www.FretlessBass.com

Hi all,

I've recently bought a Breedlove fretless acoustic, my first fretless but definitely not my last!

Anyway, it came equipped with D'Addario EXP phosphor bronze roundwound strings (45-100) and I really want flats on there, firstly as I'm already seeing marks on the fingerboard, but also because I prefer flatwound strings.

I have a set of D'Addario Chromes (45-100) which are the same diameter as the EXPs but have slightly less tension (according to the D'Addario website).

Is there any reason why I can't just put these straight on to the acoustic? I assume the string tension remains the same whatever type of bass they're on. Does this sound about right?

Any thoughts appreciated.

Yes, changing over to flat wound strings on this type of instrument is fine. String tension is a function of string design/materials, given pitch, AND scale length. The factory tension specification is dependent upon one scale length (usually 34 inches) for the note specified. If your instrument has a different scale length then strings designed for 34" scale will have an altered tension when tuned to normal pitch.

When changing string type, or brand name, it is almost always necessary to adjust the tension rod (neck relief) and re-intonate the bridge.

On Acoustic Electric Basses (AEB) the bridge is often fixed (Ala acoustic guitar) so your options for intonating the bridge are none - to spending money with a luthier to re-slot and reposition the saddle(s). Thus it is important to install strings that intonate well with the fixed bridge position of your AEB.

If your AEB has an adjustable bridge you are fortunate, your options are much greater.

Firstly, I would get rid of the original round wound strings as soon as possible to avoid rutting the fingerboard.

The DeAddario EXPPBB170 Coated Phosphor Bronze Wound set has these tension specs. From http://www.juststrings.com/dad-exppb170.html

1st G .045 47.5
2nd D .065 55.7
3rd A .080 47.4
4th E .100 40.2

DeAddario Chromes are a good choice. They come in four tensions...
From http://www.juststrings.com/daddarioelec ... romes.html
ECB80, ECB 81, ECB82, ECB84
According to the information at JustStrings, the ECB81 set is closest in tension and gauge to your existing set. HOWEVER, they are not exactly the same so you will still probably need to adjust your neck tensioning rod.

This set should also be fairly close regarding intonation. Most likely the intonation will be a bit different. On instruments without adjustable bridges it may be necessary to try several different strings sets until you find one that intonates well, thus avoiding expensive bridge modification. Use your ear. If a set just does not sound musical, or you cannot get used to finding notes in the higher regions of the fingerboard then it might be that the new strings are substantially different in intonation characteristic than the set for which your instrument was originally set up.

Just because the sets are by the same manufacturer does not guarantee that two different lines within that company will have similar intonation characteristics. Conversely, a set from a different company may have the exact intonation characteristic you need. You may have to experiment with various sets until you find the one that works well for you and your axe.

Your highest priority should be finding a string set that intonates well and sounds good. Tension is secondary as adjusting the neck tensioning rod(s) is usually an easy operation.

Adjusting the tensioning rod (neck relief) is an essential skill if you intend to be a master of your instrument. If I were in your shoes it would seem prudent to use this as an opportunity to get your feet wet doing neck adjustment to achieve your perfect neck relief. Acquire the tool required for tension rod adjustment, be sure to read up on the technique used in neck adjustment and relief. There are many sources available on the net as well as here on this site. It is possible to damage your instrument if you improperly adjust the tensioning rod, so please read up on it, and get some advice or help from a knowledgeable person should you be unsure of your ability to work with tools.

Try to find a fellow bassist with many sets of used strings. I never throw out my old strings and have boxes of various sets that are still in good shape. See if you can borrow an assortment of old strings and try different sets that might be good candidates.

Search FretlessBass.com for "strings", you will find some interesting reading and also some other contenders for your string choice.

Good luck, and welcome to the Fretless Bass community.

That has got to be the most complete answer I've EVER received to ANY of my forum posts. Thank you!

Yes, the Chromes are ECB81 which are about as close to the Phosphor Bronze as I think I could hope for in terms of tension and string diameter. You've pretty much confirmed what I was thinking that if I put the Chromes on I may just need to tweak the neck slightly. As the action is perhaps a little high for my tastes at the moment I'll probably just see where everything settles once the strings are on and then maybe pull the neck back up a touch if the tension is a little too low.

I suppose I'm really just trying to make sure I don't do anything that might result in long term damage to what so far seems like a very nice instrument.

Again, thanks for your reply!

Adjusting Action Height on an AEB.
This information applies to AEBs and instruments with non adjustable bridge. If you have an adjustable bridge please ignore.

Presuming that you want your fretless axe to Mwah and be easy to play.
Once you adjust the neck on your AEB to be as flat as is possible (minimal relief = better Mwah). Check your action height. After adjusting the neck relief your action may be either too low, or too high.

If your action is still too high you will probably want to lower it for good playability and Mwah. If action too low, the notes will choke and need to be raised.

Action height is the gap between the fingerboard and the bottom of the strings, usually adjusted at the bridge after you have adjusted neck relief. More action height yields a solid tone but less Mwah. Less height provide better Mwah but a less percussive tone. Most fretless players opt for more Mwah. This means that a low fast action height is usually preferred for fretless bass.

