How to increase a guitar's treble response?

[LFL Steve]

Originally Posted by redir

The bridge and the ball end of the string seating on the bridge plate still has so little to do with an electric guitar hence why...

...I'm still confused.


LOL!

The thread is discussing the acoustic properties and sound of the OP's particular guitar, not the electric properties, per the OP (several times). Since it has an acoustic-type bridge and saddle, these elements also pertain to fully acoustic guitars with similar bridge (that is, nearly all of them). Plus, all the different viewpoints are fun to read!

[LFL Steve]

Alan, yes, lots of interesting aspects to this!

Originally Posted by Alan Carruth

Sure. If the pins are loose they can rattle, or otherwise move in ways that could absorb sound at certain frequencies. I'm not sure how much of an issue that is. I have yet to figure out why a pin that is tight in the hole, but doesn't have the same taper (so it's only tight at one end) would affect the tone if it's not rotating. If it's not moving relative to the bridge it should not change the sound. and, of course, that doesn't have anything to do with the pin material.

If the pin is tight in the hole then it won't rattle. Even if the tapers are mismatched and it's tight at only one end, as long as it's tight enough there won't be movement vis-a-vis the bridge, and there won't be rattling noise. However, it definitely CAN change the sound, not by movement relative to the bridge, but by adding mass to the system at that point. This is discussed previously in the thread. The less mass the pins have, the less they will dampen the amplitude of the top excursion, and the less they will shift the resonant frequency lower in the spectrum.

Originally Posted by Alan Carruth

The whole purpose of the bridge is to tell the string how long it is, so that it can make the correct pitch. It does that best when the bridge itself doesn't move at all, and all of the vibration of the string stops at the top the saddle. In practice, of course, the bridge has to move, since it's glued down to the top, and if the top doesn't move there's no sound. Bridge motion in this sense does affect the tone, being the basis of 'wolf' notes, but that as nothing to do with the pin material except insofar as their mass changes the resonant pitch and the overall impedance of the system.

The only way I can think of for the string to be moving behind the saddle is if the saddle top itself is fairly fairly sharp, so that the string can rock around that high point. The section of the string between the saddle and the pin is flexible, and will hardly transfer any force at all as far back as the front of the pin, and the motion will stop where the string touches the bridge in front of the pin.

Yes, the saddle establishes a node point where there is no lateral movement as the string vibrates, and hence establishes the bridge end point of the speaking length of the string (the other end point is established by the nut or the fretted note). However, the string is definitely moving behind the saddle; the guitar wouldn't work acoustically if it weren't. Along the speaking length of the string, the vibration is lateral. As the string moves through one cycle, the tension on the string core changes. This tension is transferred along the full length of the string, from the tuning post to the ball end. The segments of the string outside the speaking length are not moving laterally (we'll grant an exception for Fender headstocks that are missing their string tees) but they are moving lengthwise. This motion, along the length of the string, is transferred through the string core to the ball, to the bridge plate, to the top system. Since the string is stopped at the saddle fulcrum and anchored at bridge plate, the part of the system comprised of the saddle, bridge, and plate exert a rocking motion (assuming the assembly is rigid), and the pins are along for the ride. This rocking motion is transmitted to the top, which in turn vibrates to produce (most of) the sound we hear. The pins are vibrated by the same force but they have so little surface area compared to the top that they don't really generate any sound themselves; they're a minuscule part of the whole vibrating surface.

Originally Posted by Alan Carruth

The string changes tension twice per cycle of vibration; it's tighter when it's 'up' and when it's 'down'. This is a 'small' change, only a few percent of the string tension itself. Experiments I've done show that this 'tension' signal can have an effect on the sound, and that it acts at the top of the saddle.

This is part of what I described above, though the tension signal does not "have an effect on the sound;" it IS the sound, or at least the acoustic component (the vibrating guitar top).

Originally Posted by Alan Carruth

So I have to say that all of the evidence I've seen says that there is no sound for the pins to transmit to the bridge, or anywhere else. They're along for the ride, and vibrate with all the other parts of the bridge in that sense. For them to transmit some sound there has to be relative motion.

I agree with this. The pins don't transmit sound from the strings to anywhere else; it's the other way around. Vibration is transferred to the pins from the bridge. The role of the pin is just to occupy the open shaft in the bridge so that the ball doesn't slide sideways and come out.

Originally Posted by Alan Carruth

I keep putting out the challenge, though. If anybody can actually measure a vibration in the string at the pin I'd like to see the data and how it was obtained. I can't think of any good and simple way to do this. If you can show this, and how it affects the tone, then I'll happily admit that I was wrong. I'm always ready to learn more about guitars. You'll have to be pretty convincing...

Detecting a vibration at the pins would be straightforward. As you've pointed out, the pins are vibrated as part of the system, and that vibration comes from the strings (through the ball, the plate, and the bridge). Clip a snark on a pin top, and you'll measure the vibration. Or glue on a piezo and run a signal out. Or is this not what you meant by "at the pin" in your challenge?

Fun stuff!

