what is "farting out"?

pie_man_25 · #1 01-04-2011, 02:34 PM

I've heard the term being tossed around both here, elsewhere on the internet, and from a number of fellow musicians when talking about amplifiers. What does "farting out" or "farting" mean, and what is happening when this happens?

I'm assuming it's when the amp pushes the speakers too hard and they make a farting sound, is this right?

Mo'Phat · #2 01-04-2011, 02:36 PM

How I understand it is it's either when you exceed the mechanical limits of the speaker (it tries to move further than it can), and the sound is awful.

OR, it's when you try to push your amplifier louder than its watts will allow and you have clipping. That clipping results in a sound through the speaker that is awful.

Phalex · #3 01-04-2011, 02:37 PM

It's when you push the amp past it's theoretical limit, and still need more.

Yeah, you nailed it.

Mark Perry · #4 01-04-2011, 03:07 PM

Flatulence.

tsunami1052 · #5 01-04-2011, 03:10 PM

http://en.wikipedia.org/wiki/Farting

sorry it slipped.

NWB · #6 01-04-2011, 03:19 PM

Typically happens after you give your amp some chili.

Ah, couldn't resist...

christw · #7 01-04-2011, 03:25 PM

Quote:

Originally Posted by pie_man_25

I've heard the term being tossed around both here, elsewhere on the internet, and from a number of fellow musicians when talking about amplifiers. What does "farting out" or "farting" mean, and what is happening when this happens?

I'm assuming it's when the amp pushes the speakers too hard and they make a farting sound, is this right?

It isn't a farting sound exactly... Mo'Phat covered the causes. The sound of an amplifier clipping is different than that of a speaker reaching it's xmax but neither are pretty sounds unless of course you like some muddy, dirty blues geetar.

AwkwardLoudness · #8 01-04-2011, 03:50 PM

Quote:

Originally Posted by Mo'Phat

How I understand it is it's either when you exceed the mechanical limits of the speaker (it tries to move further than it can), and the sound is awful.

This is correct. It's when the speaker is pushed beyond its excursion limit...farty sound ensues.

Quote:

Originally Posted by Mo'Phat

OR, it's when you try to push your amplifier louder than its watts will allow and you have clipping. That clipping results in a sound through the speaker that is awful.

I realize that 'farting out' is more of a colloquial than technical term, but to me this not farting out. Clipping is a bad thing only with solid state amps, and sending that nasty clipping transistor signal to the speakers won't necessarily cause the speakers to reach the farty threshold. Tube clipping is generally desirable...if the cab can handle the power without maxing out, though some bassists only like clean sounds.

billfitzmaurice · #9 01-04-2011, 03:59 PM

Quote:

Originally Posted by AwkwardLoudness

This is correct. It's when the speaker is pushed beyond its excursion limit...farty sound ensues.

I realize that 'farting out' is more of a colloquial than technical term, but to me this not farting out. Clipping is a bad thing only with solid state amps, and sending that nasty clipping transistor signal to the speakers won't necessarily cause the speakers to reach the farty threshold. Tube clipping is generally desirable...if the cab can handle the power without maxing out, though some bassists only like clean sounds.

+1. Farting out is caused by over-excursion, and excursion is relative to frequency, so farting out is usually heard only on the lows. If it sounds nasty on the low E but fine from A on up it's farting out. Amp clipping is broadband, and results in the creation of higher than normal levels of harmonics, so it's heard mainly in the mids and higher.

THORRR · #10 01-04-2011, 04:03 PM

Farting is the same as the old school term: BLATTing.

If you're pushing them hard enough to BLATT or FART
you're wrecking them and they will blow out if you continue
it for any length of time. The voice coil will heat up and
melt the insulation = shorting out = dead. And/Or you'll
crack / tear / explode your speaker cone = dead.

see below:

John D · #11 01-04-2011, 04:10 PM

How can you recognize the difference between excessive amp clipping and pushing the speaker beyond its mechanical limits?

billfitzmaurice · #12 01-04-2011, 04:14 PM

Quote:

Originally Posted by John D

How can you recognize the difference between excessive amp clipping and pushing the speaker beyond its mechanical limits?

You read my reply two posts up.

