ScanSpeak D3004/664000


The D3004/664000 is a 4Ω tweeter from the ScanSpeak Illuminator series. It’s virtually the same tweeter as the D3004/660000, but uses a very exclusive (expensive) 1” dome diaphragm made of 99% beryllium instead of a 1” textile dome.

It offers a very sturdy build quality with a rubber coated metal faceplate. Its large roll surround and textile dome diaphragm provides a frequency response to 40KHz with outstanding off-axis dispersion and low distortion.

The unique AirCirc Magnet System and its rear chamber results in elimination of reflections and resonances that compromise the performance of traditional motors.

This very nice tweeter not only measures well, but also sounds great and is capable of low cross-over points.

ScanSpeak Spec sheet: D3004/664000

T/S Parameters:


Nice consistency between the samples and almost the same resonance frequency as the manufacturers specification.









Free air impedance measurement:
Sample 1 = Green
Sample 2 = Blue

A perfect match between the two samples.







Frequency measurement conditions:

The tweeter is measured mounted in a 14 liter Dayton Audio enclosure (PartsExpress part #302-721) baffle with the following conditions:

Baffle size: (WxH): 21,59×35,56cm (8,5″x14″)

Driver position: Mounted on center-line with driver unit center 8cm from the top of the baffle.

Mic position: 1m distance, on tweeter-axis.

Smoothing: No smoothing applied.


0deg tweeter-axis
Sample 1 = Blue
Sample 2 = Red

Virtually the same frequency response between the two samples. At 3.5kHz the baffle diffraction is noticed as a dip in the frequency response. This dip is reduced in the off-axis measurements. The tweeter has a slightly dropping top-end frequency response from 15kHz to 25kHz. Very extended frequency response in both ends.


0deg = Blue
15deg = Red
22.5deg = Green

30deg = Blue
45deg = Red
60deg = Green




Measurement setup:

  •     Tweeter near-field measurement at 10cm
  •      Frequency Range Tweeter: 500-10000Hz
  •      Baffle size WxH: 21,59×35,56cm (8,5″x14″)


The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 85dB, 90dB and 95dB at 1m. This setting simulates normal to medium-high and high listening levels.


85dB @ 1m (click on picture to zoom)

Left = Sample 1

Right = Sample 2


90dB @ 1m (click on picture to zoom)

Left = Sample 1

Right = Sample 2


95dB @ 1m (click on picture to zoom)

Left = Sample 1

Right = Sample 2


The odd-order harmonics are very low, even at higher levels throughout the tweeters usable frequency range. The harmless 2nd order harmonics is a bit elevated compared to the odd-order harmonics.

There is no sign of the odd-order distortion remnants from the cone break-up, which is common for metal domes. Usually hard domes with a cone break-up at 20-30kHz has some odd-order distortion remnants between 6.5-10kHz.

To sum up, this is a very low distortion tweeter and it can be used as low as 1.5kHz with an appropriate filter.