Designing an Acoustic Transmission Line with Spice

Below is a collection of technical articles on acoustic transmission lines. The contents have been published in the magazine AUDIOreview in a monograph divided into three parts (AR 408, April 2019; AR 409, May 2019; AR 410, June 2019) entitled Progettare una linea di trasmissione utilizzando Spice (Designing a Transmission Line with Spice).

Introduction and Historical Notes

Origin and development of acoustic transmission lines.

LTspice

Brief introduction to the LTspice circuit simulation program.

Radiation Impedance

A little more on acoustic impedance.

The Simulation Model

Introduction to the operating principles of a simulation model based on electrical circuit theory.

Analogies: Mobility and Impedance

A method for designing mechanical and acoustic systems.

The Equivalent Electrical Circuit and the Coupled Controlled Source

Description of the complete analog circuit and a useful Spice tool.

Model Validation

Simulation and measurements in comparison.

An Alternative Method for SPL Simulation

Development of a tool for fast SPL display in Spice.

The Speed of Sound in the Transmission Line Pt.1

An open debate.

The Speed of Sound in the Transmission Line Pt.2

Polyurethane foam as an absorbent material.

The Simulation with Foam

Optimization of the Simulation Model for the Foam.

Transmission Line Configuration

First simple design and addition of a coupling chamber in the simulation model.

Other Systems Compared

Transmission line, bass reflex and closed box in comparison.

Some Considerations and Tips

A few tips for the basic settings of a transmission line.