Flanger vs Phaser

[Josemitejam]

Hi Y'all,


As I'm preparing to build both an Electric Mistress and then ultimately the Flange with No Name, I'm reading a lot into flangers and listening to a lot of different pedals. I've noticed that there are quite a few ways that the difference between flangers and phasers is, or can be, explained...which sort of drives me crazy.... Some times the video/article is not wanting to go too in-depth for the sake of maintaining their audience's attention, therefore getting information that I can never seem to completely and totally verify with another video/article.

I would love to see this thread where members here can post:


1. A technical description

or

2. A poetic/metaphorical description


...whatever you think can best get the idea across!


This is probably the description that has made the most sense to me so far, although I don't know for certain if it is entirely accurate or not. It was posted as a comment under a "That Pedal Show" episode called "Six Awesome Flangers Compared". Here it is:



"For those still confused about flanging vs phasing:

Flanging (and chorus, slapback and longer delays) is a full-frequency delay, where all elements of the guitar signal are delayed by the same amount.  The delayed signal is then overlaid on the original dry signal.  Flanging is the shortest delay, and results in severe cancellations of most of the original guitar signal across the full frequency range, leaving a heavily comb-filtered resulting signal.  That super-short delay time is then modulated to give the impression of movement in the flanged sound.

Chorus is a longer delay, which results in less-severe comb-filtering and retains the movement effect from modulating the delay time.  Longer delays reach a critical minimum at which your ear/brain can just perceive two distinct sounds; just before/at this point is "doubletracking" and just after is the shortest slapback delay.

Phasing is frequency-dependent delay. Only a narrow band of frequencies gets mixed with the original signal at the right phase to be cancelled.  So rather than the mostly-cancelled (with a few narrow bands remaining) sound of flanging, phasing retains the full wide-range sound with a single notch of cancelled frequencies.  That notch is then moved around to give the impression of movement.  More stages of phasing  yield additional notches, and perhaps a more complex sound.

The above was heard in the video in the way the phaser retained the lows and much more of the overall guitar sound, while the flanger could sound like a very narrow filtered band of remaining guitar sound.

The differences in the sound are all about the electronic methods used to create the different effects."



And here's another from Wampler:



https://www.wamplerpedals.com/blog/talking-about-gear/2019/03/what-is-the-difference-between-chorus-flanger-and-phaser/



I'd love to hear your description of it! And perhaps this thread can one day be used by someone as confused and curious as I am right now to sort through some great answers, one of which will "click", I'm sure.

[Mark Hammer]

I realize many people will say that the biggest difference between phasers and flangers is that the number of notches produced in a phaser remains constant (e.g., 4 stages gets you 2 notches), while the number of notches in a flanger gets larger and smaller.  Actually, the number of notches and peaks in a flanger remains fairly constant - infinite - but appears to get larger and smaller as more and fewer of them fall within hearing range and what the signal source and amplification can reproduce.  I once had a 24-stage phaser demonstrated for me (twelve notches!), and using white noise as a signal source it sounded VERY flanger-like, largely because as it started to sweep downward, more and more of the notches and peaks created fell within a range where they could actually be heard.

So, with that out of the way, and setting sheer number of audible notches aside, one of the major differences is that the spacing of notches in a phaser remains constant, while they get squished closer together in a flanger as it sweeps downward (i.e., towards the maximum delay time), and spread farther apart as it sweeps upwards towards the shortest delay time.  The net effect of this - both the apparent change in number of notches and peaks, and their squishing together - is that the signal is perceived as gradually getting "infected".

Having said that, there is a range of delay times where flanging and chorus overlap.  Some flangers can be made to "sound like" chorus pedals, and a little bit of tweaking will make a chorus sound sort of flanger-like.  As time delay changes, not only does the location of the notches change, but also the change in pitch arising from modulating change in delay time.  At the very short delay times, and very slow sweeps, of flangers, our attention is focussed on the comb filtering produced, and the pitch change is almost imperceptible.  As the range of delay times gets longer, and modulation speeds faster, our perception tends to shift to both the pitch deviations and the lag between clean and delayed versions of the signal.  A chorus is still producing comb-filtering; it's just not what we're noticing most.

At one level, it seems funny that a simple shift of a few milliseconds yields such a larger change in our perception.  But at another level, not really.  Consider the human face.  Move a person's eyes 5mm further out from their nose, or move their upper lip 5mm further down from the tip of their nose, and their face takes on a fundamentally different character to us and makes it easy to distinguish in a police lineup.  Flangers and choruses exploit how our perception is drawn to this or that characteristic with only very small shifts.

