Corner Freq. 'Guide"

[petemoore]

159.2  Hz
 I found this number with a 10k and a .1uf at the Lab's Notebook R/C Calculator page, Very nice Page, thank you J. Orman!!
 What I'd like to know is Hertz, what 159.2 of them would sound like...lol...I understand the 6db per octave rolloff, but I have no reference as to what pitch that would sound at... :shock:    
 Then I believe comes Khz...Kilohertz?
 Then what...MegaHertz...at some point were talkin' radio or microwave
 By the By, anyone know of a page that states the frequency of, and plays sine [or other] waves?

[Ansil]

hmm  isn't 80hz the Low E string.    i know i asked this question last year and finally someone i belive jack had the right website lots of other people chimed in but a few were wrong but they had gotten the info from a wrong website.

so in theory it should be around seventh fret on the A string.

[Jason Stout]

What I'd like to know is Hertz, what 159.2 of them would sound like

Pete, I found a nice program which will show you exactly what 159.2, or 16,000 Hz, or 80Hz....sounds like!

http://www.nch.com.au/tonegen/

download the .zip or .exe if you use windows.

[Mike Burgundy]

Be advised that pure sine waves - or sawtooths or block waves for that matter - don't sound like what you'd expect. "Real" sound is a little too complicated for that.
The best way to get a feel for frequencies IMHO is to tinker with a lot of CD's and a 31-band graphic EQ. These are used a lot in live-engineering, where impromptu changes at rather specific frequencies are necessary (think monitors, and that one sound guy who could always kill the feedback before the audience heard it wistle).
My trick  is to memorise ONE frequency (test-channel we have here on the TV - exactly 1kHz) and work from that.
It can be quite surprising to *hear* what a certain frequency band actually sounds like, and often it's not too related to the pure sinewave of the center frequency, at least not to your ears.
Pop-quiz: if you want a bass-drum to *really* kick and go whoomph, what frequency would you boost?
20Hz/31Hz/40Hz/50Hz/63Hz/80Hz/100Hz/125Hz/160Hz/200Hz250Hz/315Hz?
The answer (only pick one, and were talking live band in a, say, 300-people venue with reasonable gear) might surprise you.

[petemoore]

I'll take a stab and say:  315hz

[black mariah]

I'd start around 125Hz and work down from there. That's where my guitar WHOOMPS, so it seems logical. :lol:

I use a 31 band EQ on my guitar. I love it. I'm super picky about certain frequencies, so even a ten band EQ wouldn't cut it for me. I had a really nice 4-band parametric number but it just didn't have the control I need. When you have a 31 band EQ and start putting numbers with frequencies it makes a LOT of difference in how you approach everything. From your effects to your pickups, even to your playing style. The trick is learning all this stuff, but not letting it hurt your head. Otherwise you become Eric Johnson, searching for the perfect battery compartment material for your tone. :lol:

[brett]

Hi.  One hertz (Hz) is one cycle per second (cps).  Up to about 20 Hz and you "feel" the vibration, but above about 40Hz you can definately hear it.

Middle "A" on your guitar (the one two frets up on the G string) is 440Hz. A on the low E string is 220Hz.  A on the high E is 880 Hz.  So you can see that a regular guitar mostly covers about.  200Hz to 2000Hz (2kHz).  

So why do we amplify, filter, etc from 20Hz to 10kHz?  Music quality depends a LOT on undertones and overtones.  Play any string and you'll get harmonics of the string (e.g. 880Hz, 1.76kHz, 2.64kHz).  Play two strings and you'll get their fundamentals plus harmonics plus intermodulation (e.g. two "A"s give something that's not an "A" - 440Hz+ 880Hz = 1.32kHz).  Play 3 strings together and the whole thing gets completely out of control  :wink: .  

Anyway, it's all these high-order interactions that make music rich.  So we need to preserve frequencies up to at least 5kHz and preferably 10 or 15kHz for the sound to be harmonically rich.

