|Open String Frequency:||Hz|
|Number of Frets:|
|Show frequency response plot|
|Show fundamental frequency marker|
|Show 16 harmonics|
(inches from bridge)
Welcome to the new version of the old Pickup Response Demonstration Applet. No longer an Applet, this is now implemented in compatible HTML5 technology and adds many features and improvements.
This is a demonstration of the effects of physical parameters of guitar pickups on the frequency response of the instrument. These include position, width, and combinations of multiple pickups with various levels and polarities. This is all based on the equations derrived in the articles referenced below.
This model completely ignores the electrical characteristics of the pickups (inductance, capacitance, loading, etc.) as well as the instrument's body resonances. They are all important factors for the sound, but for the purposes of this discussion the focus is on the physical parameters.
This page should work on most browsers and iPads.
The main display is a classic frequency response plot. The X axis marks the frequency on a log scale running from 30 Hz to 15 KHz. The Y axis is also a log scale, dB, with 0 dB as our reference point. -10 dB is 1/10 the power.
If you hover the mouse over the plot you can see the frequency and amplitude at that point displayed in the lower left.
Above the plot we have a ruler, a drawing of a vibrating string, guitar neck, bridge, and an electromagnetic guitar pickup. These happen to be the same width as the plot, but they are separate, and the X axis here is per the ruler.
The top ruler is calibrated in inches from the bridge up the neck. The second ruler ticks off selected fret locations.
You can mouse on the pickup to move it around and see the effects of the pickup position on the frequency response. With multiple pickups you can shift-click to move them all at once.
The guitar parameters are below the plot on the left. Changing them updates the plot.
The pickup table allows you to add and remove pickups, set the position, width, level, and polarity of each independently.
The checkboxes on the right enable some interesting plot features.
The Fundamental Frequency Marker feature notes the range of the fundamental frequencies over the range of the neck. You can mouse on the vibrating string and see how the fundamental pitch maps onto plot frequencies.
The Show 16 Harmonics feature displays the amplitudes of the harmonics of the note being played.
The concept of frequency response here is somewhat abstract as one just plays individual notes on a guitar string and it is not a filtering function as such. But if you ripped out the frets and slide the pitch up, the levels of the fundamental and harmonics would follow this curve.
Should the curves be the same for pickups placed at, say, 1/4 the way from the bridge and 1/4 the way from the nut? No, because sliding up the neck is part of the frequency response mechansim and that loses the symmetry.
But for an open string, the discrete harmonics should be the same. To see that effect, turn off the plot and just display the first 16 harmonics, and compare those at symmetrical ends of the vibrating string.
|5 String Bass B string||31 Hz|
|Bass E string||41|
|Bass A string||55|
|Bass D string||73|
|Bass G string||98|
|Guitar low E string||83|
|Guitar A string||110|
|Guitar D string||147|
|Guitar G string||196|
|Guitar B string||247|
|Guitar high E string||330|
|Mandola C string||131|
|Mandolin G string||196|
|Mandolin D string||293|
|Mandolin A string||440|
|Mandolin E string||660|
|Rickenbacker 325 (Lennon) guitar||20.75|
|Short scale guitar (Mustang, Jaguar)||24|
|Most Gibson, Rickenbacker, Guild electrics||24.75|
|Most Fender electric guitars||25.5|
|Short scale bass||30.0|
|Medium scale bass||32.0|
|Long scale bass||34.0|
Response Effects of Guitar Pickup Position and Width, Donald Tillman. An analysis of the freqency response characterstic of pickups due to their physical location and width.
Response Effects of Guitar Pickup Mixing, Donald Tillman. An analysis of the effects of mixing the signals from two and three pickups.
Pickup Response Demonstration Applet, Donald Tillman. The 2000 vintage Java technology version of the current page. At this point it's painful and difficult to run.