Philthy Thoughts

By Phil Maneri

The electric bass community often discusses the merits of top-loaded bridges vs string-through-body loading. Camps are quite divided with their self-reported observations. Some people talk about increased sustain through-body with increased volume and punchiness, others talk about how they don’t notice a difference. In true internet fashion, each camp thinks they are right and the other person who thinks differently is an idiot. I’ll sidestep this for the moment and share some observations about top-loaded bridges vs strings-through body that helped me form my own opinion.

Any place a string touches the instrument along its span can affect the performance, sometimes for the better, sometimes not so much. At its simplest, you have a termination at the bridge end, the saddle passover where it enters the playing field, the nut at the other end (or zero fret) where open string rotation stops, then the tuning area where the string tension is applied. There are a myriad of variations of this structure, but somewhere in the middle of it all, the string is playing a note. That note, and the arc of its attack, sustain, decay, and release, are all influenced by anything the string touches. 

The string movement through its contact points with the instrument engages the body and neck, which start to vibrate in sympathy with it. In turn, the string gets more movement from the body and the neck feeding back to it. When an instrument creates a loop of string movement, body movement, string movement, etc., the whole thing gets a feeling like it’s playing itself. The more resonant and alive the instrument is, the longer it takes to get to the decay of a string envelope; in other words, the note is sustained longer.

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String variables are an entirely separate topic and will be ignored, here. Saddle materials are significant, but straightforward. Softer materials, like plastic, yield darker notes with less precise attack, harder materials, like bone or metals, yield harder attack and brighter notes. These differences are subtle, at best.

Nut variables are similar; they just show up on the other end of the string. [Sidebar: once the note is stopped or fretted inside the playing area, the nut is bypassed as the string termination point. The material and structure of that nut then become less relevant. As soon as you fret a note, the fret material becomes far more significant in the tone. The nut’s impact is reduced significantly to almost be irrelevant. It does still touch the string, which leads to the next point.]

The more places a string is touched – even outside the playing field – the more chances you have of introducing sonic changes to the strings sound and envelope. Sometimes, the feedback relationship can get contaminated by multiple connections with different vibration patterns. Like if you touch a spinning top, it tends to wobble and topple over. The double bass construction bears that in mind. The tailpiece is part of the overall string picture. The material and how it’s constructed contribute a lot to the overall sound of the bass. Those string after-lengths between the bridge and where the string joins the tailpiece are tuned to address wolf tones and other variables in the course of a complex setup. This is significant, because there are very few places the string touches the instrument on a double bass. Even the string ball ends are connected to the tailpiece and don’t touch the instrument across the top, at all. The tailpiece then terminates against the end block, where vibration gets soaked up into almost nothing. That is the exact opposite of a string-through electric bass concept.

Strung-through-body instruments have essentially an entrapped afterlength – or at least a super-short afterlength, if you assume the string is terminated when it enters the body as it passes through the bridge. That is open for debate; in fact, that’s where much of that controversy between string-through and top-load arises from. The use of the body as tailpiece could be construed as allowing the string to more directly influence the rotation of the string, enhancing the mutual feedback concept, or it could be viewed as a mute, reducing the significance of the tailpiece and actually hindering the movement of the string with multiple conflicting string contact points. Contrarily, it could be viewed as mostly irrelevant, because the string is terminated to wood at the break point entrance to the body, after which the influence is significantly reduced. Try to measure that, if you like, but don’t get mired in minutiae and miss the bigger issue. 

A far more significant variable is break angle across the saddle. There is a sweet spot for break angle across any saddle. There is no hard and fast rule here; there is no range that’s useful across all strings and woods and construction. Individual differences between instruments, setups, and strings complicate that relationship. If you have too much break angle, the string tends to shut down somewhere and often loses bass and note length. It can even rise up from the saddle a bit and create false takeoff points, leading to buzzing or incorrect intonation. However, too little angle and you loose stability, note length, clarity and low end. The notes can outright buzz like crazy, as the terminus isn’t defined.

Experimenting on instruments with movable tailpieces can show you that more clearly, like a Les Paul with a Tune-o-matic bridge and separate tailpiece. I notice that screwing it all the way to the body doesn’t add anything significant or change the sonic connection to the body, but sometimes the extreme angle shuts the string down and mutes it. In addition, the string can be kinked and/or disturb the relationship of the core to wrap. With too much stress on the string, you can lose clarity and low end. As you raise it up, you notice a sweet spot where everything sounds as good as is possible. You’ll notice an increase in overtones and note character, until it reaches too shallow a break angle and the whole thing starts to fall apart again. The overtones take over and fundamentals decrease. Eventually, the tone fractures and loses clarity. Approaching 0 break angle, the string begins to buzz and sounds unusable. 

