This section is dedicated to the analysis, testing and modeling of high performance drivers for DIY use. A significant number of drivers are currently available to the DIY through different suppliers.
These are all drivers I played with in search for a "good" project
or simply because I had them on loan to measure for a fellow DIY
enthousiast. Before engaging in any DIY project, it pays to
measure T/S on cone drivers or frequency responses, impedance etc on
planar and ribbon drivers. I have the tools, both measurement and
simulation. Each project came with a learning curve and I feel
that all of this has given me more insight in the compromises one has
to make in chosing his or her "ideal" speaker.
T/S parameters are measured using LAUD 3.12. The T/S test amplifier has a frequency response from 3 Hz to 100 kHz, -3dB or 5 Hz to 40 kHz, -1dB and is stable in any load.
The acoustic measurements are performed using LAUD 3.12. Microphone used is an ACO Pacific, model 7012, response flat from DC to15 kHz, 0.5 dB up at 20 kHz, 1 dB up at 30 kHz. This condenser microphone will handle 164 dB SPL with less than 3% harmonic distortion. The latter was considered a must for large signal testing.
A CinePro 1K2 in bridged mode is used for large signal testing of the transducers as it is capable of delivering over 1 kWatt to the load.
Modeling is performed in LEAP 4.6. This modeling program is powerful and accurate. All modeling is performed for the same size box, sealed or vented applications. This results in different system Q factors but will give a clear indicator which drivers can be fitted in small boxes. Smaller box size is in a lot of applications just a SOAF must. Smaller box sizes are prime candidates for electronically assisted alignments. In these cases box size is traded in for amplifier power.
Copyright (c) 1997-99, by Rudi A. Blondia, ALL RIGHTS RESERVED. Last update: January 2005.