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Multiband compressor questions

Postby GS1 » Sun Sep 02, 2018 2:28 am

Haven't posted here recently but got a lot of good tips/info about different aspects of the overall recording process a couple months back so I figured I'd see if some of the people who were good enough to take the time to reply to my earlier threads (or anybody else)might be able to share their take on what I'm currently focusing on...

As I explained in the earlier threads here I'm using a DP008ex to put tracks together...this has a single band input compressor as well as a mastering MBC;both have a bunch of presets w/adjustable parameters;while you can adjust attack/ release/ make-up gain/threshold,+ ratio on the input compressor the mastering MBC just allows you to set the last 3...

I've done a lot of online research/study (including info here at SOS)and have a developing understanding of things ,as well as getting some experience using both,seeing what's what....

What I'm posting about is the latter + its use in mastering...

The limitations of the built in MBC don't allow for specific determination of dB reduction;you have to rely on judging results as well as seeing how much a simple unmarked meter shows the visible amount of compression going on(at lower ratio/higher threshold settings there's no obvious indication of it)..

Still I'm applying the info I've studied to the extent I can and see how to do things like-

Solo the bands to see what each sounds like

Work w/levels/ratio/threshold using it more like a dynamic equalizer


I've developed a sense of what needs to be louder/softer in the mix and where to find it in the bands,and using a results -based empirical approach to seeing what combination of threshold/ratio produces a given sound that can be increased/decreased using the level(make-up gain )

Without the capacity to specifically determine things as all the online info suggests though(I.e how much in dB the input vol is, where setting the threshold /ratio produces a given # of dB reduction etc. )its a guessing game as to what exactly is going on and consequently I'd appreciate any feedback about how to operate within the limitations of my current set-up...i.e.

Should I be focused on using low ratios/high thresholds as a rule of thumb?

Should I be using the same ratio on all 3 bands?

I've tried transferring the parameter settings that worked for a given preset to another and saw right away the results were different so,I'm assuming that the unadjustable aspects of each-
(knee/attack/release/crossover) are involved here....of course the presets for each style have info about what each bands default settings focus on...

Given this kind of situation I'm wondering how pros familiar w/more sophisticated plugins etc would modify their MBC approach to get the best results..

As always thanks in advance for any feedback....
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Re: Multiband compressor questions

Postby James Perrett » Sun Sep 02, 2018 1:22 pm

While the manufacturers' marketing departments might push MBC as a mastering tool, it is used surprisingly rarely by real mastering engineers. In your case, given your limited facilities, I would probably only use it to fix problems like pops and sibilants. For real mastering you need much more control than you appear to have on your system.
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Re: Multiband compressor questions

Postby desmond » Sun Sep 02, 2018 6:03 pm

Yes, MBC is best used imo to fix specific problems that you have no better tool for (eg, if you can't go back and fix the mix).

And in that case, there is no recipe, you need whatever settings you need to fix the particular issue you have.

It's not really a "polish my mix" tool, imo...
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Re: Multiband compressor questions

Postby GS1 » Sun Sep 02, 2018 6:46 pm

Appreciate the above replies/viewpoints-

I'm using it as part of my approach as I feel it adds quite a bit to the mixdown results...which for the most part are made up of tracks without much compression used in tracking process....mainly for things like boosting lows/kick-bass in mix or cutting highs of hihat...since I'm using a limited track approach to set up mixes and doing a lot of submixes on individual tracks as opposed to having things recorded on individual tracks available throughout the tracking process to adjust levels, this is a factor w/the completed mix that MBC used as a form of dynamic EQ like this seems to be able to counter and set up a better balance of levels on each of the bands..I'm only a couple months into this stuff and still developing a sense of setting levels that will result in a balanced end result w/everything clearly audible as opposed to masking etc...

I've been reading a lot of articled on using it in mastering i.e.Ian Shepherds stuff etc but am aware re-first reply above that it isn't used by others as a regular part of things inmastering- or if it is used, its part of a parallel compression approach...

No doubt my current tracking approach makes it more useful than it would be w/a 24+ track capacity re-being able to get a balanced mix during mixdown leading to the mastering focus shifted to limiting/normalization etc....
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Re: Multiband compressor questions

Postby CS70 » Sun Sep 02, 2018 7:50 pm

If it sounds good, it's good - and everybody has their own workflow and tools.. that said, if you find yourself wanting to change (improve) the sound of the mix at the mastering stage a lot (and a multiband can really transform things, it's not a subtle tool), it's generally a better thing to actually *mix* the track so that it sounds darn good before mastering.

By doing so, the mastering stage can deal with the few alterations that are needed to make your amazing mix sound equally good on different playback systems: small EQ adjustments, maybe mono-izing and tightening the bass, limit to reach the desired loudness, and so forth.. all while preserving the great sound of the mix as much as possible.

It's also very hard to that by using the same monitoring and room you use when mixing, as it something need fixing, you would have fixed in the mix.. and the reason you didn't , is because you couldn't hear it. That's why you generally want at least a separate room and system for mastering - with pristine acoustic and very detailed monitoring. It's usually far cheaper to send to a reputable mastering engineer.

