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 
Systemrelated exaggeration in the frequency band of 17 kHz. Due to its symmetry, this can be easily equalized with the crossover. It is the purpose of a sound guide to act as an acoustic amplifier. The Vifa XT300 (XT25TG30/04) is an excellent match for the waveguide. Extremely even bundling without any disturbances worth mentioning. Due to the large dome (30mm voice coil), a slightly stronger directivity from 8kHz. Recommendation: plan a slight increase> 8kHz in the high frequency on axis.  
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

ConclusionThe Peerless XT25TG30/04 and the Waveguide WG300 are a very attractive combination for extremely levelstable installations, for example in the home theater. Can be used from 1,5 kHz. I think I'll test it out 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) 
Good linearity. Almost full level already from 1,1kHz. The efficiency is, with an average of 92dB / 2,83V, above average. All 3 drivers are almost congruent in their amplitude response. Very good.
The impedance response scatters a little more, especially around the resonance frequency. There is a slight interference around 2,3 kHz. This is also evident in the amplitude frequency response with a slight dip. 

Unfortunately, when measuring 7 new specimens have a very unpleasant picture.
The spread of the measured specimens is considerable and amounts to + 1dB at 5kHz, + 3db at 3,5kHz, above this it gets a little better. The resonance frequency varies between 1,1 and 1,8 kHz. None of the specimens is nearly as linear as the first 3 measured. With at least 3 of the measured specimens, it can be assumed that the voice coils are decantral to such an extent that they “clamp” on one side. 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 °) 
Quite even omnidirectional behavior. For a 25mm dome, the frequency response goes up very far. No points of criticism.  
Monacor DT101SK decay behavior

Even and fast swinging out.  
Monacor DT101SK harmonic distortion

The harmonic distortion is low. K3 remains below 900% at all measured levels from 1Hz. From 1,2 kHz even below 0,3%. K2 rises evenly with the level and always remains at a very low level. Higher order distortion components are completely negligible.  
Rating

ConclusionThe Monacor DT101SK measures itself well in all respects. It is very broadband applicable. A lower crossover frequency of 1,5 kHz is definitely feasible, depending on the concept and level requirements. The omnidirectional behavior is equivalent to a 25mm dome without sound guide. The touch quality and workmanship are okay, the harmonic distortion is low. And the whole thing for cheap 33,90 € (RRP) Addendum: There are, at least with one of the measured batches, considerable 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 (dispersion) 
Good linearity with full level from 2000Hz. The average efficiency is 90dB / 2,83V. Considering the fact that it is an 8 ohm driver, a good value (compared to 4 ohm tweeters you would have to add 99 dB to the DT3). The amplitude responses of the two measured drivers unfortunately vary significantly below 5kHz.  
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 
The Monacor DT99 shows low harmonic distortion from 2kHz. Recommended separation:> = 2kHz with at least 12dB / octave.  
Rating

ConclusionA very inexpensive tweeter with decent measurements. Unfortunately, the two measured specimens scatter more than hoped. The internal structure (especially the centering of the oscillating unit) is designed to be a bit “windy”. Otherwise the measurement results are impeccable across the board. Can be used from 2,5 kHz. 

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 (dispersion) 
Very good linearity. Full level from 1,8kHz (exception blue). High efficiency (94dB / 2,83V). From 3kHz low dispersion, below that up to + 2dB. No problems are to be expected with separations> = 2,5 kHz.


Monacor DT25N impedance (dispersion) 
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

ConclusionMonacor 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 (consisty) 
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 directivity (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 ° does the frequency response become somewhat unsteady above 10kHz. The Monacor DT300 and the Waveguide WG300 harmonize well with each other. 

Monacor DT300 / WG300 burst decay 
Overall smooth and fast decay, delayed by 7kHz and 13kHz.  
Monacor DT300 / WG300 harmonic distortion 
The Monacor DT300 on the WG300 shows low harmonic distortions. K2 rises evenly with the level and always stays at a low level. K3 only rises below 2kHz, above that extremely low. Harmonic distortions of higher orders are negligible. Regarding the harmonic distortion one could crossover the combination DT300 / WG300 without hesitation at 1,5kHz. Unfortunately, the impedance response does not allow that.  
Rating

ConclusionThe 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. 