Fader 8- can you give me a subjective explanation expander?

[Morerecords]

Well, you're the man in the know, I rarely use them, except with a sidechain for special effects, but I have never really "interalized" the use of expander, what I mean is- I never think to myslef "that will sound great with an expander on it"

 

Anyway, I could use some insights, if you have any you want to sahre. Yours will probably be more traditional, which I plan to grasp and then immediately abuse while making techno records....

Thanks in advance

MR

[vagrantmuse]

Hmm, I'm not Fader-8...think I can contribute?

 

An expander can be thought of like a "reverse-compressor." While a compressor strives to make the loud sounds softer and the soft sounds louder, an expander makes the soft sounds softer and the loud sounds louder. The controls are similar, but must be thought of in reverse.

 

Here is a scenario: You've recorded an acoustic guitar track, but between phrases, you can hear the HVAC in the background. The gaps are too short, so a gate sounds abrupt and unrealistic. Using an expander, you can set a threshold, after which the volume is severely ramped downward, but in a smoother manner than cutting off the signal completely. Or, to think of it conversely, it will increase the volume of the guitar signal, thereby reducing the noise floor.

 

So, in one more set of terms, a compressor limits the dynamic range of a signal, while an expander aims to increase it's dynamic range. Hope this helps. Cheers

[ski]

I had a conversation with fader8 about this on the phone recently. I think I get it but I haven't fully internalized it yet either (sorry fader8, it's not your fault -- I suffer from expander-stoopit-itis). But one thing about your explanation jumped out at me. If you could please help me understand...

 

You said "an expander makes the soft sounds softer and the loud sounds louder". Does it actually amplify the louder portion? Or does it pass the "loud" portion at unity and lower the volume of the softer portion proportionately?

[prjkt]

where a compresser reduces the sound level above a certain point, an expander reduces the level below a certain point, and extreme example of this would be a gate, where sound is muted when it's level is below a certain point

 

hope that helps

[Morerecords]

I would like to know some of the uses for expansion from the 60's/70's guys, usually once I understand their intentions with regards to engineering, I can take what I need from it, and then apply it to contemporary applications.

 

I know expansion was used ona lot of snare drums, so that would give me the idea that expansion could be used on "snappier" sounds, or, I have never heard of expansion on a bassline... Usually that means I would try it, but for the most part, I am just not lyrical about using expansion yet, and I would like to be...I can and will make my own rulkes, but I would like a starting point....

[fader8]

Yours will probably be more traditional, which I plan to grasp and then immediately abuse

 

LOL! That's the story of my life. Grasped and abused! OK MR, as long as this doesn't turn into another one of those long rambling hypothetical tome threads!

 

First, it's best to confine it to upward expansion, which is what the Logic expander is. The basic concept is dead simple. Any signal, eg transient, etc., that is higher than the threshold setting, will have its gain multiplied in proportion to the ratio setting.

 

So effectively, as vagrant pointed out, the loud stuff gets louder. The Logic expander defaults with auto-gain enabled, so shut that off. With auto-gain, it just sounds like the softer sounds get quieter, which is not what the expander is actually doing, per se. In some ways, expanders and gates are very similar which is why they're often built into the same plug-in, but an expander, (in its simplest form like the Logic one) has much different uses.

 

In mixing, it's very useful when you want to give something a push. Say I've got a nice gentle rhodes humming along but when I get to the bridge, I've got a few snare pops. Routing the snare to the rhodes expander's sidechain can make the rhodes "sing along" with the snare, ie the snare hits, pushes up the rhodes which then decays nicely back down based on your expanders release settings. 80-150mS might be nice for that. If you want the snare to punch through a bit more, delay the onset of the expander by adding 15-20mS attack time. Very common for kick and bass too. I tend to think that Fusion, as a genre, may not have ever existed without the expander, LOL!

 

One cool technique for techno, trance, etc., on an arpeg'd synth, is to parallel process through an expander to an effect. Try that with a short plate. Lots of clever stuff you can do with these expander gizmos!

[fader8]

Does it actually amplify the louder portion? Or does it pass the "loud" portion at unity and lower the volume of the softer portion proportionately?

 

Strictly speaking, signals below the threshold remain at unity, and signals above it have their gain increased. Now that's not pure gospel for every expander and that's only for upward expansion. I thnk what you and I were discussing was downward expansion, which increases dynamics proportionatley below the threshold only. Another subject really.

 

See, this is how the "tome" threads get started!

[Morerecords]

thanksF8, that works

Not sure what "tome" means, you love to bring that debate up though

I tell you same as day one, I am not into numbers, or anything mystical or esoteric- That was my whole beef with that discussion...That was one of my first threads and my intro to forums, it was pretty rough! Reason to drink for sure-however, I never need one although I do remember you got one thing right about my profile, I love my scotch!

