For both reading and writing:
For reading only: MP3, FLAC, OGG, OPUS, M4A (AAC and ALAC). Quantum might not recognize multi-channel or high sample rate audio files in these formats.
Warning: the AU file format used by Quantum (also known as Sun/NeXT audio, SND, or "basic audio") is unrelated and not compatible with the *.au files used internally by the Audacity free editor, although they use the same file extension. Audacity can both load and export audio files in the AU format used by Quantum though.
Yes. Quantum supports mono, stereo and multi-channel files (including 5.1 and 7.1) as long as the individual channels correspond to stereo/spatial information (and not to different "tracks"), and as long as there is enough memory.
If the channels correspond to different "tracks" (such as vocal, bass, etc), it is preferable to split the tracks into individual files and to transform them separately. The reason is that Quantum locks the phase of all channels of a multi-channel file in order to preserve the stereo (or spatial) field. Locking the phase between unrelated tracks on the other hand might result in a deterioration of the quality, which is why unrelated tracks should be transformed individually - using separate files. If a given track is stereo, it should be extracted into a stereo file rather than in two mono files.
The maximum is 4 times slower or 4 times faster.
Note that within the application, the slider (see (1) in the figure below) only allows you to choose from 2 times slower to 2 times faster (which is the recommended range). You must type a value directly in the number field (2) next to the slider to choose a higher ratio up to the maximum. Transforming more than 2 times slower or faster might result in lower quality.
There is no limitation as long as you have enough disk space and enough processing time. Quantum has been tested with audio files of several hours of duration, and might be able to process even longer files.
There are a few caveats though:
No. However, you can save in a 24-bit or 32-bit format (see Section 3.2.3 ) and apply dithering afterwards using your favorite DAW.
Quantum is accurate up to a single sample even with audio files of more than one hour, as long as the quality is set to 3 (default) or greater. With lower quality settings, the result can drift from a few samples.
Even if the time stretching ratio is displayed as rounded in some parts of the user interface, the exact entered value is remembered and used, up to the 10th decimal point.
This depends on many factors. Using a 44.1 kHz stereo file, it generally takes about 5 - 10 seconds to produce 1 minute of audio on a 3 Ghz processor using the default quality setting.
Yes, on most computers, Quantum is faster than real-time with the default quality setting of 3. The highest quality settings (5) is designed for off-line processing, and may not achieve real-time speed on all computers.
No, the current version is only available as a stand-alone application. A future version might be available as a plugin.
Some DAW might support drag and dropping audio files or tracks to the "Input Files" list of Quantum, and then drag and dropping back the transformed files or tracks from the "Output Files" list. While not as practical as a plugin, this feature might simplify the workflow when working with both a DAW and Quantum.
Yes and no.
For example, if there are 4 CPU cores, and you transform 10 files, Quantum will start transforming the 4 first files at the same time using the 4 available CPU cores, and the 6 other files are held in a waiting queue. As soon as one of the files is finished, the corresponding CPU core immediately starts processing the next file in the queue, keeping all the CPU cores busy.
Note that by default, Quantum uses at most half the number of logical CPU cores available, which might not always correspond to the number of physical CPU cores available. This setting can be changed in the global settings (see section 4.3.2)
Whatever XY is, the answer is probably no.
Quantum does one thing, and does it well. That one thing is time stretching audio files.
Transforming a 5.1 audio file at 192 kHz takes less than 100 MB at quality 3, and less than 300 MB at quality 5 (maximum). In fact 50 MB is sufficient to transform a stereo, 44.1 KHz file.
Note that transforming multiple files simultaneously using multiple cores may require proportionally more memory.
If the maximum memory is not sufficient to transform a file (for instance if it has many channels and/or a high sample rate), Quantum will not transform it and display an error message. If the maximum memory does not allow transforming multiple files at the same time, Quantum will automatically reduce the number of files that are transformed simultaneously, meaning that the number of CPU cores that are used will be reduced too.
Quantum only requires an internet connection when you ask it to:
Apart from that, no internet connection is required while using Quantum. In particular, no internet connection is required to validate a license key.
None, apart from the protection from the
Only a license key (also known as a "serial key").
There are not separate demo version and full version. There is only one version that runs in demo mode as long as no license key is entered. As soon as a valid license key is entered, all features are enabled and the application runs in "full" mode.
