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cross delay, Aux tricks, Phase, Stereo Image Enchancement
Old 3rd July 2005
  #1
Lives for gear
 

cross delay, Aux tricks, Phase, Stereo Image Enchancement

I was hoping everyone could share some delay & stereo enchancement tricks.

Does anyone use any phase tricks to make really wide cool sounding delay
or to tweak out the stereo image on a track or the whole mix for a effect here and there?

What hardware or plugin delays are really good?

I watched a video at http://www.sawstudio.com/LiveVideoPromo.htm

BAND SESSION PART II - CREATING THE BASIC MIX (right around after 6 mins)
shows a basic cross delay

What other tricks are there?
Old 4th July 2005
  #2
One with big hooves
 
Jay Kahrs's Avatar
I do that kind of stuff to FX returns or whatever all the time.

The real trick is knowing when to do it and when not to.

If you invert the polarity (which is different then phase) on one side then you'll get a super wide stereo image, but the trade off is that the effect is gone in mono.

Fuk around with it a bit and develop your own tricks, create some new sounds.

One of my favorite hardware delays is the lowly Alesis Midiverb 4. It's dirt cheap, easy to tweak and sounds fairly decent. Granted it's no PCM42 but whuddawant for $200?
Old 4th July 2005
  #3
Gear Nut
 
jakerbean7's Avatar
 

Quote:
Originally Posted by Jay Kahrs
If you invert the polarity (which is different then phase)
Could you explain this, please?
Old 4th July 2005
  #4
Gear Guru
 
u b k's Avatar
 

if you use a stereo delay with the taps set to have 20-100ms difference between them, you'll get a single repeating delay that sounds really wide.

delays and verb are generally the only things panned hard in my mixes. sometimes i tuck percussive stuff or various earcandy out there too. i'm a delay slut, i use it more than verb. but only barely.

i don't own it, but i've used it and the psp42/84 (lexicon emulation) sounds very good, as does the uad1 mod delay.

loud delays can hype up the width, but fx that are tucked way in are what give mixes depth and a more impressive bigness imo. i like to make my mixes "bone wet", or maybe "soaking dry". that's much harder to do ITB than if you have an analog desk or summer.


gregoire
del ubik
Old 4th July 2005
  #5
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doorknocker's Avatar
2 things I often do, these are pretty common techniques I guess:

-Mirror delay return: Say you got two acoustic guitars panned L/R, pan the delays to the opposite end, the delay of the L guitar would be hard R then and vice versa. Works great with delays set to 4th/8th/etc.

- In PT, I often set up two different delays, a 'precise' one set to say 8th notes and a 'diffuse' one that's more like a 'flutter echo'. I use the stock Digi delays for the precise one and the Bomb Factory TelRay for the diffuse one. This often works well for vocals, with the 2 delays spread out but set to 'barely audible'.

I always check the panning, phase, etc in mono on one speaker.

Andi

www.doorknocker.ch
Old 4th July 2005
  #6
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Big 3rd's Avatar
 

Quote:
Originally Posted by Seti808
I was hoping everyone could share some delay & stereo enchancement tricks.

Does anyone use any phase tricks to make really wide cool sounding delay
or to tweak out the stereo image on a track or the whole mix for a effect here and there?

What hardware or plugin delays are really good?

I watched a video at http://www.sawstudio.com/LiveVideoPromo.htm

BAND SESSION PART II - CREATING THE BASIC MIX (right around after 6 mins)
shows a basic cross delay

What other tricks are there?
Hey man, great link, very helpful.
Old 4th July 2005
  #7
One with big hooves
 
Jay Kahrs's Avatar
Quote:
Originally Posted by jakerbean7
Could you explain this, please?
I could but this is way better. http://www.digitalprosound.com/Htm/T...SquareOne1.htm

FWIW...that took about 40 seconds to find in a Google search.

Peace,
Old 4th July 2005
  #8
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audioez's Avatar
 

any autopan on a spx box...whoooo hooo, but tricks are for kids. :(
Old 4th July 2005
  #9
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Darius van H's Avatar
 

Stereo enhancment trick: split your signal into M/S and add distortion just to the S
Old 4th July 2005
  #10
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DrFrankencopter's Avatar
The short answer for how polarity and phase are different is that phase is a function of frequency and polarity is not (i.e. a reverse polarity signal is 180 degrees out of phase at all frequencies).

Cheers,

Kris
Old 4th July 2005
  #11
Gear Nut
 
jakerbean7's Avatar
 

Quote:
Originally Posted by DrFrankencopter
The short answer for how polarity and phase are different is that phase is a function of frequency and polarity is not (i.e. a reverse polarity signal is 180 degrees out of phase at all frequencies).

Cheers,

Kris
I was pretty tired yesterday (stuck in front of the computer in zombie mode) and was somehow reading that he was saying polarity and phase are not related. I do understand the difference. Although I still say they are both functions of time.