Of course it's perfectly possible to use post processing on a mix to make it pop (and boy a multiband can do that - just as it can totally butcher a mix), but it ain't "mastering", it's just adding another layer of effects.
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Re: Multiband compressor questions

Postby GS1 » Sun Sep 02, 2018 8:20 pm

CS70,Thx for the detailed reply..could you explain what you're referring to when you use the term-"mono-ize the bass"?
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Re: Multiband compressor questions

Postby CS70 » Mon Sep 03, 2018 6:03 am

It's simply the technique of making everything under say 100Hz mono.
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Re: Multiband compressor questions

Postby GS1 » Mon Sep 03, 2018 11:06 am

Thx for the clarificatuon-

What would be the advantage of doing this w/lows?

Also in my understanding of things mastering deals w/the completed mixdown of individual tracks to one stereo track and this seems to be something that would take place prior to it as part of mixdown track prep...unless you're referring to a different methodology....????
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Re: Multiband compressor questions

Postby desmond » Mon Sep 03, 2018 11:09 am

GS1 wrote:What would be the advantage of doing this w/lows?

We don't really get directional information from low frequencies - hence why you get systems with two speakers and one sub for the bass. Plus, the low frequencies typically carry a lot of energy, so making sure both channels/speakers spread the load equally makes sense.

If you've ever heard tracks where the bass is just in one channel, it's quite weird (especially on headphones!)
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Re: Multiband compressor questions

Postby CS70 » Mon Sep 03, 2018 11:16 am

It may (or may not) benefit a given track to make sure that the low end energy is spread equally over the two stereo sides (some of course may be already mixed like that). But it was just a random example of the many little corrections that are supposed to be the focus of the mastering stage. Certain tracks may need it, others don’t.

The point is that these changes do not alter the timbre of the mix, only improve its playability.

In an ideal situation mastering simply means removing headroom from the stereo track. But if there are things to fix, and for some reason you can’t go back and fix them in the mix, mastering is the place.

The reasons for which you may not be able to fix them in the mix are varying, from “no more budget” to the fact that you can’t hear the problem in the mixing room.
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Re: Multiband compressor questions

Postby GS1 » Mon Sep 03, 2018 2:57 pm

Thx again for continued feedback,good to get ideas relating to mastering as a whole-
but to turn things back to original thread subject,putting aside the pros/cons of using MBC as part of post-mixdown process(in the context of my approach w/the DP008ex,this means that I'm dealing w/the stereo master track the unit creates from the individual track mixdown)

What kind of approach to the adjusting the limited preset-related parameter settings (as explained in first thread post) would you recommend...?

What guidelines if any in terms of threshold/ratios would you use?

Using the latest completed mix as an example of where I'm at w/this,my focus was making sure that the low-end bass/kick which are an integral part of the track cut through a dense mix w/sustained pad/keyboard playing rhythmic parts etc along w/different melodic sections ...also just generally having things be at the right levels in the context of the overall mix...

After a few mixdowns I got the result I was after then listened to the stereo master track w/each of the presets to see what focus aspects sounded like;found about 4 of them to choose from where the mix sounded good...

Next time I work on this track I'll be adjusting the parameters of whichever preset I decide on...probably focusing on trying to get the low end to have more bass /kick without being too much for the total mix context...other things sound good in the mix and won't be as much of a focus as on other tracks where a few aspects needed tweaking...

Instead of just focusing on raising or lowering the low bands' make-up level as a form of dynamic EQ much like you'd adjust the bass/treble controls on a playback system,I spend some time seeing what effect on things different threshold/ratio adjustments produce and how this affects the amount of make-up gain used as a means of establishing the balance of three bands....and most likely will do this w/the other 2 bands as well...all in the interest of seeing how to get the best end result...

Feedback on the best way of doing this is what I'd appreciate...

I understand the semantic difference implied in viewing using MBC as "another level of effects" instead of being mastering per se as defined in terms of a focus on normalization/limiting/dB levels of end result however as I've outlined above the way I'm using it is a regular step in processing the mixdown in terms of levels/EQ-type factors in each band prior to normalization....

As well as getting more perspectives on this continuing the subtopic here about where bass/low-end across the board sits best in the mix is something I'm also interested in ...my set-up is limited to mono tracking however I do a lot of recording one instrument to two tracks panned wide and EQ'd differently as well as mixing down some of the tracks to the stereo master track then copying the result back to two mono tracks as part of the submix ...bass is usually centrally panned so it ends up on both sides of the end result stereo field...if its originally tracked using the dual mono approach I set the pair just R/L of center and usually use the same approach for the kick.....
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Re: Multiband compressor questions

Postby CS70 » Mon Sep 03, 2018 4:17 pm

Not totally sure what you're after - stuff that you mention such as.-.

making sure that the low-end bass/kick which are an integral part of the track cut through a dense mix w/sustained pad/keyboard playing rhythmic parts etc along w/different melodic sections ...also just generally having things be at the right levels in the context of the overall mix


..is all stuff that you would actually do by, well, mixing properly. If your kick doesn't cut thru the mix, you just work the mix until it does (for example better balance, or counter-equalizing bass and kick, ducking, removing midrange content from guitars and pads etc).

