LAB­O­RA­TORY TEST RE­PORT

The tech­ni­cal per­for­mance of the Dynaudio Fo­cus 60XD is ex­cep­tion­ally good, es­sen­tially show­ing what it’s pos­si­ble to achieve...

Australian HIFI - - ESOTERICA -

New­port Test Labs mea­sured the fre­quency re­sponse of the Dynaudio Fo­cus 60XD as 18Hz to 32kHz ±3dB. (See Graph 1.) This is not only an ex­cel­lent re­sult, it also ex­ceeds Dynaudio’s own spec­i­fi­ca­tion, which is 18Hz to 24kHz ±3dB. The su­perb low-fre­quency ex­ten­sion sug­gests to me that Dynaudio is us­ing equal­i­sa­tion to ex­tend the low-fre­quency re­sponse rather than just de­pend­ing on the raw per­for­mance of the driv­ers and cab­i­net. In ad­di­tion to be­ing ex­tended, the re­sponse is ex­cep­tion­ally flat, with­out any ‘skew’ that would favour either the high or low fre­quen­cies. Across the band from about 200Hz up to 16kHz, the re­sponse is within ±1dB… it doesn’t re­ally get much bet­ter than this.

The high-fre­quency re­sponse of the Dynaudio Fo­cus 60XD is shown in Graph 2. This was mea­sured by New­port Test Labs us­ing a gat­ing tech­nique that sim­u­lates the re­sponse that would be ob­tained in an ane­choic cham­ber. Again it is re­mark­able for its smooth­ness, flat­ness and ex­ten­sion. The Dynaudio Fo­cus 60XD has user-ad­justable high fre­quency re­sponse, via a three po­si­tion switch, so the lab has shown all three re­sponses. Al­though the +1dB trace (red trace) looks to be ex­actly +1dB, the –1dB trace (blue trace) looks to be about –2dB rather than just –1dB. There’s no doubt that it does al­low fine ad­just­ment though.

Graph 3 also shows the high fre­quency re­sponse of the Dynaudio Fo­cus 60XD, but this time shows the dif­fer­ence in the fre­quency re­sponse when the speaker is op­er­ated with­out the grille (black trace) and with the grille fit­ted (red trace).

You can see that the most lin­ear re­sponse is re­turned when the grille is not present, with the grille in­tro­duc­ing small dips in the re­sponse around 3kHz, 6kHz, 9.5kHz and 15kHz and at­ten­u­at­ing the re­sponse by about 2.5dB above 20kHz. All four dips are so slight—and so high in fre­quency—that I doubt they’d be au­di­ble even in di­rect A–B com­par­i­son, but there’s no doubt the speak­ers de­liver flat­test re­sponse with the grilles re­moved. Note that if you like the level with the Tre­ble switch in the –1dB po­si­tion when the grilles aren’t fit­ted, you’ll prob­a­bly pre­fer the Tre­ble switch to be in the +1dB po­si­tion when the grilles are fit­ted.

The Dynaudio Fo­cus 60XD also has a ‘Speaker Po­si­tion’ con­trol to re­duce the level of bass if the speaker is placed close to a wall or a cor­ner. The ef­fect of this con­trol was mea­sured by New­port Test Labs and the re­sults are pre­sented in Graph 4. Graph 4 shows the re­sponse when a nearfield mea­sure­ment tech­nique is used, which sim­u­lates the re­sponse that would be ob­tained in an ane­choic cham­ber. You can see that the Speaker Po­si­tion switch is es­sen­tially a sin­gle-band para­met­ric equaliser with a cen­tre fre­quency at around 90Hz and a band­width of around two oc­taves. These traces were mea­sured with the speaker well clear of all bound­aries, for which the cor­rect set­ting was ‘Neu­tral’, and you can see from the black trace that the Dynaudio Fo­cus 60XD’s bass driv­ers per­formed per­fectly across their de­signed op­er­at­ing range, ex­tend­ing from 18Hz to 220Hz ±3dB. If the speaker were to be placed against a wall, the prox­im­ity would ‘boost’ the red trace up to equal that of the black trace, and if the speaker were close to a cor­ner, the cor­ner prox­im­ity would ‘boost’ the blue trace up to equal that of the black trace.

Graph 5 shows the in-room re­sponse of the Dynaudio Fo­cus 60XD mea­sured us­ing a pink noise test sig­nal, with the cap­ture ex­tended up to 10kHz. Again the low-fre­quency ex­ten­sion is ev­i­dent, and the smooth­ing ef­fect of av­er­ag­ing the traces shows even-bet­ter the flat­ness of the re­sponse from around 250Hz up, where it al­most tracks the graph­ing line.

Graph 6 is a com­pos­ite plot show­ing the in­di­vid­ual re­sponses of the driv­ers. You can see the bass driv­ers cross­ing to the midrange at 200Hz and the midrange driver to the tweeter at 2.5kHz. The main trace is the same as shown in Graph 1.

The tech­ni­cal per­for­mance of the Dynaudio Fo­cus 60XD is ex­cep­tion­ally good, es­sen­tially show­ing what it’s pos­si­ble to achieve from a loud­speaker sys­tem when the de­signer has com­plete con­trol over not only the acous­tic part of the de­sign, but also the elec­tron­ics. It also shows the su­pe­ri­or­ity of elec­tronic cross­over net­works over their pas­sive coun­ter­parts and how sen­si­bly im­ple­mented elec­tronic equal­i­sa­tion can im­prove per­for­mance—es­pe­cially bass ex­ten­sion.

Out­stand­ing per­for­mance in ev­ery aspect of per­for­mance. Steve Hold­ing

graph 1. Fre­quency re­sponse. Trace be­low 1kHz is the av­er­aged re­sult of nine in­di­vid­ual fre­quency sweeps mea­sured at three me­tres, with the cen­tral grid point on-axis with the tweeter us­ing pink noise test stim­u­lus with cap­ture un­smoothed. This has...

graph 2. High-fre­quency re­sponse, ex­panded view show­ing ef­fect of tre­ble con­trol. (Red trace +1dB. Black trace 0dB. Blue trace -1dB.) Test stim­u­lus gated sine. Mi­cro­phone placed at three me­tres on-axis with tweeter. Lower mea­sure­ment limit 1kHz.

graph 6. Av­er­aged in-room fre­quency re­sponse us­ing pink noise test stim­u­lus with cap­ture un­smoothed. Trace is the av­er­aged re­sults of nine in­di­vid­ual fre­quency sweeps mea­sured at three me­tres, with the cen­tral grid point on-axis with the tweeter.

graph 7. Com­pos­ite re­sponse plot. Red trace is out­put of midrange driver. Dark blue trace is ane­choic re­sponse of bass driv­ers. Light blue trace is gated (sim­u­lated ane­choic) re­sponse (ig­nore be­low 2kHz). Black trace is av­er­aged in-room pink noise...

graph 3. High-fre­quency re­sponse, ex­panded view, at 0dB with­out grille (black trace) and with grille fit­ted (red trace). Test stim­u­lus gated sine. Mi­cro­phone placed at three me­tres on-axis with dome tweeter. Lower mea­sure­ment limit 1kHz.

graph 5. In-room low fre­quency re­sponse show­ing ef­fect of speaker po­si­tion con­trol. Neu­tral (black), Wall (red) and Cor­ner (blue). Pink Noise Stim­u­lus.

graph 4. Low fre­quency re­sponse show­ing ef­fect of speaker po­si­tion con­trol. Neu­tral (black), Wall (red) and Cor­ner (blue). Nearfield ac­qui­si­tion.

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