audio schematics for filters to isolate fundamental or harmo

Guest
I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

Does anyone know if schematics for these devices (the simpler the
better) are available online?

Thanks...
 
<mad.scientist.jr@gmail.com> wrote in message
news:1186067946.526402.178780@g12g2000prg.googlegroups.com...
I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
Click to expand...
You're playing only one note at a time, then?

2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

1. Low pass (tracking) to take all the high off
Click to expand...
2. High pass (tracking) to take the low off

(Tracking filters because of the possible range of notes you can get from a
guitar covers about 4 octaves).

Does anyone know if schematics for these devices (the simpler the
better) are available online?

Not me. I suppose I could Google.
Click to expand...
 
<mad.scientist.jr@gmail.com> wrote in message
news:1186067946.526402.178780@g12g2000prg.googlegroups.com...
I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

Does anyone know if schematics for these devices (the simpler the
better) are available online?

Thanks...
Click to expand...
http://www.amazon.com/Active-Filter-Cookbook-Second-LANCASTER/dp/075062986X

Bob
 
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?
Click to expand...
A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | http://myspace.com/mytriplethreatband
 
"Todd H" <bmiawmb@toddh.net> wrote in message
news:848x8t4wxv.fsf@ripco.com...
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ |
http://myspace.com/mytriplethreatband
Click to expand...
Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.


Bob
 
sycochkn wrote:

"Todd H" <bmiawmb@toddh.net> wrote
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.


Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.
Click to expand...
You clearly didn't understand the application wrt guitars.

Graham
 
Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?




On Aug 2, 3:04 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:
sycochkn wrote:
"Todd H" <bmia...@toddh.net> wrote
mad.scientist...@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.

Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.

You clearly didn't understand the application wrt guitars.

Graham
Click to expand...
 
What if it was just for one note (guitar string) at a time?

On Aug 2, 2:23 pm, Todd H <bmia...@toddh.net> wrote:
mad.scientist...@gmail.com writes:
I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / |http://www.toddh.net/
X Promoting good netiquette |http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/|http://myspace.com/mytriplethreatband
Click to expand...
 
"sycochkn" <sycochkn@earthlink.net> writes:

"Todd H" <bmiawmb@toddh.net> wrote in message
news:848x8t4wxv.fsf@ripco.com...
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ |
http://myspace.com/mytriplethreatband

Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.
Click to expand...
I love analog filters when they're appropriate solutions to the
requirements.

Now, if you have an analog filter that'll satisfy these requirements,
write it up in dissertation form, take a few classes, and a Ph.D. in
Electrical Engineering is well within your grasp. Otherwise, I'll
simply suggest that the requirements as stated are somewhere between
"ill suited to analog" and "provably impossible in analog."

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | http://myspace.com/mytriplethreatband
 
mad.scientist.jr@gmail.com wrote:

Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?
Click to expand...
One string doesn't mean one frequency.

So no.

Graham
 
Todd H wrote:

"sycochkn" <sycochkn@earthlink.net> writes:
"Todd H" <bmiawmb@toddh.net> wrote
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.


Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.

I love analog filters when they're appropriate solutions to the
requirements.

Now, if you have an analog filter that'll satisfy these requirements,
write it up in dissertation form, take a few classes, and a Ph.D. in
Electrical Engineering is well within your grasp. Otherwise, I'll
simply suggest that the requirements as stated are somewhere between
"ill suited to analog" and "provably impossible in analog."
Click to expand...
Pretty damn hairy even in DSP.

Graham
 
mad.scientist.jr@gmail.com writes:

What if it was just for one note (guitar string) at a time?
Click to expand...
Same answer unless you isolate it to a single tone from that guitar
string, which knocks out teh time-varying nature of it. If you get
down ato a singel note, you can notch filter the hell out of
somethign to try to remove the fundamental. And a low pass filter
from hell could try to preserve the fundamental and kill everything
else.

But playing a single note just isn't terribly musical.

--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | http://myspace.com/mytriplethreatband
 
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:46B2A18E.95EBAD0F@hotmail.com...
mad.scientist.jr@gmail.com wrote:

Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?

One string doesn't mean one frequency.

So no.

Graham
Click to expand...
Band stop filter removes the fundamental, Band pass filter removes the
harmonics. Q and band width determines how much. The filter suggested does
either. You would need one for each string. You would need to combine the
signals in a simple mixer circuit.

Bob
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> writes:

Todd H wrote:

"sycochkn" <sycochkn@earthlink.net> writes:
"Todd H" <bmiawmb@toddh.net> wrote
mad.scientist.jr@gmail.com writes:

I am looking to build one or more filters that would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

A time-varying non-linear one, best I can tell.

You'll need DSP for this to have reasonable success. The math you're
trying to emulate is quite non-trivial.


Do you have something against analog filters. The filters in the book I
suggested are quite stable inexpensive and not too complicated.

I love analog filters when they're appropriate solutions to the
requirements.

Now, if you have an analog filter that'll satisfy these requirements,
write it up in dissertation form, take a few classes, and a Ph.D. in
Electrical Engineering is well within your grasp. Otherwise, I'll
simply suggest that the requirements as stated are somewhere between
"ill suited to analog" and "provably impossible in analog."

