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Soundtheory Gullfoss
5 5 out of 5, based on 1 Review

An unconventional EQ with a unique approach to our age-old craft.


25th April 2019

Soundtheory Gullfoss Standard by Diogo C

Soundtheory Gullfoss

Thanks to digital technology and breakthroughs in computer power we have witnessed the arrival of audio processors that are far beyond what was possible ten years ago, and compared to the classic designs what we have in hands now would be easily described as science fiction material in the 1970s. Rising developer Soundtheory joins the high-tech ranks with Gullfoss, a plug-in that makes “intelligent” adjustments that are automatically and dynamically generated from the incoming signal — I’d describe its action as a unique form of dynamic equalization. In some ways it’s something similar in proposition to iZotope Neutron, Melda MAutoEqualizer and sonible smart:EQ plug-ins, although each of them have their own particular inner-workings and set of controls that sets one apart from the other. Gullfoss is perhaps simplest and straightforward to use of this current batch of forward-thinking EQs, it doesn’t boast a big feature list and there are only a few of parameters to play with, so it’s a rather minimalist plug-in. Let’s have a look at the available parameters:

  • Recover and Tame: Perhaps the most important parameters on Gullfoss, recover and tame will deal with respectively “dominated” and “dominant” components of a signal. Recover emphasizes the dominated aspects while tame will counter dominant portions. In practice, we can verify that in general terms more energy equals dominant. For example, a monophonic synthesizer bass line can be quite a dominant element while ghost notes on a snare or other nuances can be entirely dominated on a busy mix.

  • Bias: Determines the relationship between “recover” and “tame” for what Soundtheory calls “borderline cases”, situations where the plug-in has to decide which way to work. Positive values favouring more recovery. Inversely, negative values will give tame the precedence.

  • Brighten: The most intuitive and self-explanatory parameter — turn it up for more high frequency content, turn it down if a “darker” sound with less top end is wanted.

  • Boost: Raises low frequency whilst lowering the mid range. Alongside “brighten” it’s used for setting the frequency balance.

  • Range limiters: two controls for high and low frequencies to determine the frequency range where the plug-in acts, which works in the same way as a sidechain and is highly useful as it allows the user to tackle only the desired areas.

  • Gain: clean output gain with output level meter. There are also horizontal input and output level meters on the lower portion of the interface along with an action meter on the left side, so one can instantly visualize all the relevant information.
Other key difference from other “smart” EQ plug-ins is that using Gullfoss is unlike any other equalizer, and presenting it as such is actually a bit misleading — not because it doesn’t equalize a signal, but because it doesn’t feel like using an equalizer at all. It feels like something else, and I’m not quite sure we can set a parallel to anything else out there. Unlike other EQs, Gullfoss does not allow for a usual equalization curve alongside its smart component, and this should be a big change for most users. For example, you can throw a shelf or parametric band to adjust a certain frequency range. In this regard, it’s worthy bringing up an explanation from the developer’s website:
Gullfoss is an intelligent equalizer that listens to a signal and decides how to prepare the audio so that your brain can get the most information out of it. The real time analysis of Gullfoss uses Soundtheory’s computational auditory perception model to understand which audible elements are competing for your attention.
The first part of the sentence above is something that I can wrap my head around as it describes the preliminary part of the process, but the second part is a bit mysterious, so let’s bring it to the real world. I’ve chosen three totally different situations to test Gullfoss:

First one was a synthesizer track with a percussive edge and lots of resonance coming out of a Moog DFAM. Gullfoss did a great job, taming the excessive high frequency content coming from the ladder filter inherently resonant character while also making the low end tighter and intelligible. Most importantly it sounds natural and not overly produced despite the busy action on the display, and I was very impressed with it. Could I solve this with my other plug-ins? Yes, I’d probably slap a dynamic EQ and get it done. Would it sound as good? Probably. Would it be so effortless? Definitely no. Gullfoss wins this one, and it’s a big victory.

Second test was a guitar bus on a death metal song. This bus consisted of two insanely distorted guitars as one expects from the genre, and Gullfoss ultimately failed to deliver any satisfactory results. It didn’t fix a resonance problem in the low end without making it sound overly bright and thin, which I countered by taking the low end out of the processing and by lowering the “brighten” parameter, but in this case my regular parametric EQ moves were more effective, and Gullfoss couldn’t do much against it. In this particular case running it prior to the EQ with subtle settings wielded the best results, but I’m also not sure if I need it in the first place, so I’ll take it as a draw.