No internet connection is necessary when entering a license key to register the application and unlock all features.
Quantum is available for buying on its home page here. There are three places where you can buy it:
If you installed the demo version and plan to buy the full version from the Microsoft Store or from the Mac App Store, you must uninstall the demo version first!
Note: Quantum is free for users that have already bought a license for Tachyon. The Tachyon license key can be used to activate the demo version of Quantum. Note however that the reverse is not true, a Quantum license key cannot be used to activate Tachyon. Quantum license keys are less expensive than Tachyon's. To activate Quantum if you already have a Tachyon license key:
Quantum is simply installed like any other application from the
When you buy Quantum, you should receive an email with a Licence key. If not, contact your reseller.
To install Quantum:
Yes, you can download it from here.
Note that there is only a single version that acts both as a demo version and as a full standalone version (from KVR): it runs in demo mode as long as no license key is entered, and in full mode as soon as a valid license key is entered. When you buy Quantum, what you actually buy is a license key to unlock all features.
For that reason, the application will ask you to enter a license key every time you start it. Just click on the button to use it in demo mode, and then on .
If you have installed the demo version and plan to buy the full version from the Microsoft Store or from the Mac App Store, be sure to uninstall the demo version first!. Else you might end with two versions installed.
The 30 seconds limitation allows you to try before you buy. However, this does not mean that the application is free for less than 30 seconds audio files. If you plan to continue using it after a 30 days evaluation period, you must buy it.
Yes as long as Quantum is not used on more than one computer at a time. Else, you need additional license keys.
This is only valid if Quantum was bought from the KVR Marketplace. The
The application is associated to your
Just download the demo version on your new computer, install it, start it, and enter your license key. This will unlock all features.
If you still have the email with the license key, you can copy it from there. In the Quantum application, you can then use the button when your license key is asked.
If you still have your old computer, you can start Quantum, choose the, menu, and click on the button. You can then paste the license key on a text file and transfer that file to your new computer.
Yes. The Windows and the MacOS version must be bought separately. There is no way to transfer from one to the other, because they come from two different stores.
No, you can just download the demo version for Mac (or Linux), and then enter the license key of the Windows version you initially bought to unlock all features. This also works the other way around. The license key is not bound to the operating system. This also works between the 32-bit and 64-bit Windows versions.
You can use the, menu to view the license key on your old computer. Right-click on it and choose the context menu to copy it to the clipboard. From here you can paste it in a text file and transfer it to your new computer. On the new computer just paste the license key on the dialog that asks for it when you start the demo version. You can also use the , menu after the application has started.
No. Only the supported versions (Windows 64 bit and MacOS) are available on the Microsoft Store and the Mac App Store.
Yes. What you need to do is to buy one of the supported versions (Windows 64-bit or Mac OS) from the KVR Marketplace (do not buy from the Microsodft Store or from the Mac App Store). You will receive a download link for the installer and a license key. Just ignore the download link. Download the demo version of the unsupported version you want, start it, and enter the license key to unlock all features.
Remember this is unsupported. Try the demo version first and be sure it fits your needs!
Quantum is proprietary software. It comes with the following End User License Agreement.
Quantum can be uninstalled like any other application from the
Warning: if you uninstall and reinstall Quantum, you will need to enter a license key again.
While the process of time stretching mostly preserves the loudness, it frequently increases the level of individual peaks, which would result in clipping. This is especially true with modern mastering that have been brick-wall limited with virtually no headroom. By default, the Quantum application automatically reduces the loudness of the transformed files as necessary to prevent clipping (peak normalization).
This behavior can be modified by disabling the "Prevent Clipping" option in the transformation settings. See section 3.2.3 to change the setting on individual files, or section 4.3.1 to change the setting globally. Disabling this option might result in clipping on the transformed file, unless the output file format is set to one of the 32-bit float formats. Note that with these formats, samples might still be above the ±1 maximum "normalized" value and do clip when played, but the true values are not lost and a DAW can then normalize them properly or apply a suitable dynamic range compression.
In general, we recommend you transform audio files with sufficient headroom to prevent clipping or automatic lowering of the volume. Audio files normalized to EBU R128 for instance rarely clip when transformed. Dynamic range compression, brick-wall limiting and any other form of loudness maximization is better done after time stretching, if ever.
