 40 lb across the set changes relief, and a bajo set up for heavy strings may buzz. The action and relief guide covers what to measure.
Tips
- Tuning the whole bajo down a half step removes about 11% of the tension, roughly 30 lb across the set.
- Gauges from Fortaleza, GHS or La Bella of the same construction weigh almost the same as D'Addario's: type them in String by string.
- After a gauge change, check the octave at the 12th fret with the intonation checker.
Frequently asked questions
What gauge strings does a bajo quinto use?
D'Addario's EJ85 uses .026 (×2) on F, .036 (×2) on C, .046 (×2) on G, .030 and .062 on the D course and .036 and .078 on the A course. All ten are wound.
How much tension does a bajo quinto set have?
D'Addario publishes 269.1 lb (122.1 kg) for the EJ85 set on the bajo quinto: 21.4 to 30.2 lb (9.7 to 13.7 kg) per string.
What are the notes of the bajo quinto strings?
From the 5th course to the 1st: A1 + A2, D2 + D3, G2, C3 and F3, which is 55, 110, 73.42, 146.83, 98, 130.81 and 174.61 Hz at A 440.
Can I use bajo sexto strings on a bajo quinto?
Yes, leave out the 6th course (low E). The other five courses are tuned the same, so the gauges and tensions carry over on the same 25.5″ scale.
Are there light gauge bajo quinto strings?
Some brands sell lighter sets; Fortaleza ships the F1 with .023–.078. Type the gauges into String by string to compare their tension with the EJ85.