 

 

thanks again!

MR

[ski]

Not sure what "tome" means

 

"Tome" is the sound of the word "time" going through an updownward expandipressor.

 

I think...

 

[pantomimeHorse]

Not sure what "tome" means

 

"Tome" is the sound of the word "time" going through an updownward expandipressor.

 

I think...

 

 

Whereas, "Emo" is where you reverse it in the Sample Editor

and truncate the end of the resulting audio region ...............

 

-

C

[ski]

Whereas, "Emo" is where you reverse it in the Sample Editor and truncate the end of the resulting audio region

 

And and if if you you put put it it through through a a delay delay it it would would sound sound like like Emo, Emo, right? right? :mrgreen:

[fader8]

"Tome" is the sound of the word "time" going through an updownward expandipressor.

Or, how you might pronounce it if you went off your diet and experienced sideways expansion. Not to be confused with "toime" which is a result of sideways compression, aka the "girdle" effect.

 

Here is a scenario: You've recorded an acoustic guitar track, but between phrases, you can hear the HVAC in the background. The gaps are too short, so a gate sounds abrupt and unrealistic. Using an expander, you can set a threshold, after which the volume is severely ramped downward, but in a smoother manner than cutting off the signal completely.

While the expander will produce the desired effect in that scenario, it's important to grok that the expander, unlike a gate, will alter the amplitude envelope shape of your signal above the threshold. If that sounds good, then fine, but sometimes it won't. Sometimes a gate set with a low attenuation range, followed by an expander, results in better control in situations like this.

 

I know expansion was used ona lot of snare drums, so that would give me the idea that expansion could be used on "snappier" sounds, or,

Once upon a time, that was true. And it's still true if you want to further isolate a snare hit on a noisy/leaky track. But there's better weapons for making things snappier now. Try the Enveloper plug-in. Other good 3rd party stuff is the UAD Transient Designer and the Oxford TransMod.

[vagrantmuse]

"Tome" is the sound of the word "time" going through an updownward expandipressor.

Or, how you might pronounce it if you went off your diet and experienced sideways expansion. Not to be confused with "toime" which is a result of sideways compression, aka the "girdle" effect.

 

Here is a scenario: You've recorded an acoustic guitar track, but between phrases, you can hear the HVAC in the background. The gaps are too short, so a gate sounds abrupt and unrealistic. Using an expander, you can set a threshold, after which the volume is severely ramped downward, but in a smoother manner than cutting off the signal completely.

While the expander will produce the desired effect in that scenario, it's important to grok that the expander, unlike a gate, will alter the amplitude envelope shape of your signal above the threshold. If that sounds good, then fine, but sometimes it won't. Sometimes a gate set with a low attenuation range, followed by an expander, results in better control in situations like this.

 

I know expansion was used ona lot of snare drums, so that would give me the idea that expansion could be used on "snappier" sounds, or,

Once upon a time, that was true. And it's still true if you want to further isolate a snare hit on a noisy/leaky track. But there's better weapons for making things snappier now. Try the Enveloper plug-in. Other good 3rd party stuff is the UAD Transient Designer and the Oxford TransMod.

 

Quite true. To expand on the snappy idea, the expander can be used, but the problem (and the reason plugs like TransMod were made) is that even the best expanders are slow in comparison to transients. As a result, these plugins were designed to be incredibly quick on the attack (as in, milliseconds) and also on the release. This way, the artifacts generally associated with compression/expansion are not evident.

 

Also, on the idea of expanders, I really dislike the Logic expander. Thought I would toss that out there

[Morerecords]

As always, thanks F8!!!

(and everyone elese too)

Let me know if you write a book one day, frankly, If you have time and ever want to start a weblog....

or if you want to contribute to mine... www.soundshift.blogspot.com

just let me know

[Morerecords]

on the subject of transients, there's a free pluggie called Bittersweet that I have really enjoyed lately, google it, you might like it too.

[ski]

See, this is how the "tome" threads get started!

 

Great. Go ahead. Blame it on me...

 

(j/k)

 

Strictly speaking, signals below the threshold remain at unity, and signals above it have their gain increased. Now that's not pure gospel for every expander and that's only for upward expansion. I thnk what you and I were discussing was downward expansion, which increases dynamics proportionatley below the threshold only. Another subject really.

 

But why O learnéd one? I mean, I wasn't asking if, like, the expansion of the universe was like a sideways expander acting in 11 dimensions or anything...

 

Seriously tho, would it be fair to say that upward and downward expanders achieve the same effect using two different approaches?

 

Also, can you tell by the nature of the controls on an expander plug if you're looking at an upward or downward expander?

[fader8]

Seriously tho, would it be fair to say that upward and downward expanders achieve the same effect using two different approaches?

