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Serial vs. Parallel Compression

Disclaimer: I am fully aware of how broad the scope of this question is, and how each specific track calls for individual techniques.

That being said, can we discuss when you would want to use serial compression vs. parallel compression?

Certain instruments?
Certain styles of music?
Analog vs. digital compressors?
Individual tracks or busses?
Different intended effects?

I’m looking for general discussion, aneCDotes, guidelines, thought processes, links to other trusted resources, examples, you name it.

Thanks in advance!


pcrecord Sun, 02/18/2018 - 18:33
Serial compression allows for gentle compression by using 2 low ratio settings to get control without killing the dynamics too much.
Parallele compression allows to blend the uncompressed signal with a compressed signal, either to put a stable reinforcement to a dynamic performance or to put back some dynamics to a compressed signal.
To me those technics apply to any instrument, any style (maybe with the exception of classical music).
Serial compression is easier on the same track.
Parallele works with a buss or a copy of the track.

One thing I sometimes do on vocals with punk or more heavy genres is to use distortion as a compressed fill in signal. (With saturn or reamped to a guitar cab)
I take the compressed/saturated signal and put it under the clean signal to add character and a more stable presence in the mix.

Creativity has no limit ! ;)

kmetal Sun, 02/18/2018 - 22:01
i use parallel most on drums and bass, although they'll also be some in series as well on the drum submixes, and individual tracks. i think the effect of summing and processing in stages was just considered part of the flow when LFC's ruled. it seems to have come to light clearly now, both externally and within the DAW.

one place i almost always use comps in series would be the master bus. one for the peaks, one for general shaping. vocals tracking is another place thats cool if you can do it during tracking. you can run one compressor gently or even off, just for its tone. when you compress during tracking, the performer is really interacting with the processing in the moment, and it becomes part of the performance. this is a different effect to compressing after tracking. both have a time and place and sometimes no place being there at all.

im a huge fan of the mix/blend functions in alot of the new pluggins (M/S too). i like the immediacy and the simplicity. parelell processing can bring havok to an otherwise good thing if phase and delay compensations come into to play. the mix knob takes care of that easily.

im trying to get a handle on dynamic eqs and multiband comps, as that is the rage it seems. i think ill puke if i see another product described as "Neve style" its like anything with xfomermer is now neve.

i think digital compression requires a bit less than the analog counterparts, and ive been liking clean digital compressors and limters lately, the new stuff sounds good. for tone shaping analog compressors are where i go. although the eureka channel comp is super transparent. i like DBX, UA, and TLA, compressors alot.

DonnyThompson Mon, 02/19/2018 - 04:35
I like and use both, I still use Serial Reduction when the situation and the available gear allows .... They are both different beasts, but can both be very useful.
Back when I had OB gear, I would often front load vocal tracks with serial gain reduction; usually a "faster" FET type of reduction for grabbing those quick transient peaks, followed by an Opto, which gave a nice overall smooth reduction...but I rarely used "heavy" settings on either, usually just a DB or two; and most of the time, I would just barely "kiss" the VU of the second compressor. That's not to say that you couldn't swap positions of the two devices...both orders had their own vibe.
I started working with Parallel Reduction back when I was first learning on consoles; it just became a sort of "second nature" patch-in for me, part of my engineer's "trick bag", and the way I liked to mix. I used it a lot on drum tracks, drum room mics - but, for other apps, too... I still use Parallel quite a bit on backing vox and guitars.
These days, as Kyle ( kmetal ) mentioned in his post, many Compression/Limiting plug ins have a "mix" function, which is essentially the same thing, though I'll still find myself setting up a parallel channel/aux return inside my DAW's mixer, mostly out of old habit, LOL, but also because it allows me to tweak EQ on the reduction return, if I want. It's also easier to just reach up and adjust that fader in the mixer view than it is to open the compression plug in and adjust it's mix setting.

