Double Bass Afterlength: Big Deal?

[bejoyous]

Oh yeah, if you take your bow and bow an regular TP, you'll hear a deep rumbly note and that interferes with what is going on north of the bridge.

 

[William Hoffman]

I originally had a standard ebony TP on my bass. The bottom end of my instrument is rather large so when it was installed the afterlength was too long. This caused all kinds of weird phasing in the strings and other wolf notes (ex. Bb on the G-string would go WWwwaawwWWwwaawwWWwwaawwWW; I'd need to close the A on the G-string while playing an open A or it would sound dead)

I did some reading and tried a Wittner TP (hard plastic, about 6 oz) with the correct afterlength. The sound was significantly better, but there was still a few odd notes and there was about 3.5" of wire between the bottom of the TP and the saddle so the TP looked odd floating in the middle of the lower bout.

I thought if reducing the TP weight by 7 oz made a difference then reducing it to about 2 would be even better.

I have exactly your issues on my bass: large lower bout, the original ebony TP in the traditional position resulted in long afterlengths that did their "own thing", resounding with a wolftone, feedback when amping. So I got a longer but much lighter TP and that solved those really obvious issues and also improved the sound and volume.

I can see your point about weight. The wire TP allows the bass to vibrate more because they don't dampen it. I still have the questions about tuning those wires, and what about the vibrations the wires themselves produce?

 

[bejoyous]

I still have the questions about tuning those wires, and what about the vibrations the wires themselves produce?

Well, there's no tuning the wires. It's just whatever the length is between the bridge and the saddle. Although on mine it's approximately half the string length. If I remember right, without the shoelace weaving they all ring at about an octave above open G. With the weaving they don't vibrate or interfere with the bowed notes though.

On the Marvin, it comes with a piece of felt that is glued on for the same purpose and to make it look a bit more traditional.

With mine, you can see the bottom half of the bass. I think it looks pretty sharp. Some people really notice it but most don't.

With the Spiros I now use, I coated the lower half of the strings' threads with Gorilla Glue and shaved off the remaining threads so that the threads wouldn't go over the bridge. With Evahs, I could shave all the threads off so it was just wire from the saddle to the nut with a bump where the balls were attached to the wire tailpiece.

 

[61pollmann]

This thread reminds me of an old discussion regarding placing pickups on a bass guitar. A friend believed that having the pickup placed a certain interval from the bridge would give the best sound. My point was that as you fret notes higher and higher, the position of the pickup changes in relation to the vibrating length of the string. Doesn't the same thing apply to after-lengths on the db? If one of the after-lengths is a specific interval to the open string(i.e. 5th), doesn't that become a different interval relationship as you finger notes higher and higher? It seems to me that only on open strings would the interval be constant. I believe that the tailpiece material and wire material have a bigger influence on tone than the after-lengths. My Pollmann was noticeably improved when I installed a walnut compensated tailpiece. It is less dense than ebony. I also replaced the stainless steel airplane cable with the Pecanic braided cord. These two changes have given my bass a sound which is louder and warmer. I may go back and try the ss cable again, just for comparison, but I really like the walnut tp. Looking forward to reading your comments.

George

 

[Jake deVilliers]

If one of the after-lengths is a specific interval to the open string(i.e. 5th), doesn't that become a different interval relationship as you finger notes higher and higher? It seems to me that only on open strings would the interval be constant. I believe that the tailpiece material and wire material have a bigger influence on tone than the after-lengths.

Tuning the afterlengths keeps their vibrations on the same sonic scale as the notes you are playing.
If they are A, D, G, C then they will have a good relationship with the notes you are playing wherever they are on the neck.
If they are B-35 cents, E-45 cents, G#+25 cents and Bb-50 cents, they will have a bad relationship with every note you play on the bass.

Those phase cancellations will occur whether or not you damp the afterlengths so they are not as audible to you - they will be affecting the instrument whether you can hear them or not.

You can close your eyes to shut out a particulaly garish colour combination but its still out there!

 

[Turnaround]

You can close your eyes to shut out a particulaly garish colour combination but its still out there!

It may be there, but if you can't see it, is there an appreciable difference? And if you can't hear it??? Are you concerned for your dog?

Don't get me wrong. I'm not trying to be adversarial, I'm trying to understand. In my 60+ years I've been around this block a few times now and just when I think I finally understand I come to question it again.

When I play a string, it's not just that string's afterlength that's vibrating - all of them do. This is unlike the scale length of the string which I can damp with either hand. The afterlengths I can't dampen. And if the afterlength on the 2nd string is causing some cancellation on the note I am playing on the 3rd string, there is little I can do about it unless I dampen all afterlengths mechanically.

At the same time I can sense that the sonic character of the bass changes when I do dampen the afterlengths. And perhaps the very core of the problem lies here in modern performance (at least mine). Today I amplify my bass. I was getting some pretty nasty sounds live. I tried several things, but what solved the problem is when I damped the afterlenghts. They were being overexcited by the amplifier and overcontributing to the acoustic response that was, in turn, picked up and amplified. This is, of course, feedback. Not the nasty howl most of us know well, but feedback just the same.

