Way more than expected difference in sound from new bridge pins

[BoomChuck]

Originally Posted by Mark L

What I am more sure of, though, is that to make an "experiment" more complete, one should record the instrument, remove the original pins, and then replace the original pins and record it again. Then repeat this for the new set of pins. Actually, it might be good to do the process an additional time for each pin set, keeping the strings the same. Then scramble the 6 recordings into random order and listen to them, seeing if consistent differences appear upon analysis.

I got tired just reading that! Maybe one day...

Originally Posted by Alan Carruth

Actually, there is, if you assume that it's the different mass that has the effect.

You clearly are much more knoweldgeable about this so I'll probably just reinforce that with what I'm about to say but my initial assumption was that, since the bridge pins wedge the ball end to the bridgeplate, their rigidity would also play a part, not just mass.

Anyway, I do still hear a difference, imagined or otherwise, having now swapped back to the ebony, still on the same set of strings. I also feel a difference in how the back of the guitar resonates against my chest. Hey, I could be imagining it and that's fine by me.

All that said, I'm pretty happy with the swap, especially since I didn't expect anything out of them other than for them to look cool. Which they do. For $8, not a bad upgrade.

[RustyAxe]

Why is there always the assumption if someone doesn't hear a difference it's because they can't?

[RustyZombie]

Originally Posted by RustyAxe

Why is there always the assumption if someone doesn't hear a difference it's because they can't?

Because almost everyone trusts their own perception more than someone else's.

[sitka12]

Maybe that it is guitar dependent also. Of the 3 Martins I have had, I liked different material pins on each. I have an old overbuilt Alvarez that makes no difference on what pins are used. Maybe lighter built is easier to detect various changes.

[westman]

Chuck, I'm taking u'r lead and as Alan C says 5 grams per set for ebony pins.
I've got a string through bridge on one of my guitars so I'm thinking I'll crazy glue some ebony off-cuts (up to 5 gms) to the back of the bridge - worth a try eh ?.

[dhalbert]

Originally Posted by westman

Chuck, I'm taking u'r lead and as Alan C says 5 grams per set for ebony pins.
I've got a string through bridge on one of my guitars so I'm thinking I'll crazy glue some ebony off-cuts (up to 5 gms) to the back of the bridge - worth a try eh ?.

I'm not sure about that () but I was thinking of just wrapping a few grams of solder around my bridge pins (not each individually) or attaching a few small binder clips to some of the pins (could do it on top or underneath). I have a kitchen scale that weighs to the gram. That would be an interesting experiment. I'm just trying to think of the easiest way to add weight to the bridge. (BoomChuck could try something similar with the old pins.)

[jseth]

I think that a change in bridge pin material has much more noticeable effect on a less-expensive guitar with less expensive pin material...

When you get into a fine instrument with bone pins (or some such), I believe the sonic difference to be negligible...

[easynote]

Wrong thread

[fazool]

Originally Posted by paulisdead

I haven't been 'here' that long but I believe the appropriate reply is-

And we're off...

Now, that's funny.

I stole it for use in another thread (thank you)

[TBman]

When I first raised the question many moons ago young grasshopper, I was quickly swatted across the wrist of my fretting hand by forum members. Let ye not fall into the depths of depravity that a "bridge pins made my guitar sound better" thread can be, whatever the excuse (strings not seated correctly - really? For how many years?, )

Seriously though, maybe if the strings worked their way up as you said and weren't making as full contact as possible with the bridge plate......

I might try brass pins at some point (if the forum deities allow, lol)

[fazool]

Originally Posted by TBman

...

I might try brass pins at some point (if the forum deities allow, lol)

A certain former AGF sponsor makes a similar product that always results in a popcorn-worthy thread that typically ends in napalm.

[Goodallboy]

Originally Posted by RustyAxe

Why is there always the assumption if someone doesn't hear a difference it's because they can't?

Because many times they can't, unless everyone's hearing is equal, which I'm pretty sure isn't true.

[earri]

I can't vouch for your experiment and/or whether proper controls were set, but I hear a clear difference in the recordings you posted - as you aptly described.

I'm a believer, at least on your guitar.

[Alan Carruth]

A couple of points...

The easiest way to add mass at the bridge is with poster adhesive ('Blu Tac' or 'Fun Tac' are a couple of brands). It looks like modeling clay, but won't leach oil into the wood. It's easy to stick on a little wad of the stuff and see what happens. It's very useful for finding the best way to tame a wolf note.

Changing the mass at the bridge alters two things; the 'impedance' of the bridge, and the resonant frequencies of the vibration modes of the top that are active at the bridge. Impedance is a measure of how hard it is to move something at a given frequency. Adding mass to a system raises the impedance at all frequencies, but more at high frequencies than low ones. Thus going to heavier bridge pins should generally cut down on the power, since the top is now harder to move, but it cuts it down much more in the treble, so the guitar tends to sound 'bassier'.

Strings have their own impedance, and it's generally pretty low as compared with that of the top, since the strings are much lighter than the top. When you couple together two things that can vibrate the rate of energy transfer from one to the other depends on how closely the impedance matches. With a close match, such as you see on a banjo, the energy gets out of the string in a hurry, so you get a sharp attack and not as much sustain. A solid body electric will have a very large impedance mismatch, and the energy tends to stay in the strings for along time, giving a weak acoustic sound with lots of sustain. Going to heavier bridge pins usually gives more sustain.

Adding mass at the bridge tends to lower the resonant pitches of those top modes that move a lot at the bridge. What that does to the sound depends a lot of where those modes started out, and how they relate to the pitches of the notes you're playing, and also to the resonances of other parts of the guitar, such as the air in the box, and the back. If you start out with a top resonant mode just a little above the pitch of the open G string (which is a common range), adding a little mass can drop it down to a more exact match with the note you're playing. This can alter the timbre of that note a lot, and even cause it to become a 'wolf' note of one sort or another. If it starts out as a close match, adding mass can shift it away from that. Something similar can happen if the top resonance is very close in pitch to a resonance of another part of the guitar. Of course, the pitch shift can as easily cause things to go out of line as into it. The point is that in some cases seemingly small changes can lead to big effects, simply because you've crossed a tipping point.

From what I've seen 'better' guitars tend to be more sensitive in many ways than the 'affordable' ones. In part this is simply because there tends to be more going on in a better guitar; more 'moving parts' in a sense means more chances for things to line up in 'interesting' ways. OTOH, there are times when some behavior that causes a 'wolf' on an affordable instrument is not a problem on a better one because the complexity of the response of the better instrument masks the problem.

[stephenT]

Originally Posted by BoomChuck

Mm, sorry, just to be clear: I do not believe that it is the bridge pins, their quality or their material, that are affecting the sound.

Because you're in the next room listening or are you just guessing?