Hideaway TL Sub Revisited

Following the publication of the original Hideaway TL Sub project in audioXpress July 2006, Bjørn Johannesen submitted a follow-up of its “invisible” subwoofer project, using a new updated driver - a Peerless 10˝ SLS 830668 woofer - and a slimmer profile to fit under its new couch, with only 15cm of free space. The article was originally published in audioXpress, October 2007.

This article, a Danish blueprint for an “invisible” subwoofer was originally published in audioXpress July 2006 and it is the first of two by Bjorn Johannesen. In this first article, the author describes a successful transmission line to replace a vented sub, inspired by Rick Schultz articles. A project where the first approach revealed a resonance frequency lower than expected — lower than the driver’s Fs, leading him to study Martin J. King’s quarter wave design.

Inspired by debates on the Internet about quarter wave designs with Tang Band 3˝ full-range drivers, the author decided to design its own quarter wave loudspeakers. This article was published in audioXpress, March 2007 and the results were simply spectacular, generating worldwide interest. Recently, Bjorn Johannesen created a successful business with his own speaker company, called KVART & BØLGE, which means Quarter & Wave in Norwegian and Danish.