Applying those concepts to the bass, you’ll find the same results, but it’s much harder to manipulate that angle when the tail and the saddle are carried in the same structure. You have to modify the neck angle to address the break angle off the back of the saddle when given the same string height settings. If you pitch the neck higher, the break angle increases, If you pitch the neck shallower that angle decreases. Somewhere in there is the sweet spot. This is the salient point. With string-through setups, the break angle is always quite severe. It may be in the sweet spot, or it may not, but moving significantly away from that severe angle is usually not possible.

Moving back to the other side of the string – the break angle across the back of the nut. The same variables are at work, here, as bridge break angle. As is true with nut materials, the differences in break angle aren’t as significant when the note is fretted or stopped on the fingerboard. One of the many ingenious little things about Sadowsky basses is a spring-loaded adjustable string tree across all the strings. This thing is made out of a Floyd Rose string bar and a couple little springs over the screws to keep it elevated when you swap out strings. That bar allows infinite variation of the break angle across the back of the nut. It is a subtle thing, but combined with nut slot grooming, it can allow one to really dial-in the sound and feel of the open strings. You can accomplish something similar by using string trees, like Fender does on the D/G strings, or varying the wind on the string post – closer or farther away from the peg head – but those tweaks are far more rough. In reality, that distinction doesn’t change sound as much as the bridge side of things, though. Its most significant effect is in reducing buzz from insufficient break angle or weird intonation by too much break angle that moves the takeoff point away from the front of the nut because of string arching across the top of the nut. When the takeoff point moves back from the front of the nut slot, you’ve effectively shifted the frets towards the bridge and increased the distance between the zero fret and fret one, disrupting the equation that lays out the frets – making it impossible to play in tune. 

Looking at break angle on both the nut and the saddle reveals something else. Changes in the break angle across the bridge and nut modify flexion of the string. The tension, however, is fixed with string construction and tuning; but the greater the break angle, the stiffer the string feels under the fingers. The more shallow the break angle, the more supple the string feels. One can manipulate that angle during setup to affect the playing feel of the instrument with the same string height and neck relief. Double basses saddle height (the wood block at the edge of the side the cable from the tailpiece passes over) is often increased to decrease break angle across the bridge and increase suppleness of the string feel. Conversely, the neck pitch or overstand can be changed to increase break angle, firming up the string feel. It’s much more obvious there, where everything is so much bigger than on an electric bass. The severe break angle of a string-through instrument, with its lack of available movement away from that angle, ties your hands at adjusting that variable.

Lastly, many strings just don’t like all that bending and twisting at sharp angles. Any time you give a string stress and added torsion from bends or drastic angles, you increase the likelihood of disturbed string rotation that can lead to falsing, intonation instability, shorter notes, and less precise attack/ sustain/ decay envelopes. If you’ve ever tried to install a Labella flatwound string on a string-through-body bass, you’ll know that it’s likely to have the core and the wrap separate and ruin the string from the harsh angles. While a Rotosound RS66 isn’t as likely to do that, the stresses that apply to the string to destroy the Labella are still there. The torsion introduced by those angles can stress a string into falsing and impeded rotations, which are far more profound reducers of string-to-body feedback than the potential advantage to “body coupling” that you might realize from string-through installation. 

Break angle is required for precise string movement, but too much angle or significant twisting and turning of the string, even outside the area of the speaking length, can decrease that precision. The balance point is finding the sweet spot in break angles both at nut and saddle, while removing as much other impingement or influence in the string anywhere else. In my view, the string-through arrangements can really stifle your options, there, causing way more potential disfunction in the string than you might gain from increased coupling with the body. Remember, in a double bass, the ball ends don’t touch the body at all, and the tailpiece itself is attached to the edge of the bass well outside the bass top or any significant point of movement on the bass – the exact opposite of electric bass string-through connection. I suggest that removing torsion and extreme bends across the string span would be far more advantageous than any coupling increase strings-through-body might create. Keeping things simple on either end of the string and minimizing other contact points between it and the instrument creates more direct feedback loop with the string than you could ever realize by strings-through.