How to Use Buss Compression
Tutorial Details
- Difficulty: Beginner
- Completion Time: 30 minutes
Compression can be a pretty confusing subject. With so much jargon and literally thousands of different compressors to choose from it’s no wonder some less experienced producers get a little stumped from time to time.
One area of compression that appears to remain a mystery to some is that of buss compression. This is one that I’m asked about a lot, so let’s take a look at the ins and outs of the process and shed some light on the subject.
Every few weeks, we revisit some of our reader's favorite posts from throughout the history of the site. This tutorial was first published in May of 2009.
Step 1 - What is Buss Compression?
Essentially buss compression is no different to any other compression treatment. The only real discerning factor here is that buss compression refers to the practice of applying a compressor to a whole group of instruments or even the entire mix.
If your not familiar with the term ‘buss’ don’t worry — it’s really just jargon for group. Many different manufacturers and DAWs have different names for groups, such as auxiliaries or busses. They all do more or less the same thing and group several instruments together.
A drum group is perhaps one of the best examples of when we would use a buss/group and indeed buss compression. It’s very likely that you would insert individual compressors on some of your separate drum tracks,s but even with this processing when combined the drums may lack cohesion.
By routing all your drum tracks to a group or buss within your DAW you are able to adjust the volume of the whole drum track and even apply EQ and other processors to them as one. You should notice your drums take on a more consistent dynamic signature, and you will also enjoy higher perceived volume levels and a natural cohesion of the sounds. This is sometimes referred to as ‘audio glue’.
Basic buss routing in Logic Pro
Step 2 - Single Band Buss Compressors
There are a few different types of compressor that are commonly used as buss compressors — single (or full band) and multi-band models.
Some consider a true buss compressor to be a traditional single band compressor of a very high quality or with custom components. Technically, any single band compressor in your plug-in list can be put to work as a buss compressor but some would argue that such a critical task deserves a dedicated processor. Some cheaper tracking compressors may introduce unwanted artifacts and dramatically reduce dynamic range.
There are several companies making dedicated single band buss compressors. These are usually geared towards mastering but are just as useful when used on drum or instrument busses. These plug-ins often emulate hardware or are modeled on famous hardware units. This component modeling often eats a fair amount of CPU overhead and therefore latency induced by these plug-ins can be higher than more straight forward processors.
A great example of a modeled buss compressor is the ‘Waves G Master Buss compressor’. This is directly modeled on the compressor in the master section of the famous SSL 4000 G console and is actually endorsed and licensed by SSL themselves. This is super close to the real thing and has to be heard to be believed. Throw one of these on your master buss and the separate elements in your mix should magically become one.
Waves G Master Buss compressor
Universal audio also make some great buss compressors including their own take on the SSL model and another from Neve. They also provide a great buss processor as part of their precision mastering range. The precision mastering compressor has a few really cool functions such as a high pass filter to avoid pumping effects and a wet/dry mix function.
UAD precision buss compressor
UAD Neve 33609 buss compressor
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Basic loop dry
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Basic loop treated with SSL buss compression
Step 3 - Multi-band Compression
Multi-band compression is arguably not dedicated buss compression but can be used in exactly the same way with great results.
Mastering grade multi band compressors can be indispensable tools for reducing the dynamic range of a group of instruments (or your mix) without coloring the overall sound. They do this by using several compressors, each acting on a specific frequency range. These ‘slices’ are divided using crossover or bandpass filters and usually fully adjustable.
Waves linear multiband
Using this method means you can home in on problem areas of your mix without affecting others. Although you may not get the cohesive effect that single band buss compressors achieve it will certainly marry mix elements together to some degree. Of course if you feel the need you can experiment with a mixture of multi-band and single band bus compression.
UAD Precision multi-band compressor
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Basic loop treated with multi-band compression
Step 4 - Buss Compression in Mastering
Bus compression in mastering is very common and a lot of buss compressors are actually specifically designed for the task. A buss compressor will often be one of the first processors in a mastering engineer’s chain and is important in achieving a polished final master.
The mastering buss compressor’s main job is to reduce the dynamic range of the mix, taming peaks and therefore raising quieter sounds. This will all result in a louder more defined mix but the whole process should occur transparently and be pleasing to the ear.