Thanks for the replies,

Jake
Old 4th July 2005
  #12
Lives for gear
 

Quote:
Originally Posted by jakerbean7
I was pretty tired yesterday (stuck in front of the computer in zombie mode) and was somehow reading that he was saying polarity and phase are not related. I do understand the difference. Although I still say they are both functions of time.
Literally, polarity reversal is not a function of time; there is no "t" in the mathematical formula (X' = -X), whereas there is for a simple phase shift (X'(t) = X(t+w)).

More generally, polarity reversal is a memoryless process (takes place in zero time, looking at a single amplitude value only) and thus has no time component.

Further, there is no way to achieve polarity reversal as a function of time, except as an infinite number of infinitely narrow bands, each delayed for half a cycle at its individual frequency.

Phase and polarity are essentially unrelated, except in the case of a repeating wave that is symmetric about the zero axis (which, if my rusty math serves, must be made up of only odd harmonics of the fundamental frequency.) This is essentially an accident of symmetry, and something that doesn't happen in real life (which has transients.)

Simple case: imagine a pulse that goes from 0 to 1 and back to zero. A polarity inversion would give you a 0/-1/0 pulse, but you can't get there by doing anything with phase or other time-dependent functions only.
Old 4th July 2005
  #13
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DrFrankencopter's Avatar
Quote:
Although I still say they are both functions of time
No, polarity is time invariant, it's really like a sign convention. pin 2 hot versus pin 3 hot, woofers out versus woofers in. It's constant over frequency (and therfore time).

Polarity is like a subset of phase, it's a special case refering to an either 0 or 180 degree phase shift across all frequencies (including DC).

Cheers,

Kris
Old 4th July 2005
  #14
Lives for gear
 

Quote:
Originally Posted by DrFrankencopter
Polarity is like a subset of phase, it's a special case refering to an either 0 or 180 degree phase shift across all frequencies (including DC).
Polarity isn't a subset of phase, since it is essentially impossible to achieve a frequency-dependent phase shift across all frequencies (and completely impossible to invert DC via phase shift.)

Polarity inversion and phase shift happen to give the same results for an very special set of cases, but this is more or less accidental.
Old 4th July 2005
  #15
Lives for gear
 

cool link about phase and polarity J. Moose thanks!


I need a solid plugin stereo delay!
I hope the roland/uad space echo comes out soon that is going to be the one!


keep the tips and tricks coming guys!
Old 5th July 2005
  #16
Gear Nut
 
jakerbean7's Avatar
 

Quote:
Originally Posted by dkatz42
Polarity isn't a subset of phase, since it is essentially impossible to achieve a frequency-dependent phase shift across all frequencies (and completely impossible to invert DC via phase shift.)

Polarity inversion and phase shift happen to give the same results for an very special set of cases, but this is more or less accidental.
I think this nails it down for me. Thanks!

Jake
Old 5th July 2005
  #17
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max cooper's Avatar
 

Quote:
Originally Posted by jakerbean7
I was pretty tired yesterday (stuck in front of the computer in zombie mode) and was somehow reading that he was saying polarity and phase are not related. I do understand the difference. Although I still say they are both functions of time.

Thanks for the replies,

Jake
Next time you're at your recording rig, flip the polarity of one channel. There won't be any effect with regard to time. Right?
Old 5th July 2005
  #18
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DrFrankencopter's Avatar
Quote:
Polarity isn't a subset of phase, since it is essentially impossible to achieve a frequency-dependent phase shift across all frequencies (and completely impossible to invert DC via phase shift.)
Sure you can invert DC with phase.....it just takes forever!

When I said that polarity is 'like a subset of phase'...what I really mean is that polarity can be defined by phase response, whereas phase cannot be defined by polarity (at least I don't think so). You can easily look at a bode plot and determine the polarity of a system from it's phase response, whereas knowing that two signals are reverse polarity tells you nothing about their individual phase characteristics.

dkatz42 I believe that you are correct in everything you wrote in this thread....however I also think that I'm correct. We're just approaching it from opposite ends. I routinely use phase response to analyze systems, so I approach phase and polarity from an analysis perspective, whereas you seem to have approached it from a signal generation perspective. I've been talking about identifying polarity and phase, and you've been talking about accomplishing it. I've been talking about phase response and you've been talking about phase shift.

At any rate I guess the whole point is that many people use the term 'flip phase' , or 'phase switch' when they should say polarity.

