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Basso Profondo & Vienna Boys Choirs from VSL

Company's choral library range extended

Vienna Symphonic Library Basso Profondo Choir choral ensemble sample virtual instrument

VSL’s latest releases add two choral libraries to their product range, both recorded in the large hall at their Vienna Synchron Stage facility. The first, Vienna Boys Choir, makes the world-famous ensemble available as a sampled virtual instrument for the first time, whilst the second, Basso Profondo Choir features six contrabass singers and promises to deliver a mesmerising exploration of the lowest range of the human voice.

Both new libraries were inspired by the production of choral recordings for the Amazon Prime fantasy series ’The Rings of Power’, the prequel to ‘Lord of the Rings’. The recording sessions for Bear McCreary’s score took place at Synchron Stage Vienna in 2020 and 2021, and was the VSL team’s first collaboration with the Vienna Boys Choir, as well as the inaugural performance of the Basso Profondo Choir, an unusual ensemble of six oktavists.


Vienna Boys Choir captures an ensemble of 20 boys performing in Hall A, with a range of long and short notes, legatos and marcatos of AA (ah) and UU (oo) vowel sounds, along with humming and a variety of consonants combined with long and short vowel sounds. Basso Profondo Choir then benefits from additional techniques including short and long crescendos and diminuendos, and a range of lower register effects such as deep shouting, rises and falls, prayer-like performances, laughs and more. The pitch range spans from A1 to A#3.

VSL Vienna Boys Choir GUI Synchron PlayerBoth libraries are hosted in VSL's Synchron Player.

Mic Choices

As with many of VSL’s offerings, each library is available in Standard and Full versions. Both provide the same set of articulations, and differ only in the amount of microphone positions. The Standard versions offer four choices: Close and Mid stereo arrays, and Main/Room Decca Tree stereo and mono (left/right and centre). The Full versions then include Main Surround, High Stereo (3D) and High Surround (3D) options, and the Vienna Boys Choir also gains an additional Mid stereo option.

A range of mixer settings offer pre-configured sound characters ranging from classic to ambient, and as with all Synchron products, it is possible to mix in stereo, surround or immersive audio formats including Dolby Atmos and 9.1 Auro 3D.


Both libraries run in VSL’s Synchron Player, which is supported on PCs running Windows 10 or 11, and Macs running macOS 10.14 and above. VST, VST3, AU and AAX plug-in versions are available. Authorisation is carred out via PACE's iLok system, either via a USB dongle or iLok Cloud (the latter requires a constant internet connection). The storage requirements for each library are as follows:

  • Vienna Boys Choir Standard: 3GB
  • Vienna Boys Choir Full: 5.7GB
  • Basso Profondo Choir Standard: 6.1GB
  • Basso Profondo Choir Full: 10.1GB

Pricing & Availability

Both libraries are available now, and are currently (6 December 2023) being offered at the following introductory prices:

  • Vienna Boys Choir Standard: €135 (usually €165)
  • Vienna Boys Choir Full: €210 (usually €255)
  • Basso Profondo Choir Standard: €135 (usually €165)
  • Basso Profondo Choir Full: €210 (usually €255)

To mark the occasion, VSL are also offering previously released voice libraries from the Synchron-ized Series and Big Bang Orchestra Series at promotional prices.

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