But back to phasers.  All Uni-vibes and clones are also phasers.  However, where phasers produce very focussed deep cancellation and obvious notches that grab our attention, vibes produce a broad shallow "dip".  As such, the location of the dip does not attract our attention nearly as much as its movement.  Most phasers will have Rate controls that allow them to sweep very slowly.  In contrast, vibes NEVER sweep as slow as phasers do, simply because if they did you wouldn't be able to hear the effect.  They need to be move about at some minimum speed for us to perceive the effect.  Phasers draw so much attention to the current location of the notch (aided and abetted by hiking up the resonance/emphasis), that one could probably invoke something like the "Filter Matrix" setting (i.e., manual tuning of notch location) from an Electric Mistress on pretty much any phaser and be able to hear changes to location, where doing so on a vibe would be largely inaudible.  You will also never find a Resonance/Feedback/Emphasis control on a vibe, because wide and shallow dips don't lend themselves to emphasis nearly as much as focussed notches do.  And many players prefer vibes over phasers primarily because they do not draw attention to "where are the notches and peaks now?", but simply makes things sound more "animated" in a non-specific way.

Once again, a simple matter of how our attention to different sound qualities is directed by what is most readily audible.

[Digital Larry]

the spacing of notches in a phaser remains constant,

I have never heard that, or if I did, it went over my head.

One other aspect of flangers that makes them distinct is that the upper notches/peaks are at integer multiples of the lowest notch/peak.  For most musical sounds that consist of a fundamental with harmonically related overtones, the flanger can enhance or nearly fully cancel any single note that comes through whose overtones match this.  You'll hear this if you set a flanger for zero sweep and use a distorted guitar tone.  Play notes up and down - some of them almost completely disappear.  Or, just play one note and let the flanger sweep over it.

There is also the possibility of creating a "through-zero" flanger, which in the DSP world you make by sending your dry signal through a short fixed delay before mixing it with the (inverted) modulated delay.  At the point where the two delay times match, but the signals are 180 degrees off from each other, the entire signal gets canceled.  Think "Life in the Fast Lane" for a well known example of this type of sound (which was probably created the old fashioned way during mixing with two tape recorders, but that's not practical in this day and age).

[garcho]

Some non-technical observations:

I would put money on chorus being the most used and flanger being the least used, in terms of how often you hear it, and how much artists use it within a song itself. I would say phaser is right in the middle.
In my opinion, chorus is the least unnatural sounding, flanger is the most unnatural sounding. Funny, as flanging originally comes from mechanical action, which strikes me as something a human would consider "natural" sounding, like an acoustic instrument. Again, I would say phaser is in the middle of the two.
I can think of a couple styles of music that chorus is ever-present in, I can think of an entire region of Earth that loves putting phaser on anything with strings, but I can't think of any examples for flanger.

I think rock and roll peeps are drawn to phaser and flanger at a young age because those names sound cool, whereas chorus doesn't sound cool at all. Imagine being 16 and seeing a rack of pedals at Guitar Center, you only have money for one. Are you going to get the actually useful pedal called "C-1"? Or are you going to get the psychosaurus freakfactory extravagantastic phaser bomb? So the phaser comes home. After getting a bunch of out of control airplane swooshing and laser beam warble, and dirty looks from bandmates, it's set aside and forgotten about. Maybe that disappointment prevents more guitarists from discovering how they want to use flanger and phaser to make music, instead of sound effects.

As far as the other extreme is concerned - more experimental weird music - what is lacking from most mod pedals (until recently) was interesting LFO and envelope control. Listening to a triangle sweep of resonant flanging over and over and over for minutes at a time is neither compelling nor experimental, it's just kind of annoying.

[Digital Larry]

As far as the other extreme is concerned - more experimental weird music - what is lacking from most mod pedals (until recently) was interesting LFO and envelope control. Listening to a triangle sweep of resonant flanging over and over and over for minutes at a time is neither compelling nor experimental, it's just kind of annoying.

One interesting sound I put together with SpinCAD a few years back was a stereo flanger where the LFO was a sample/hold set to change every few seconds with some smoothing on the output.  The end result is that the LFO wasn't always moving, but every few seconds you'd perceive some sweeping and the stereo image would change.

[Mark Hammer]

Interesting comment, gary, and probably close to the truth.  I suspect one of the reasons why phasers are more popular and widely used than flangers is because, compared to the recorded tracks that motivated us to want a flanger, the real thing tends to disappoint.

Why is that?  I'll say it's because the classic recordings  that made you turn around quickly and ask "What WAS that?" applied flanging to mixed-down tracks, often including drums.  Blending multiple instruments/sources together provides greater coverage of the audio spectrum.  Once again, I'll invoke the principle that there has to be some sort of content for the increase and decrease in number of notches to be audible.  And having multiple instruments exposed to the same master comb-filtering does that  One can certainly hear the flanging effect applied to a single undistorted guitar or bass, but it never seems as dramatic as you hoped it would be, based on "recording X".  And that's relatively true whether it is "normal" pedal-flanging, like a Boss BF-2, or something that is able to achieve through-zero flanging.  Heavily distorted guitar - which provides lots more harmonic content - begins to yield a bit of the same pleasure of flanging that a mix-down track does.

