Overview:
The Monacor DT-300 is an 8Ω tweeter from the Monacor Number One series
Due to its large dome diameter of 30mm and the high efficiency the DT-300 is destined for higher sound pressure levels and lower crossover frequencies. Perfectly suitable for 2-way systems of high volume levels with a crossover frequency of >2kHz, available at a very competitive price.
Key features:
- 30 mm silk cone
- Low resonant frequency
- Excellent dynamic response and a high stability even with low crossovers
- Ferrofluid of high liquidity for a fine brilliance
- Especially suitable for high-performance applications and D’Appolito arrangements in the top hi-fi range
Monacor Spec sheet: DT-300
The 169mm WG-300 waveguide is custom made for the DT-300 tweeter.
Key waveguide features:
- Increase of the sound pressure
- Perfectly matched to the dome tweeter DT-300
- Limited omnidirectional radiation in the lower high range
- For avoiding reflections from walls nearby
- For PA applications of specific room segments
T/S Parameters:
(click on picture to zoom)
Slightly lower Fs than the official specification. Good consistency between the two tweeter samples.
Impedance:
(click on picture to zoom)
Sample 1 = Blue
Sample 2 = Green
Double impedance peaks, but but good consistency between the tweeter samples in their usable frequency range.
Frequency:
Frequency measurement conditions:
The tweeter is measured mounted on a baffle with the following conditions:
Baffle size (WxH): 24×35cm with 18mm round-over.
Driver position: Mounted on center-line with driver unit center 8,8cm from the top of the baffle.
Mic position: 1m distance, on tweeter-axis.
Smoothing: 1/24 octave smoothing applied.
DT-300:
(click on picture to zoom)
Top left: Frequency response on-axis (Blue=sample1, Red=sample2).
Top right: Frequency response 15deg off-axis (Blue=sample1, Red=sample2).
Lower left: 0deg = Blue, 15deg = Red, 22.5deg = Green
Lower right: 30deg = Blue, 45deg = Red, 60deg = Green
For a tweeter in this price range it has a very good consistency and the tweeter samples measures virtually the same. Besides the dip at 6.8kHz it has a smooth frequency response.
DT-300 + WG300:
(click on picture to zoom)
Top left: Frequency response on-axis (Blue=sample1, Red=sample2).
Top right: Frequency response 15deg off-axis (Blue=sample1, Red=sample2).
Lower left: 0deg = Blue, 15deg = Red, 22.5deg = Green
Lower right: 30deg = Blue, 45deg = Red, 60deg = Green
The waveguide raises the level about 8-10dB at 2kHz. The tweeter and waveguide combo can be equalised by a small capacitor. That means that distortion may be significantly reduced in the crossover region since the tweeter dome doesn’t need to move much because of the acoustic amplification from the waveguide.
Distortion:
Measurement setup:
- Tweeter near-field measurement at 10cm
- Frequency Range Tweeter: 500-10000Hz
- Baffle size WxH: 24×35cm
The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 95dB at 1m. This setting simulates a high listening level. A 2.2uF cap is used for the tweeter+waveguide combo measurement.
95dB @ 1m (click on picture to zoom)
Top left: DT-300: Sample 1
Top right: DT-300: Sample 2
Lower left: DT-300+WG-300 + 2.2uF cap: Sample 1
Lower right: DT-300+WG-300 + 2.2uF cap: Sample 2
Rather high second-order distortion compared to the odd-order distortion profile. Lowest recommended cross-over point is 2kHz.