4331B and 4333B - JBL Professional

Accurate, smooth reproduction94 dB SPL. 1 W, 1 m (3.3 ft)Components: 380 mm (15 in) low frequency loudspeaker,high frequency compression driver withhorn/lens assembly; the 4333B is also furnished withan ultra high frequency transducer.Mountablein vertical or horizontal orientationBalance controls located behind the removable grilleRear mounted switch for bi-amplificationpassive crossoverOiled walnut or textured gray enclosureThe 4331B and 4333B Studio Monitorsor fullThe 4331B and 4333B are rugged, powerful studiomonitors designed for mixdown and mastering controlroom applications The result of an extensive researchand development effort, they represent a refinement ofthe classic JBL two-way studio monitor loudspeakersystem that has been relied on by a major segmentof the recording industry for the past 15 years.The transducers installed in each system are identical:a newly developed 380 mm (15 in) low frequencyloudspeaker and a wide range highfrequencycompressiondriver equipped with a newly developed horn/lensassembly with the addition of an ultra-high frequencytransducer in the 4333B which extends the bandwidthto 20,000 Hz.The network design integrates the performance of theindividual drivers, taking into account their location onthe enclosure baffle panel and the acoustic effects of theenclosure itself. A switch is provided on the crossovernetwork for the optional selection for use as a fully passivenetwork or a section of a bi-amplified system.Low Frequency LoudspeakerHtgh Frequency Compression DriverTreble reproduction is provided by a wide range corn- >pression driver capable of high power output and linearresponse characteristics. Its 44 mm (1% in) edgewoundaluminum ribbon voice coil is suspended within a powerfulmagnetic field produced by a 4.5 kg (10 lb) magneticassembly The aluminum diaphragm is pneumaticallyformed of anodized aluminum foil. Output of the diaphragmis directed through the concentric channels of aphasing plug prior to final distribution by the horn/lensassemblyHorn/Lens AssemblyControlled high frequency distribution is accomplishedby an exponential horn and slant-plate acoustic lens.The cast construction of the horn provides rigidity toeliminate resonance. Its taper rate determines thevertical dispersion pattern of the assembly and causesthe waveform generated by the compression driver toexpand at a controlled rate, providing the properacoustic load on the driver diaphragm. The acousticlens is analogous to a divergent optical lens, regulatingthe distance traveled by energy at various points alongthe wavefront. The precisely calculated hyperboliccurvature on the projecting surface of the lens determinesits specific horizontal distribution pattern.The acoustic lens is mounted with hook-and-pilemounting tape so it can be remounted allowing thecabinet to be oriented vertically or horizontallyUltra-High Frequency Transducer (4333B system Only)Overtones extending to 20.000 Hz are reproduced by acompression driver having an integral diffraction horn.The 44 mm (1% in) edgewound aluminum ribbon voiceAccurate, solid low frequency reproduction is providedby a 380 mm loudspeaker. The cone is selected foroptimum stiffness, density and mass to provide the criticallow frequency bandwidth and transient responserequired for monitor applications while maintaininghigh efficiency Its 100 mm (4 in) copper voice coil ismanufactured of wire milled to a flat ribbon, then tightlywound on the narrow edge by hand. Edge winding ofthe voice coil increases the amount of conductor in themagnetic field, resulting in greater transient responseand efficiency The 8.5 kg (18% lb) magnetic assemblyincorporates JBL’s unique Symmetrical Field Geometry(SFG), a design which greatly reduces second-harmonicdistortion and results in cleaner tighter bass.