Pretty damn hairy even in DSP.
Click to expand...
Amen.

--

--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | http://myspace.com/mytriplethreatband
 
On Thu, 02 Aug 2007 20:18:21 -0000, mad.scientist.jr@gmail.com wrote:

Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?
Click to expand...
The problem is that if you want to remove the harmonics well,
you need a very sharp filter. If you had only a single note,
you would tune the filter to put the cutoff just above the
fundamental, so the 2nd harmonic would be well attenuated.
You could select a suitable filter by consulting a filter design
book, which shows the responses of various filter types and
orders (at roughly 2 orders per op-amp stage). What you would
quickly discover is that a really sharp cutoff requires a lot of
stages, and the values of their components have to be really
close tolerance.

But that's for a single, fixed-fundamental note. If you play another
note into that same filter, the alignment won't be correct: If the
new note is a bit lower, its 2nd harmonic will now fall in the
passband of the filter. If the new note is higher, the fundamental
will fall in the stopband.

Don't bother to think about trying to make the filter adjustable
to somehow track the note being played: Such a many-stage
filter with lots of critical components is really tough to adjust
dynamically, but that's not the problem... it's figuring out
what the fundamental is that you want to tune it to! This
is called "pitch tracking" and it is a non-trivial problem.
It's especially difficult for plucked strings like a guitar
because the "2nd harmonic" is not exactly twice the
fundamental, but moves around as the note attacks and
decays. That means that the 2nd harmonic sort of
"rolls through" the fundamental waveform, so simple
schemes that look at waveform zero crossings get really
confused.

Perhaps if you explain what your ultimate goal is, we
can give better suggestions. But basically, you will need
to use digital methods if you are serious about pitch
extraction, and even then this is just "borderline" possible.

Best regards,



Bob Masta

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Signal Generator
Science with your sound card!
 
"Bob Masta" <NoSpam@daqarta.com> wrote in message
news:46b3158a.672278@news.sysmatrix.net...
On Thu, 02 Aug 2007 20:18:21 -0000, mad.scientist.jr@gmail.com wrote:

Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?


The problem is that if you want to remove the harmonics well,
you need a very sharp filter. If you had only a single note,
you would tune the filter to put the cutoff just above the
fundamental, so the 2nd harmonic would be well attenuated.
You could select a suitable filter by consulting a filter design
book, which shows the responses of various filter types and
orders (at roughly 2 orders per op-amp stage). What you would
quickly discover is that a really sharp cutoff requires a lot of
stages, and the values of their components have to be really
close tolerance.

But that's for a single, fixed-fundamental note. If you play another
note into that same filter, the alignment won't be correct: If the
new note is a bit lower, its 2nd harmonic will now fall in the
passband of the filter. If the new note is higher, the fundamental
will fall in the stopband.

Don't bother to think about trying to make the filter adjustable
to somehow track the note being played: Such a many-stage
filter with lots of critical components is really tough to adjust
dynamically, but that's not the problem... it's figuring out
what the fundamental is that you want to tune it to! This
is called "pitch tracking" and it is a non-trivial problem.
It's especially difficult for plucked strings like a guitar
because the "2nd harmonic" is not exactly twice the
fundamental, but moves around as the note attacks and
decays. That means that the 2nd harmonic sort of
"rolls through" the fundamental waveform, so simple
schemes that look at waveform zero crossings get really
confused.

Perhaps if you explain what your ultimate goal is, we
can give better suggestions. But basically, you will need
to use digital methods if you are serious about pitch
extraction, and even then this is just "borderline" possible.

Best regards,



Bob Masta

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Signal Generator
Science with your sound card!
Click to expand...
I think the OP lilkes to play a bit with electronic music applications. It
would not be that difficult to make a filter for each string, with a midi
pickup. Getting satisfactory results with a normal pickup would probably be
very difficult. moderate attenuation of the fundamental or harmonics is
probably all he wants to do. The OP has been messing around with preamps a
bit.

Bob
 
sycochkn wrote:

"Eeyore" wrote
mad.scientist.jr@gmail.com wrote:

Thanks to everyone for your replies.

To clarify, the signal would only be from one string.
Would that make it easier to build (such with an analog filter) ?

One string doesn't mean one frequency.

So no.

Band stop filter removes the fundamental, Band pass filter removes the
harmonics. Q and band width determines how much. The filter suggested does
either. You would need one for each string. You would need to combine the
signals in a simple mixer circuit.
Click to expand...
You don't know much about musical instruments do you ?

A single guitar string produces many notes.

Graham
 
mad.scientist.jr@gmail.com wrote:

What if it was just for one note (guitar string) at a time?
Click to expand...
A guitar string produces many notes.

Graham
 
On Aug 2, 7:19 pm, mad.scientist...@gmail.com wrote:
I am looking to build one or morefiltersthat would

1. isolate an electric guitar tone's fundamental tone (ie filter out
the harmonic overtones)
2. isolate an electric guitar's harmonic overtones (ie remove the
fundamental tone)

What kind of filter(s) would I be looking for?

Does anyone know if schematics for these devices (the simpler the
better) are available online?

Thanks...
Click to expand...
 
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