Australian HIFI - - CONTENTS -

Many dif­fer­ent paths lead to au­dio nir­vana. With his W8 de­sign, Sven Boenicke has taken the one less trav­elled…

When he started build­ing speak­ers more than 20 years ago, Swiss record­ing en­gi­neer Sven Boenicke had ab­so­lutely no in­ten­tion of build­ing con­ven­tional loud­speak­ers.

‘ In to­day’s hifi mar­ket with an over­whelm­ing num­ber of brands (some say 20,000 world­wide!), the question is: Does any­one need so many?’ Boenicke writes on his web­site: ‘ And does it make sense to re­peat again and again what has been ‘in­vented’ and built thou­sands of times be­fore? Ap­plied to the realm of loud­speaker build- ing, we clearly think that it makes no sense yet again to build a bass-re­flex box made from MDF, damp it with foam, put a dome tweeter and one or two cone-driv­ers on the per­pen­dic­u­lar front baf­fle, coat the box with plas­tic (lac­quer), mount spikes and have a standard cross­over net­work…’

So right from the out­set Boenicke aimed to be dif­fer­ent to all those 20,000 other loud­speaker man­u­fac­tur­ers… and it must be said that his W8 is cer­tainly dif­fer­ent.


The side-fir­ing woofer on the Boenicke W8 is a Tang Band model with a rated di­am­e­ter of 165mm, a mov­ing di­am­e­ter of 140mm, a Thiele-Small di­am­e­ter of 120mm and an ac­tual cone di­am­e­ter of 105mm. It’s run as a full­range driver, so there’s no low-pass fil­ter in the cross­over net­work for it: essen­tially, it’s as if you’re con­nect­ing the ter­mi­nals of this woofer di­rectly to the out­put ter­mi­nals of your am­pli­fier. The out­put from the rear of this driver is routed to a port on the rear of the cabi­net via a labyrinth, about which more later.

As you can see from the pho­tographs, there are two driv­ers on the front baf­fle, the lower of which is made by Tang Band, has a pa­per cone and is rated as hav­ing a nom­i­nal di­am­e­ter of 100mm. My mea­sure­ments put the mov­ing di­am­e­ter of this driver at 90mm, the Thiele/Small di­am­e­ter at 82mm and the ac­tual cone di­am­e­ter at 70mm. The strange pro­tu­ber­ance you can see at the cen­tre of this driver is a wooden phase plug. Un­like most such phase plugs, whose ends are mostly curved into a dome or bul­let-head shape, the top of Boenicke’s phase plug is com­pletely flat, though the edge where it joins the side of the plug is beau­ti­fully rounded-off.

The cross­over ar­range­ment for this Tang Band driver is also un­usual, be­cause although it’s pro­tected from be­ing over­driven by low-fre­quency in­for­ma­tion by a first-or­der fil­ter, this driver, too, is al­lowed to op­er­ate ‘way into the high fre­quen­cies—there is no high-fre­quency roll-off. The side-fir­ing bass driv­ers are re­cessed into the cabi­net and sur­rounded by a wide band of black neo­prene-like ma­te­rial that’s 40mm wide. I found this to be quite eye-catch­ing and at­trac­tive— even if it did make the driv­ers seem larger than they ac­tu­ally are.

The top­most driver mounted on the baf­fle is a Foun­tek F85 wide-range 75mm unit, whose 52mm di­am­e­ter cone is made from alu­minium and driven (in com­bi­na­tion with a fer­rite mag­net) by a cop­per voice coil that’s 20mm in di­am­e­ter. Foun­tek rates the F85 with a fre­quency re­sponse that ex­tends be­yond 20kHz, so the W8 has no tweeter… well, no tweeter as such. There is a tweeter mounted on the rear of the speaker (a Mana­cor DT-25N with the ‘N’ in­di­cat­ing that it has a neodymium mag­net) but since, due to its lo­ca­tion, it can­not pro­vide di­rect ra­di­a­tion, it is pre­sum­ably in­tended ei­ther de­liver ‘am­bi­ence’ and/or re­flected sound to add to the for­ward and side­ways out­put from the F85. The DT-25N tweeter is a high-qual­ity 25mm di­am­e­ter silk soft-dome de­sign.