DonnyThompson Mon, 02/26/2018 - 03:35
kmetal, post: 455869, member: 37533 wrote: think digital compression requires a bit lo
Maybe? I think it's a great topic for discussion.
In my own experience, I think that I was able to get those various compression sonic vibes easier with OB pieces - although the degree to which was dependent upon both the device and the signal strength going into them.
As mentioned, I can recall using various pieces where I had them set at near unity gain - not exactly but certainly not using "dramatic" levels of reduction, and hearing big changes ( mostly for the better) in terms of sonic melding, or what is now so commonly referred to as "glue". While this is obtainable with digital simulations, (and there are some plug Compressor sims I really do like), it seems I have to use "heavier" settings to get that sort of vibe than I used to back when I was using hardware.
There was a studio - other than my own - that I used to work at frequently as an engineer for hire, and they had a Focusrite Red Stereo Opto Limiter that I loved to strap across the 2 bus; and I would set it so that the signal was just barely kissing the circuit... the VU was barely moving... yet it added such a beautiful cohesiveness and smooth "sheen" to the mix...
I've not yet been able to get "that" vibe with the "analog type" of digital sims/re-creations using the same settings I used to use on the HW. I'm not saying I can't get that sound with analog modeled plugs at all ... because I can... but it seems to require more dramatic settings to get that sound out of them.
And, like you Kyle, and others here, there are times I want something much less colored. There are a few plugs I like to use for those times when I want a "clean" compression; Waves RChannel has a very nice Compressor that does what it does without adding "character". Samplitude's stock basic no frills Compressor is another one similar to the Waves plug - its sorta hard to describe, but it's almost like it's compressing without it being noticeable that that is what it's doing.
In any case, I do love having options for different types of signal response.
Although, there are still times I like to use HW.
I have an old and cheap DBX 163 that I used the other day for tracking bass - the Focusrite ISA One Pre and DI has inserts on it for processing on the way in ( adjustable to insert post or pre), so I plugged the bass onto the DI section, inserted the 163 into the ISA, and ended up gettting a great sounding bass track that I'm really not going to have to do much of anything with in the mix.
Could I have gotten that sound recording "clean" and then adding processing ITB? I'm sure I could have, with a little work and tweaking. But it sure is nice that I don't have to, and that the tone I ended up with was "instant".

kmetal Mon, 02/26/2018 - 12:15
Thats interesting D. I find digital compressors so accurate and fast, that i feel like i use less of it. maybe its because by the time you 'hear' the compression its typically too much, since theres not the analog noise, phase, and harmonic distortions, masking and enhancing (in some cases) the signal? when i think digital compressors i think compression first then tone, with analog its tone first, that guides the choice. not that there isnt nice clean analog comps, or pleasant sounding digital, which both sound good. also, its alot easier to do parallel and series in the digital realm, so thats probably another reason, it seems like im using less in digital.

ive grown to become a big of channel strips, analog and digital. Rcomp is a classic, one of my all time favs, and ive been digging the TG12345 vintage channel as well. ive been borderline addicted to the fabfilter limiter. i love how effective it is, with this nice sheen on it. ive had to refrain from downloading the eq and compressor demos, since it'd mean a tease, or a couple missed meals. best to keep my eyes forward lol.

kmetal Fri, 03/09/2018 - 07:42
pcrecord, post: 456147, member: 46460 wrote: Fabfilter Pro L2 with the LUFS metering = can't live without it. ;)

yeah man i bet! i havent took the plunge yet. i like the multi-channel functionality too.

to be honest metering has been bothering me lately since it lags when the cpu starts hitting hard. i've been trying to think of a way to decouple the metering somehow, or get an outboard meter.

pcrecord Fri, 03/09/2018 - 08:33
kmetal, post: 456148, member: 37533 wrote: yeah man i bet! i havent took the plunge yet. i like the multi-channel functionality too.

to be honest metering has been bothering me lately since it lags when the cpu starts hitting hard. i've been trying to think of a way to decouple the metering somehow, or get an outboard meter.
Humm that's odd... My setup will crash the audio engine long before meters would fail..
Did you check the refresh rate of the meters, most DAW have the option to change this.. Slower may not impact the visual too much but could be more stable.

kmetal Sat, 03/10/2018 - 06:35
i didnt know there was an option to check the refresh rate, ill have to look into it. its happend to me on several different systems (pc/mac/home/studio/DP/PT/Sam). Sam doesn't crash on this laptop, but playback response will lag when you press spacebar, and the meters get too, when dsp/cpu gets up past 50%. im wondering if the graphics card i have for the desktop will ease the meter issue. i also have isotope insight which i havent tried yet. metering is critical with all these different formats and standards out there.

pcrecord Sat, 03/10/2018 - 18:32
kmetal, post: 456156, member: 37533 wrote: i also have isotope insight which i havent tried yet. metering is critical with all these different formats and standards out there.
In the past, I always used Pro L and Insight on my master but since Pro L2 came out I only use L2.
One less plugin is better for processing time...


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