November 200430

German company Fohhn havebeen building powered,processor‡controlled PA speakersfor over a¥decade and their Xperience IIIsystem is part of a¥much larger range thatextends from small portable systems toinstallation and touring components. As isnow commonplace, the system comprisesseparate main speakers and subwoofers, tokeep it as compact and manageable aspossible, but a¥noticeable departure fromthe current trend is the use of Class‡D‘digital’ amplifiers, digital signal processingand passive crossovers. Rather than havingan amplifier in every speaker box, theXperience III has its the amplification insidethe sub cabinets and uses passivecrossovers to feed the main speakers, whichin turn house further crossovers to split thesignal between the cone driver and thecompression horn. A basic system comprisesa¥single sub plus two main speakers and isconfigured for mono‡sub, stereo‡topoperation. In configurations using dual substhe amplifiers can be used in bridge modeto increase the peak power handling perside, and the whole system can then be runin full‡range stereo. Popular alternativeconfigurations to the basic one referred toabove include two mains and two subs, orfour mains and two subs.

Sub stanceAs the subwoofer is the heart of thesystem, it makes sense to look at that first.The XS3 uses a¥custom‡built 15‡inch drivermounted in a¥dual‡chamber reflex cabinet,also known as a¥back resonator. (In effect,this creates two fairly broad resonant peaks,which are combined to give a¥nominally flatfrequency response over the cabinet’sintended range.) Considering its power, theXS3 is surprisingly compact at 430 x 590 x520mm, and because Class‡D amplifiers (inthis case driven from switch‡mode powersupplies) can be made much lighter thanconventional class B or A/B designs, it

weighs only 36kg, despitebeing manufactured frombraced marine ply. Twowheels are built into thebottom of the cabinet at therear for easy transport, andthere are two side handles,one top handle and onebottom‡edge handle. Blacktextured paint provides anattractive and durable finishand a¥mounting plate isfixed into the top of thecabinet to accept a¥threadedmounting pole for the mainspeaker. The 15‡inch driver isprotected by a¥metal grille,and a¥thin layer of acousticfoam in front of it preventsthe ingress of dust.

All the sub’s connectionsare on the rear panel. Toallow the greatest flexibilityof connectivity, the signalinputs (stereo) are on combiXLR connectors that can alsoaccept quarter‡inch jacks.Link sockets are alsoincluded for daisy‡chainingmultiple cabinets, and asthese are of the opposite‘sex’ to the inputs, they canalso be used as inputconnections where the‘wrong’ sex of XLR connectoris available, as might be thecase when using a¥simple‘inputs only) stage box.Feeds for the main speakersare on standard Speakonconnectors.

There is little adjustmentfor the user to mess up, noteven an input gain trim control, thoughthere is the facility to adjust the relativebass level (35‡130Hz) by +/‡6dB to suit theoperating environment. There’s alsoa¥stereo/mono switch; stereo must beselected when driving two main speakersfrom the same sub. A ground‡lift switchhelps avoid ground‡loop hum in difficult

situations, and a¥bridge‡mode switch putsthe internal amplifiers into bridge mode forsystems where two or more subs are beingused. Other than that, there’s just a¥mainsswitch and a¥mains inlet, which in this caseis on a¥Powercon connector rather thana¥standard IEC socket, the reason being thatPowercons are locking connectors and so

On test

SOUND ON SOUND LIVE

Fohhn Xperience IIIActive PA System

This German‡made PA costs a¥bit more thansome, but if top sound quality is your priorityit’s well worth a¥look.

Reviewed by Paul White

Testinfo

Active PA system

Fohhn Xperience III

The XT3ND cabinet (top) and XS3 subwoofer.

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are unlikely to become detached during use.If there’s a¥downside to this, it’s only thatyou have to remember to pack the correctmains cables. Soft‡start circuitry preventsswitch‡on thumps.

Three‡band processing is used inside thesub to allow separate limiters to operate onthe source signal as transparently aspossible, the three ranges being 35‡130Hz,130Hz‡2kHz and 2kHz‡20kHz. This is verypractical, as something like a¥snare-drum hitthat might cause limiting in the mid bandwon’t affect the gain of low‡frequencysignals, which would be the case if a¥singlefull‡band limiter was being used. A limit LEDon the rear panel shows when the limiter isbeing goaded into action.

Cooling for the amplifiers is viaa¥quiet‡running fan that responds to thesystem temperature, though Class‡Damplifiers are more efficient thanconventional Class‡B types and so generateless heat in the first place. In fact, the onlyexternal heat sink is the rear panel, and innormal operation this only runs at 14degrees above the ambient temperature.Under standard operating conditions thefan rarely comes on at all. The culminationof this combination of components is a¥subthat works from 35Hz‡500Hz witha¥maximum SPL of 128dB.