I am not a recording engineer, but I have had significant experience in the recording processes, and I am quite familiar with the extraordinary measures recording technicians have to employ to eliminate annoying sound attributes. So the discovery that I needed to damp the afterlengths when amplified was not a particular surprise to me. But it sure got me to questioning (again) why one would not routinely do this - amplified or not.

I'm just going to have to stop thinking or stop caring...

 

[Square Bear]

amplified is a different story. i think what jake (and others) are trying to say is that if the afterlengths are not in the realm of western pitch, they are always fighting the frequencies you are playing. since they have to be tuned to something, it may as well be something beneficial. if they are not helping your acoustic sound they are hurting it. that's the gist of it as i understand.

 

[Jake deVilliers]

amplified is a different story. i think what jake (and others) are trying to say is that if the afterlengths are not in the realm of western pitch, they are always fighting the frequencies you are playing. since they have to be tuned to something, it may as well be something beneficial. if they are not helping your acoustic sound they are hurting it. that's the gist of it as i understand.

Bingo!

 

[Turnaround]

amplified is a different story. i think what jake (and others) are trying to say is that if the afterlengths are not in the realm of western pitch, they are always fighting the frequencies you are playing. since they have to be tuned to something, it may as well be something beneficial. if they are not helping your acoustic sound they are hurting it. that's the gist of it as i understand.

Sorry, I can't quite buy this. Sounds plausible on the surface, but a sympathetic frequency that is a half-tone from what I am playing will have significantly more amplitude than one that is a quarter-tone away. Thus the impact of the non-western pitch will not be particularly significant. It's far more likely that the quartertone afterlengh will be induced to vibrate at a multiple of the fundamental note played anyway.

It's akin to sounding an octave harmonic on a string. If your finger position is not dead on the octave, the octave harmonic will still sound. You may be "off" by a quarter-tone in position, but the string is induced to the correct harmonic. So can sub-semitone (or larger) conflicts with respect to afterlengths really contribute to a difference in sound? I wonder....?? And if they do, and do so negatively, why not just damp them and be done?

After all this, can the audience hear the difference?

 

[Gearhead43]

The magic fairies like the afterlength tuned to play "It's a small world".

 

[William Hoffman]

Sorry, I can't quite buy this. Sounds plausible on the surface, but a sympathetic frequency that is a half-tone from what I am playing will have significantly more amplitude than one that is a quarter-tone away. Thus the impact of the non-western pitch will not be particularly significant. It's far more likely that the quartertone afterlengh will be induced to vibrate at a multiple of the fundamental note played anyway.

It's akin to sounding an octave harmonic on a string. If your finger position is not dead on the octave, the octave harmonic will still sound. You may be "off" by a quarter-tone in position, but the string is induced to the correct harmonic. So can sub-semitone (or larger) conflicts with respect to afterlengths really contribute to a difference in sound? I wonder....?? And if they do, and do so negatively, why not just damp them and be done?

After all this, can the audience hear the difference?

Turnaround, you're right about the quarter tone "off" inducing the nearest harmonic. Pluck your G string at a sharp F# and you hear the G harmonic. But what the others are getting at here isn't the "quarter tone off" in the afterlengths so much as where the afterlengths are several whole tones (plus or minus a few fractions of tones) "off". It's that random non-selection of odd notes that can't contribute to the notes you are playing. And if they can't contribute beneficially, what are they doing? Nothing? I don't think so. Even if inaudible to everyone except my dog and maybe me, there will be dissonant vibrations within the bass. These cancel each other out. The bass is not in tune with itself.

Without sounding adversarial, Mr. T, I'd like to turn your point around (heh heh ). I think the point about the "quarter tone off" actually resounds sympathetically )) with the point others are making here. Your observation actually supports harmonizing the afterlengths, at least harmonizing them "more or less" (e.g., within a quarter tone), with the open string. Because if the afterlength tones can't contribute beneficially, then they must be subtracting from what your bass could be sounding like or, in the worst case, they will actually create dissonance.

The audience normally won't hear the difference. But A/B a bass that is "in tune" with itself with one that isn't. The bassist hears and feels the depth of the harmonized vibrations. The audience might say "wow, that bass sounded great", but we don't expect them to know why. I certainly did hear and feel a remarkable difference when I adjusted the afterlengths the other day, maybe because my afterlengths before the change were so far off they were actually creating dissonance and odd overtones above the bridge.

Fact is, it's all one string. The length below the bridge has to have a physcial impact on the sound, one way or the other. Helping or in the worst case hurting. Similarly, the ends of the string above the nut in the peg box will also vibrate (adding to sustain) if they are not dampened by nut grooves that are too deep or by the string crossing over another string or a peg. My luthier told me to try and wind the D and A strings so they pass over the pegs without touching them. I've never heard of anyone trying to harmonize those, but heck, what do I know... cheers, Bill

 

[Turnaround]

Thanks, Bill. I appreciate your reply. I guess I am just a bit lazy and take the appropach of damping the afterlengths instead of tuning them.

I do understand that the entire instrument is a system, and it will behave as a whole. So unwanted vibrations, from a string or anything else, will affect the system negatively. I accept that the frequencies of the afterlengths are affecting the sonic character of my bass, but I wonder how much impact there will be. Even if the only answer is "some impact" I should probably pay "some" attention to it.

Thanks all for your input.