In contrast, it takes MUCH less spectral content for phasing to be obvious.  You can stick it on a Hofner "Beatle bass" with the muting pad on, and it still sounds great.  A phaser may not end up meshing with one's style, or what a song wants, but it's never a disappointment compared to the recording that made you interested in one, the way that a flanger can be a disappointment.

I think it is also fair to say that it is easy to get bad sounds from a full-featured flanger, when the controls are set wrong, but harder to do so with a phaser.  MY first flanger was a PAiA Phlanger.  It used a Reticon SAD-1024 and had five controls, including one for mixing wet and dry, in addition to control-voltage inputs.  Some great sounds, but set those controls the wrong way, and you're thinking "Why did I waste my time and money on this?".  In contrast, one of the all-time best-selling phasers (as well as its many clones) has ONE control...and people love it.  In some respects, the ability to get everything you wanted out of it with one knob made people like it.  Compare this to former forum regular Ton Barmentloo's Flanger Hoax pedal for EHX (I traded notes with Ton recently.  Happy to report he's alive and well.) that SHOULD have been a world leader, given the sonic possibilities it provides, but has vanished into the mist because it is just too complicated for the folks who find one speed knob on a Phase 90 perfect.

[idy]

At first read I thought "well, that's been answered a thousand times" and then people go and answer it better.

By putting a name and description to "Flanger Disapointment Syndrome" Hammer has hit the nail on the zero point and drawn back the curtain on one of youth's mysteries.

It's not tape flange, which is in turn the most garish effect in the arsenal of the 20th century producers. I never thought about the application to an entire track as opposed to just the guitar.

Through zero is the magic moment, and all the explanantions of the old school tape manipulation miss what I think is essential; the second tape machine has to be set slightly faster than the main unit. With the finger's drag, the speed begins at unity. With more pressure the speed sags. The listener feels the "ghost" slipping away into the past, then just when it's about to melt away or separate into an echo the direction changes and it begins to catch up. And then just when the brain tells us we're back to normal the "delayed" signal begins to go faster... arriving before then source... breaking the time space continium in an impossible explosion of freedom. Mind blowing.

And this is done not in a mechanical wave, but to follow the drama of the source, breaking free at climaxes. Whereas the flanger pedal as just a thing that goes whoosh whoosh, or sproing sproing. 

[PRR]

...flanging originally comes from mechanical action, which strikes me as something a human would consider "natural" sounding, like an acoustic instrument. .....

Flanging, as originally implemented, is putting two *identical* tracks side-by-side, and shifting them through time against each other.

Until we become Time Lords, this is not "natural". How much of our life could be different if we could slide events against each other? I'm sitting waiting on a callback from the Vet; with Time Lord power I'd just shift that event into the Now.

Chorus is, as implied, multiple voices semi-together. (If natural voices, "together" is never exact; if using the *same* voice to "chorus" we need to shift it a bit so it is not just an overstrike.)

[garcho]

I meant I would assume that an effect achieved mechanically would have more in common with acoustic sound sources, but in this case it achieves the opposite. Tape machines and recorded sound are electronic as well, and probably most importantly, so I suppose it was a poor example of a moot point 

[12Bass]

Flanged strings sound awesome, IMO... those high overtones are an excellent application for a through-zero sweep.  I also really like the sound of a flanged full mix.  But then, I tend to prefer a high (near-zero), slow, sweep with minimal regeneration, for a natural swoosh to infinity and back.  At longer delay times, a flanger is essentially just a chorus pedal, though chorus pedals generally lack regeneration.  I'll echo that more complex designs like the A/DA Flanger provide so much adjustment range that relatively few combinations are pleasant, with some being downright obnoxious... sometimes in the best way possible!

[StephenGiles]

PRR I hope your animal (dog?) is OK, our greyhound has a very slow healing leg ulcer which has meant weekly visits to our vet since late January for inspection and dressing change!

Thanks for all the fascinating posts above. Having been woken up at 5.30am by early starters and very noisy dustmen, reading this thread has really woken me up even more and got me thinking. An experiment I want to try is this - put Adobe Audition or similar on 2 PCs, feed identical signal into both, then play with speed change option on one PC (I can't remember what they call it), mix outputs and see what happens.

The function is called Automatic Pitch Correction, which can also be found in Audacity (free).