Main eventHandling the top end is the XT3ND cabinet,loaded with a¥custom‡built, 12‡inch driverand a¥time‡aligned, one‡inch, horn‡loadedcompression driver powered bya¥Neodymium motor. A passive crossover isbuilt into the cabinet, as mentioned earlier,and includes overload protection for thehigh‡frequency driver. This 8Ω design

produces a¥40‡degree vertical, 90‡degreehorizontal directivity and has a¥maximumpower handling of 450W (900Wshort‡duration peak), with a¥maximum SPLof 130dB. As the frequency range of thiscabinet is 65Hz‡20KHz, it can be used asa¥full‡range speaker if driven froma¥separate power amplifer, and because ofthe way the cabinet sides have beenangled, it can also be used as a¥floormonitor at either 35 degrees or 55 degrees.Overall, the cabinet measures just 390 x 590x 390mm (slimmer than my Mackie cabinets)and weighs 22kg, making it a¥fairlycomfortable lift. Like the sub, it is built frommarine ply with a¥textured paint finish andhas two Speakon connectors for input andlinking. Two edge handles are built in, aswell as a¥pole‡mount socket in the bottomof the cabinet and mounting bushes in theside for flying or installation. There’s alsoa¥safety chain point on the rear of thecabinet. Protective covers for the main andsub speakers are available as optionalextras.

Testing, testingSystems Workshop, who distribute Fohhn inthe UK, were kind enough to supply a¥‘twosubs, four mains’ 2kW system for review,which I¥tested while handling the sound foran outdoor charity concert staged ona¥football field. The acts ranged from a¥solosinger/guitarist to some pretty loud rockbands, and there was also a¥need forbackground music during the change-oversbetween bands. Incredibly, the entire systemturned up packed into the back of a¥VWGolf with the back seat down flat, so it getsfull marks for portability!

Setting up the speakers was triviallysimple and involved erecting the poles andstands, then linking the main speakers tothe subs using Speakon cables. As I¥wasusing a¥very basic stage box fitted with allthe same sex of XLR connector, standardmic cables were used to run the mixer outsto the link inputs of the subs. This meant

I¥didn’t need to use gender‡changeradaptors (but these are always a¥good thingto have in your tool box). The bass controlswere set to their mid (flat) position and assoon as I¥had my mixer hooked up anda¥few mics and DI boxes plugged in, wewere ready for a¥soundcheck.

First on was the singer/guitarist. I¥wasimmediately impressed with the vocal clarityand smoothness presented by the Fohhn PA,as well as the quality of the guitar sound. In

fact, I’d go as far as to say it was one of thebest vocal sounds I’ve had from any PA atany realistic price, a¥fact all the morestartling given that I¥was using a¥set ofAdam Hall’s LD‡series back‡electret vocalmics, which retail at less than £50 each.(I first ‘discovered’ these when reviewingthem and decided to buy four for my live kitas they fill the dual needs of sounding greatand being expendable! See the reviewelsewhere in this issue.)

Next on was pop/rock band Ember,featuring a¥female singer/guitarist, bass,drums, keyboard and electric guitar, thelatter DI’d from a¥Boss pedalboard withintegral speaker simulation. Again, the vocalclarity was superb and didn’t seem in theleast bit disturbed by the kick drum andbass guitar which were now poundingthrough the system, not to mention someangsty lead guitar and power chords. The

31November 2004 SOUND ON SOUND LIVE

Fohhn Xperience III PAPros• Portable.• Easy to set up.• Excellent sound quality.• Expandable in logical stages.

Cons• No input gain trim.• You don’t have the flexibility to leave the sub

behind for bar gigs unless you have a¥separatepower amp.

SummaryThe combination of top sound quality andportability more than compensates for the slightlyhigher cost of this system.

Information‹ Basic Xperience III system (one sub, two main

speakers), £3253; ‘Power’ system (two subs, twomain speakers), £5169. Prices include VAT.

Ê Systems Workshop +44 (0)1691 658550.‰ sales@systemsworkshop.com„ www.systemsworkshop.com„ www.fohhn.com

At a glance

“I’d go as far as to sayit was one of the bestvocal sounds I’ve hadfrom any PA at anyrealistic price.”

The rear panel of the XS3 subwoofer. CombinationXLR/jack connectors are used for the stereo inputs(left), and a Powercon locking connector is provided forthe mains inlet (top right), giving protection againstaccidental disconnection when the sub is in use.

November 200432

acoustic guitar, which was DI’d, also cameover smoothly, which is so often not thecase with more aggressive‡sounding PAsystems. What’s more, a¥stroll to the otherend of the football pitch confirmed that thevocal projection was excellent, though therelatively high directivity of the systemmeant that those buying beer and foodfrom the tents to either side of the

stage weren’t getting such great coverage.Angling the outer pair of top cabinets toaround 45 degrees remedied this prettywell, which does show that you have to planfor coverage, not just ‘out front’ volume, atspeciality events such as this.