I may have some of these ideas mixed up, but I *think* they are basically ok.  cheers

[Greg Moss]

Be advised that pure sine waves - or sawtooths or block waves for that matter - don't sound like what you'd expect. "Real" sound is a little too complicated for that.
The best way to get a feel for frequencies IMHO is to tinker with a lot of CD's and a 31-band graphic EQ. These are used a lot in live-engineering, where impromptu changes at rather specific frequencies are necessary (think monitors, and that one sound guy who could always kill the feedback before the audience heard it wistle).
My trick  is to memorise ONE frequency (test-channel we have here on the TV - exactly 1kHz) and work from that.
It can be quite surprising to *hear* what a certain frequency band actually sounds like, and often it's not too related to the pure sinewave of the center frequency, at least not to your ears.
Pop-quiz: if you want a bass-drum to *really* kick and go whoomph, what frequency would you boost?
20Hz/31Hz/40Hz/50Hz/63Hz/80Hz/100Hz/125Hz/160Hz/200Hz250Hz/315Hz?
The answer (only pick one, and were talking live band in a, say, 300-people venue with reasonable gear) might surprise you.

I'd have to say it would depend on the style of music, the kit and the room.
For more modern rock and metal kinds of sounds I usually go for around the 63-80Hz range.  around 100 for older rock and punk.  125-160 can be very untidy in a lot of rooms.  I think that 200 has a  nice transient in the low end, but often it steps on the lower frequency content of a good full snare drum sound.

Sorry I opted not to pick one. I'm curious to see what your thought are...

Greg

[Mike Burgundy]

you're through for tha washing machine. You all are - I'm thankfull not to see anyone shouting 20! 20! 20! over here - that's what our DJ's often think of as low end...
63 is the real low end bang for rock, if you want boomier sounds you go up to 200Hz although you must be really careful not to get the "boombox" effetc as stated. Metal double kicks can be accentuated at up to 2.5kHz!
Once again, get a 31-band (or a parametric, but a graphic generates more understanding of "where" the frequencies are), stick on a fave CD and tinker to your hearts content. There's no better learning than just doing it and really listening.
Here's another one:
Why does a five-string bass sound *very* good (on low-B too) through a Glockenglang cab that has a 12dB/octave rolloff below 45Hz? The lowB has a fundamental of 31Hz.

[petemoore]

Yupp i just pulled up Media Player, and listened to some 'gutter folk/punk' on the 'EDGE' and the EQ, and yupp, that's a good way to find out what's Nasal mid, high sizzle and bass mud...Probly have to do it a few times before I can assign numbers to the  sounds.

[Mark Hammer]

The thread starts off with the term "corner frequency".  Some clarification is needed about filter frequencies at this point.

When referring to a "corner" frequency, the notion is that frequency response either above or below that point is essentially flat or flattish.  The "corner" can vary in their steepness.

In many, many instances, corner frequency calculations pertain to single-pole filters.  So, for instance, the R/C combination immediately after the clipping stage on a Tube Screamer, or the highpass and lowpass sections on the Big Muff tone control, or the feedback resistor and cap in an op-amp, etc. etc.  These all yield reductions of 6db/octave at the designated corner frequency.

What does that mean?  It means that the amount of level reduction produced continues along at that "rate", both above and below the corner frequency.  If you have a lowpass filter with a 1khz "corner frequency" (what many, including myself would likely call a "rolloff"), the level of a 2khz signal will be 6db lower than whatever things are at 1khz, another 6db down at 4khz, and so on.  

Additionally, things are not flat right out to 1khz either.  Indeed, the corner frequency is simply the point at which the filtering action becomes discernible.  There is some minimal filtering action *below* the corner frequency (in the case of a lowpass filter), and plenty of content is not severely affected *above* the corner frequency.  The farther out from the corner frequency you go (in the direction of its filtering action), the greater the impact.

This is one of the reasons why BBD-based effects use multi-pole filters (often up to 12 stages of lowpass) to assure that the clock signal is WAYYYYYY down in level compared to the audio signal.  It's also one of the reasons why I advocate exploring 2-pole filters for fuzzes, because they do a better job of keeping the fizz out than a single-pole filter with the same or even lower corner frequency.