Cheers,

Kris

PS: For a stereo delay trick..to get back on thread topic, try running a 20 ms delay on one side, pitched down 5 cents, and a 40ms delay on the other pitched up 5 cents. Your ear gets pulled to shorter delays and higher pitches, so putting the higher pitch on the longer delay helps keep the overall image centered.
Old 5th July 2005
  #19
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Bob Ross's Avatar
 

Quote:
Originally Posted by Darius van H
Stereo enhancment trick: split your signal into M/S and add distortion just to the S
I've done a similar trick based on the (apparently patented) workings of the Modulation Sciences' StereoMaxx Spatial Image Enlarger: derive sum & difference signals from the desired track or tracks (this even woks on the entire mix), delay the Difference signal by 10 - 30 ms, mix this delayed difference signal back into the left channel & delayed difference signal w/ polarity inverted back into the right channel. Delay time & level will determine how wide things get...and they can get pretty freakin' wide! Plus it's 100% mono compatible, since the effect just cancels itself out completely when collapsed.
Old 5th July 2005
  #20
Lives for gear
 

Quote:
Originally Posted by DrFrankencopter
Sure you can invert DC with phase.....it just takes forever!
Yep, longer than most folks are willing to wait after they push the button...
Quote:
Originally Posted by DrFrankencopter
When I said that polarity is 'like a subset of phase'...what I really mean is that polarity can be defined by phase response, whereas phase cannot be defined by polarity (at least I don't think so). You can easily look at a bode plot and determine the polarity of a system from it's phase response, whereas knowing that two signals are reverse polarity tells you nothing about their individual phase characteristics.
Makes sense, I think. My point was that you cannot practically achieve polarity reversal with phase manipulation, nor the other way around.
Quote:
Originally Posted by DrFrankencopter
dkatz42 I believe that you are correct in everything you wrote in this thread....however I also think that I'm correct. We're just approaching it from opposite ends. I routinely use phase response to analyze systems, so I approach phase and polarity from an analysis perspective, whereas you seem to have approached it from a signal generation perspective. I've been talking about identifying polarity and phase, and you've been talking about accomplishing it. I've been talking about phase response and you've been talking about phase shift.
Agreed. My signal processing background is a bit weak, but with an infinite number of infinitesimals, you can do almost anything, it just takes forever...

My perspective is from the practical side of things, what can be accomplished operationally with reasonable amounts of thrust.
Quote:
Originally Posted by DrFrankencopter
At any rate I guess the whole point is that many people use the term 'flip phase' , or 'phase switch' when they should say polarity.
Exactly.

And thanks for the theoretical perspective.
Old 6th July 2005
  #21
Registered User
 

These is some awesome stuff guys. Lots of stuff I haven't thought of. Keep it going I'm saving this stuff in a word document for future experimentation!

Cheers.
Old 6th July 2005
  #22
Lives for gear
 

Hello,

Could you please elaborate on this method a bit ... ie. what are "sum & difference signals" ? If I am wanting to expand the stereo bus signals ... do you mean just making a copy of the L and R ??

Quote:
Originally Posted by Bob Ross
I've done a similar trick based on the (apparently patented) workings of the Modulation Sciences' StereoMaxx Spatial Image Enlarger: derive sum & difference signals from the desired track or tracks (this even woks on the entire mix), delay the Difference signal by 10 - 30 ms, mix this delayed difference signal back into the left channel & delayed difference signal w/ polarity inverted back into the right channel. Delay time & level will determine how wide things get...and they can get pretty freakin' wide! Plus it's 100% mono compatible, since the effect just cancels itself out completely when collapsed.
Old 6th July 2005
  #23
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Bob Ross's Avatar
 

Quote:
Originally Posted by jlsgear
Could you please elaborate on this method a bit ... ie. what are "sum & difference signals" ? If I am wanting to expand the stereo bus signals ... do you mean just making a copy of the L and R ??

Sum & Difference are similar to the concepts of Mid & Sides in an M/S stereo mic array: Sum is basically Left plus Right; Difference is Left minus Right.

Left + Right is just a fancy way of saying "mono". But Left - Right yields only those signals that are not common to both channels, so for stereo program material it usually consists exclusively of ambience (either real or synthetic) and things containing lots of spacial cues.

You can easily derive Sum & Difference if you have a hardware M/S matrix box, and even if you don't it's pretty easy to cobble together a matrix using a few spare console channels & the polarity reverse switch. (Or by hacking up a couple mic cables.) Input #1 is Left, Input #2 is Right; Output #1 is L+R, output #2 is L-R.

If you want to expand the entire stereo buss signal using this "StereoMaxx" technique, you first assign everything currently going to the Main Stereo 2-mix buss to an unused stereo group or an Aux Send. Patch these new stereo group (or Aux) outputs into the matrix inputs #1 & 2.

Ignore the L+R output of the matrix. Take the L-R output only from the matrix & connect that to a delay set for approx 20ms, 100% effect, no feedback. Patch the output of the delay line to a mult, return two mult outputs to a pair of unused faders which are assigned to the 2-mix buss (but are *not* assigned to that secondary stereo group or Aux Send that you assigned everything else to). Pan one fader hard left, the other hard right, and invert the polarity of one of these faders only.

The amount that you return these faders into the mix, as well as the delay time you've dialed in, will determine the width of the effect. Quite often you can get full program material to sound like it's coming from 10 feet past where your speakers are located!

(Thanks to Eric Small for turning me on to this trick.)

Last edited by Bob Ross; 12th July 2005 at 02:18 PM.. Reason: 'cuz I'm an idiot
Old 6th July 2005
  #24
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any specfic plugin techniques?

Use a some aux sends groups buss etc?
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