icoil is suspended ulthln an intense magnetic field provldedby a 15 kg (3X lb) magnetic assembly The voicecoil is bonded to a ring diaphragm pneumatlcallyformed of alumlnum alloy foil The diffraction horn mamtamsa Mrlde. controlled disperjlon pattern, even atextremely high frequenciescFrequency Dividing NetworkThe 4331B and 4333B systems are provided wth a hghlevel, passive frequency dlvldmg network The circuitryhas been designed Mnth conslderatlon for the variousperformance characteristics of the dnverj and theirlocatlons on the enclosure baffle panel The networkshave been deslgned for continuous high power appllcation, capacitors are non-mductlve, non-polarized typesmth high AC current capacity and special inductors areused to mimmlze power losses withm the network Eachinductor is calibrated on a sensitive electronic bridgeand Its value set preciselyThe networks are equipped urlth terminals andswitch so that they may be used for high frequencytransitions as bl-amplified systems or full passive networksfor conventlonal systemsEnclosureIn keeping wth current trends In studlo design thatencourage creatlvlty JBL studio monltor enclosuresfeature contemporary stylmg and are offered In twofmlshes. each urlth a complementary grille color Theenclosure, however. contrlbutes as much to performanceas 11 does to the monltoI’s handsome appearance TheInternal volume of the enclosure and physical conflgurationof the ducted ports are carefully designed to properlyload the new low frequency loudspeaker foroptlmum bass response and to control cone excursion,thus mimmlzing dlstortlon and maximizing powerhandlmg capacity of the dnver To ellmmate resonance,the enclosure is constructed of dense 19 mm (3/4 In) and25 mm (1 In) stock wth a 15ply baffle panel, all ]omtsare carefully interlocked and glued, the back, side, topand bottom panels are lmed with acoustic dampingmaterial and are each stiffened bymultlple braces gluedand screwed to the panel and to the adlacent surfacesof the enclosureTest ParametersThe accompanying graph and speclflcatlons were compliedfrom measurements made under standard laboratorytest conditions The complete loudspeaker system,includmg the enclosure. was mounted flush in the centerof a large. flat baffle in an anecholc environment Callbratedcondenser microphones were suspended at ameasured distance from the sound source, sufflclently outof the near field All associated electronic equipmentwas checked and calibrated before tests were runc

SpecifkanonsEnclosureVolume156 L 5 5ft3EnclosureDlmenslons781 mmx578 mmx514 mm30% lrlX223/4 IrlX2OX I”Power Capacity’(B!-amplrflcationconflguratIon)Below 800 HzAbove 800 HzNominal Impedance75 watts cOntlnuOuS s,ne wave75 watts continuous we wave30 watts continuous sine wave8 ohmsNet Weight433184333BShtpplng Weight433184333860 kg 1321b62 kg 1361b63 kg 1391b65 kg 1431bJPower Output24331843338100.5 dB SPL101 dB SPLMeasured at 3 0 m (10 ft) in a roomvolume of 57 m3 (2000 cu ft) wth% rated power inputAccessories(for bl-ampllficatlon)5233 Electronic Frequency DudlngNetwork, single channel 5234 ElectronlcFrequency Dlwdlng Network,dual channel 52-5123 CrossoverCard required for the low frequencytransItIonFrequency43318ResponseSine Wave. On-AXIS35 to 15,000 Hz. k3 dBX-Octave Band(500 Hz Reference)-4 dB at 31 5 Hz,-1 dBat 1 kHz,+2 dB at 10 kHr43338Sine Wave, On-AXIS35 to 20.000 Hz 23 dB%-Octave Band(500 Hz Reference)-4 dB at 31.5 Hz.-0 5 dB at 1 kHz,+Z dB at 20 kHrPolar Response43318No less than -3 dB at 60° horizontaland 30° vertical to 12 kHr43338No less than -3 dB at 60° horizontaland 30° vertical to 16 kHzSensitivity3 94 dB SPL measured at 1 m (3.3 RIwith 1 W Input averaged from 100to 1000 HzCautionSo”ndpress”relevelsprod”cedbythe43318or43338mayca”sepermanenlhearing loss The suggesfed max,m”m exposure is 115 dBA for no more than 15mlnufes (Depanment Of Labor Bullefl” #x341JBL continually engages I” research related to prod”ct improvement New materialsprod”ct,on methods and destgn ref~nemenfs are ,ntrod”ced (“to ex,st,“g prod”&v&ho”, no,,ce as a routine express~o” of that phliosophy For th,s reason any ~“rrentJBL prod”c, may d,“er I” some respect from 1,s publIshed descrrpt,on but will alwaysequal or exceed the original design spe~lflcations ““less otherwise statedDistortIon% Power, 99 dBSPL/3 0 m (10 ft1.Slngie Frequency1% or less third harmonic generationfrom 35 to 800 Hz2% or less third harmonic generatlonabove 800 HzCrossover4331843338FinishGrilleFrequencies4800 Hz800 Hz and 8500 HzTextured gray or oiled walnutBlack fabric with the gray finish,Dark blue fabric with walnutProfessional DfvfsionJames B. Lansing Sound, Inc.8500 Balboa BoulevardNorthridge. California 91329 U.S.A.