For those in­ter­ested in the prove­nance of the driv­ers Boenicke is us­ing, Tang Band is a Tai­wanese com­pany that once man­u­fac­tured its prod­ucts in Tai­wan, but moved pro­duc­tion to China a few years ago. Foun­tek is en­tirely a Chi­nese com­pany.

Mana­cor In­ter­na­tional is a Ger­man com­pany that makes prod­ucts in many dif­fer­ent coun­tries around the world, in­clud­ing China. Mun­dorf (which makes the cross­over com­po­nents that are men­tioned in the fol­low­ing para­graph) is head­quar­tered in Köln, Ger­many.

The cross­over net­work uses high-qual­ity Mun­dorf ca­pac­i­tors (a trio of them), two air-cored in­duc­tors (not cross-mounted, but spaced suf­fi­ciently far apart to en­sure that there can be no mag­netic in­ter­ac­tion be­tween them) and a sin­gle 10W re­sis­tor. All com­po­nents are hard-wired to­gether with sin­gle-strand wire and glued to a small sec­tion of MDF that’s fixed in­side the cabi­net. The in­put leads to the cross­over ter­mi­nate at their other end to a sin­gle pair of WBT-0703 Cu Nex­tGen speaker ter­mi­nals that are mounted on a small metal plate that iden­ti­fied my re­view sam­ple speak­ers as ‘Se­rial: 025’.

As for the cabi­net it­self, it’s a work of art… even if the artist is the pro­gram­mer of a triple-axis com­put­erised nu­mer­i­cally con­trolled (CNC) router. You see, un­like most wooden cab­i­nets, which are made of wood that has been shred­ded into tiny par­ti­cles which are then soaked in glue and squeezed to­gether into the shape of a board (a ma­te­rial also known as par­ti­cle board, or what man­u­fac­tur­ers pre­fer to call MDF… medium den­sity fi­bre­board), the cabi­net of the Boenicke W8 is carved from a real tree. In­deed you can even spec­ify what type of tree you’d like it to be carved from: wal­nut, oak, ash or cherry.

What Boenicke does to cre­ate the cabi­net is get two solid slabs of real wood into which it ‘carves’ (all the work is ac­tu­ally done by a CNC router, as noted above) a labyrinth of val­leys and de­pres­sions, with the same val­leys and de­pres­sions mir­ror-im­age-carved into the other slab of wood. These two mir­ror-im­aged pre-carved slabs are then glued to­gether (look care­fully and you can just make out the fine join that runs around the cen­tre of the cab­i­nets) upon which those val­leys and de­pres­sions be­come in­di­vid­ual en­clo­sures behind driv­ers or, in the case of the side-fir­ing woofer, a ‘tube’ lead­ing to a small rec­tan­gu­lar (94×45mm) port lo­cated low down on the rear baf­fle.

Boenicke’s web­site doesn’t spec­ify the fre­quency re­sponse of the standard W8 de­sign, nor does it spec­ify the sen­si­tiv­ity, or the min­i­mum im­ped­ance. What it does say is that the W8’s sen­si­tiv­ity ‘ varies be­tween 84dBSPL and 88dBSPL/w/m de­pend­ing on fre­quency’ and that the nom­i­nal im­ped­ance is 4Ω. It also doesn’t men­tion the size or weight of the speak­ers. The lo­cal Aus­tralian dis­trib­u­tor’s web­site is more in­for­ma­tive about cabi­net di­men­sions and weight (776×114×260mm and 10.5kg) but rather con­fus­ingly says the sen­si­tiv­ity is 87dBSPL/watt/m.

The very light weight of the W8s will no doubt come as a sur­prise to you—con­sid­er­ing the speak­ers are made from solid wood—but it cer­tainly didn’t to me, be­cause I had al­ready found it very easy to carry both speak­ers at once—those curved bass re­flex ports make great car­ry­ing han­dles!—when I was mov­ing them from room to room. Pre­sum­ably the weight varies de­pend­ing on what type of wood the cabi­net is made from, but nei­ther Boenicke nor Au­dio Magic make men­tion of any such vari­a­tions.

