Datasheet © www.heissmannacoustics.de  
Measurements in 20x40cm baffle, 10mm rounded, in 70cm distance at 2,83V. Level scaled to 1m.
The Waveguide was milled with a CNC adapter plate mounted on the tweeter. 



XT25TG30 / 04 Sound pressure at angles 
Systeminduced overshoot in the frequency band of 17kHz. This can be due to their symmetry very easy to equalize with the crossover. It is the purpose of a sound guide to act as an acoustic amplifier. This results in a more uniform bundling and higher load capacity. The Vifa XT300 (XT25TG30 / 04) fits perfectly with the waveguide. Extremely uniform bundling without significant disturbances. Due to the large dome (30mm voice coil) slightly stronger directivity from 8kHz.Recommendation: On the axis a slight increase> 8kHz in the tweeter schedule.  
XT25TG30 / 04 Sound pressure standardized at angles to 0 ° 
Here, the frequency response was linearized on axis. The 2. Picture (sonogram) clearly shows the excellent uniform straightening behavior of the combination of XT300 and the waveguide.  
XT25TG30 / 04 decay behavior 
Minimal delayed decay by 2kHz. Otherwise perfectly.  
XT25TG30 / 04 harmonic distortions

As expected, the distortion decreases compared to the variant without waveguide. The XT300 already showed very good distortion even without waveguide, but with a significant increase of K2 under 3kHz. With Waveguide the effect is also present but attenuated by about 5dB. In sum, very low distortion. Even with 100dB, everything from 2kHz remains below 1%. K3 moves at the measurable limit.  
Rating

SummaryThe Peerless XT25TG30 / 04 and the Waveguide WG300 are a highly attractive combination for extremely lowlevel installations, eg in home cinema. Can be used already from 1,5kHz. I think I'll test that in Cinetor. 

Keyword: tweeter
Test Monacor DT101SK
Datasheet © www.heissmannacoustics.de  
Measurements in DIN baffle in 70cm distance at 2,83V. Level scaled to 1m  
Frequency response and impedance (consisty) 
Very good linearity. Full level already from 1,1kHz. The efficiency is above average, with an average of 92dB / 2,83V. All 3 drivers are almost congruent in amplitude response. Very good.
The impedance path scatters, especially around the resonant frequency a little more. A slight disturbance shows up at 2,3kHz. However, this shows neither in the decay behavior nor in the sound and can be considered harmless. 

Unfortunately, when measuring 7 new specimens have a very unpleasant picture.
The scatter of the measured copies is at 1kHz + 5dB, at 3kHz + 3,5db, it gets a bit better. The resonance frequency varies between 1,1 and 1,8kHz. None of the specimens is nearly as linear as the first 3 measured. For at least 3 of the measured specimens it can be assumed that the voice coils are decentralized to the extent that they "pinch" onesidedly. The black curve is one of the three first measured DT101SK and thus serves as a reference. 

Monacor DT101SK sound pressure at angles (15 °, 30 °, 45 °, 60 °) 
Very uniform omnidirectional behavior. For a 25mm dome very far reaching frequency response. No criticisms.  
Monacor DT101SK decay behavior

Smooth and fast decay, slightly delayed by 10 and 15kHz.  
Monacor DT101SK harmonic distortion

The harmonic distortions are very low. K3 remains below 900% at all measured levels starting at 1Hz. From 1,2kHz even under 0,3%. K2 rises evenly with the level and always stays at a very low level. Clinker components of higher order are completely negligible.  
Rating

SummaryThe Monacor DT101SK measures itself in all respects very well. He is very broadband applicable. A lower crossover frequency of 1,5kHz is quite feasible, depending on the concept and level requirements. The omnidirectional behavior is impeccable. Touching quality and workmanship are good, the harmonic distortion very good. And the whole thing for cheap 33,90 € (RRP) Addendum: There are, at least for one of the measured batches, significant problems in terms of manufacturing consistency 

Test Monacor DT99 One of the cheapest tweeters in the Monacor range
Datasheet © www.heissmannacoustics.de  
Measurements in DIN baffle in 70cm distance at 2,83V. Level scaled to 1m  
Monacor DT99 Sound Pressure & Impedance (Scattering) 
Good linearity with full level from 2000Hz. The efficiency is on average at 90dB / 2,83V. In view of the fact that it is a 8Ohm driver is a good value (Compared to 4Ohm tweeters would have to add the DT99 3dB). Unfortunately, the amplitude responses of the two measured drivers vary considerably below 5kHz. This can also be seen on the impedance gears. Cause is probably a lack of centering of the vibrating unit.
Also different Ferrofluidgaben can be a cause. The upshifted and flattened impedance curve (black) may also indicate a "sticky" voice coil. So it could be that I got a broken copy. 