Third and final test was on the stereo bus of a jazz project that I’m currently working on. It’s a simple project, with mixes that only have two recorded tracks for electric guitar and vocals alongside a return channel for the reverb send. I’m also the recording engineer for the project, so I’m taking extra care to capture it without thinking of “fixing it in the mixes” and so far it’s been a successful approach. There wasn’t much for Gullfoss to improve or fix here, so all it did was to make it sound “different”, not better or worse. And that’s another draw.

Out of three tries I had one excellent result and two which are somewhat inclusive, which confirmed my initial suspicion: Gullfoss can be used anywhere and just like most audio processors it doesn’t work all the time, but the major difference is that I can’t tell when to use it or if I should use it all the time. I know when to reach for a parametric EQ or multiband compressor, but I can’t really say when Gullfoss needed - or if I need it all the time! In the end we all want our tracks to sound “good”, but that’s something entirely subjective and that are based on our artistic views, so ultimately it’s up to each one to test these tools and draw their own conclusions. Nevertheless, Gullfoss is an intriguing processor and one worth exploring, it can solve problems that may be hard to deal with otherwise but right now I’m more inclined to recommend it for newcomers than for grizzled veterans.


The scores:

Sound quality: Gullfoss is mostly transparent, and depending on the settings you may not even notice that it is running, which indicates a very smooth processing that only leaves a footprint when pushed to extreme settings. It’s undeniably a good sounding plug-in that can work on certain situations, it won’t fix a bad song or make St. Anger’s snare sound good, but it can be a valuable tool for both the novice producer looking for an aid and the experienced engineer who wants to add a different approach to the age-old craft of improving sound quality. In my experience it worked best to re-balance busy tracks and crowded modern mixes where powerful elements are all competing for attention, and it was also good as a first line of treatment against weird resonant spikes and tonal imbalances, smoothing things out so they could be further processed with regular EQ and compression. The lasting impression is good, although only extended time will tell if stays or not in the chain.

Ease of use: The small number controls and clean interface makes Gullfoss quite easy to approach and also relatively easy to master. It shouldn’t take long before the user gets acquainted with the parameters but ultimately my experience with it was a bit of playing dice as it may or may not work on the program material. Having said that, I’ll look at the bright side and towards the best possible outcomes i.e. the plug-in improves the material, and when that happens the road to get there presents no obstacles, it’s really easy to use. Perhaps my only complaint is the small click area for the parameters, it’s not really a big issue but something that could be improved with a bigger font size along with a wider click area. In terms of performance Gullfoss runs relatively smoothly without overly taxing the computer, but it’s not a lightweight plug-in and adds some extra latency (1028 samples @ 48kHz), so keep that in mind when running big sessions with multiple instances of the plug-in - for what is worth my tests were all conducted on a MacBook Pro (15-inch/mid 2015) with Pro Tools 2018 and Mojave OS. Lastly, the documentation is quite concise but does a good job on explaining the core aspects and functionality of the plug-in, but I wouldn’t mind more in-depth material.

Features: Echoing the passage above, Gullfoss’ feature set may be minimal but it’s also very powerful, and each control plays a big role on determining the end results. The whole concept that drives the plug-in is very well-defined and focused, and the feature set is adequate and does its job of supporting it. It’s hard to ask for feature X or Y to be added in this context of this plug-in, it’s pretty tight and cohesive — on its own terms of course. I appreciate the bold approach of not including “vanilla” filters but on the other hand I think a dynamic parametric band would do wonder here.

Bang for buck: Gullfoss has price tag that is fair and in line with most of the EQ plug-in market, and if you find that it elevates your setup then it is totally worthy of the investment. Having said that, this is where things get a bit tricky. On one hand, I can see Gullfoss being a valuable tool to improve a certain track on a mix or a stereo bus on mixing or mastering situations. Slap it there, play with the parameters and something good may come out of it and that’s great if the end results are satisfactory. On the other hand, I can also see some shrugging it off entirely and dismissing it based on its rather unconventional approach. Those that are more attached to the rudiments and fundamental techniques of our craft may consider it too enigmatic and may find that it’s too much out of their hands. I must confess that I fall more on the second camp than on the first, thus I’m balancing my score accordingly, Nevertheless, I fully recommend reserving some time to properly evaluate it, and fortunately there’s full-working demo that last for two weeks so everyone can find out if Gullfoss works or not for them.

