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Thafknar is the app formerly known as Rooms!. For obvious reasons concerning the uniqueness of the name, we decided for a name change. As a side effect, which we are sorry for, users of Rooms! who update to Thafknar need to reinstall their in-app purchases. Go to the Settings view of the Thafknar app, select In-App Purchases in the action menu at the top right, scroll to the bottom of the IAP list and tap Restore all previously purchased items. Restoring purchased items is free of charge.

This text describes Thafknar 7.0-7.2. The manual for Rooms! 5.0-6.7 is still available here.

You may want to read the notes in About Impulse Responses and Convolution if you are new to convolution reverb. Also have a look at the page Installing Impulse Response Files.

What is Thafknar?

Thafknar is an iOS application for recording audio and for adding reverb to audio files and to audio streams. It supports Audiobus 2, Audiobus 3, Inter-App Audio and AUv3, where the latter is described in more detail in Using Thafknar's Convolution Reverb as an Audio Unit. The Audio Unit functionality is an in-app purchase "Convolution Audio Unit".

Audio files can be uploaded to the app via iTunes File Sharing or by Document Interaction. With iOS 11+, you can also use the iOS Files app. Uploaded files, and files created by the app, can be shared by iTunes File Sharing, by Document Interaction or by e-mail. Two types of reverb are supported by the app: Algorithmic reverb created by an iOS Audio Unit, where you can control all parameters of the reverb effect unit, and convolution reverb. Via AUv3, Thafknar offers its convolution engine as an audio unit extension.

Thafknar's Audio Recorder view allows you to save M4A/AAC or WAV files with various sample rates and bit depths and later add reverb to these files. Using playthrough, you can in realtime add reverb to the sound captured by the microphone or from an external sound source.

The Files view shows files in the Documents directory of the app and in its iCloud Drive container: Sound files (e.g. the recordings created in the Audio Recorder view), cancelled recordings, impulse response archives and image files. There are various functions to handle these files, like listening to audio files or extracting impulse response archives to the impulse response library.

Reverb settings can be edited in the Parameters view, saved as presets and then be invoked in the Presets view. With the Preset Buttons functionality (in-app purchase "Preset Buttons") you can configure 3×3 grids with buttons for comfortably selecting presets, including Sounding Presets for playing sound clips. The buttons can be decorated with labels or with images.

Some functions of the Thafknar app are operable by MIDI control. The details are configurable in the Settings view. This is another in-app purchase "MIDI Control".

For a perfect experience, earphones / headphones or external speakers are recommended. For the playthrough functionality with microphone input, earphones / headphones are mandatory, otherwise a feedback loop is formed.

System requirements

Up to version 5.2, the app runs on all iOS devices (iPhone, iPod touch, iPad) with iOS versions ≥ 5.1.1.

Starting with version 6.0, due to App Store and Audiobus 3 requirements, the minimum target system of the app is iOS 9.3.5. The embedded AUv3 app extension needs iOS 10.3.3 or later.

Audiobus, IAA and iCloud support are available on iOS versions ≥ 7. Slide Over and side-by-side view support is available on iOS versions ≥ 9 and iPad Air 2 or better.

For using convolution reverb in realtime, at least an iPad 4 or iPhone 5 is recommended. Impulse responses that are too long will lead to reduced sound quality or even to stuttering or missing sound. You can try the suitability of your device with help of the included demo impulse responses. In case of performance problems, try using a longer buffer duration.


Thafknar supports the following languages:

Privacy policy, background operation, access to microphone

This is the privacy policy declaration required by Apple: Thafknar Privacy Policy Declaration

Thafknar does normally deactivate its audio session when the app is sent to the background and in consequence gets suspended by iOS. There are however a number of situations where the audio session is kept active:

In any of these cases, Thafknar stays running in the background, which is signalled by a red status bar. This signal cannot be suppressed; it is a means of iOS to protect your privacy by pointing to the fact that an app with the audio session category AVAudioSessionCategoryPlayAndRecord is active in the background, which could potentially be recording the microphone input. The signal is given even if the app does not actually record anything. The only way to get rid of the red status bar would be to change the category to AVAudioSessionCategoryPlayback, but unfortunately an iOS bug prevents this. You can read about this issue here and here. Rest assured that Thafknar does not capture microphone input unless you tap the Start button in the Recorder view or use the playthrough functionality. On iOS 7 and later, you can use the device's privacy settings to prevent Thafknar from accessing the microphone (in the Settings app of your device, go to PrivacyMicrophone and deactivate the switch for Thafknar). In this state neither the audio recorder nor playthrough functionality can be used – you will get a warning when you tap Start in the Recorder view or tap the microphone icon.

Avoid keeping Thafknar active in the background when you don't need this. This consumes processing power that might be missing for other apps, and of course it is a waste of battery energy.

How to use the app

The usage of the app is explained in the User manual. There is also a Version history and list of known deficiencies.

Demo videos

Auguste Larriu, Antienne, played with Wersi OX7 YouTube
Nicolas Lebègue, Duo du 4e (ton), played with Wersi OX7 YouTube
Clive Luis, Thafknar Reverb - Loading Acoustic IRs from 3 Sigma Audio YouTube