Monacor DT99 sound pressure at angles (15 °, 30 °, 45 °, 60 °) 
Uniform and for a 25mm dome typical omnidirectional behavior.  
Monacor DT99 decay behavior

Even and fast decay over all frequencies.  
Monacor DT99 harmonic distortion 
Monacor DT99 has low harmonic distortion as of 2kHz. Recommended separation:> = 2kHz with at least 12dB / octave.  
Rating

SummaryA very cheap tweeter with decent readings. Unfortunately, the two presumptuous specimens scatter more than hoped. The inner structure (in particular the centering of the oscillating unit) is designed somewhat "windy". Otherwise, the measurement results by the bank are impeccable. Can be used from 22,5kHz. 

Test Monacor DT25N
Datasheet © www.heissmannacoustics.de  
Measurements in DIN baffle in 70cm distance at 2,83V. Level scaled to 1m  
Monacor DT25N sound pressure (scattering) 
Very good linearity. Full level already from 1,8kHz (exception blue). High efficiency (94dB / 2,83V). From 3kHz low dispersion, including to + 2dB. With separations> = 2,5kHz no problems are to be expected.


Monacor DT25N Impedance (Scattering) 
No disturbances recognizable. The different pronounced impedance peaks indicate different quantities of ferrofluid. From 3kHz almost congruent course.


Monacor DT25N Sound pressure at angles (15 °, 30 °, 45 °, 60 °) 
Monacor DT25N shows a good and uniform directional characteristic.  
Monacor DT25N decay behavior 
Overall smooth and fast decay over all frequencies.  
Monacor DT25N harmonic distortion 
From 3kHz low harmonic distortion. If separated by 3kHz, K2 stays well below 1%. K3 rising sharply below 2kHz, practically not available. Higher order clutter components are negligible. The measurement was carried out at 95dB / 1m.  
Rating

SummaryMonacor DT25N is a really great little tweeter. Can be used especially in confined spaces such as d'appolito arrangements or eg Direct HA Edition. DT25N can be loud, usable from 2,0khz with an efficiency of 94dB / 2,83V. Unfortunately DT25N was not spared the price increases of many neodymium tweeters. Nevertheless, it still offers a very good value for the price. 


Test Monacor DT300 with Waveguide WG300 A combination for high level applications with very good directional characteristics
Datasheet © www.heissmannacoustics.de  
Measurements in DIN baffle in 70cm distance at 2,83V. Level scaled to 1m  
Monacor DT300 with Waveguide WG300


Monacor DT300 / WG300 sound pressure (scattering) 
Due to the principle, the frequency response drops evenly towards high frequencies (waveguide), which is very easy to equalize with the crossover. Noteworthy are the two burglaries at 7kHz and 13kHz.
Overall satisfactory dispersion. From 214kHz all 4 DT300 / WG300 move in a hose of + 1dB, above and below a little worse. Addendum: As for the Kits Cinetor and Cinetor HWG, the tweeters have been individually checked for quite some time now, I have several serial measurements of the DTXNUMX on the waveguide. The 2. Picture shows an example of relatively high, the 3. of very low consisty. 

Monacor DT300 / WG300 Impedance (Scatter) 
The impedance curve of the DT300 with WG300 is not very harmonious and of relatively low consisty. The differently pronounced double hump probably originated in different damping of the pole core bore to the coupling volume and in the extremely generous dose of ferrofluid. Separations below 2,5kHz are only conditionally recommendable. 

Monacor DT300 / WG300 sound pressure at angles (090 °) 
Directional behavior is very uniform, thanks to the waveguide concept. The bundling behavior <= 2kHz results from the narrow baffle (20cm). Only at angles> = 45 ° is the frequency response above 10kHz somewhat restless. Altogether the Monacor DT300 and the Waveguide WG300 harmonize well with each other. 

Monacor DT300 / WG300 decay behavior 
Overall smooth and fast decay, delayed by 7kHz and 13kHz.  
Monacor DT300 / WG300 harmonic distortion 
The Monacor DT300 on the WG300 has very low harmonic distortion. K2 rises evenly with the level and always stays at a low level. K3 only rises below 2kHz, above that extremely low. Harmonic components of higher order are negligible. From the harmonic distortion one could disconnect the combination DT300 / WG300 without hesitation at 1,5kHz. Unfortunately, the impedance gear is in the way.  
Rating

SummaryThe Monacor DT300 with the Waveguide DT300 is on the whole a good tweeter. In particular, the level stability, the high efficiency, the low harmonic distortion and the uniform radiation behavior under angles are to be emphasized. Big downside is the lack of constancy of the driver. 