What both companies do men­tion is that there are three ver­sions of the Boenicke W8, in­clud­ing a ‘Standard’ ver­sion, which is the one I re­ceived for re­view. The two other ver­sions are the W8 SE and W8 SE+. Full de­tails about the dif­fer­ences be­tween these two and the ‘Standard’ W8 re­viewed here can be found on Boenicke’s web­site.

Although the W8s are not par­tic­u­larly tall, their height, com­bined with their small foot­print, light weight and the fact that three of the driv­ers are near the top of the cabi­net, mean that the cen­tre-of-grav­ity (COG) is rather high. I ini­tially pre­sumed that the out­rig­ger feet that are sup­plied with the speak­ers were to help sta­bilise the cab­i­nets so they can’t be eas­ily tipped over… and they do help sta­bilise the cab­i­nets, but not, it must be said, by much, so even with the feet fit­ted you’d still have to ex­hibit some care if you have bois­ter­ous an­i­mals or chil­dren. So it would ap­pear that the out­rig­ger feet serve some other pur­pose.

As for the de­sign of these feet, I didn’t know what to make of it, be­cause the de­sign and im­ple­men­ta­tion are quite strange. The out­rig­ger it­self com­prises two pieces of metal that are screwed to­gether. One sec­tion has screw threads that allow you to screw in two ad­justable feet. The other sec­tion acts as a kind of ‘rec­tan­gu­lar key’ that slots into a

The cabi­net of the Boenicke W8 is carved from a real tree. You can even spec­ify what type of tree you’d like it to be carved from

match­ing rec­tan­gu­lar void at the bot­tom of the W8’s cabi­net. What con­fused me is that the size of the ‘key’ of metal and the void are dif­fer­ent, so the ‘key’ is very loose and ‘rat­tly’ when it’s in­side the void. If you want to hang some num­bers on that ob­ser­va­tion, the ‘key’ is 88mm wide and the slot is 92mm wide… a 4mm dif­fer­ence. The key is 10mm thick; the slot is 11mm high. There is a third screwed foot, but this foot screws into a threaded re­cep­ta­cle in the base of the speaker it­self, in the cen­tre to­wards the front, and it is a very tight fit.


As with all loud­speak­ers, it is es­sen­tial they be placed cor­rectly in your room if they are to pro­vide op­ti­mum per­for­mance, and the Boenicke W8s are no ex­cep­tion… ex­cept that the side-fir­ing woofers and rear-fir­ing tweet­ers mean that small dif­fer­ences in po­si­tion will make greater sonic dif­fer­ences than would be the case when po­si­tion­ing more con­ven­tional front-fir­ing speak­ers.

The first thing you need to es­tab­lish is whether you like the bass re­sponse bet­ter when the side-fir­ing woofers are facing each other, or when they’re facing away from each other. This will re­quire much shift­ing of the speak­ers, but this won’t be a prob­lem, due to the light weight of the cab­i­nets mak­ing the process very easy. If it’s of any help to you, I found that the W8s per­formed best with the bass driv­ers facing in­wards in the three room lay­outs I tried, but room acous­tics are vari­able, so your mileage may vary, as they say…

Once you have es­tab­lished the bass driver ori­en­ta­tion you most pre­fer, you’ll then need to hear the dif­fer­ences in sound when the speak­ers are close to a rear wall or fur­ther away from it.

These dif­fer­ences will be in­flu­enced not only by the dis­tance be­tween the wall and the cabi­net, but also by how ab­sorp­tive that rear wall is. If it’s made of brick, or glass, or con­crete, for ex­am­ple, you’re going to get a whole lot more high-fre­quency ‘splash’ from that rear-fir­ing tweeter than if it’s made of some other ma­te­rial. And if you have drapes or book­shelves behind the speak­ers, mov­ing the speak­ers nearer or closer won’t have nearly the same ef­fect. Note, how­ever, that mov­ing the speak­ers closer to, or fur­ther from, rear and/or side walls will also af­fect the vol­ume level and ex­ten­sion of the W8s’ low fre­quen­cies.

