Is this a good mandolin?

[CelticMusicLover]

Found a mandolin on a web-auction for a reasonable price, and couldn't resist to buy it. However, the seller didn't mention what brand it is. Anyone here who knows what it might be?

NOTE: The picture is from the auction-site; I haven't recieved the instrument yet.

[brewerpaul]

That could be almost anything-- it's a generic A style mandolin. Just about every mandolin maker makes these.
It will probably benefit from a good setup: making sure the neck is straight , bridge in the correct position etc. From the picture, it looks like the bridge is crooked, but this is very easy to fix.
If you have a good luthier nearby, it may be well worth your while to show him/her your new mandolin to see what work it needs doing. Or, for starters you can search the web for "mandolin setup" and try some of the steps yourself.
Let us know how the new instrument is.

[Tim2723]

There's not much to add to Paul's assessment. Those are generic A-style instruments offered under a great many labels. It was most likely built by the Samick Guitar Works in China and could have any name (even a famous one) on the label.

The only truly 'bad' mandolin is that which is either so inherently defective or so severely damaged that it cannot, by reasonable means, be made playable. Do as Paul suggests and have it looked at by a technician. Many of the simpler set up steps can be easily accomplished by the player with just a little care and good instruction that is readily available on the Net.

The first thing is to get a fresh set of strings on it and to place the bridge correctly. Both are easy to do and are skills every mandolinist needs to learn from the outset. The bridge is quite certainly in the wrong spot and until it is correctly placed the instrument will not play in tune. Mandolins have floating bridges (not glued down) and need to be adjusted from time to time. It's not a concern, it's normal.

From the picture it looks like there might be a problem with the nut. The nut should have eight slots to accommodate one string each. They are in pairs and sometimes the thin bit of plastic that separates two strings may break off, leaving one wide slot where two should be. If that's the case, a repair technician can easily fix it. There are equivalent pairs of slots on the saddle of the bridge. These may need tending to also.

Good luck with it, and enjoy it.

[mutepointe]

I didn't know mandolins have floating bridges. I don't own one. either. Here's my question, if an experienced person found the sweet spot for the bridge, couldn't this just be marked off? Would the sweet spot change over time or other variables like different weight strings or weather or the way a person played or the music that a person tended to play?

[Tim2723]

A lot of players attempt to mark off their bridge position and many go to extremes to keep it from moving when changing strings and such. But it never really works over the long run. Variations in strings, changes in weather, etc, all affect the mandolin. The bridge on most modern instruments includes adjusting mechanisms for height as well. You may need to raise or lower your bridge as seasons change. Some instruments come with more than one bridge to be used at different times. Floating bridges are part and parcel of the mandolin's sound as well. A fixed (glued) bridge has been used many times by many manufacturers, but there's always a change in the basic timbre.

Knowing how to adjust the bridge is just a natural part of mandolin ownership. I sometimes check and adjust the bridge during a performance when needed.

[buddhu]

Except for mandos with guitar-style bridges such as those used by Crafter and Thomas Buchanan, pretty much all mandolins have floating bridges.

I suppose it is perfectly possible to mark the bridge position once established, but the bridge position may need a slight nudge if the string gauges change drastically. The other thing is that it is so easy to check intonation and bridge position if one uses an electronic tuner, that it hardly seems worth marking the top. I check intonations regularly on my mandolins and on the rare occasions that it's drifted I just nudge the bridge. Takes a couple of minutes.

Like Tim said, positioning the bridge correctly is an essential skill for a mandolin player to have.

To minimise the chance of the bridge going out of position during string changes, most mando players change one string at a time rather than taking all off at the same time.

[s1m0n]

I didn't know mandolins have floating bridges. I don't own one. either. Here's my question, if an experienced person found the sweet spot for the bridge, couldn't this just be marked off? Would the sweet spot change over time or other variables like different weight strings or weather or the way a person played or the music that a person tended to play?