[Mark Hammer]

While, in theory, "mechanical" and entirely electronic flanging ought to be identical, in practice they can sound different, simply because one's hand is not an LFO.  So the resulting comb-filtering will be the same, but the feel will be different.

This unit, IIRC, was purportedly one of Frank Zappa's secret weapons for his"pillowy" sound.  From what I understand, used in tandem with envelope-following.  Note the external/internal switch for delay-time modulating control-voltage.

[ElectricDruid]

Nice unit, with a lot of options. I like the symmetry control on the LFO, and then a Range switch so it goes from super-slow to really fast. And 1V/Oct CV input too! So you can feed your analog sequencer into it, or anything out of your modular!

[Mark Hammer]

Although pretty much everything it does in the way of producing echoes can be duplicated by a 50-cent PT2399, one of the things I like about my old blue rackmount MXR Digital Delay is that it has expression-pedal control, positive and negative feedback, and an LFO range function that will get you modulation speeds up to 1000hz for quasi-ring-modulator sounds.

[Digital Larry]

While I can't say that Frank Zappa did not use the flanger in question, I do recall the "pillowy" remark being made about the Micmix dynaflanger.  I recently got a line6 HX Effects which includes the "Dynamix Flanger" patch.  It's also marked as a "line6 Original" which it clearly is not.

Some recent discussions:
https://line6.com/support/topic/49148-dynamix-flanger-help/

an older blog post from one of the designers, including schematic and block diagram:
https://dynaflanger.com/forum/php/viewtopic.php?f=12&t=612

I think you could cram that into 5 or 6 1590BBs!

Also, to cut to the chase, the most outrageous example of this effect in use that I could find, starts about 1:30-
https://www.youtube.com/watch?v=lFXVEo0G6Mk

[edit] - I should add that the lyrics which are pre - 1:30 are NSFW and may cause some distress.  It seems like sort of a companion piece to the Who's "A Quick One While He's Away".

[Mark Hammer]

You may be correct, although I believe the Micmix and Wasatch were both out around the same time.  Given that the Dynaflange has the envelope follower function built in, rather than provided by an external device, I'm inclined to go with your assertion.  Of course, the Wasatch might have been used for some things it was good at, and the Dynaflange used for anything demanding a "pillowy" quality.

And great example, by the way.  Inspiring.  Thanks.

I should add that I know of no phasing unit that includes similar functions as the Dynaflange.

[Digital Larry]

See: https://www.afka.net/Articles/1983-02_Guitar_Player.htm search for "flanger".

For the solo which has the three digital delays, check the end of this piece.  I mean check the whole thing, but the crazy thing with the delays is right at the end.  I only hear two of them to be honest, but who knows what happened a few seconds later?

https://www.youtube.com/watch?v=blRdi-EQw_Q

Wild feedback and whammy bar, not to mention Frank's exploration of exotic sounding modes.

I think Pigtronix has/had a phaser with envelope features.  Also, Craig Anderton's book that I had in college had an example of an envelope triggered phaser on the little plastic record that I LOVED and have sought to recreate whichever way.

[anotherjim]

A thing about phasors is that the wet/dry mix is often acting on the same "sound". Delay based effects are mixing progressively later versions of the dry sound which with musical sounds are not very often identical in frequency content over time. In other words, a partial won't cancel if it's no longer present in the same amount in the dry signal as it was in the delayed sound. From a guitar, the partials decay rapidly into the sustain phase.

[garcho]

^ Yeah, I suppose it's just the quality of the effect that's responsible for why phasers get grouped with chorus and flanger. Maybe being the "odd man out" in terms of filters - the all-pass - is not just a coincidence. Vibrato seems like a half-sister to the modulation family. Tremolo is more like a cousin.

[Mark Hammer]

See: https://www.afka.net/Articles/1983-02_Guitar_Player.htm search for "flanger".

For the solo which has the three digital delays, check the end of this piece.  I mean check the whole thing, but the crazy thing with the delays is right at the end.  I only hear two of them to be honest, but who knows what happened a few seconds later?

https://www.youtube.com/watch?v=blRdi-EQw_Q

Wild feedback and whammy bar, not to mention Frank's exploration of exotic sounding modes.

I think Pigtronix has/had a phaser with envelope features.  Also, Craig Anderton's book that I had in college had an example of an envelope triggered phaser on the little plastic record that I LOVED and have sought to recreate whichever way.

1) Thanks for that interview link.  I thought I had read all of them in GP but somehow either I missed this one, had forgotten its content, or only part of it was originally printed.  It IS rather lengthy for a GP piece.
2) Yeah, I hear only two as well, although I'm listening through the tiny speakers in my monitor, not "real" speaker cabs.
3) Thanks for reminding me about the Pigtronix unit.  You're right.  That said, it's pretty unique in that regard (i.e., use of envelope).