I have to ad­mit that I had a great deal of dif­fi­culty po­si­tion­ing these speak­ers. My prob­lem—if you’d call it a prob­lem!—was that they sounded ab­so­lutely fab­u­lous no mat­ter where I placed them in the room, yet at the same time they sounded ab­so­lutely dif­fer­ent in each of those po­si­tions… almost as if I were lis­ten­ing to en­tirely dif­fer­ent loud­speak­ers.

Ob­vi­ously a part of this is be­cause of driver ori­en­ta­tion, with the bass driv­ers fir­ing in op­po­site di­rec­tions not only to each other, but also all the other driv­ers fit­ted to the cabi­net, and the front-fir­ing speak­ers fir­ing in com­pletely the op­po­site di­rec­tion to the rear-fir­ing tweeter. How­ever I think the other is­sue is that be­cause the op­er­at­ing bands of the four driv­ers over­lap each other right across the fre­quency band (ex­cept at the very low­est fre­quen­cies), in­ter­fer­ence pat­terns are cre­ated as the wave­fronts from the var­i­ous driv­ers in­ter­act, and these pat­terns re­sult not only in fre­quency re­sponse vari­a­tions but also in tonal vari­a­tions. The only thing I can be sure of is that the Boenicke W8s sounded like no other speak­ers I have ever heard be­fore.

You can quite eas­ily prove this to your­self by play­ing a mono­phonic sig­nal through the Boenicke W8s. In­stead of hear­ing a solid, mono im­age di­rectly mid­way be­tween the speak­ers, you’ll in­stead hear a sound­stage that is still eerily almost stereo-like in its pre­sen­ta­tion, with im­ages po­si­tioned at dif­fer­ent places across the stage, de­pend­ing on the pitch of the in­stru­ment and the notes be­ing played. I was so in­trigued by this that I did a full ‘walk-around’ in the room and found that this ef­fect was clearly au­di­ble through­out the lis­ten­ing room. At the same time I found that when I was lis­ten­ing from behind the speak­ers, the rear-fir­ing tweeter meant that the sound qual­ity when I was lo­cated behind the speak­ers was very nearly the same as the sound qual­ity I ex­pe­ri­enced when I was po­si­tioned di­rectly in front of the speak­ers.

The ob­ser­va­tions made in the pre­vi­ous para­graph are very pos­i­tive ob­ser­va­tions, be­cause it means that not only will the Boenicke W8s sound very good no mat­ter where you place them in the room, they will also sound very good no mat­ter where you place your­self in the room… even if you po­si­tion your­self behind the speak­ers. For those lis­ten­ers with open-plan room lay­outs, where they might be sit­ting at ei­ther end of the room, or in the middle, this will be a god-send.

As for the sound qual­ity it­self, it’s very bright and bouncy, and un­can­nily re­al­is­tic, with the over­all tonal bal­ance favour­ing the midrange… though if you are sit­ting on-axis in front of the speak­ers, there’s a bit of tre­ble bril­liance mixed in as well. That the sound favours the midrange and tre­ble in this way means the Boenicke W8s do ab­so­lutely glo­ri­ous things to the voices of fe­male vo­cal­ists. It’s as if the speak­ers were specif­i­cally de­signed to make their voices sound bet­ter than they al­ready are.

The Boenicke W8s do ab­so­lutely glo­ri­ous things to the voices of fe­male vo­cal­ists.…

The clar­ity of the midrange sound is ex­tra­or­di­nary as well, with a crisp­ness that lets you hear ev­ery lip-sound and ev­ery in­take of breath, but with­out the ‘sharp­ness’ that af­fects some loud­speak­ers.

