testing pickups

This is slightly off-topic, I guess, but here goes. My daughter is winding and testing pickups for a school science project. We're assembling a pinecaster as part of the project, so this is sort of almost related to tele discussions. Anyway, she has a range of different pickups now with different strength magnets and different gauges of wire (36 & 42). They all sound ok. She's measured DC resistance on each of them (from about 290 to 7K Ohms), and she has recorded some music and individual notes from each. Any suggestions for good ways (and maybe programs) to analyze the recordings of each pickup? We're both new to this. We've downloaded the program Sonic Visualiser, and it looks interesting, maybe. I guess, basically, what should she test or look for in each sound file?

In the end, my daughter sees this project as a way to get a tele and I figure there are worse motivations. She's been teaching herself to play guitar with a small acoustic parlor guitar we have and she really wants to go electric.

This may not be the technical answer your looking for but the things on the sides of your head are the best test equipment you could have.

If you like the way it sounds, the specs are moot !!


Even playing with the space of the pickup in relation to the strings can play on the tone...............good or not so good.


Your daughter has found an awesome pass time !

Sure, she should judge which one she likes best using her ears and personal judgement. But how will that help her learn something about science and earn her a good science project grade?!

I've not done any search on the 'net, but I suspect there'll be free programs that can analyse mp3 samples (say a G note, or a short riff). Normalise it (same average amplitude) and look for the frequency spectrum -> should provide the relative amounts of harmonics even/odd order, etc. I think they use FFT (or was that reverse FFT? can't remember any more).

There are also sampling 'oscilloscopes' that run off a PC sound card. You can capture a waveform and see the attack and decay (e.g. are there any differences when different strength magnets are used, etc).

Let us know how you go. HTH

EDIT: if you can measure / estimate the resistance, inductance, etc, you can model it using spice/pspice/ltspice and compare theory to actual

Have you tried Audacity? It does spectrograms and its free.

That sounds like a really awesome project by the way. Back in my school days the coolest thing I ever built was a bridge made of popsicle sticks!

I'll check out audacity. Sonic visualiser makes nice looking spectrographs, we just have to figure out how to read/configure them.

Ya Audacity would be perfect for that.
I have a rather old copy, its about two years old and it has a frequency analysis tool. It can only analyze about 30 seconds of a sound file but it does produce a pretty nice looking graph.

Even better, the frequency analyser has an export button that can output a text file with frequency and amplitude for the sound sample. You could create a graph using Excel from that text file that would show show the frequency trends of each pickup in an overlapping fashion for comparrisons. That would probably work the best IMO

All things being equal for pickup placement, and force of a strum I think it would work very nicely to make a point.

I'm using an older version of Audacity but here is a picture of what the freq analyst tool can do. Sorry about my dog.

http://www.tdpri.com/telephoto/data/547/medium/freq.JPG

Here's the text file that you could export and use in Excel.

http://www.tdpri.com/telephoto/data/547/medium/text.JPG

If it was me I'd be interested in demonstrating the frequency response and output of the different windings.

With a Piece of Hardwood, a Bandsaw and an old junk tuner...She might find this useful for Testing ?

http://img.photobucket.com/albums/v234/mellecaster/Business%201/DSCF5498JPG.jpg

I'm using an older version of Audacity but here is a picture of what the freq analyst tool can do. Sorry about my dog.

http://www.tdpri.com/telephoto/data/547/medium/freq.JPG

Here's the text file that you could export and use in Excel.

http://www.tdpri.com/telephoto/data/547/medium/text.JPG

Dog's a bit flat.