Category: Blog

  • Wimpy cardioid

    This is a great article on how to blend cardioid bass into a main system. https://www.merlijnvanveen.nl/index.php/en/study-hall/76-lack-of-impact

  • A note from the experts

    Nice article, outlines the challenges, yet provides no practical guidance 🙁 https://purifi-audio.com/blog/tech-notes-1/time-phase-alignment-acoustic-center-lobing-etc-14

  • Acoustic centre

    Nice little article for how to determine driver distance/time to a specific listening position.

  • Frequency response

    My favourite modelling plot. Each driver is linearised, and then the final on-axis frequency is levelled as well. I always say that the complexity in this project is the bass. Given that there are 24 bass drivers in the system, it’s no surprise. The glitches at the XO are an artefact from bringing XO filters…

  • Directivity Index

    Based on modelling, the DI is a bit weird at the XO. I suspect that this is a modelling glitch as the XO’s are exported from Acourate as FRD and loaded into modelling (VCAD) as general functions G(f). Only good/proper real measurements in an anechoic chamber will get data to determine and sort out.

  • Directivity

    The Keystone + Bedrock system directivity design is slowly converging. Getting close to the final step, namely to book an anechoic chamber and do lots of measurements.

  • Hornstone

    Trevor has recently found himself with a new horn based system, which made a big impression on all of us. So much so that John is now courting designing and building a horn system. He calls it “Horn Bang”. So have started thinking what a horn would be like in a version of the Keystones…