All of this is separate from, though related to, centre-frequency, which is the aspect of an equalizer or resonant filter for tailoring sound.  Most resonant filter sections used for providing boost and cut also have a 6db/oct slope on either side of the centre frequency.

[jplaudio]

Note frequencies for standard E tuning

1         E = 82.4069      

2         A = 110.0000    

3         D = 146.8324    

4         G = 195.9978    

5         B = 246.9417    

6         e = 329.6277    

159 hz is between a E and E flat ( first and second frets on the D)
440 hz is fifth fret on the high E

A complete list is here:
http://www.phy.mtu.edu/~suits/notefreqs.html
and here:
http://www.techlib.com/reference/musical_note_frequencies.htm

Guitar fundamentals cover four octaves up to 1318Hz on a 24 fret neck.

Most guitar pickups have a resonant frequency between 2000Hz to 5000Hz which emphasizes the overtones.
http://www.buildyourguitar.com/resources/lemme/table.htm

[Hal]

wanna understand it better?  Hook up a function generator to a speaker.  You'll be able to both see and hear what happens at low frequencies, and realize u can start to hear stuff as you move the dial up to about 40 hz.  After that, sweep it up, and see how high you can hear :-D.  Also, listen to the differances between square, sawtooth and sine waves.  

My physics teacher did this as a demo, but also hooked up a string to the speaker, to demonstarate resonance.  Cool stuff.

[brett]

I'm not so sure that our scales ARE based on perfect tonal separation of notes (as per this web site)

and here:
http://www.techlib.com/reference/musical_note_frequencies.htm

Aren't scales CLOSE to equal tones, but ACTUALLY equal temperament?

The equal temperament system evenly distributes tonal discrepancies over the fretboard.

This IS being a bit picky, I know, but trivia is my middle name. :oops:  
cheers

[petemoore]

Multi Pole...hmmm  :?:
 Can you recommend any cool multi-pole filters I might like to try on a Fuzz Box?
  I have a Notch Filter that's real handy 1.

[Mark Hammer]

The most under-your-nose multi-pole filters out there are the cascaded lowpass sections that you find on virtually all the ROG amp simulators.  Those 15k/2n2 sections you see in pairs?  That's what they are: 2-pole lowpass filters.  The intent is to provide something that sounds closer to what such amps might sound like after the transformers and speakers have had their way with the signal.

When it comes to fuzzes and such, 2-pole filters are not necessarily "where it's at", but I will describe their effect as being the difference between planing the edge of a board, and sanding it.  With a single-pole lowpass, like you find on the Rat-style tone control, a certain amount of fizz still gets through, albeit at a much lower amplitude.  With a 6db/octave slope from a single-pole filter you need to start the rolloff much lower in order to achieve significant reduction in those frequencies where the fizz occurs.  If the filter is 2-pole, you can start much higher up and still achieve as much fizz-reduction, because of the steeper action of the filter.  The result is nice definition without the sharp edges.  That's why I liken it to sanding vs planing.  Or maybe the better analogy is the difference between a filed edge and a round edge created with a router, or a low-res image with and without aliasing.  You get the point.

Note that because of the steeper action of a multi-pole filter, the apparent treble loss will be greater for the same corner frequency.  So, if you had a single-pole filter that rolled off around 5khz, you'd have less treble if you simply added another stage of the same filter for a 2-pole unit.  To keep the same bite in a 2-pole version, you'd probably want to bump the corner frequency up a bit.

As a practical example, the 15k/2n2 combos in the ROG amp simulators provide a corner frequency of roughly 4.8khz.  I'm going to say off the top of my head that this filter combo probably appears to deliver as much "bite" as a single pole filter of 15/3n3 with a corner frequency of about 3.2khz simply because the single-pole version lets through more high end by virtue of its shallower filtering action.

Make sense?

[puretube]

that BMPdeLuxe from Stephen got a nice 2p lopass before clipping...

- have a nice trip - I`m leaving tomorrow, also -