LiquidMidnight · #13 01-04-2011, 04:15 PM

I don't know if this description will make any sense without an example, but amp clipping sounds like a nasty distortion. Speaker overexersuion sounds like a really bad rattle in the cabinet.

John D · #14 01-04-2011, 04:56 PM

Quote:

Originally Posted by billfitzmaurice

You read my reply two posts up.

OK, your response is consistent with everything I know about speakers and amps. However, to believe this I have to believe that a 23 Watt Ampeg SB-12 is capable of overdriving and Emenince Beta 12, 12" 8 OHM speaker rated @ 250 Watts and 4.4 mm XMAS. This puts JimmyM's rant in perspective. By the way, this is with the SB-12 volume at about 10 o'clock and the bass and treble controls at dead noon. Thanks for your input and any additional information you wish to share.

BigOldHarry · #15 01-04-2011, 04:59 PM

Not to be confused with "Mud Fart" which I've always taken to mean "Dull, lifeless, bass-heavy tone"

pie_man_25 · #16 01-04-2011, 05:29 PM

wow, this is all making sense now. So, the speaker has a maximum distance that it can travel - maximum excursion, or XMAX - and if the speaker is driven BEYOND that distance, it rattles against the frame/basket, or whatever it is called that holds the coils, which, if persisted, will likely result in destroying the speaker, by either destroying the cone or melting off the insulation and shorting out the speakers. This is NOT to be confused with the clipping of the amp - which to the extent of my knowledge is what causes distortion, at least when combined with some compression.

I think I've had that happen with a couple cabs I've had -
1) with an old regal amp, and
2) with a 110 practice cab that I have made with a fixed up radioshack speaker

If I put the regal amp past 5, which was the point when it actually started sounding off very much at all, the speaker would make this terrible rattling noise. I then decided to make the 110 cab, which has a slot that fit my warwick 125 watt head. I tried using it a little for band practices, but it wouldn't compete well enough and when pushed loud enough it would also rattle, which is weird because the speaker was rated for 125 watts.

Clammy · #17 01-04-2011, 05:31 PM

Quote:

Originally Posted by BigOldHarry

Not to be confused with "Mud Fart" which I've always taken to mean "Dull, lifeless, bass-heavy tone"

"Mud farts" usually require a change of underwear, too! (sorry, couldn't resist!!!)

Cheers!

billfitzmaurice · #18 01-04-2011, 05:47 PM

Quote:

Originally Posted by John D

OK, your response is consistent with everything I know about speakers and amps. However, to believe this I have to believe that a 23 Watt Ampeg SB-12 is capable of overdriving and Emenince Beta 12, 12" 8 OHM speaker rated @ 250 Watts and 4.4 mm XMAS.

No, it won't. If you hear clipping of a 23 watt amp into a Beta 12 it's from the amp, not the driver.
But that's not the source of Jimmy's rant. His beef is about 1000 watt rated speakers that will fart out at 400 watts, and 106dB SPL ratings that are impossible to achieve.

ubersku · #19 01-04-2011, 05:55 PM

Can't help it...

Come to one of our rehearsals and it will give you the true sense of the word. Yes, pun intended.

John D · #20 01-04-2011, 07:22 PM

Quote:

Originally Posted by billfitzmaurice

No, it won't. If you hear clipping of a 23 watt amp into a Beta 12 it's from the amp, not the driver.
But that's not the source of Jimmy's rant. His beef is about 1000 watt rated speakers that will fart out at 400 watts, and 106dB SPL ratings that are impossible to achieve.

Sorry Bill, but now I am really confused. Earlier you said, "Farting out is caused by over-excursion, and excursion is relative to frequency, so farting out is usually heard only on the lows. If it sounds nasty on the low E but fine from A on up it's farting out. Amp clipping is broadband, and results in the creation of higher than normal levels of harmonics, so it's heard mainly in the mids and higher.

Now, you say, "If you hear clipping of a 23 watt amp into a Beta 12 it's from the amp, not the driver."

I'm not trying to be a smart Alex; I'm really looking for some help here. My amp is only distorting on the lowest notes on the E string (~E - A). Above that I just get normal tube compression/overdrive.

Sorry if I misunderstood JimmyM's rant, but I thought it was about speakers not being able to handle the advertised power ratings, which based on your earlier post seemed to be what I was experiencing.