Thanks to IGOR PECEWSKI
The NEW (April 2012) Kaplan strings are D'Addario's entry into the premium orchestral strings market.
The Kaplan double bass strings are designed primarily for bowed string players. They were created to provide a rich tone, variable dynamics, and excellent bowing response. They are clear, yet warm in their tonal color - regardless of what register you're playing in.
This is accomplished by mixing various string winding materials to achieve the best playability and sound from every string. So, while all Kaplan Bass strings have a stranded steel core, the Kaplan Bass G string is titanium wound, and the A and D strings are nickel-wound. The E string is tungsten-wound.
These strings should be a favorite among the most discerning orchestral musicians. The strings are are reportedly very easy to bow, with a fast response, and have a "soft" feel both under the left hand and under the bow - making them an "easier" playing string. Yet they have a great range of dynamics and sound - you can really get them projecting loudly, without having the note distort out of tune.
And yes, they can be played pizz! For classical pizz, they have the appropriate and expected big, round tone. They are a darker sounding string, by design, so they don't have the brightness you might expect in "modern jazz," but they're not dead and thuddy, either.
The strings are scaled to fit 3/4 size bass with a playing length of 41 3/4 inches (1060mm). The medium tension strings are the best choice for a majority of players, but light and heavy sets are also available.
These new strings are made of a "longer-lasting" alternative to nylon, called "Zyex." That's where they get their name, obviously.
Zyex is a "polyketone fiber," which you really don't need to know. What you do need to know is that D'Addario has actually been making strings out of this material (for other instruments, like classical guitar and violin) for many years. They just reformulated their blend, and they are now making Upright Bass Strings using Zyex.
Physically, the strings are a touch thicker than Pirastro Obligatos, and they don't exhibit the "roll" when plucked that other synthetic strings (including the Obligatos) sometimes do. They also sound a bit "darker" than Obligatos - with a bit more "growl," at least to my ears. Under the bow, they speak very quickly, and the pizz sustain rings clearly without overstaying its welcome - simply stated, they have a warm, gut-like tone (which is a common description of synthetic strings). They are similar to many of their contemporaries, to be sure - but obviously, there are differences too.
One thing that many people report as unique about the strings: kind of like wine (and bassists), they actually get better with age. Fresh out of the package, you might be a little underwhelmed - on some basses, they might sound a bit "zingy," can sometimes have uneven response from string to string (especially the D string) and the lower strings can have a tendency to sound a little scratchy under the bow. These idiosyncrasies seem to work themselves out once you've put a little mileage on the strings; they settle down, tone-wise, and the balance and arco response tends to improve.
Tonally, they have good volume, with nice fullness - especially the higher strings (some players have felt that the E string is a little "shy" compared to the other three.) Tuning stability is good, and they "start" quite easily under the bow.
Overall, they are a lower-tension, hybrid string that works well for lots of varied situations, but I wouldn't put them on a bass the same day I had a gig. But give them a little time to break in, and may well be worth the wait.
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