It's the physics of vibrating string - the 'sweet spot' is the location that puts the 12th fret exactly half way between the bridge and the nut*, so that the open string and the note at 12 fret are an octave apart. The 50% ratio between vibrating length and musical octave is Pythagoras's eureeka discovery, I believe.

The only factor which changes over time is neck angle; once the neck starts bending up, that shortens the scale length. Moving the bridge forward by a minute amount will stop that from affecting the tuning.

But in practice your suggestion is correct; on many older instruments it's possible to see the footprint of the bridge in the wear-pattern on the soundboard. particularly with banjo skins. On older instruments you can also often find that the bridge location has been marked in pencil on the deck at some point.p. People often do this when they want to change all the strings at once, instead of one at a time. You can't rely on this mark alone because bridges aren't always perfectly perpendicular. It's the location of the top of the bridge where the strings break that matters, not the location of the feet.

*With a minor adjustment necessary to adjust for the fact that wires of varying thickness can have slightly different vibrating lengths when bent over the same edge. If you think about it, the geometry of bridge, string, and fretboard/soundboard is right triangle, the shortest side of which is equal to the height of the bridge + 50% of the string thickness. That extra amount changes the vibrating length by just enough to affect tuning. Compensated (ie, notched) bridges are one solution for this, and another is putting is putting the bridge at an angle with the bass side just slightly farther back than the treble side.

[mutepointe]

Thank you all. I really appreciate how YOU PEOPLE always have answers to questions. And often simple and complex and even different answers.

[Rob Sharer]

It's the physics of vibrating string - the 'sweet spot' is the location that puts the 12th fret exactly half way between the bridge and the nut*, so that the open string and the note at 12 fret are an octave apart.

The bridge will never end up there - that's the theoretical bridge location, before any compensation. The bridge will always sit somewhere behind this point, even the treble side.


Rob

[Tim2723]

Eureka is attributed to Archimedes upon his revelation that the volume of an irregular solid can be determined by its displacement of water. But I think it was Pythagoras who discovered the relationships of string length to notes.

Rob's comment brings up two interesting observations. First, on a popular mandolin site, it is often recommended that a new player place his bridge by accurately measuring the distance from nut to twelfth fret and doubling it. Invariably, the newbie writes in to ask why that didn't work perfectly. Second, those who swear by marking or otherwise guaranteeing that their bridge never moves almost always end up with intonation problems eventually since the bridge can not only move slightly but can, as Simon points out, begin to lean, seemingly staying in exactly the same place yet changing the ideal string length.

You really have to be prepared to make this simple adjustment when necessary.

I recall a discussion concerning why a fixed bridge can work so well for the guitar yet be problematic for a mandolin. I believe the answer centered around the relatively short length of the mandolin and the effect of even a small error compounded by the very short strings. That is, that a guitar's length makes it significantly more forgiving allowing for a greater tolerance. Others noted that guitars can indeed have intonation errors attributable to perfect bridge placement.

[brewerpaul]

That bridge position at 2X the 12th fret distance is a fair estimate, but the proof comes when you actually fret a note at that 12th fret. It should be exactly an octave higher than the open string.

[Tim2723]

Yes, no matter where the bridge ultimately rests. It may even be at a slight angle for some instruments to compensate for string thickness and other factors. The octave test is the first measure of success.

[CelticMusicLover]

Sorry for not being very talkative; I figured I'd wait until I'd gotten the instrument. Now that I've got it, all I can say is that I'm very dissappointed with it After tuning it for a while, the part where the neck and body meet started to crack. :/

[MTGuru]

Oh, that's not good. So sorry. Can you tell us more about the instrument now - the name and model, and where it was made?

[CelticMusicLover]

Oh, that's not good. So sorry. Can you tell us more about the instrument now - the name and model, and where it was made?

It's unbranded (no name or model whatsoever). All I know is that the seller bought it in Germany (he told me in an e-mail). I suspect it's a massproduced faux-mandolin Should've been more patient and bought something better/more expensive.