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Tannoy DC8T (March 12 issue)
p2 Sound quality
p3 Conclusion
p4 Measured performance
All Pages

test_equipment

 

MEASURED PERFORMANCE

Our pink noise frequency response shows the bass/midrange unit delivers a smooth, peak free output up to 1kHz as before. The smoothness of output suggests low colouration, something our decay spectrum backs up. Our pink noise analysis shows that the Tannoy goes very low, flat down to 60Hz from forward output, below which the port takes over, peaking acoustically at 36Hz. With port output measuring +4dB over forward output at 80Hz, it is approximately 10dB up at 36Hz which is why there is plenty of subsonic oomph.


The horn takes over above 1kHz and this explains  a small dip at 1.5kHz. Above this crossover point the horn’s output extends smoothly up to 20kHz. It is the exceptional smoothness of output that shows just how far Tannoy have developed this drive unit; few loudspeakers are as even and accurate.


The DC8 T is very sensitive, producing a massive 91dB Sound Pressure Level from one nominal watt of input (2.84V), but partly because its impedance is low, measuring 5 Ohms with pink noise. The bass unit has a very low DCR of 2.7 Ohms and where low frequency power is drawn (30Hz -200Hz) the DC8 T is a 4 Ohm loudspeaker our impedance analysis shows.


Acoustic damping imposed by the port is broad around 36Hz, keeping the usual peaks / phase shifts low, an aid to amplifier matching (valve amps should be set to 4 Ohms).


A long term 200mS decay spectrum was very clean, being free from peaks although the cabinet is hot in places. The horn was very clean, giving a decay spectrum up with the best and approaching that of an electrostatic. The two front drivers generate very little distortion, less than 1% bass distortion from 25Hz to 100Hz and then less than 0.2% up to 6kHz, a very good result. The port is less linear, like most, producing  8% distortion 20Hz-30Hz declining above this frequency to 5% at 40Hz and 1% at 70Hz.


The newly upgraded DC8T is remarkably flat and accurate in its forward response and will sound less shouty and bright than most rivals. It is, however, a very accurate and smooth performer under measurement. NK

 

 


FREQUENCY RESPONSE (what it means)

tannoy-definition-dc-8t-fr1

Green - drive unit; Red - port

 

IMPEDANCE (what it means)

tannoy-definition-dc-8t-z

 

DECAY MAP 200mS (what it means)

tannoy-definition-dc8t-deca



 

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