Not exactly. In upward expansion the audio below the threshold is untouched but the sample values above it get multiplied via the ratio setting.

 

For example Logic's upward expander, with a threshold of -30 and a ratio of .5:1 . . . .(auto-gain off)

 

Input -30 and it outputs -30.

Input -20 and it outputs -16.

Input -10 and it outputs -2.

 

Start out with a signal that had a 20dB dynamic range, from -30 to -10, it's now expanded to be a 28dB dynamic range, approximately. It gets stretched. Nothing below the threshold gets stretched or affected at all.

 

In downward expansion, it's the opposite. The samples above the threshold are untouched and the dynamic range below the threshold is increased proportional to the ratio setting.

 

For example, (Oxford Dynamics) with a threshold of -10 and a ratio of 2:1 . . . .

 

Input -10 and it outputs -10.

Input -20 and it outputs -30.

Input -30 and it outputs -50.

 

So if you started out with a signal that had a 20dB dynamic range, from -30 to -10, it's now expanded to be a 40dB dynamic range, approximately. It gets stretched. Nothing above the threshold gets stretched or affected at all.

 

So choosing one or the other is important because obviously the sound is going to be different depending on which end of the signals dynamics you're stretching!

 

Also, can you tell by the nature of the controls on an expander plug if you're looking at an upward or downward expander?

 

Notice the ratio numbers are on either side of "one", eg .5:1 vs 2:1. Also, most expander plug-ins are downward, so you'll rarely find one that's upward. (Except Logic's!)

[ski]

Wow, thanks SO much Señor 8 -- that totally clears things up for me.

 

You rule! 8)

[dkgross]

..and..once again, you blew up my brain.

 

 

[IainPetrie]

I LOVE expanders, why? because they are brilliant noise gates IMO, ive been using the multipressoras it seems to be the only one with a downward expander. i find it extremely useful when recording softer signals into the mic, eg a softly plucked acoustic. i can effectively remove top end hiss without losing the musical midrange as the notes fade out

 

very good on toms if you find they are ringing too long

 

also anyone know of any plugin expanders that are low on cpu juice?

[camillo jr]

Routing the snare to the rhodes expander's sidechain can make the rhodes "sing along" with the snare, ie the snare hits, pushes up the rhodes which then decays nicely back down based on your expanders release settings. 80-150mS might be nice for that. If you want the snare to punch through a bit more, delay the onset of the expander by adding 15-20mS attack time. Very common for kick and bass too.

 

So, this example with the kick and bass, you'll be having the bass pushed up with the kick? Or are you trying to keep it out of the way of the kick?

[fader8]

So, this example with the kick and bass, you'll be having the bass pushed up with the kick? Or are you trying to keep it out of the way of the kick?

Hey camillo,

Both. This is very similar to what you would do with a compressor for 4 on the floor dance music, etc. but in that case you have a loud kick and a loud bass line so the comp drops the bass during the kick and is bringing the bass line back up based on it's release time.

 

Switch gears and consider a jazz ensemble or a pop ballad or something. (Boz Skaggs, Harbor Lights. . comes to mind. Give that link a listen and you'll hear the Kepex working.) You have a soft bass line with a louder kick that is far less frequent. So you want the bass to be a little more exciting when the kick plays, ie you want it to "sing along". But you don't want it to mask the kick so be sure to set the expanders attack time long enough so it occurs just as the kick decays. Get it?

[Holger Lagerfeldt]

Now fader8, that was an easy question the OP had.

 

I'd like to steal some more of your time (just for fun) and challenge you to explain the 4 dynamic modes and all the relevant functions in the Flux Solera in detail.

 

Let me know when in 2009 you will be ready to present your thesis.

[fader8]

I'd like to steal some more of your time (just for fun) and challenge you to explain the 4 dynamic modes and all the relevant functions in the Flux Solera in detail.

LOL! Yeah, bless them, the manual did get better for Solera II but it's still a beast to use if you're away from it for a while. If you forget some of its "rules" you can get all messed up!

 

And I'm still not totally clear on its signal flow. It really needs a block diagram. Maybe I should do that. Damn it, Holger, now I have something else on my to do list!

[Holger Lagerfeldt]

The (pro) mastering world would be eternally grateful.

 

It really needs a breakdown explanation in terms of signal flow and how things really interact (threshold, ratio, range, hysterisis, angel's share) in all 4 dynamic modes.

 

I mean, what exactly do you get when you set a low threshold with some hysterisis (which BTW is a bit of a misleading term here I would say) in combination with a high ratio BUT in combination with a low range, using the so-called D-Expander? (answer=some very cool low level upward compression like sound)

 

Now add the other 3 modes at the same time and you have a block diagram nightmare on your hands.