The bass is full-bod­ied, with a warm rich­ness that does beau­ti­ful things with sound from cello and double-bass and is par­tic­u­larly kind to the bari­tone voice… James Tay­lor for one. Just lis­ten to the way the Boenicke W8’s de­liver Tay­lor’s voice on the open­ing lines of Suzanne ( Just yes­ter­day morn­ing/they let me know you were gone) and you’ll be try­ing to see if your mu­sic server can queue up a playlist com­prised of songs by fa­mous bari­tones to see how well it can en­hance them as well. The only lim­i­ta­tion to the bass was one of ex­ten­sion… these speak­ers don’t dig too far down into the depths. Also on the plus side, how­ever, they don’t try to fake it: the vol­ume roll-off with de­creas­ing fre­quency is smooth and con­trolled, with no dou­bling au­di­ble so, for ex­am­ple, you won’t hear a ‘false’ note play­ing at C2 (65.4Hz) if the ‘real’ note is ac­tu­ally at C1 (32.7Hz).

A part of this bass warmth might be due to the W8 cab­i­nets act­ing as very ef­fi­cient res­onators… as one might ex­pect from any solid wood en­clo­sure sur­round­ing an air mass (i.e., almost all stringed in­stru­ments). Put your ear up against the wall of any cabi­net built by most high-end speaker man­u­fac­tur­ers and you’ll hear very lit­tle in the way of sound. Put your ear up against the cabi­net of the Boenicke W8 and it’s like lis­ten­ing at the door of a con­cert hall. No doubt these cabi­net vi­bra­tions also con­trib­ute to the unique sound of these loud­speak­ers.

One thing the Boenicke W8s are not is ef­fi­cient. Us­ing the ‘Au­dio Tool’ SPL meter app on my mo­bile phone showed that the Boenicke W8s were about 10dB less ef­fi­cient than my ref­er­ence loud­speak­ers, which their man­u­fac­turer rates with an ef­fi­ciency of 89dBSPL. This means that although I only need to use 16 watts of my am­pli­fier’s power into my ref­er­ence speak­ers to pro­duce my pre­ferred sound pressure level, I’d have to use 160-watts of power to get the same level from the Boenicke W8s. My am­pli­fier is rated at 200-watts per chan­nel into 8 so I was able to com­fort­ably achieve this with­out run­ning the am­pli­fier into clip­ping, but it points to the need to use a powerful am­pli­fier to get best re­sults from the W8s. [ Edi­tor’s Note: In a re­sponse to an ear­lier re­view of the Boenicke W5s, in which re­viewer Daniel Stiel com­mented on the low ef­fi­ciency of the W5 de­sign, Sven Boenicke, the de­signer, ad­vised in an email fol­low-up to that re­view that he con­sid­ered ‘proper am­pli­fi­ca­tion’ for his speak­ers to be am­pli­fiers that are ca­pa­ble of de­liv­er­ing 1,000-watts per chan­nel into 4 loads.]


I re­ally trea­sured my time re­view­ing the Boenicke W8s. Their dy­namic, lively pre­sen­ta­tion of any mu­si­cal ma­te­rial I pre­sented to them made for ex­cit­ing lis­ten­ing ses­sions that caused me to re-eval­u­ate what traits I con­sider most im­por­tant in a pair of loud­speak­ers. The fact that the sound­field they cre­ated was so to­tally dif­fer­ent from that cre­ated by my own speak­ers, yet at the same time so en­joy­able, made me won­der how many dif­fer­ent paths might lead to au­dio nir­vana. Sven Boenicke has cer­tainly dared to take a com­pletely dif­fer­ent path. Will you? Ernest Den­man

12dB/oc­tave slope be­low this fre­quency sug­gest­ing that this driver is mounted in a sealed en­clo­sure. As you can see, both the side-fir­ing and front-fir­ing driv­ers cover much the same fre­quency range, but have com­pletely dif­fer­ent fre­quency re­sponses in­di­vid­u­ally.

Graph 3, which shows the im­ped­ance of the Boenicke W8s, shows that ac­cord­ing to the IEC 60268-5 standard it should at­tract a ‘nom­i­nal’ im­ped­ance rat­ing of 4Ω. The im­ped­ance is quite un­usual, be­cause it only rises above 8Ω be­tween 750Hz and 2.4kHz. Even the res­o­nant peaks reach only 6.3Ω (at 27Hz) and 7Ω (at 58Hz). The wrin­kles in the re­sponse at around 150Hz sug­gest some mi­nor cabi­net res­o­nances (but the wrin­kles in the re­sponse at 100Hz and 1kHz are glitches caused by the test in­stru­men­ta­tion and should be ig­nored).