[Alan Carruth]

RogerHaggstrom wrote:
"I won't convince Alan, but I know from experiments that the hardness of the seating of the ball ends will affect both volume and trebles."

You won't convince me without actual objective data.

Steve B wrote:
"However, the string is definitely moving behind the saddle; the guitar wouldn't work acoustically if it weren't."

I spent a lot of time several years ago looking at the forces the string produces on the saddle as it vibrates. I reported on it in a talk at an ASIA Symposium, and there's a copy of the resulting article on my web site; a .pdf entitled 'String Theory' (I couldn't resist). It's on the 'Acoustics' page. The string produces several 'signals' that get passed to the saddle top. I've also done some work since on the relative contributions of the different signals from strings on a guitar, which I've spoken of but not published in a formal sense.

One, a small tension change signal, is produced primarily by nylon strings when they 'roll' off the finger tip. If you ever made a 'spinner' out of a big old button you know about that. It's an attack transient on plucked strings but causes major headaches for young fiddle players, and Hurdy-gurdies.

The largest force is produced by the transverse excursion of the string. This can be either 'vertical' with respect to the soundboard, or 'horizontal'. Just because the pick goes from side to side that doesn't mean the string ends up going that way. The pick is like a cam; some of the horizontal motion gets changed to vertical. The vertical component of the motion pulls the top along with it, producing a 'loudspeaker type' motion in the lower bout, which is very effective at making sound.

The amplitude of the 'tension' signal varies from string to string, but it averages about 1/7 of the 'transverse' signal. At that ratio if the string is making an angle of about 15 degrees relative to the top plane the transverse signal is stronger than the tension signal at the bridge.

The 'tension' signal rocks the bridge fore and aft. A given tension change produces a lot less rocking motion than the same force in the vertical transverse direction does, in part because we make guitar tops to resist bridge rocking.

The rocking motion pulls part of the top 'up' and pushes part 'down', so it works a lot less efficiently than the transverse force in making sound.

I did two different experiments, driving a guitar string on a single plane using different methods with controlled force, and got the same result each time. When the string moved 'vertically' with respect to the top it produced ~20 dB more sound at a meter distance out from the top than it did when it was moving 'horizontally'. That's a difference in power of 100 times.

If the tension signal were the main driver then archtop guitars, where the bridge doesn't rock, would sound an octave lower in pitch than flat tops with the same strings, since the tension change is frequency doubled with respect to the transverse force. Do they?

"Detecting a vibration at the pins would be straightforward. As you've pointed out, the pins are vibrated as part of the system, and that vibration comes from the strings (through the ball, the plate, and the bridge). Clip a snark on a pin top, and you'll measure the vibration. Or glue on a piezo and run a signal out. Or is this not what you meant by "at the pin" in your challenge?"

Since the pins do move along with the bridge a sensor that 'reads' the motion of the pin itself is going to pick up the motion of the top/bridge too. What we need is something, like a piezo or a resistive force sensor, that can read the force between the pin and the bridge or plate at (say) the ball end. I've done some work with PZT piezo ceramic, and isolating the signal might be a problem; those things produce output in shear as well as in compression/tension.

[Jon S.]

I must say, I'm surprised, myself, that my thread has the legs to reach 4 pages.

Here's my personal approach to changes and mods to gear of all types, in this case, a guitar:

1. Ask first whether the guitar is close to where you want it to be and you want "a bit more," or is far from what you're seeking:

a. If the former, proceed to try changes and mods.
b. If the latter, sell it now.

2. Assuming 1a, as you proceed, change one variable at a time. Otherwise, you'll never be certain what's impacting - or not impacting - what.

3. Start with the simplest, least intrusive, least costly changes.

4a. Proceed to more complex, more intrusive, more costly changes only after determining the former ones aren't sufficient.
4b. But don't go so crazy that you end up wasting time and money that you could have spent better by following 1.b (selling the guitar) and putting the proceeds towards another (I call this the "Blues Junior Rule" ).

Applying my own standards to myself and my own guitar that's the subject of this thread, here's how I'm starting (the listed items are on order now and are all easy and inexpensive):

1st change: Try different pick(s).

2nd change: Try different strings.

3rd change: Try different bridge pins.

In my case, I'll probably stop after 3. The guitar's basically OK. I'm just looking for "a bit more brightness." If 1-3 give it to me, great, if not, the sun will still rise in the morning and I'll still be writing and performing my music.

This being said, the 4th change, if it comes to it, would be to replace the stock Tusq bridge with a bone bridge. At present, though, I don't envision undertaking that.

[Fathand]

Originally Posted by Jon Silberman

This being said, the 4th change, if it comes to it, would be to replace the stock Tusq bridge with a bone bridge. At present, though, I don't envision undertaking that.

A saddle change will easily do more than pin change. I'd make that #3

[Jon S.]

