Up for test is the Scan-Speak Illuminator D3004/6020-00 1″ Textile Dome Tweeter, 4 ohm.
This is the second time I have tested this. The reason for the second test is simply to have a better apples-to-apples comparison now that I have switched to using Dayton’s OmniMic measurement system. Product specs can be found here.
Small Signal Parameters and Impedance
Results as measured via Dayton’s DATs measurement tool. Which is a very little handy tool to have. 😉
- f(s)= 737.50 Hz
- R(e)= 3.17 Ohms
- Z(max)= 11.60 Ohms
- Q(ms)= 6.047
- Q(es)= 2.272
- Q(ts)= 1.652
- L(e)= 0.43 mH
Frequency Response and the following Harmonic Distortion measurements were taken using Dayton’s OmniMic measurement system.
The frequency response measurements below are on-axis (0 degrees) and off-axis (15, 30, 60 degrees), measured at 2.83v/1m.
Harmonic Distortion Testing
Maroon – Fundamental
Blue – THD
Red – 2nd Order Distortion
Pink – 3rd Order Distortion
Green – 4th order
Teal – 5th order
Testing done in the nearfield to emulate 90dB and 96dB output at 1 meter.
The Fs is measured at approximately 737hz. To get an idea of what this means on the high-pass crossover, let’s evaluate the HD results. At 96dB output the THD (blue) is 1.25% at 1khz. The THD is less than 0.50% down to 1.3khz where it is comprised almost entirely of 2nd order distortion above 1.5khz. Above 1.5khz there is about 10-20dB separation between 2nd and 3rd order components.
Measured sensitivity is right around 86.5dB. On-axis, there’s about a 5dB dip centered around 14khz. At 30 degrees off-axis, the response is down approximately 4.5dB at 10khz. At 60 degrees off-axis, the response is down approximately 9.5dB at 10khz. The trough in response from 1.5khz to 5khz is made to appear worse thanks to the high Qts on the low end and the rising response above 3.5khz. There’s a 7dB swing from 2khz to 8khz thanks to the upward rising response on-axis.
Bottom line: Okay response linearity with great distortion values. Great polar response with very low distortion above 1.3khz. This would make a good option for a tweeter in a 2-way system where there is a need to cross low to mate with a larger woofer. The response linearity may cause you some headaches here but with DSP and the sensitivity of this tweeter, you have some ‘headroom’ to scaled down the rising response to help smooth it out, if needed.
Comparison Against the Gladen 28mm
For what it’s worth, here are some pictures and data comparing this Scan d3004/602000 to the Gladen 28mm tweeter tested here.
Here is the on-axis response of both compared directly to each other. Black is the Scan, Blue is the Gladen 28mm:
Here’s a comparison of the Scan, Gladen 28mm, and Gladen 20mm (just for the heck of it):
And the response comparison of all three. Again, Scan is black, Gladen 28mm is blue and the Gladen 20mm is red. You can see from this comparison just how linear in response the Gladen 20mm is compared to the larger sibling and the Scan (but the Gladen 20mm cannot cross as low as these other two).
Update 03/18/15: Consistency Check
I recently initiated a Group Buy on these tweeters and with the multitude of tweeters ordered, I wanted to see how well the quality control was for each set. The below image is of an impedance sweep from (7) different units, all brand new in box. As you can see, the differences are negligible with the largest delta in Qts being 0.006 and Fs being 0.60Hz. That’s fantastic!
PS: If you would like to help me keep up funds for testing additional drivers, there’s a little ‘contribute’ button that goes through Paypal all the way at the bottom of every page. Any little bit helps.