Double Bass Afterlength Question

[billiard]

I've always read that the general consensus is that the afterlength be 1/6th of the playing string length. A friend just left an Ampeg baby bass to me and the factory afterlength is set to basically 1/4th the playing scale string length. Each of the strings' after length resonates at two octaves above each strings tuning (E A D G), with the exception that the E's after length rings at a Major Third of E two octaves above the E (A Flat).
If I were to change it to 1/6th, what tonal differences should I expect to experience?
Thanks in advance.

 

[Mark_T]

I've heard a number of theories on how the afterlength should be tuned, so I am not sure there is any general consensus.

 

[billiard]

I've heard a number of theories on how the afterlength should be tuned, so I am not sure there is any general consensus.

How do you have yours set please? What other theories have you read about?

 

[Mark_T]

How do you have yours set please? What other theories have you read about?

It's been ages but at least one luthier who worked on my bass said "one octave and a tritone above the pitch of the playing length". Not sure where that is in terms of "one sixth of the playing length". I think I have also heard things that were more consonant that tritones (don't recall the details but in the realm of "an octave and a fourth" or some such). In my experience this is not a settled question at all, though.

If you have a way of setting it to precisely one sixth of the playing length, by all means, try it out.

Also, I don't mean to sound patronizing but I am somehow thinking that the precise tuning probably matters a bit less on an Ampeg Baby Bass than, eg, a Gagliano (neither of which I have so ).

 

[evanrunyon]

On an acoustic instrument, everything that vibrates has some effect on resonance. To what degree depends on the particular vibrating part and its context amidst all the other vibrating parts—that’s why there’s an infinite number of approaches to, not just afterlength/string length ratii, but overstand, bridge angle break, tailpiece mass, various wolf tone modifiers, etc. Everything works in concert with each other and it’s all about finding a balance between all your various bits.

On a baby bass, though, the nature of the way the thing’s amplified means you almost certainly won’t hear any of those effects no matter what you change (other than the pickup, of course). If you’re getting a weird dead spot or a wolf tone then by all means mess with the afterlength, it might do something, but it’s not going to alter the overall resonance to any noticeable degree. Plus, the thumpiness of the baby bass is kind of part of its characteristic charm.

My experience is with a Sendel (Colombia-made Ampeg clone) that I used for salsa, merengue, cumbia, etc. I swapped out the original bridge for a solid wood replacement and it sounded exactly the same, I also replaced the endpin and tailpiece to the same effect (that is, none).

Also, just for the data—went over to my double bass and checked, afterlengths are two octaves and a fifth above the open string. Roughly.

 

[billiard]

Thanks all for the replies!

 

[coyote1]

I've always read that the general consensus is that the afterlength be 1/6th of the playing string length. A friend just left an Ampeg baby bass to me and the factory afterlength is set to basically 1/4th the playing scale string length. Each of the strings' after length resonates at two octaves above each strings tuning (E A D G), with the exception that the E's after length rings at a Major Third of E two octaves above the E (A Flat).
If I were to change it to 1/6th, what tonal differences should I expect to experience?
Thanks in advance.

IMO the ‘afterlength’ discussion is analogous to the discussion about a brass nut on a guitar. With a brass nut, it ONLY impacts open strings. The moment you play anything other than an open string, you’re relying on the fret and not the nut.

Likewise with afterlength. First question you should ask: do you even desire resonance from the afterlength? If so, on which notes do you desire such resonance? If you’re playing jazz, IF you desire such resonances you might want them on notes in the Bb scale. That is where a huge amount of your playing occurs. Then figure out whether you frequently play mic’ed or otherwise amplified, and whether such resonances might contribute to EQ and feedback issues.

 

[billiard]

IMO the ‘afterlength’ discussion is analogous to the discussion about a brass nut on a guitar. With a brass nut, it ONLY impacts open strings. The moment you play anything other than an open string, you’re relying on the fret and not the nut.

Likewise with afterlength. First question you should ask: do you even desire resonance from the afterlength? If so, on which notes do you desire such resonance? If you’re playing jazz, IF you desire such resonances you might want them on notes in the Bb scale. That is where a huge amount of your playing occurs. Then figure out whether you frequently play mic’ed or otherwise amplified, and whether such resonances might contribute to EQ and feedback issues.

Interesting. Thanks for the reply.

I usually stick foam behind the tailpiece and strings to just tighten everything up when tracking a real DB, unless like you just said,... the overtones are in key.

 

[Povl Carstensen]

My 5c: afterlengths in tune can give a supple "reverby" effect, which is nice. The other aspect IMO, is that a shorter tail gut gives a more direct, "quicker" response of the bass. I reckon because the tailpiece is allowed to "wobble" less.

 

[james condino]

Less time worrying about the afterlength and more time on the afterparty...

 

[DoubleMIDI]

One sixth of the playing length would be two octaves and a fifth above the open string … mathematically and onlyvif the string keeps the same in the afterlength which it doesn‘t if it not plain gut or plain monofiber nylon.

The spreading of the windings below the silk gives less mass per length unit which results in a higher pitch.

Since the spreading of the windings is individual to each string (at least the starting by point), even a new string would have a different pitch with the same afterlength.

I mostly read to have the afterlength at two octaves and a fourth. That would be an even longer afterlength.

Keep in mind that the resonance of the afterlength mostly keeps the same with stopped notes, so tuning it to different pitches just moves the resonances to different stopped notes.

Since open strings have a higher resonances due to the hard nut compared to the soft damping finger flesh with stopped notes it makes sense to tune it at two octaves and a fourth to avoid an afterlength resonance with the open string.

But you never get the same underlength interval for all four strings unless you have a tuneable tailpiece.

I would stay away from low harmonics of the open string (plus octaves) which basically leads to the fourth or tritone. The minor seventh is too close to the overtone seventh, a minor sixth would be possible, perhaps a bit higher, but anything else might be too close to lower harmonics and resonate with them.

I mostly would stay away from the fifth, but I think anything else has a rather minor influence.

 

[BPM Strings]

The goal of tuning afterlengths is not necessarily to make them resonate with any of the played pitches. If you think about it, that would only be possible if you only played in a couple of keys. Rather, it is a means of controlling the entire afterlength and tailpiece resonating system. This is a tool that we use to influence the timbre of the instrument and control wolf tones. The consensus for the other orchestral strings is 1/6 of the open string length which will sound at around two octaves and a fifth, but since basses are tuned in fourths many people prefer to tune them to two octaves and a fourth. When thinking about afterlengths it is important to consider that changing the afterlength also changes the distance from the tailpiece to the saddle, which IMHO probably does more to influence the timbre and wolfs than the pitch of the afterlength.