Originally Posted by Fathand

A saddle change will easily do more than pin change. I'd make that #3

Agree that a bridge change would be way more impactful than a pin change. It is, though, a more complex change (on a guitar with a piezo saddle PUP, I'm not comfortable doing it at home so now we're looking at spending yet more time and money). The pin change is simple, cheap (see below), and takes essentially zero time as I'll pull the stock pins for a string change anyway. Hence my prioritization.

https://www.amazon.com/dp/B0002HLL8Q...roduct_details

[RogerHaggstrom]

Originally Posted by Alan Carruth

RogerHaggstrom wrote:
"I won't convince Alan, but I know from experiments that the hardness of the seating of the ball ends will affect both volume and trebles."

You won't convince me without actual objective data.

Hold your horses. I have bought a couple of small Thin Film Pressure Sensor Force Sensors. This one too. This one too.

I plan to put one or two under a ball end (with an elongated metal plate with a small hole for the string to be threaded through in the middle with the sensors sandwiched between the bridgeplate and the metal plate above and below the ball end) on the next parlor guitar when restoring, hoping that a standard resistance measuring instrument will give me a signal when plucking the string. If I can see the needle move, I know for sure.

I don't know if the measuring instrument is fast enough for the pressure difference to show, though. I will let you know how it turns out.

[Jon S.]

Originally Posted by RogerHaggstrom

Hold your horses. ...

My '67 Viking 1 has only one "g."

[printer2]

Originally Posted by RogerHaggstrom

Hold your horses. I have bought a couple of small Thin Film Pressure Sensor Force Sensors. This one too. This one too.

I plan to put one or two under a ball end (with an elongated metal plate with a small hole for the string to be threaded through in the middle with the sensors sandwiched between the bridgeplate and the metal plate above and below the ball end) on the next parlor guitar when restoring, hoping that a standard resistance measuring instrument will give me a signal when plucking the string. If I can see the needle move, I know for sure.

I don't know if the measuring instrument is fast enough for the pressure difference to show, though. I will let you know how it turns out.

So you are going to drill a hole in the sensor and stick the string through it?

[Alan Carruth]

I've wondered about the frequency response of those resistive pressure sensors too: I've always used piezo ceramic, which has it's own issues. Old telephones worked on a carbon button mic; essentially the same thing but bigger.

A lot of top transducers are thin piezo elements sandwiched between contacts. The mass of the outer contact resisting the acceleration of the top provides the force to produce a signal. In your case one would expect the pressure change from the string to swamp the acceleration signal, but.... Would it make sense to do the experiment on a rigid beam to avoid that?

[RogerHaggstrom]

Originally Posted by Alan Carruth

I've wondered about the frequency response of those resistive pressure sensors too: I've always used piezo ceramic, which has it's own issues. Old telephones worked on a carbon button mic; essentially the same thing but bigger.

A lot of top transducers are thin piezo elements sandwiched between contacts. The mass of the outer contact resisting the acceleration of the top provides the force to produce a signal. In your case one would expect the pressure change from the string to swamp the acceleration signal, but.... Would it make sense to do the experiment on a rigid beam to avoid that?

I have to see if I can make a hole for the string without destroying the sensors.

I'm planning to firstly see if I get a signal at all. If I do, see if I get a signal from just pushing down (or up) the top. Lastly, using some plywood on the top to make it rigid and see if I still get a signal. Maybe there can be some conclusion from that experiment.

But I don't have them yet, and I don't know if the multimeter needle will move.

[EZYPIKINS]

Have heard about Tusq saddles transferring better than bone to an under-saddle pickup.

That said, My OM-28e has a Tusq saddle. My 000-28eMD has bone.

Both guitars sound great unplugged. The 000-28eMD has a noticeably less treble when plugged in. Just an EQ difference.

Have Gibson electrics that have bone. Have never tried them in the same channel. So I get no problem there.

Have a friend with one of these. He says he really likes it. Not sure if he's ever even used it live or not.

[Jon S.]

Here's where I am presently.

I obtained and tried a wide variety of picks I don't usually use of a wide range of materials, thicknesses, and shapes.

I replaced the prior owner's .10 gauge electric strings with Elixir Nano 80-20 10's (though I substituted an unwound .18 for the included .23 wound 3rd).

I like the replacement Elixir Nanos. Interestingly, I'm noticing no loss of strength of the sound when playing the guitar in humbucker mode alone despite the bronze coatings on the lower 3 strings - that's pretty cool (and was unexpected).

The real eye - or should I say ear - opener, though, is hot much more treble I'm getting from cheap and thin (much more so that I've used for years) D'Marzio and Dunlop pics. For my purposes here, .50mm pics actually sound best but I can't handle how much the bend so, for now, I'm using the .60 and slightly thicker ones.

The brass pin holders are a disappointment. Not that they don't work as advertised but I'll never know from the two sets I copped on Amazon because neither fits my guitar's pin holes (one set is too thick, the other too thin).

[mercy]

Theres the problem with replacing pins. I have a tin of them and none fit my guitar. If you have one that fits, you could have a set of pins custom made by Colossi Saddles

[printer2]

Originally Posted by Jon Silberman

The brass pin holders are a disappointment. Not that they don't work as advertised but I'll never know from the two sets I copped on Amazon because neither fits my guitar's pin holes (one set is too thick, the other too thin).

This reminds me of a story I heard as a kid.