ISL 2 from NUGEN Audio is a true-peak brick-wall limiter for post production, broadcast and mastering work, with loudness and surround support.
ISL 2 at a glance
| Developer | NUGEN Audio |
|---|---|
| Type | Effects / Limiter |
| Formats | VST3, VST2, AU, AAX |
| Operating systems | Windows XP or later, macOS 10.6 or later |
| Architecture | 32-bit only |
| Free trial | Available |
| Price on Plugin Boutique (October 2026) | €241.96 |
What ISL 2 does
The limiter is built on true-peak algorithms that follow ITU-R BS.1770 and related standards, including the true-peak detection that Apple specifies for Mastered for iTunes material. Setting a true-peak ceiling lets the limiter handle the rest of the chain, so producers do not need to leave extra headroom to guard against intersample overs.
The developer states that true-peak limiting is used to ensure that downstream codecs such as mp3 and AAC do not introduce clipping. Directional integrity can be kept while controlling the surround centre channel in atmospheric material.
Key features
- True-peak ceiling control. A single true-peak limit is dialled in, and the limiter manages the output ceiling against intersample peaks, which the developer presents as a way to avoid sample-peak limiting errors.
- Standards-based true-peak detection. Detection follows ITU-R BS.1770 and the related standards, so the output can be checked against broadcast and streaming loudness targets.
- Steering and ducking meters. Processing visualisations include steering and ducking meters that show how the limiter is reacting, which the developer describes as a guide to settings.
- Surround centre channel control. Atmospheric ambience can be tamed in the surround centre channel while preserving the directional integrity of the mix.
- Brick-wall output. The output is a true brick-wall limited signal across mono and surround layouts up to 7.1.
ISL 2 compared with similar plugins
Other true-peak limiters in the catalog include FabFilter Pro-L 2, a limiter with VST3, VST2, AU and AAX builds for Windows and macOS. SSL X-Limit is also a limiter from Solid State Logic with VST3, VST2, AU and AAX builds for Windows and macOS. BUTE Limiter 2 (Surround) from Signum Audio is a limiter with VST2, AU and AAX builds for Windows and macOS, and it differs from ISL 2 by its format list and the absence of VST3.
| Plugin | Developer | Type | Formats | Systems | Price |
|---|---|---|---|---|---|
| ISL 2 | NUGEN Audio | Limiter | VST3, VST2, AU, AAX | Windows, macOS | €241.96 |
| FabFilter Pro-L 2 | FabFilter | Limiter | VST3, VST2, AU, AAX | Windows, macOS | €167.59 |
| SSL X-Limit | Solid State Logic | Limiter | VST3, VST2, AU, AAX | Windows, macOS | €14.88 (regular €49.98) |
| BUTE Limiter 2 (Surround) | Signum Audio | Limiter | VST2, AU, AAX | Windows, macOS | €108.09 |
| BUTE Limiter 2 | Signum Audio | Limiter | VST2, AU, AAX | Windows, macOS | €64.46 |
Price and availability
ISL 2 was listed on Plugin Boutique in October 2026 at €241.96. A free trial is offered. Prices change often, so the store page shows the current one.
ISL 2 FAQ
Is there a working serial key or keygen for ISL 2?
A working serial is the string most often typed with the plugin name, and a registration code, activation code or keygen query follows the same pattern.