New­port Test Labs mea­sured the sen­si­tiv­ity of the Boenicke W8 speak­ers as 81.5dBSPL at a dis­tance of one me­tre, for a 2.83Veq in­put. This is a very low fig­ure and one that’s almost 3dB lower than the min­i­mum fig­ure spec­i­fied by Boenicke. It is, how­ever, higher than the mea­sure­ment New­port Test Labs made on the smaller Boenicke W5 de­sign, which was mea­sured at 79dBSPL un­der the same con­di­tions and po­si­tioned that de­sign as hav­ing the low­est sen­si­tiv­ity of any speaker ever tested by New­port Test Labs. The W8’s re­sult puts it in a tie for the third-low­est sen­si­tiv­ity ever mea­sured by that lab, but more im­por­tantly means you’ll need to use con­sid­er­able am­pli­fier power to drive these speak­ers to high SPLs in a lis­ten­ing room. How­ever if you use too much power, you will heat the voice coils, re­duc­ing ef­fi­ciency even fur­ther and pos­si­bly run­ning the risk of dam­ag­ing one or more of the driv­ers.

Graph 5 is a com­pos­ite graph that places the fre­quency re­sponses shown in Graphs 1, 2 and 4 to­gether, so you can see the ‘fit’ be­tween them. The pink trace on this graph shows why it’s pos­si­ble to ig­nore the peaks shown on the gated si­nus (blue) trace be­cause this trace essen­tially shows the re­sponse that would be per­ceived by the hu­man ear… you re­ally don’t hear those sharp peaks and dips.

The very low ef­fi­ciency com­bined with the low im­ped­ance of the Boenicke W8 will make am­pli­fier match­ing cru­cial to ex­tract­ing best per­for­mance. I as­sume one rea­son for the low ef­fi­ciency is the con­sid­er­able bass ex­ten­sion Boenicke has been able to ex­tract from this de­sign: 42Hz is an ex­cel­lent re­sult for such a small cabi­net. Although the fre­quency re­sponse is not the smoothest I have seen, it’s cer­tainly ac­cept­ably flat at 42Hz to 40kHz ±5dB, par­tic­u­larly con­sid­er­ing most of the vari­a­tion is caused by the in­crease in out­put at fre­quen­cies higher than 3.2kHz, which is the high­est ‘G’ on a pi­ano key­board. Steve Hold­ing

‘As for the de­sign of these feet, I didn’t know what to make of it, be­cause the de­sign and im­ple­men­ta­tion are quite strange.’

Graph 5. Com­pos­ite re­sponse plot. Red trace is out­put of bass re­flex port. Black trace is ane­choic re­sponse of side-fir­ing bass driver. Green trace is sine re­sponse of front-fir­ing bass/midrange driver. Pink trace is pink noise trace above 900Hz (stopped at 20kHz). Blue trace is spliced lf/hf trace from Graph 1.

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 been man­u­ally spliced (at 1kHz) to the gated high-fre­quency re­sponse.

Graph 2. Low fre­quency re­sponse of front-fir­ing bass re­flex port (red trace), side-fir­ing woofer (black trace), and front woofer/ midrange (green trace). Nearfield ac­qui­si­tion. Port/woofer lev­els not com­pen­sated for dif­fer­ences in ra­di­at­ing areas.

Graph 3. Im­ped­ance mod­u­lus of left (red trace) and right (yel­low trace) speak­ers plus phase (blue trace).

Graph 4. Av­er­aged in­room fre­quency re­sponse us­ing pink noise test stim­u­lus. Trace is the av­er­aged re­sults of nine in­di­vid­ual fre­quency sweeps mea­sured at three me­tres, with the cen­tral grid point on-axis with the tweeter.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.