LABoRAToRy TEsT REsuLTs

The Dynaudio Emit M10 returned excellent performance throughout all Newport Test Labs’ tests

The frequency responses returned by the Dynaudio Emit M10 in the tests conducted by Newport Test Labs were uniformly excellent. Graph 1 shows the overall in-room response and you can see it’s exceptionally flat, extending from 78Hz to 23kHz ±3dB. This response is a ‘free-field’ response, with the speaker positioned on a stand well away from room boundaries, so moving the speaker closer to one or more boundaries would increase and extend the low-frequency response.

Graph 2 shows a detailed view of the high-frequency response of the Emit M10 with its grille on (red trace) and with it off (black trace). You can see that the grille causes a very small, narrow-band dip in the response centred at about 3.8kHz. This dip is so high in frequency and so narrow that I doubt it would be audible, but you always have the option of removing the grilles, which will deliver a flat response right out to 20kHz, after which it rolls off at around 12dB/octave to be 3dB down at 23kHz.

Newport Test Labs also measured the direct low-frequency response of the Emit M10 by using a nearfield technique that simulates the response that would be obtained in an anechoic chamber, the results of which are shown in Graph 3. This graph clearly shows the different low-frequency roll-offs that will result if you use the Emit M10 in its bass reflex incarnation (without the port bung, see the black trace), or in its sealed cabinet incarnation, with the rear-firing port stopped by the foam bung (blue trace). In bass reflex mode, the response rolls off very steeply below 100Hz to the cabinet’s tuning frequency in this mode at 60Hz. Of course the output from the port (red trace) partially compensates for this roll-off. In this case, the peak output of the port is somewhat lower than the tuned frequency. In sealed cabinet mode, the bass/midrange driver still starts rolling off at 100Hz, but only very gradually (12dB/octave) exactly as loudspeaker theory predicts. The smoothness of all the traces on this graph shows there are no unwanted cabinet resonances.

Tests of impedance showed that it drops to 5.5Ω only at one point in the audio band (200Hz) when the speaker is in bass reflex configuration, and at two points (20Hz and 200Hz) when the cabinet is sealed, which justifies Dynaudio’s specification of 6Ω, since according to the IEC standard that governs this, manufacturers are permitted to claim an overall impedance of 6Ω so long as the impedance never drops

below 5.1Ω. You can see from the traces that the cabinet’s tuning frequency is 60Hz in bass reflex mode and 75Hz in sealed cabinet mode. The 60Hz tuning means that even if you optimally position the cabinet to maximise bass output, you won’t get appreciable output below this frequency, because response would roll off at 24dB/octave below it. Dynaudio’s engineers also know a thing or two about making a loudspeaker ‘real world’ safe for any amplifier that’s driving it, because they’ve sensibly made the impedance start rising above 7kHz, and keep rising. Excellent design. As you can see from the blue trace, phase angle is mostly kept within ±30°, which is also excellent design and in the only area where it deviates outside this range the impedance is 8Ω or higher, so the speaker will remain easy to drive despite the phase angle.

Figure 5 shows the in-room frequency response out to 10kHz using a pink noise test signal, which shows how the human ear would perceive the Emit M10. There’s still the roll-off below 100Hz (the speaker being positioned as noted previously), but apart from what is a very small (approximately 1dB) lift in the response between 125Hz and 380Hz, the response is almost completely linear: well within ±1dB out to the 10kHz upper limit of this graph.

The final graph prepared by Newport Test Labs is a composite, which places several of the traces from the previous graphs on the same graph, and shows ‘extended’ versions of the nearfield traces. The extended version showing the output of the bass reflex port shows that it has a little unwanted output between 500Hz and 1.4kHz—energy from the rear of the bass/midrange driver. It’s so low in level compared to the main output that it would have no effect on the direct sound, but it does appear that the resonance just above 1kHz does have a small direct effect on the bass/midrange driver’s cone movement.

Small loudspeakers are always inefficient, and the particular test used by Newport Test Labs to gauge efficiency is weighted against small speakers, because it also takes output at low frequencies into account (most manufacturers measure efficiency only at one frequency, and almost always choose the frequency at which the output of the loudspeaker is highest!). So although Dynaudio specifies sensitivity at 86dBSPL, Newport Test Labs, using its standard procedure, reported efficiency at 84dBSPL, which is about exactly what I would have expected from a two-way loudspeaker of the Emit M10’s dimensions.

As you have no doubt already gathered, the Dynaudio Emit M10 returned excellent performance throughout all of Newport Test Labs’ tests. It is a very well-designed loudspeaker. Steve Holding