Dayton Audio WT3 Woofer Tester Review
- Product Name: Dayton Audio WT3 Woofer Tester
- Manufacturer: Dayton Audio
- Performance Rating:
- Value Rating:
- Review Date: April 17, 2008 18:50
- MSRP: $ 99.88US.unit
Primary Use: Woofer impedance measurement, Thiele/Small parameter generation
Secondary Use: Impedance measurement of drivers other than woofers and a variety of passive components.
System Type: USB (USB 1.1 compliant, USB 2.0, preferred).
Connector: 1 pair, built-in alligator clips
Power requirement: Unit draws power from USB port; no batteries or external power supply required.
Test signal: Upward-swept Sine wave
Frequency Display/Sweep Width (Hz): Adjustable LF & HF points
LF Limits: 1 Hz to 10 kHz
HF Limits: 10 Hz to 20 kHz
Software: Program included, must be installed manually
Calibration resistor supplied
Hardware manufactured in China, software in USA.
Warranty: Warranted free from defects in material and workmanship for 5 years from date of purchase .
- Easy to install & easy to use
- Impressively accurate measurement data
- Quirky user interface
- Limited data post-processing capabilities
- Minimal help section & user manual
The writer of the article implies that WT3 cannot provide SPL. While it's true that it cannot measure the driver's SPL it can calculate it.
In order to determine V(as) in WT3 for the driver being tested there are 3 methods:
1. input the driver SPL @1w/m as provided by the manufacturer (assuming you have a spec, and redundant in the context of this discussion)
2. mount the driver in a known (volume) closed enclosure and resweep
3. add a known mass (coins, plasticine etc) to the driver cone and resweep
When using either of the latter 2 methods, WT3 will automatically calculate the driver sensitivity and display the SPL @1w/m
*I have found both the closed box and added mass methods in WT3 to be very accurate as compared to micrphone SPL measurments
In fact, PE is now bundling a low cost (but sutably precise) digital scale to permit easy mass addition. This is the easiest method I have found.
I tried using coins as suggested by the WT3 docs (eg a Nickel is 5g) but found they jumped around too much.I now use a small "cookie" of automotive sealer (aka dum dum) that I roll into a ball, weigh, then flatten and place centered on the dome. It seems to have just enough tackiness to prevent "decoupling" when the sweep occurs. (after entering the mass of the added weight into the WT3 sotware)
after completing thee steps you will now have the driver V(as) AND SPL
Works for me!
All of the volume levels for both audio out and record in should be at the max and the balance be set to the middle. If your settings are not these you will possibly see anomalies (i.e. strange spikes or dips, jagged plots, etc...) in the plot graphs.
Also in Vista on some systems the USB ports can be individually adjusted, so if you set it up on one port for testing and then the next day use a different port you may see anomalies in the measurements.
And as stated in the article there is a 90 second stabilization time for the unit, it is necessary to wait otherwise there will be anomalies in the test graphs.
And if you have it set up properly and calibrated and are getting strange graphs there could be two other causes:
1) Other noise in the testing area (i.e. kids, dogs barking, etc...) these things will affect the plot (testing should be done in a semi-quite room.
2) The .ini file became corrupted, just delete it and restart the WT3
Hope this helps.