On most AEBs the height at the bridge is not adjustable. On an acoustic instrument you can shim the saddles, or the neck heel (bridge end of heel) to raise the action, but as you said "As the action is perhaps a little high for my tastes". So lowering the action may be what you seek.

Lowering the action without altering your optimally adjusted neck relief is the goal. You have a few alternatives.

Cut deeper string grooves in the saddle(s).
Sand, or file, down the bottom of the saddle(s).
Shim the neck at the heel (bolt on neck only).

Of these alternative, shimming the neck is the only reversible option so is the method of first choice for most situations.

Raise action = Shim located at Headstock end of heel.
Lower action = Shim located at Bridge end of heel.

To shim a neck you need to remove the neck. Before you remove the neck, decide how much change in action you need (at the bridge) and write it down on a piece of paper, then consider this figure again before committing to shimming your axe. Shimming is reversible so there is little possibility of ruining things but it is wise to be confident in the amount of change you seek in your action. First remove the strings, remove the neck screws and plate (if present), and gently rock the neck out of it's pocket without damaging the finish or wood. It may require a few gentle taps with a soft mallet. Keep in mind that the neck heel is usually tapered so it will probably want to come out by raising it out of the pocket vertically. Don't try to slide it out in the direction of the neck headstock.

The desired change in action height determines the thickness of the shim needed. A heel shim will need to be much thinner than the change in height desired by a ratio of approx. 1:4. Some experimentation may be needed. You can derive the shim thickness arithmetically. Just think about the distances involved and calculate the ratio, then divide the desired action height change by that ratio. For an 1/8" change a 1/32" shim will be a good starting approximation (at 1:4 ratio).

In practice, experimentation works about as well as the calculated method so I won't go into it. I have provided the seed so you may figure it out yourself if motivated to get into the details.

Neck shims are typically 1/4" to 3/8" in the narrow dimension, and as wide as the neck.

Your shim stock can be made from just about any material but hardwood or brass is commonly used. If your shim is on the bridge end of the heel it should be shaped to conform to the neck heel shape. You can glue it in place on the neck, or just place it in the neck pocket. Either way, once the screws are tight, it wont be moving. I read about an individual who cut feeler gauge blades into the right shape. This would provide excellent micro adjustment potential.

Fit the neck back in its' pocket making sure that the shim does not move. Replace the neck plate and screws and tighten.

String it up, tune, and check action height. If it's OK you are done. Else repeat entire process using a different shim, adding a layer, or thinning your existing shim, until satisfied.

String Tension and Technique

Since the title of this topic is String Tension I thought a few words on this subject might be of interest. Aside from the tension characteristics of specific string sets this is also a topic of technique and playability.

I am biased to standard and high tension strings for fretless playing. I don't like the feeling I get from low tension sets. The things I say here are my opinions, not necessarily hard fact. Hopefully a bassist who prefers low tension strings will add their perspective on this topic, and why they work for him/her.

String tension greatly effects the way you play. As you develop technique you soon realize that the tension of your strings provide tactile feedback telling you how hard or soft, how fast or slow, and where you can hit the strings. The string tells you when too much right hand strength hits the limit of the string before it "craps out". There is a feeling imparted back into your fingers from the strings that is similar to the rebound that a drummer gets after striking the head. A firm string rebound facilitates cross string raking (Ala James Jamerson) and several other other right hand techniques. One could say that strings talk to you. Low tension strings speak with a sort of shyness (don't hurt me), standard and higher tension strings speak more strongly (come on! Hit me). This isn't about the sound they make, it is about the way they feel as you play.

Standard and high tension strings have greater sustain. The string will "Tell" you when a note has decayed to a certain fall off point where volume diminishes more rapidly. Low tension strings hit this point sooner. I have no need of a compressor with standard and high tension strings.

Low tension strings feel "flabby" to me, but then I developed my technique in an era where lower tension strings such as Thomastic Infield did not exist. Some players who have adopted a more gentle touch prefer low tension strings.

Higher tension strings rebound faster allowing faster playing. They can absorb more energy from your fingers so have (in my opinion) a greater dynamic range. This permits a certain degree of volume control using right hand technique that softer strings can't match because they crap out sooner.

I can do a 128th note roll using two finger up/down double strokes (Flamenco technique) on a standard tension string. When the same thing is attempted on low tension strings the lack of quick response yields an indistinct sound lacking 128th note definition. In real life situations I just about never play excessively fast licks but I like to have that potential available. It's sort of like having a car that can go fast. According to the law one should never have need of that capability yet it dramatically enhances the driving experience.

Going back to the drum analogy, one could say that low tension strings are similar to an oil filled head, and high tension strings are like a standard drum head. I suppose in some respects this can be a stylistic preference, oil filled heads are great for certain types of music.

When you pluck a string it goes slightly sharp for a small amount of time because the energy you put into the string increases the tension. Test this while plugged into a tuner. The harder you hit the string, the sharper it will go, then quickly return to normal pitch as the imparted energy dissipates. This characteristic seems to be of shortened duration on low tension strings, they do seem to go sharper, but then return to pitch quicker (in milliseconds). This goes hand in hand with less sustain and more Thump on low tension strings, so can be either a positive or a negative depending on ones preferences.

Bottom line, don't use excessive right hand strength or your pitch will be slightly sharp at the very beginning of your notes. If you are in the habit of hitting the strings hard, tune 2 cents flat.