• Home
  • Mid-Horns
  • K53k Adapter!
  • Tweeters
  • Gallery
  • Why Symmetric Tractrix
  • Links
  • Testimonials
  • Contact & Ordering
  • Whats New
  • Fastlane Catalyst
  • Slant Riser
  • More
    • Home
    • Mid-Horns
    • K53k Adapter!
    • Tweeters
    • Gallery
    • Why Symmetric Tractrix
    • Links
    • Testimonials
    • Contact & Ordering
    • Whats New
    • Fastlane Catalyst
    • Slant Riser
  • Home
  • Mid-Horns
  • K53k Adapter!
  • Tweeters
  • Gallery
  • Why Symmetric Tractrix
  • Links
  • Testimonials
  • Contact & Ordering
  • Whats New
  • Fastlane Catalyst
  • Slant Riser

Fastlane Audio - Catalyst

The Fastlane Audio Catalyst project was inspired by the Klipsch OJAS speaker. I appreciate the simplicity of the design and the top-mounted horn concept, while preferring a smoother and more modern horn geometry over the traditional multi-cell Altec-style horn.


Instead, I chose to modify one of my own designs, the Eliptrac-400.


The Eliptrac-400 is a 300 Hz elliptical tractrix horn developed by myself and Al Klappenberger. The design was created to reduce corner reflections and diffraction effects commonly associated with rectangular horns, while improving directivity control, and overall clarity.


The goal of the Catalyst project was to combine the effortless dynamics and realism of horn-loaded  systems with improved imaging, reduced listening fatigue, and a more refined presentation suitable for long term listening.


The bass section of the Catalyst utilizes a front-ported enclosure tuned to approximately 40 Hz. The design was optimized to provide improved low-frequency extension and impact while preserving transient response and overall system efficiency. The front ported configuration allows for greater placement  flexibility within the listening environment , reducing sensitivity to rear -wall spacing and minimizing boundary interaction issues commonly associated with rear-ported designs.



Catalyst DIY Project.

Catalyst is a 2-way speaker with top mounted horn - crossover 800Hz

1.8 cuft internal

12

Eternal dimensions 21.5Hx15.5Wx13D


15



Cutting Template

22

Counter sink woofer.


Catalyst DIY Project.

Catalyst is a 2-way speaker with top mounted horn - crossover 800Hz


Cutting template

12

Port template, counter sink with 1/2 rabbeting bit.

Assembled for testing

15

Crossover 800hz.

22

Crossover is a constant-impedance 2nd order with a boost shelf centered around 15khz. 


Bass response taken at the port.

12

3D printed grill

15

3D printed risers

22

3D print or DIY risers



Woofer

12

Eminence Delta Pro 12


HF

15

Beyma CP750ND-8   WWW.USSPEAKER.COM

Crossover ALK AP-12-800

22

Crossover is DIY No longer available from ALK.

 Crossover schematic included with Catalyst horn purchase. 

Color combinations.

12

15

22

Attenuation

12

0 center +- 1db settings

15

Inspiration

22



Add a footnote if this applies to your business

Copyright © 2026 Fastlane Audio - All Rights Reserved.

Powered by

  • Sovol Unicorn mod.
  • Super Heresy WIP
  • Cutting template

This website uses cookies.

We use cookies to analyze website traffic and optimize your website experience. By accepting our use of cookies, your data will be aggregated with all other user data.

Accept