Attached Thumbnails
Soundtheory Gullfoss-gullfoss.png  

  • 11
30th April 2019

Soundtheory Gullfoss Standard by macfrans

Soundtheory Gullfoss

Point of Interest
Having studied linguistics and phonetics at university I was intrigued by the idea behind Gullfoss : Using a model of the cochlea ( part of your ear) to determine how a given audio stream would have to be adapted in real time to sound "good" to the obviously abstract ideal listener. One might say that Gullfoss plays, to a certain extend, the role of the "average listener's ear" and adapts the equalisation of the incoming audio hundreds of times per second to fit that abstract persona.

The setting
I have a treated room, use quite excellent gear, but as I grow older and my room is not the ideal size I opted for IK-Multimedia's ARC long ago and the past few years for Sonarworks speaker and headphone calibration. Together with a precise hearing test and resulting EQ curve I have basically done all I could to adjust for both age and room when mixing. Nevertheless I have installed a couple of different speakers (all with sonarworks profiles) including some cheap ones to test before something goes out.

Even then, i sometimes had a mix come back with remarks "too this" or "too that" which is of course also due to the fact that I don't mix full time and write software and courseware too. So I want to stress here that I know I have my own shortcomings ;-)
And in comes Gullfoss.



That extra bit
I had a file just send back to me which did not quite "work" on the exhibition floor with a less than ideal setting for audio. Pressed for time I decided to run it through my newly acquired Gullfoss ( Early Adopters Price) on the master and I immediately heard a sense of equilibrium that I somehow had not been able to get with all my UAD and FabFilter plugs. Now I know there are tons of real good mixing engineers who will now cry out "Well, you must have done something wrong if you can't get it to sound right with that kind of gear!" And I agree. I should have. But I somehow still missed it, pressed for time, ears too tired , wrong setting on UAD's beautiful AMPEX.. I know, it was my own fault.
The point is I didn't notice and Gullfoss caught that bit IMMEDIATELY and instantly. I rendered, sent back the file and it was hailed as the coming of the Final Master.

I have had this response a few times since then.
Gullfoss is an excellent tool to have in your setup.
It helps where your own judgement is maybe a bit compromised ( for whatever reason).

At the helm

In practice you can use TAME or RECOVER and bias the algorithm towards one of those in its focus. Used on acoustic guitar it can eliminate sharpness or harsh pick sounds, used on drums it can liven up a kick with recover. You have to see it work to understand how fast it adapts. This is NOT a static equaliser, not even a dynamic equaliser. This is a continuously adapting EQ that matches an "ideal ear" either extremely ( with higher percentage settings ) or minimally ( lower settings). It allows you also to exclude lower and higher parts from processing by moving two RED BARS across the screen ( no limitation) so using it as an intelligent DE-ESSER is also possible. Or honing in on that SQUIEK from the fretboard...



I agree with reactions on GS that you don't necessarily need it all the time. Sometimes it does not "find much to do" as the graph will not move very much even when upping TAME and RECOVER. This means that your audio is already "in the zone" as far as Gullfoss is concerned. Happy to say that at least THAT has happened to me too.

Some GS-members have been comparing it to TDR NOVA, HarmoniQ, UNFILTER or Sonible Eq's ( All of which i own and have used) but I must disagree with them. Gullfoss is not like anything I have seen or heard before in my 25 years of digital audio. Test it for free for two weeks , try it on your masterbus ( last in chain before any Room -Correction) or on individual busses. I think you will find a place for it in your toolbox.

Happy Mixing!

  • 9
30th April 2019

Soundtheory Gullfoss Standard by blayz2002

Soundtheory Gullfoss

I've been a user of Gulfoss for maybe a year now. Since I first used it, it's the last process I do before bouncing my mixes to go to mastering. I have to say it's an awesome product, especially if used right on mixes.

Personally I reserve it for the mix bus, and I don't like to feel as though I'm trying to shortcut to a great mix or not try and learn and fix mix problems 'in the mix'! So, I don't add it to my mix bus until I feel I have a great mix, and it always seems to take it a few percentage further than I can.

