AudioThing Fog Convolver Review (WINNER ANNOUNCED)


As a dyed-in-the-wool atmosphile, I’ve had a long love affair with reverb and delay-based effects. I usually gravitate towards algorithmic reverbs since ambient soundscapes seldom rely on realistic spaces, so for years I turned my nose up at anything having to do with convolution, but in retrospect, I’ve come to appreciate how creative convolution processing has far more implications than just virtual acoustic reverberation. Having said that, you’re probably wondering what changed my mind…

Fog Convolver, developed by Dublin-based sound design lab AudioThing, hit the market late last month at a generous introductory price of fifty euros / just under sixty U.S. dollars. It comes stocked with over two hundred high quality impulse responses made from a wide variety of sound sources, and features a basic set of controls optimized for a hassle-free, no nonsense workflow.

The Review

The first thing that really grabbed me was its streamlined GUI. So many wonderful instruments and effects are bundled up in horribly unattractive interfaces, so it’s always nice to see a plugin that doesn’t make you want to scrub your eyes with an S.O.S pad. As for the factory content, I was especially impressed by the high definition recordings in the “Objects” and “Organic” impulse response folders. Obviously, top-tier recording equipment was used to capture distinct sounds like a lit match extinguished in water, raindrops splashing on an umbrella, granules of dry rice spilling into a glass bowl, and even hot grease sizzling in a frying pan.

While I can’t tell you that Fog Convolver offers anything that other convolution plugins don’t, it’s simple, modest design (similar to AudioThing’s previous plugin Frostbite) proves that less actually is more in certain situations. I don’t think convolution should be a complicated process, and it seems developer and founder of AudioThing Carlo Castellano feels the same way. The controls are intuitive. The preset browser combined with the ability to import external impulse response libraries saves you from having to create your own preset folder. Upon import, Fog Convolver saves the file location within its internal database, storing corresponding ATP files in a subfolder contained therein, so when you save over a patch, ATP files are automatically updated.

The visual representation of the selected impulse response appearing within the center display will change in accordance with the controls in real-time, which I’ve actually never seen before. It’s nice to be able to see what’s actually happening to the audio when you fine-tune the Pre-delay and Fade-In/Out parameters. I just love the In/Out Curve controls, allowing you to create very natural or unnatural late reflection times. I was even surprised by the way the LowPass and HighPass filters affect the visual representation of frequency content.

We were so impressed with Fog Convolver that we thought we’d pick the developer’s brain, so we scheduled an interview with the man behind the curtain, Carlo Castellano…

The Interview

BPB: Obviously, developing your own convolution plugin from the ground up is no small task. What do you think originally inspired you to create Fog Convolver?

CARLO: I was always fascinated by impulse responses and convolution in general. When I started developing my first plugins I started researching stuff to make my own convolution engine. Then, after watching a Diego Stocco video about convolution processing, I knew I was on the right path.

BPB: I can’t help but notice some rhythmic impulse responses in the factory library. Do you see future versions of Fog Convolver somehow becoming more and more focused on rhythmic ideas?

CARLO: I’m actually working on a convolution engine where you can load rhythmic impulses and time sync them with the Host. This can make the convolution processing less static, but there are still many problems to solve, so it will be a long project.

BPB: There are some really creative impulse responses in the factory library made from things like cocktail sticks, aluminum foil and packing peanuts. I was surprised by how these simple recordings often result in huge atmospheric spaces. Did you make these recordings yourself?

CARLO: Yes I did most of the Factory Bank. I experimented over a couple months with recordings of many objects and places and then selected the “right” ones. It’s amazing how anything can be turned to an ambience/reverb effect.

BPB: Approximately how much time and research would you say went into developing Fog Convolver, and do you think your knowledge and skillset as a developer was elevated by the experience?

CARLO: Approximately six to seven months of work, and of course I did learn tons of new things about plugins, especially debugging for different DAWs on different systems, which I think is the hardest part of the job.

BPB: What do you think makes Fog Convolver stand apart from other convolution reverbs? There are plenty to choose from; there are even some free convolution plugins that are actually quite good. Your thoughts?

CARLO: Most of the other convolution plugins I used were rather “clumsy”, too simple or very expensive. Fog Convolver GUI is simple and easy to use. The factory bank contains more than 250 impulses from analog gear to organic stuff. You can easily organize your presets and make your banks with the preset browser (categories, tags, rating, etc.) which I don’t think other convolution plugins have. Of course, Fog Convolver is not a new concept per se, but rather the way I see a convolution plugin should be.

BPB: Being a relatively simple plugin, do you have any big plans for Fog Convolver’s overall flexibility, or do you think too much of that sort of thing would detract from its simple, approachable look and feel?

CARLO: I’m already planning to make a Fog Convolver Pro. I’ve got lots of emails/feedback about new features that could really improve the plugin, like a four band EQ, LFOs/sequenced gates and more.

BPB: I’m very impressed by Fog Convolver’s interface, so minimal and tidy, similar to your last plugin Frostbite, which I reviewed not long ago. Did you design the GUI yourself, or is there a graphic designer onboard?

CARLO: There is a graphic designer onboard: the super talented John Gordon. We work actively together to bring both simplicity and beauty to our plugins. I usually have a rough idea of how I want it, he does his magic and then we fine tune it together.

The Verdict

On the whole, Fog Convolver is a capable and affordable third party convolution plugin with a bright future ahead. Within just a few weeks from its initial release, a v1.0.5 update has been made available, and the developer has been very open to customer feedback and feature suggestions on the KVR forum. We don’t know when to expect a Pro version, but we do know that plans for a host-syncable convolution engine are in the works, even though we probably won’t see the finished product anytime soon. These things take time. But regardless of where all of this is headed, I’m very happy with what Fog Convolver already is: a no-fuss, no-frills sound design tool with a modest feature-set, a beautiful interface, and a very useful impulse response library.

The Giveaway

AudioThing is kindly giving away one Fog Convolver license to one lucky BPB reader! To enter the giveaway, simply leave a comment below. Only one comment per person is allowed (duplicate comments will be removed). Please don’t reply to other people’s comments and use the main “leave a comment” button.

The giveaway is now CLOSED. The winner (picked by a random draw) is AK (a******.k*****[email protected])! Congrats! :)

Thank you all for entering the giveaway and many thanks to Audio Thing for the awesome prize! BPB is going on a 15-day vacation now and we’ll bring you lots more freebies and giveaways when we return. Thanks for reading BPB!

AudioThing Fog Convolver Review


On the whole, Fog Convolver is a capable and affordable third party convolution plugin with a bright future ahead. We don’t know when to expect a Pro version, but we do know that plans for a host-syncable convolution engine are in the works, even though we probably won’t see the finished product anytime soon.

  • Features
  • Sound
  • Workflow
  • Performance
  • Design
  • Pricing
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About Author

Bryan Lake is a sound designer and a musician. He publishes sound design tutorials and sound libraries on his website Sound Author.


  1. Heh. I have that Diego Stocco video, too. Really cool and inspiring stuff. Really dig the idea of this plugin.

  2. Nice to see continued development in this area of the reverberation market. Looking forward to more from this interesting company.

  3. Hey I’m down to get a free license! Great article, I’ve been looking into this bpb for only a few weeks now, but you have some solid articles. Thanks for the information. I blog over at if you have some time to check it out!

  4. Does a great job of allowing the user to really sink their teeth into what convolution is capable of, without getting too lost. Very pleasant GUI as well- AudioThing has a winner with this one.

  5. Looks fun! Been using Waves IR-L for my convolution reverbs so far, but always love looking at the next thing.

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