Being able to play below the open E string is an essential part of the skill set for the modern bassist. Most orchestral bass parts reach below the low E, and not being able to play these notes means not really having all of the professional tools necessary for the job. Reaching these low notes means either having a five string bass or an extension.
I am not a luthier and am therefore basing these comments solely on my own experiences and those of my colleagues. I welcome any comments or insights into the world of extensions and five string upright basses.
In many ways, having a five string bass is the ideal low note solution. Being able to play the low notes on the fingerboard makes life much easier, and it helps with good finger patterns. The major disadvantage to five string basses is the difficulty in finding a decent instrument. Luthiers seem to build five string basses much too thickly. This produces a boxy, tight, “woofy” sound unfortunately associated with five string basses. Disadvantages also include closer string spacing (requiring an adjustment of left hand and right hand technique) and probably a more difficult sale when you decide to move on to another bass (although there are always people hunting for good five string basses).
I have a colleague who has converted four string basses to five string basses, and he has reported positive results. This is a radical procedure to perform on a bass. It requires adding another tuning peg (and usually having to rearrange the layout of the other pegs in the peg box), and will almost certainly require a new fingerboard. A new neck is also advisable for this procedure, although I have played conversions that kept the old neck and just had an extra wide fingerboard mounted. This procedure adds more tension to the instrument as well, which may or may not affect the structural soundness of the instrument.
Most bass players already own 4 strings, so putting an extension on is usually the most practical option to acquiring low notes. Getting an extension involves a lot of fairly permanent hardware modification to your existing bass, although this modification has been minimized by many modern extension makers. Still, at the very least your scroll will be somewhat defaced and your nut will be altered to make room for the extended fingerboard. One big advantage of an extension bass over a five string bass is that the spacing between the strings remains normal, so no new bow techniques need to be learned to play the instrument. Also, the extension will not negatively affect your tone (unless it’s a poorly designed extension that is plagued with buzzes) and will most likely help the tone of the G string. I found that fact out when I got my first extension. My open G string (and all of the harmonics on that string) always sounded a little closed when compared to the other strings, but leaving that low extended C string open let the G string spin much more freely. People were always amazed when I demonstrated this—it was a very obvious transformation.
Extensions come in three flavors: the Stenholm-style machine, the “stick”, or the “stick” plus closers. The simplest of these extensions is commonly called the “stick”. It has a closer for the low E—no other moving parts. This is the cheapest of all the extensions and in many ways is the easiest to learn to play since there is no additional mechanism. The disadvantage of these is obvious once one starts playing with it in a bass section. Holding low notes gets extremely tiring on the “stick”, and shifting from low notes to high notes makes you look like a fool. Both other extension styles are an attempt to solve these problems.
The traditional extension for orchestra players is the Stenholm extension. This machine consists of a series of levers beyond the E string that close the low notes. Low notes are very easy to close, and the left hand never has to reach above the scroll. Unfortunately, these extensions are very heavy. Basses with Stenholm-style extensions are often so scroll-heavy that the bass rests on the top rib and the scroll when on the floor, not on both ribs. Also, many luthiers refuse to work on Stenholm-style extensions, so it can be difficult to get them repaired. They are also fairly complicated devices with many moving parts that can get bent, rusted, broken, and buzzy.
The newest form of extension is an amalgamation of the previous two styles. It is a “stick” extension with closers (like a permanently mounted guitar capo) for each individual low note. These have become very popular in recent years. Playing a low pedal note is even easier on this style than on the Stenholm style. The player can simply close the appropriate lever and blast away. It is nice to be able to just have a low Eb, D, or Db string. They are certainly more complex mechanisms than the “stick”, although not as complex as the Stenholm.
My extension is of the latter type, and it was made by Chris Threlkeld-Wiegand of the Heartland String Bass Shop. He used to work for the Robertson & Sons Violins Shop in