I'm generally not even into double figures with settings most of the time to be honest, but it does a great job of opening up a mix and balancing it.

For me it's one of my best purchases for mixing recently along with Sonarworks and Voxengo SPAN (which is free!).

Thanks Gulfoss Team!

  • 3
3rd May 2019

Soundtheory Gullfoss Standard by Harvey Specter

Soundtheory Gullfoss

I'm going to give a quick and less technical review on this plugin.

As someone who would rather just get on with composing rather than be bogged down by production (which really kills the creative flow) I decided to try out Gulfoss as I'm prone to having too much top end in my mixes and too low mid range.

I tend to use Gulfoss maybe with more extreme settings than others, I'm usually around the 30% level and even up to 40% on the raw source electronic source material.

I say raw because Gulfoss goes first in any chain, if your audio has already been eq'd and compressed it does not work as well. It really needs to be the first plugin to process the audio. When applying eq after Gulfoss it now tends to be for sound sculpting needs than fixing issues as Gulfoss really does sort out a lot of problems before hand giving you a great starting point from which to use tools to give you that sound you are after.

Top tip, have Gulfoss on your reverb insert after the reverb, suddenly your reverb now comes alive.

I put this on the raw tracks as well as any groups. And yes I put it on the overall output buss before any 'mastering' process.

Worth the money? Oh yes very much so, in fact the only downside are the cryptic controls but I am getting around it nicely. It saves so much time and also can help when your ears get too tired and you start adding needless high eq.

  • 7
19th May 2024

Soundtheory Gullfoss Standard by dicky0001

  • Sound Quality 5.0 out of 5
  • Ease of use 5.0 out of 5
  • Features 5.0 out of 5
  • Bang for buck 5.0 out of 5
  • Overall: 5
Soundtheory Gullfoss

I have literally never bothered reviewing a plugin before (there’s plenty of people who love doing it so generally leave it up to them!) but I was compelled to write something for this plugin.

I am an award winning film composer, music producer, I also own and run a residential recording studio and we’ve been lucky to have some of the biggest acts in the world at our studios.

I was skeptical regarding’ “this plugin will fix all your mix worries and make everything sound golden” but it’s actually magic in a different way to what I was expecting.

I tend to make music with a HUGE track count (200+) and a lot of microphones capturing acoustic instruments + instrument plugins/synths etc. This often means that despite many years of mixing and production knowledge, inevitably there will be masking and getting everything to sit where I want it can be an incredibly TIMECONSUMING process.

For me Gullfoss is a polishing and time saving plugin, and not a fix-a-mix plugin (though it definitely can help with that.) I have a tendency to do a lot of subtractive EQ to create space in a mix. But with huge track counts, mixes can end up sounding darker than intended. Gullfoss for me, brings life back during the mastering process, without having to do a million automation edits, opening project files, then re-approaching a mastering file, then limiters exaggerate certain frequencies etc and back to the drawing board.

Overall this is what I found:
•Excellent mixes - Gullfoss can allow you to colour the mix in different ways, it’s a heightener rather than a dismantle and re-build. Even on a mix that my mix engineer did an insane job on, I found it a creative weapon without having to try and explain what I wanted in order to squeeze 2% more out of his mix I was 98% happy with.
•Average mixes/unfinished mixes to send to clients - too bright? Easy to calm a mix without tonnes of time taken. Too dark? Give it some shine. Masking? Adjust and print
•Tracked but nothing mixed: artists always want to have something to listen to quickly straight after a session. This is a crucial time when you don’t want an artist to listen to something they’ve spent a lot of money on in a studio, to have ANY doubt over. Gullfoss will allow you to do this quickly and put a smile on their face at the end of it, buying you time to do the actual nitty gritty mixing process and then polish.

Ultimately, Gullfoss (to me) is now a tool I cannot live without. To use an analogy, it’s the fastest F1 pit stop crew on the grid: saving you time, effort and peace of mind that nuts and bolts are securely fastened. But without the knowledge of how to drive an F1 car, you might find that you’ll spin off in the first corner. Learn to mix, do it well, do it badly, try and try again, but know that in the pits, everything can be tightened and get you around the track whatever the weather.

10/10