It is for these reasons we tend to try and use the highest quality compressors we can here. Low ratios and high attack/release settings are also desirable as they tend to reduce any noticeable artifacts and drastic gain changes. These mastering compressors tend to work at very high resolutions and use advanced algorithms to achieve their sound, so its always advisable to splash out on the best you can afford for this task.
Although basic results are possible with cheaper plug-ins, using a stock compressor bundled with a DAW might not be the wisest move here. Saying that, some DAW manufacturers are making real steps in this area and are starting to supply mastering grade plug-ins as standard.
Step 5 - Parallel Compression
The way in which your buss compressors are routed has a huge impact on the final result. To create loud, high density signals while retaining strict control over the wet/dry mix of the compression effect we can use parallel compression. This is essentially a form of buss compression but requires a little routing to take place.
By making a duplicate of your instrument or master buss, you are able to place your buss compressor on one of these and leave the other 100% dry. The buss compressor can then be used with much more aggressive settings and mixed in to taste. This way the final signal mainly consists of the untreated dry audio and retains most of its original character. This is really great for drums but can be used on pretty much any group of instruments including your masters.
Parallel compression routing in Logic Pro 8
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Real drum sound dry
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Real drum sound parallel compression
Step 6 - Serial Compression
Another great way of routing your buss compressors is in serial as opposed to parallel. This involves using multiple compressors (perhaps of different kinds) on the same channel or buss. These compressors can be used at different stages in your effects chain and can achieve much more transparent compression than one compressor alone.
Try this on your master buss to catch wayward peaks on your mix and create cohesion. The separate compressors on the chain can be chosen for their specific features or character, giving you a cocktail of your favorite processors.
Mastering project using 3 buss compressors in series
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first :] nice article
Good article. Thank you.
Mo,
What plugins would be good alternatives for those that you mentioned in your tutorial?
Most starting producers don’t have Waves or UAD i think.
Hi there… yep as Gagi points out below T-Racks, Voxengo and also Sonalksis are very good plugs that wont break the bank.
…. But saying that if im honest if you are serious about mastering your own material it can be worth investing in one quality buss compressor… from the likes of UAD, Sonnox, URS, Waves, SSL etc. I realise they are expensive for the relative beginner but they are well worth the £$€ ;)
Really nice, thx :)
Great stuff as always Mo
Can you finish that house tune series sometime?
Glad you enjoyed the tut… will certainly put the house series back in the list and try and continue where i left off.
I think we finished at the start of the arrangement / drum intro… so would be some further arrangement technique next and maybe some work on a breakdown.
I think t-racks 3 and voxengo compressors are pretty good.
good tut.
Great.
Excellent article! If you’re reading this and on the edge about something like the Waves SSL bundle. It is a decent chunk of change, but the Buss Compressor ALONE is worth it. Like Mo said, you really have to hear it to believe it. It’s hard to explain, but it just makes your mixes sound huge.
Man I really think I need to replace my ears. I can’t hear any difference betweel the ssl-compressed loop and the original… Listening through headphones. This scares me…
it is very subtle stuff ;) often its a subliminal thing, there was only a few db of compression going on there…
youll find its really varies from one track to another, some projects will certainly benefit from it more than others.
what is it i do when i put a compressor (ableton 7s standard compressor, single band i think) in a send channel i then apply the compression to the different instrument tracks of my tune by ear via send knob). AND i do not use direct compression, say on bass or lead. I compress via send only. Also, i have a multiband compressor running on the master channel. does that make any sense? sorry for sounding a bit lame
Using a send is parallel compression
Hi Kev… as Andi points out above, what you have actually created is a parallel compression buss.
Its a really great way of mixing in extreme compression at low levels and adding some real life to the sound without completely smashing its dynamic range.
And.. yep of course you can use a multiband on the master output, this is a type of master buss compression really… you could follow this by a limiter to ensure your getting the volume you need and avoiding any overs or clipping.
TY Mo!
Hi!