The back line projected well, with plentyof punch and no boomy resonances, andthough there wasn’t that deep wall ofbass you get from a¥stack of 2x15 bassbins, you have to keep in mind that itis asking rather a¥lot of a¥2kW systemto cover a¥football field. In fact, theonly practical problem I¥had was thatmy mixer was running out of outputheadroom before the speaker system,so I’d have appreciated a¥gain trimcontrol on the Sub signal inputs toremedy this. I¥had to get my mixer cliplight to come on before the Xperiencelimiter LED would even blink!

On recorded music the system alsoworked surprisingly well — I’ve heardsome horrendous music reproductionfrom PA systems, even some quiteexpensive ones, but this one managedto sound smooth and classy, evenwhen driven at close to its powerlimit.

SummaryThe Fohhn Xperience III costs rathermore than a¥typical budget PA system,but it is still very reasonably pricedwhen you consider the quality ofsound on offer, and it doesn’t costmuch more than some of the better‘plastic’ systems. I’ve always felt that

a¥PA should sound like a¥big hi‡fi, and thisone comes very close indeed. Thebeautifully built marine‡ply cabinets aremercifully free of any rogue resonances andI¥was particularly impressed by the naturalsound quality of the high end — so manysystems that use compression‡loaded hornsmanage to sound harsh or honky. A basic

‘sub plus two tops’ system wouldbe ideal for smaller pub

and club venues, whiledoubling up on that

setup, as we didfor this review,

gives youa¥systemthat’s gamefor justabout

anythingshort of

a¥large‡scaleevent. There’s also

a¥smaller system called theExperience II that uses the same poweramps but has a¥smaller 12‡inch sub and10‡inch main cabs. If you don’t need asmuch power and require an even morecompact system, that could be well worthlooking at.

During the test we had numerouscompliments on the sound quality frommusicians attending the event, and becausethe system was tested outdoors there wereno room artifacts to colour the sound.Having said that, speakers need to work

indoors as well as out, but the sensiblycontrolled dispersion pattern of thesespeakers means they should be as

venue‡tolerant as is reasonablypractical for a¥general‡purpose system.

In practical terms, the only limitationI¥can think of for this type of PA isthat, in small venues where a sub maynot be needed, you can’t use the mainspeakers on their own withouta¥separate power amplifier, as all theamplification resides in the subs. Onthe other hand, the system is soportable that you probably wouldn’tuse it without the subs anyway, unlessyou’re a¥singer/guitarist, in which casea¥pair of main speakers teamed witha¥suitable powered mixer would alsomake a¥great portable system.

As always, you tend to get whatyou pay for, and if impeccable sound isyour overriding concern, especially inthe area of vocals, I¥feel the FohhnXperience III is worth the extra cost.Its ease of use and great portability isalso a¥significant factor, as is itstough, all‡ply construction. The systemis also expandable in logical stages, soeven if you can only afford the basicpackage now, you can add to it asyour needs change. Indeed, I¥was sorryto see it disappear back into the VWGolf and drive off into the sunset.ß

On test

SOUND ON SOUND LIVE

Fohhn Xperience IIIActive PA System

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Class‡D amplifier: A class‡D amplifier is one inwhich the output transistors are operated,effectively, as switches, being either fully off orfully on, with the audio signal modulating(controlling) the switching action. Class D is veryefficient, allowing smaller power supplies to beused. The ‘D’ is sometimes mistakenly said tostand for ‘digital’ when in fact it was simply thenext letter in the alphabetical series after ClassA, Class B (and A/B) and Class C.Switch‡mode power supply: A high‡efficiencypower‡supply design which allows the PSU to besmaller and lighter for a¥given capacity.Bridging: A method of achieving more outputfrom a¥power amp. If the same signal is appliedto two channels of an amplifier, one of themwith opposite polarity, a¥speaker ouput can bederived between the positive output of onechannel and the negative of the other, allowingthe amp to apply twice the voltage across theload.SPL (Sound Pressure Level): Sound levelcalculated in decibels compared to a¥referencesound pressure, commonly 20 micropascal (20uPa), defined as the threshold of human hearing(0dB SPL). The human ear is capable of hearingan enormous range of sound pressures — theratio of the sound pressure from the minimumup to damaging levels from even short‡termexposure is more than a¥million — necessitatinga¥logarithmic scale, which also correspondsroughly to our psychological perception ofloudness.

Jargon explained

The XT3ND cabinet can also be positioned on one of itsangled sides for use as a wedge floor monitor.

Part of the Xperience III system in situ at the open‡air event where testingtook place.