Bridge material and design

Jangle_Jamie

The more I fiddle with guitar setup, the more I'm interested in what's going on.

Why are bridges made from either rosewood or ebony? Why not spruce with an ebony strip/top for the strings to sit on? I apologise for my ignorance, but I need to improve a guitar's performance -

I have a Dupont Busato Royale with a tone depth and volume that aren't quite there. The whole register is a little on the thin side, though the guitar projects well when played hard. I don't 'feel' the sound through the body as I do with some other guitars. I swapped the very light Dupont ebony bridge for an equally light rosewood bridge by Robert Ford. I'm now wondering if a different design of bridge might help. The gap between the moustachios is only 126mm, which is the smallest gap on any of my guitars. I'm wondering whether to knock the moustachios off and reposition them further apart to accept a wider bridge. I'm also thinking about bridge design - do away with the hollow, and make a solid but slimmer bridge shape. I did that on my Gallato and it seems to work fine. I have some nice pieces of ebony ready to go!

The Dupont is light in weight, is lightly braced, has a very pronounced bombe top and back and does not have a thick finish on the top - all attributes that should equal power and volume.

Thanks for any nuggets the guitar builders here can pass on!

pdg

Just a few thoughts:

Has the guitar always sounded this way, or has it changed?

Feeling the guitar through the body isn't necessarily a reliable indicator of the sound to the listener up front, depending in the type of guitar. Have you listened to other people (who know the technique) play it?

Are you playing in a "live" enough room, vs. a room with carpet, drapes, sofas, etc.? The player can't always hear the oval-hole sound well, unless it's reflected back.

Humidity can dull the tone.

Truss rod adjustments (even miniscule) can have a big effect -- how much neck relief is there?

I wouldn't worry about the moustaches, bridge length, etc.

Indian rosewood is usually the most lively bridge wood, and you need the hollowed-out underside. Bridge weight is an important variable, and Indian rosewood is lighter.

Have you tried seating the bridge firmly, by pressing a bit on it and giving it a little side-to-side force (long way)?

Of course, action is important. (I think our host Michael knows a lot about what action works best for Busato-type guitars vs. Selmer vs. Favino styles.)

Are you comparing the guitar with other gypsy jazz guitars, in the same room?

Anyway, just a few thoughts.

Twang

Break angle can make a difference. More downward pressure from the bridge can drive the top harder and make it more responsive. This is achieved by creating a steeper neck angle then raising the bridge. Too much and it can choke the top. You have to get the sweet spot. So Ive heard anyway. Might be worth exploring.

I agree with pdg that resonance isn’t an indicator of sound projection but I would say that it feels great if the whole guitar is vibrating and I think this makes me play better.

Just to add, one of the best gypsy guitars I ever played was a Dupont Busato royale. Shoulda bought it.

Buco

Whoa friend, when did Dupont Busato Royale come into the happy family?!

Well congrats either way. How often are you playing it? You have a good, healthy, number of guitars. If it's not played regularly, it'll go to sleep. With your number of guitars, I'd get the Tone Rite thingy to keep them awake.

Jangle_Jamie

I kept quiet on the Dupont - maybe I didn't even want to admit to myself that I'd bought it.

It was a good price, and had been owned since new (2009) by one person who I'm sure didn't play it much as it is pristine with no fret wear. I actually fell in love with the figured maple back and sides.

As for the break angle, I totally agree with you Twang, but that's something that is built into the guitar. It's got a good healthy break angle, though the tailpiece needs a thicker piece of leather which will raise the height slightly (by almost 1mm) and reduce that break angle just a smidge. One interesting observation is that the distance of the strings away from the soundhole is quite large (about 18mm). How does that compare with everyone else's? I would assume that the closer the strings are to the soundhole, the more resonance you get.

I sold two gypsy guitars recently, but have a couple more to sell in time (if I can part with them!)

Jangle_Jamie

Thanks for your reply PDG. Lots in there!

I think the action could be raised just a little, and I may try 11s on it too. Yes I'm always comparing my guitars, but perhaps this really is a guitar that projects. I've not heard it played by anyone else, so that's a good suggestion.

I fancy making a few bridges anyway as an experiment. I also have some rather nice looking pale moon ebony with white streaks in it.

Gouch

What is the wood, the height and the weight of the current bridge?

(And if you know, is it the original Dupont bridge, or a replacement?)

Jangle_Jamie

Both the original Dupont ebony bridge, and Robert Ford's rosewood bridge are super light, concave and very nicely made. Height for both is 17mm. Fingerboard is straight as an arrow. It plays absolutely beautifully - very slick and easy

Gouch

Thanks for the info. Immediate and fully-reversible ideas:

Put a 2mm flat pick (or 2mm shim) under each bridge foot. This will raise the action 1mm at the octave.

Try 11s

Twang

My g string measures 17mm from the guitar top to the string. I measured this at the bridgeside edge of the oval sound hole. This guitar is LOUD.

Jangle_Jamie

Thanks both of you for your info and suggestions. I've got plenty of bits of ebony and rosewood veneer for shims so will have a tinker in the next few days when I get time.