Thanx for the tute. I’ve a question too. What is the multiband compressor ment for? I thought it IS for the buss compression AND mastering? Please, why do you say It’s not? ;-)
Thanx, Stepaan
Hi Stepaan… think you misunderstood ;)
i just said that it’s arguably not seen as true dedicated buss compression. i only say this because some people only refer to single band mastering grade compressors as ‘buss compressors’… its a jargon thing more than anything else.
but of course multiband compression is ideal for mastering and use on the master buss.
Hey Mo, what kind of SSL buss compressor have you got? you have 10 before 4 on ratio settings… :)
Hi. I use the UAD emulation of the SSL buss compressor myself, i also use Duende on some tracks.
The pic of the Waves compressor is just from the companies site.
A good buss compressor, especially for parallel you can check : Density of
http://varietyofsound.wordpress.com
And it’s free :) (along with the others plugins)
I cant believe it, that is amazing lessons for FREEEEEEEE
wow ! thx for that link & for the great tutorial !
a compressor i find really good for buss compression is “stardust” by Arguru
another great freebie > http://www.aodix.com/pagestardust.html
:) thx again, great article.
Does somebody knows if a good buss compression freebie exists for Mac OSX
-except SlimSlowSlider’s C3 multiband compressor- ?
Mo,your tuts are fantastic.
Carry on mate,many thanks !!!
Hi!
I’ve got one more question. (Or maybe two ;-) )
When you were speaking about low ratio compression, which values did you mean?
And one more… I still can’t reach the desired level of Loudness in my mixes. Other reference track stilll sound more “full” or simply “louder”. Is it because my mix has serious mistakes or is it within the mastering process. Thanx a lot.
Stepaan
Awesome article. Well researched. Thumbs up!!
Great Article. I gave it a Stumble!
wow. who would be stupid enough to pay for a sound engineering course when there is so much in google! :)
Great tuts, thanks a lot
Hi Mo!
First of all – I have been digesting your tuts and I simply love them! :) Thank you very much for that, it means a lot for me to find great tutorials and information about music production.
I have one question about buss compression.
I was reading one Deadmau5 interview and he said that most producers use only one or two buss to compress (like the drum group and one on the master), but that he creates 6 or even more.
So my question is which instruments / parts to buss and then apply compression to?
For example, does it make sense to group instruments that “fight” for the same frequency range (but are playing one at a time, eg. one instrument for 3 beats in a bar and than the other for the last beat in a bar), so that they are then “glued” togheter?
Or does it go by a different criteria other than the frequency range, like in the drum group.
Thank you and I wish you a great day!
Davor
What are the best crossover frequencies to use on the low, low-mid, high-mid, and high bands of a multiband compressor for hip-hop music?
I have a GSSL 4000 Buscompressor clone as hardware in my studio and also the UAD precision and SSL and allready tested incl. the waves SSL version. And after testing all in a long studio session I can realy say the waves version sounds like SHIT! for me. I would never suggest it to any friend or user.
UAD precision and ssl clone sounds the same. but only the precision has a wet/dry, input + output knobs and the famous highpass filter option for the bass frequencies. Both sounds great and near to the hardware, but I also dont use an original SSL one. =)
Multiband compression is not my taste. I think its much better to Mix the tracks and single busses right with EQs. Serial, Prallel and also “M/S Compression” working great for me.
Otherwise a good article. Thumbs up. Good work! =)
hi, Great aticle, but if I would like to compress into a real compresssor ?
any tips for it?
thanks
Edson.
For anyone interested in “mastering” tracks on their own, I highly recommend looking into iZotope Ozone 5. It has EQ, mastering Reverb, Harmonic Exciter, Dynamics, Stereo Imaging, another EQ, and a Maximizer (everything but EQ and Reverb are multi-band). It’s a little on the pricey side, but even the metering tools alone are worth the cost, I think. It gives you a very visual way to work with your music, and even though it’s usually good practice to mix with your ears, I find the tools very helpful for times when I have to use headphones or am in a noisy environment because it helps me get a more consistent picture of what’s going on in the mix.
Nice tutorial. I see that on the parallel compression example you have you dry drum signal going to the drum buss with a compressor and a compressed signal going to same buss. However, the text says that there is a 100% dry signal in the final mix, so does this mean you don’t put the dry signal through a drum buss with a compressor or do you still compress it by routing it the drum buss?
cheers