The Problem with 5 and 7-String Instruments

Got a six-string guitar? Great. Got a four-string bass? Super. You’ll be pretty well catered-for when it comes to advice on setup.

Add an extra string down the bottom end, though and things can get a bit more unsure. For the five-string bassists and the seven-string guitarists, that fat, floppy string might need a little TLC to get it to behave and to sound good.

So, for the low-down, B-stringers, here’s a few thoughts and considerations.

Tips for the Bottom String

That low end comes with a drooping drawback. Nobody likes a loose bottom so what to do? Weird tuning wobbles, unfocused sound. What to do?

Well, string tension for any particular tuning/pitch depends on the scale length and the size of the string. Let’s look at those.

Scale Length

A longer scale length can give more tension and focus to that wobbly bottom string.

Scale length is difficult to do anything about if you already own a particular instrument. Of course, if you’re still shopping around, it might make sense to at least try out something like a 35” scale five-string bass and there’s a choice of longer scales for a seven-string guitar if you dig around. Multi-scale might even be an option if you were feeling adventurous.

Assuming you already own the damn thing, though, what can you do about scale length? Erm… Not a lot, really.

“Oh, but I read this article about extending the string’s length behind the bridge with spacers,” you say.

“Stuff and nonsense!” I reply, really emphasising the exclamation point.

You can have a mile-and-a-half of string behind the bridge or at the other side of the nut and it’ll make no difference. The scale length and string size determines the tension for any particular tuning, and the scale length is only that bit between the nut and bridge*. If anybody tells you to add spacers to make your string longer feel free to disagree wholeheartedly, because PHYSICS.

*Note: The bit behind the bridge and beyond the nut may have an impact on the compliance, or elasticity, of the string but this is more a factor in the ‘feel’ than in the tone or floppiness of any given string. More on this another time. 

String Size, then?

Yep. All things being equal, a heavier string at the same pitch will have more tension than a lighter one.

If you’re playing a lighter bottom string, try popping on something heavier. This is one area where I definitely recommend going heavy if you can.

Also, remember that not all things are equal. Differences in construction between string manufacturers can lead to differences in the strings themselves. Even two strings that have the same apparent gauge (say, 0.130”) may have differing constructions internally and can behave very differently. It might be a slow business to shop around for a different brand every time you change strings but it can really pay off in this circumstance. Remember too, that you can buy individual B-strings so you could even mix and match string brands if you wanted.

To follow on from that point (and it might help speed your quest for the perfect string), don’t let your strings get too old. Their performance will degrade as they age and you’ll definitely notice it at the bottom end.

So What Else?

Setup is important. Remember that that lower string is going to vibrate in a much bigger arc than the others so you need to have your instrument set up with this in mind. You’ll want the action set to accommodate this bigger wobble.

Relief too has to be considered. You’ll almost certainly want a little additional relief than you might on an instrument with one less string.

Give some really close attention to your nut. Slot fit for that bottom string is really important. I’ve seen a lot of poorly slotted five-string basses in particular. Slots were either too narrow and pinched the string, choking it, or they were too wide and the string could move from side to side, losing energy. A good nut—material and setup—is really important here. Correctly sized slot with a nice rounded bottom is what you want. 

And lastly, don’t forget pickup height. Use your ears to get a good balance across the strings but do not raise the pickup too much. Seriously. The natural tendency is to keep raising the pickup higher to increase output. Don’t. Too close and the magnets in your pickup can pull on vibrating strings, especially strings that are prone to wobble about in the first place. Turn up your amp if necessary, but don’t go too high with pickups.

Is that it?

Pretty much. It’s worth mentioning that an instrument’s construction can have a bearing too. Some guitars and basses will have a bit more focus at the bottom than others that are superficially similar. Play around if you’re still on the sidelines.

Phew. I think I made it without any bottom jokes.