Driver Measuring

 

 

The information provided on this page describes the process I go through to measure drivers. They are initially broke-in using a 25hz waveform from a Signal Generator at about 80% excursion.  After about 2-3 days at 25hz the the driver suspension is well broken in.  

After break-in they are measured using LspLab.  The attached "cut and post" is from two identical (???) drivers that measured less than perfect.  The advertised parameter set varies >20% from one of the T/S data sets.  Applying the advertised T/S parameters to an enclosure provides a "boomy" bass because the driver is grossly misaligned.  The advertised parameters are quite inaccurate and provide a big hump in the bass response.  Below is an illustration.   That hump in the blue line was audible and I didn't like it.  I removed the names from the drivers, but left the data sets.  I also didn't include the advertised parameter set of this driver, because some folks might correlate the T/S parameters, and get me into a defamation lawsuit.  The sole purpose of this illustration is to depict the volatility of drivers, and how LspLab works.  I really like LspLab.  It is the best tool I own.  It enables me to get the enclosure alignment absolutely perfect - even when drivers vary from manufacturers specifications.

 

LspLab is truly a godsend.  Some manufacturers maintain close tolerances with their actual/advertised Thiel/Small parameters.  I believe most do not.  LspLab removes the guesswork. It is a software/hardware tool that uses the computer soundcard and an impedance bridge to measure drivers.  After measurement, the driver's Thiel/Small parameters are modeled in the proper enclosure.  The result is the flattest response possible in the bass region with your particular driver.  The days of a few discrete alignments are over.  LspLab ushers in the latest technology available for modeling the enclosure with the the drivers exact parameters.  The density and volume of stuffing  applied in the enclosure will change the character of the bass slightly, but will remain profoundly close with this alignment method.