And, if you want to turn knobs and explore the result (a tried and tested way of learning!) without having a specific goal in mind, well it's just to do that :)

But again, there's no limit to creativity and a MBC is quite a powerful tool. Nobody says it's gotta be used in a certain way and trying things is always fun. The tool itself is fairly simple it's like having different fairly independent compressors each one acting on a specific set of frequency bands. Each of them does what a compressor does - it tames peaks according to threshold/attack setting (but only looking at the level in the specific band) and you can add makeup gain to bring out details.

The compressors are "fairly independent" because you have crossover between the bands, and lots of the magic is in there - choosing the bands. The other is that even if the bands are limited, the compressor acts on the full sum of all the original tracks, and it's able to lift up things in a way more dramatic way than any compression applied to every single band (and there, of course, also lays the danger you can wreck a decent mix in no time).

Technically there's not much more than that. With most digital MBCs, you chose your bands soloing the compressor and moving the crossover till you hear the content you want to work with, then adjust the threshold to get the amount of compression you think it's needed, attack and release depending on the content exactly like a full band compressor (say slower attack for bass freqs, faster for guitar, etc), and then remove the solo, and add makeup gain until that band's details are at the level you want. Then proceed to the next band if you want. it's tempting to look at a frequency analyzer and try to find frequency "holes" to fill - but it's generally not advisable, much better to close your eyes and listen deciding where you would want things to pop more: there's your band.

A thing to keep in mind is to stop every now and then, step back, remove all the solos and listen to the full result, possibly takling a few mins break before doing so. Like a frog is slowly warming up water, it's very easy not to notice the disaster when you it comes in small steps.

The other caveat is the usual one about compression: not letting yourself be fooled by the difference in level due to the makeup gain, but rather listen to the details that are brought up which aren't audible without compression and/or how the transients are affected and "fattened up" (or smeared!) by the tool. If you don't have any details to bring up or transients to fatten - compression is just a glorified volume knob.
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Re: Multiband compressor questions

Postby GS1 » Mon Sep 03, 2018 7:14 pm

Really appreciate you taking the time to go into things CS70...

Thx for the emphasis on soloing the bands and using A/B checking w/the other 2 during the process...

You know the factor you mentioned re-getting the bass/kick to sit in busier mix by "notching" frequencies in other instruments happening at the same time is something I'm aware of but haven't yet gotten into doing...mainly because I'm still developing a go-to EQ settings approach for everything,working on getting things to sound like I want i.e.been spending a lot of time on the kick...so something gets tracked and sounds good w/the EQ approach used for it but the next instrument gets the same "what will give the sound I want"EQ etc approach without a focus on setting up a focus area/areas to cut in the sense of having things work in the mix together...Only did this a little so far w/kick/bass where I had the areas boosted for the bass cut on the kick...but since the more I put tracks together the more I develop go-to EQ settings that I can refer to initially,I should be able to plan out a way to do this in the future as a regular part of the tracking process..

As far as ducking I haven't got a set-up in place currently that allows for side chaining but could conceivably do a manual form of it during the tracking process,_even if only dipping the vol of things on the downbeat of the bar so the kick will hit harder there...

When you refer to the bands being limited("even if the bands are limited the compressor acts on the full sum of all the original tracks"are you talking about using low threshold/high ratio limiter settings or the fact that on my unit the crossover bandwidths are preset and not specified as to where the boundaries are...?

Again couldn't tell you how much of a difference it makes being able to go over things specific to my equipment instead of just reading a lot of online info that I can only implement to some degree without any real sense of how to apply it using my unit....
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Re: Multiband compressor questions

Postby zenguitar » Mon Sep 03, 2018 7:34 pm

GS1 wrote:...mainly because I'm still developing a go-to EQ settings approach for everything,working on getting things to sound like I want

This could be something you might want to think about again. Many of the more experienced and skilled engineers and mixers here work hard to make it clear that there are no magic go-to settings for EQing different instruments. And this approach often results in a song that appears difficult or impossible to mix.

Instead, they describe listening to identfy problem frequencies in each track and then using EQ where approprate to resolve those problems.

Now, I'm not a great mixer, but I am sure that if you wanted to look again at how you are using EQ there would be plenty of good advice on offer.

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Re: Multiband compressor questions

Postby GS1 » Mon Sep 03, 2018 8:06 pm

Thx for weighing in here Andy-
I should have made it clear I was referring to using EQ in the initial tracking process to get specific instrumental sounds, not post- tracking as part of the mixdown/mastering approach..

An example of this re-kick drum is boosting between 60-100/150Hz,cutting 3--500,Hz,boosting 2-4kHz....and by go to I mean for a given kick type where exactly in those areas and by how much....

As far as post tracking EQ'ng I'm limited in what I can do using my current equipment by the fact that the unit only has a low/high shelf track EQ...and know what you mean by looking to see how things sound in the mix and where to boost/cut...since w/the shelf you can only do so much ,I try to get the sound I think will work in the mix before tracking w/the 1/3 octave EQ...but often end up doing some additional boosting/cutting once I hear how the mix sounds w/the shelf....
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