 

I've discovered that you are able to do some almost supernaturally intelligent psycho-acoustic loudness enhancement using the Alchemist (like normal parallel multiband compression but more interesting).

[fader8]

I've discovered that you are able to do some almost supernaturally intelligent psycho-acoustic loudness enhancement using the Alchemist (like normal parallel multiband compression but more interesting).

I'll have to try that.

 

Have you taken a look at Paul Frindle's new plug, (just released in AU):

http://www.proaudiodsp.com/products/dsm/

Check out the manual as the site doesn't really explain the thing at all. I'm going to try it out soon. I'm hoping his new company does well. I expect we'll see other things that are a bit outside the norm.

 

Regarding Solera, I really need to spend some more time with it. Hard to make it a "go-to" plug when you can't quite visualize what's going on. That just complicates troubleshooting too.

[Holger Lagerfeldt]

I've discovered that you are able to do some almost supernaturally intelligent psycho-acoustic loudness enhancement using the Alchemist (like normal parallel multiband compression but more interesting).

I'll have to try that.

Have you ever done multiband parallel comp for mastering (not just singleband)? And then try doing this with the comp/d-expander modes in Alchemist. It boggles the mind.

 

Have you taken a look at Paul Frindle's new plug, (just released in AU):

http://www.proaudiodsp.com/products/dsm/

Check out the manual as the site doesn't really explain the thing at all. I'm going to try it out soon. I'm hoping his new company does well. I expect we'll see other things that are a bit outside the norm.

Very interesting. No clue from the website really as to the inner workings and I guess we'll never know exactly what's going on.

 

Regarding Solera, I really need to spend some more time with it. Hard to make it a "go-to" plug when you can't quite visualize what's going on. That just complicates troubleshooting too.

I'm primarily using the Crane Song STC-8/M and SSL for master compression but the Solera is my go-to single band digital compressor. Nothing beats it for low level enhancments, i.e. retain top dynamics and bring out some low level info without bass/low mid distortion (which usually happens with this type of compression, e.g. Waves). I think the combo of ratio/range and min/max release is the reason why it sounds so natural and doesn't distort.

 

I even have made a preset for this you can have. And while I usually frown at using presets, this is a very good starting point and often works immediately.

[fader8]

Have you ever done multiband parallel comp for mastering (not just singleband)? And then try doing this with the comp/d-expander modes in Alchemist. It boggles the mind.

I was working on this percussion stem the other day that was a muddying the mix. I used RND's Splizer, cut it into 3 bands and put Solera on all 3 aux outs. All 3 use parallel comp but the mid gets sent to a little bit of plate. You can hear a snippet of just the stem Here. First half of the file is unprocessed.

 

The low and mid use a combi of Comp and DExpand to get things spiky. A neat effect and works in the mix. Something fun.

 

But I'll give the parallel multi-comp thing a try on some mastering work.

 

I even have made a preset for this you can have. And while I usually frown at using presets, this is a very good starting point and often works immediately.

Post it up, I'll give it a try!

[ski]

Also, on the idea of expanders, I really dislike the Logic expander. Thought I would toss that out there

 

Resurrecting this old thread because I wanted to take a refresher course on expanders. After playing about with Logic's expander some more I found that it can really muddy up/distort the signal at what seem like reasonable settings. Then again, what I consider reasonable might not be.

 

Anyway, it did the job on this bass part I was struggling with, bringing out the note transients to give it a sharper attack and reduce the body of the sound.

 

Two new questions...

 

1) under what circumstances would one choose "peak" over "RMS"?

 

2) attack time... if attack is zero, does this mean that the expansion occurs immediately while non-zero values represents the amount of time it takes for full expansion to kick in?

[fader8]

1) under what circumstances would one choose "peak" over "RMS"?

When you're working with transients, eg just the "attack" of an instrument, like the example you're working on. If the sidechain is measuring RMS, the bright attack could be missed because it often has a low RMS value but a high peak value. An RMS measurement could be averaging power over 20 or 30 mSec's. The attack envelope is usually much shorter than that.

 

2) attack time... if attack is zero, does this mean that the expansion occurs immediately while non-zero values represents the amount of time it takes for full expansion to kick in?

"Zero" is not really the best way to describe it. Yes, the gain process will start right away, but it will always have a shaping to it. Otherwise there would be lots of distortion. So even though the attack is 0, it may not reach it's full change for a few mSec's anyway. Depends on the plug-in though. All do this a little differently and is why they all have a different sound. The only way to get a true 0 attack time is to have lookahead.

 

Looking at the envelope from start to finish, let's say the attack was 10mS. Once the threshold is passed, the timer starts but it might take 13mS before the gain process is actually doing its full thing. After the signal gets below the threshold, there's always some hysteresis (3dB maybe) and then the release timer starts. The release will have a shape too, so again, a zero value there won't mean anything either.