Update March 2020: API Audio has announced an expanded 2500+ stereo bus compressor with updated features, including an Expanded Threshold control (+20dv to -20dv) and the new Mix/Blend function that was added to the 50th Anniversary Edition of the 2500 released last year. Learn more here.
Finding a stereo bus compressor that works for you is an important part of being a mix engineer. For many, the API 2500 has become the industry standard, as the discrete compressor offers you the ability to glue together mixes via two distinct styles of compression and add punch to the low end.
API's 2500 features a dual-channel design that can be used individually for single-channel compression or paired together in tandem for stereo use. When it comes to the styles of compression, users are able to choose between “old” and “new.” Old style employs the “feed back” compression of the API 525, while the new style gives a “feed forward” compression feeding the side chain directly from the input.
To achieve the aforementioned punch on the low end, API has included its patented THRUST circuit on the stereo bus compressor. This selectable filter puts a low-cut, high-boost EQ into the audio signal, which ultimately allows the compressor to focus less on lower frequency sounds in the mix. The result is chest-thumping low end and a stronger mid-range.
With its status as a mix bus heavyweight, it's no surprise that the 2500 has been recreated in countless different forms, including the 500 Series format and digital emulations. Watch our new VK Shootout below to hear the 2500 used on several mixes and hear the same mixes using the API 529 500 Series Module, in addition to the Universal Audio and Waves Audio plug-ins.