Past meetings of the Society
April 2007

April 2007 Meeting

Date: Sunday, April 15, 2007
Time: 6:00 PM
Place: Boston University, Life Science & Engineering Bldg, 24 Cummington St, 1st Floor Conference Room (room 203), Boston, MA 02215, (617) 271-6588

Featured Guests: Keith Larson and Brian Smith, Smith & Larson Audio,
Topic: Lecture and demonstration of automated testing of speaker drivers

What is the Woofer Tester (WT2)?, USB powered, Low power precision impedance and phase meter, Constant current drive (0 to 3mA adjustable) from -20Khz, Precision Thiele Small parameters, RLC meter, Cable tester, Vented, sealed, bandpass and Passive Radiator box design/simulator, Air core inductor designer... this is the 'Speaker Measurement Interface' from MCM-Tenma

Speaker Tester (ST), USB powered, In air acoustic testing, Swept sine and pulsed sine, MLS and Impulse modes, Time decay analysis, Distortion analysis, Interactive Crossover Designer (ICD), Use SPICE circuit defined crossovers to create bass/treble signal pairs to interactively analyze a speaker before committing to a physical implementation. - Tweeter protection circuit (a direct amp connect can lead to a disaster!), -Frequency/Phase defined method

Woofer Tester Pro (WT-Pro), Combines WT2 and ST in one box, *Additional* in box--high power Z/P test port (via external amplifier), Analyze Thiele/Small parameters from nano-Watt to 200-Watt drive levels, Reveal suspension, motor and other drive-level dependencies, Fast MLS and Step mode Impedance and Phase (fast, but less acurate)

Demonstration(s), Speaker cabinet Design, Interactive Crosssover Design, WT-Pro High Power Test-- Run speaker at high/low power, collecting TS data

In addition to demonstrating the Woofer Tester product line, Smith and Larson Audio will be awarding one Woofer Tester 2 (the WT2 is a USB based Thiele Small and RLC measurement system) as a door prize at the BAS April 15th meeting. Information on the Woofer Tester 2, Speaker Tester and Woofer Tester Pro can be found at

Directions:  At Boston University, Cummington St is an east-west street just south of Commonwealth Ave. It is one-way going west. Parking on both Commonwealth Av and Cummington St. is free and available.

From Storrow Drive going east, take the first BU exit. At the stop sign turn right on Commonwealth Ave (A left is not permitted). Bear left and at the 3rd light take a u-turn, go half a mile and turn right on Blandford St. (at a traffic light) and turn right on Cummington St.

From Commonwealth Ave going west, after Kenmore Square, after the tracks come up out of the tunnel, turn left onto Blandford (at a traffic light). Then turn right onto Cummington St.

MBTA Green line - exit at Kenmore Square or the next stop, Blandford St. & Commonwealth Av. Walk a short distance and make a left turn onto Blandford St. and right onto Cummington St.


The Boston Audio Society
PO BOX 260211
Boston MA 02126

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updated 5/8/07