Make sure Quantum is not saving files in PCM 32-bit floating-point format. This format is recognized by most professional DAW, but might not be recognized by consumer audio players.
You may want to save the transformed files in PCM 16-bit or 24-bit instead. See section 3.2.3 to change the output format in which transformed files are saved.
If a file is currently being transformed, select it in the "Output Files" list, and click on the button. In the "Transformation" tab, there is an item labeled "Processing time" that displays both the time elapsed so far on this file, and an estimation of the time remaining (ETR). The estimation might be inaccurate or unknown at the beginning of the processing, but it gets more accurate as the processing advances.
If multiple files are processed, there is no estimation of the total time remaining.
Because you are using the demo version. The full version does not have this limitation, but is not free. You need to buy a license key and to enter it in the Quantum application, or to uninstall the demo version and buy the full version from the Mac App Store or Microsoft Store.
It is possible to instead explicitly specify an output directory in which the fully transformed files are stored. See section 3.2.3 (individual file setting) and 4.3.1 (global setting). See section 4.3.2 (global setting only) to change where the partially transformed files are stored.
On the drop-down under "Time stretching factor", choose(FPS = [video] Frames Per Second). Enter the original video frame rate in the " " field and the final video frame rate in the " " field.
For example, a typical NTSC to PAL conversion plays a video track originally at 23.976* FPS (NTSC) on a 25 FPS system (PAL). In that case, to stretch the audio accordingly, enter 23.976 in the "" field, and 25 in the " " field.
*This value originates from a 29.97 FPS (the true NTSC FPS) video track converted by an approximate 24/30 ratio. An exact conversion of a 29.97 to a 25 FPS video track is generally difficult to perform with good image quality, which is why the resulting video track is typically at 23.976 FPS instead of 25. However, in case the video track is converted exactly (with an exact 29.97/25 ratio), there is no need to stretch the audio track.
When in doubt, you can also choosein the drop-down under "Time stretching Factor", and enter the exact initial and final length of the video to properly stretch the audio accordingly.
Note: Quantum does not handle video or movie files. You must extract the audio tracks from video files with your video editor in order to stretch them using Quantum.
Yes and no. There is no "preview" feature.
However, when you hit the button to transform a file, you do not need to wait until the file is fully transformed to play the result.
Just select the file (in the "Output Files" list) and hit the button (under the "Output Files" list) and Quantum will play as much audio as is already transformed. Note that you might still need to wait some seconds (and even longer for files with a high sample rate) before the first few seconds of the file are transformed and can be played. As more of the file is transformed, the player will allow you to play more.
The player itself shows both the playback position and the amount of audio produced yet (the "processing" position); see section 4.1. The current duration of the transformed audio is also displayed next to the file name in the "Output Files" list, and is regularly updated until the transformation is finished.
If the file is not fully transformed but you are not satisfied with the result, right-click on the file in the "Output Files" list, and choose from the contextual menu to cancel the transformation.
If you want a quick and low-quality preview of the whole transformed file, see section 3.2.2 to lower the processing quality (which results in faster processing).
Also note that by default, Quantum transforms files using low priority (or background) threads, to make sure the system does not get unresponsive. The consequence is that other CPU-intensive processes that do not run with background priority might sometimes "steal" CPU cycles from Quantum. You can also change the priority of the processing threads used by Quantum in the global settings described in section 4.3.2.
Note: because of a bug, sometimes the GUI does not respond when returning from sleep mode or lock screen. Just move the Quantum's main window and the problem should go away.
Generally, because the sample rate or the number of channels is not supported by the Mini Player integrated in Quantum.
This can also happen if another application has exclusive access to the default sound card.
The Mini Player in Quantum is a basic player: it plays through the operating system's default audio output, and does not try to detect or use advanced
In Quantum, right-click on a file, and choose the
Choose the Appearance" drop-down, and click on . Now Quantum looks professional., menu; select the "Appearance" tab; Select in the "
Quantum was not developed by a big company, but by a single person (Nicolas Juillerat, from Fribourg, Switzerland) working on it about one day a week. As such support is not expected to be the same as that of big companies.
You may get answers by:
Visit the Home Page of Quantum Audio Time Stretch.