ALPHA SERIES Alpha M3 & M8 Alpha Em & EF B1-18 & B1-15 S2 Sub-bass User Manual
PAGE 2/37 INTRODUCTION INTRODUCTION 3 ALPHA SERIES DESCRIPTION 3 LOUDSPEAKERS NEXO TDCONTROLLERS THE X-BOW FLYING SYSTEM 3 4 4 GENERAL SET-UP INSTRUCTIONS 5 SPEAKER WIRING FLYING THE SYSTEM TDCONTROLLERS SETTINGS INITIAL SET-UP PRECAUTIONS 5 6 9 10 ALPHA ARRAYS - SOME BASIC RULES 11 ALPHA S2 PLACEMENT SPL VERSUS FREQUENCY SPL VERSUS DISTANCE DIRECTIVITY - COVERAGE 11 11 11 14 AMPLIFIERS 16 POWER CURRENT RATING AMPLIFIER GAINS GAIN VALUE ADVANCED PROTECTIONS 16 16 16 17 17 PASSIVE CROSSOVE
PAGE 3/37 INTRODUCTION INTRODUCTION Thank you for selecting NEXO Alpha Series. This manual is intended to provide you with necessary and useful information about your Alpha System: • S2 • B1-15, B1-18 • M3, M8 • EM, EF Please devote some attention to reading this manual. A better understanding of some specific features of the Alpha Series will help you to operate your system to its full potential. This manual is intended to be comprehensive, and we hope that it will satisfy your requirements.
PAGE 4/37 ALPHA SERIES DESCRIPTION • Three UNITS (600 mm): Alpha B1-15, Alpha M3, Alpha M8. • Two UNITS (400 mm): Alpha EM. Nexo TDcontrollers The Alpha Series speakers are associated with the NX241 Digital TDcontroller, which can be configured to provide comprehensive control of the above, mentioned cabinets. For a complete description of this unit please refer to the "NX241 User Manual". You may also use one of the following analogue TDcontrollers that preceded the NX241.
PAGE 5/37 GENERAL SET-UP INSTRUCTIONS General Set-up Instructions Speaker Wiring Connectors The loudspeakers are connected via SPEAKON connectors, NL4FC and NL8FC (not supplied). A wiring diagram is printed on the connection panel located on the back of each cabinet. The pins of the SPEAKON sockets are identified in/out and connected in parallel within the enclosures.
PAGE 6/37 GENERAL SET-UP INSTRUCTIONS Cables Nexo recommends the exclusive use of multi-conductor cables to connect the system: the cable kit is compatible with all the cabinets, and there is no possible confusion between VLF, LF, MF and HF sections. Cable choice consists mainly of selecting the correct cable section (size) in relation to the load resistance and the cable length.
PAGE 7/37 GENERAL SET-UP INSTRUCTIONS • Do not allow inexperienced persons to handle X-BOW flying systems. Installation personnel should be trained in loudspeaker flying techniques and should be fully conversant with this manual. • Ensure that motor hoists, hoist control systems and ancillary rigging components are currently certified as safe and that they pass a visual inspection prior to use.
PAGE 8/37 GENERAL SET-UP INSTRUCTIONS • Always survey the supporting structure upon which a ground stack is to be built. Always look beneath PA wings to inspect the deck support and if necessary ask for the stage scrims and dressings be removed to allow access. • X-BOW components should be used to stabilise ground stacks and to ensure that cabinets remain securely registered to each other.
PAGE 9/37 GENERAL SET-UP INSTRUCTIONS TDcontrollers settings The Alpha Series cabinets will not perform correctly without their associated TDcontrollers. Sound quality and reliability are totally dependent on the correct use of the TDcontrollers, in association with the Nexo instructions, provided. All manuals & associated technical notes must be read before set-up. Please contact your NEXO agent for any literature inquiry.
PAGE 10/37 GENERAL SET-UP INSTRUCTIONS Initial Set-up Precautions When running up a system particularly one which includes brand new cabinets for the first time the power should be increased slowly to approximately 50% and the system operated at this level for two hours. During the following two hours of operation the power level should be limited to approximately 75%. This procedure allows the adhesives and suspensions within the loudspeaker components to stabilise and will extend their working life.
PAGE 11/37 ALPHA ARRAYS - SOME BASIC RULES Alpha Arrays - Some Basic Rules The concept of arraying speakers derives from two requirements: • Increased sound pressure level; • Extended coverage area. Array behaviour is very complex, and a bad design can lead to very poor results. The Alpha system was designed to be flexible, allowing the user to optimise the design for a dedicated situation; its development included a long measurement program on a very large variety of arrays.
PAGE 12/37 ALPHA ARRAYS - SOME BASIC RULES Single Cabinet Lp(1m) being the sound pressure level at 1m, the level at a distance d (in meters) is given by: Lp(d) = Lp(1m) - 20 log10(d) Sound Pressure Level (dBSPL) / distance (meters) 110.00 100.00 90.000 80.000 70.000 60.000 1 10 100 • Single Cabinet SPL versus Distance For example, if the level measured at 1 meter is Lp(1m) = 100 dBSPL, the level at 2 meters will be 94 dBSPL, 80 dBSPL at 10 meters and so on.
PAGE 13/37 ALPHA ARRAYS - SOME BASIC RULES Hygrometry and Temperature - Air Absorption Under usual conditions, air absorption increases when relative humidity decreases and increases when temperature decreases. Air absorption gives a linear attenuation, i.e. a constant value of loss of dB per meter: if 1 dB is lost from 10 to 20 meters, 2 dB will be lost from 20 to 40 meters, 4 dB from 40 to 80 meters and so on...
PAGE 14/37 ALPHA ARRAYS - SOME BASIC RULES Directivity - Coverage The two main qualities one might expect from a cabinet for array constructions are: • A good directivity control in the mid and high frequency region, which guarantees the steadiness of the interference region where dips and lobes occur; • A strong roll-off of the directivity function at the -6dB cut-off angle, which minimises the size of the interference region. The Alpha series cabinets were designed to respect these two criteria.
PAGE 15/37 ALPHA ARRAYS - SOME BASIC RULES The only situations where such arrays can be assembled with very little angle are long throw applications (very small vertical coverage) because the interferences are less significant at large distances from the array. Large Arrays (4 Alphas M3 / M8 and above) Construction of large arrays derives from important SPL requirements rather than large listening angles: although the Alpha M3 is a high Q cabinet, 4 boxes are enough to cover a 140° horizontal plane.
PAGE 16/37 AMPLIFIERS Amplifiers Pow er NEXO recommends high power amplifiers in all cases. Budget constraints are the only reason to select lower power amplifiers. If an incident occurs on an installation without protection the fact that amplifiers only generating half their rated output power (-3dB) are used will not change anything in respect of possible damage.
PAGE 17/37 AMPLIFIERS 3. Measure the Voltage at the output of the amplifier. 4. Calculate the gain using the formula Gain = 20 * LOG10(Vout/Vin) Some examples: Gain 20dB 26dB 32dB 0.1V 1V 2V 4V 37dB (1.4V sensitivity / 1350Wrms) 7.1V 0.5V 5V 10V 20V 35.4V 1V 10V 20V 40V 70.8V Vin Remember that constant sensitivity settings will give a different gain value when the amplifier power is different.
PAGE 18/37 PASSIVE CROSSOVER FUSES PASSIVE CROSSOVER FUSES Please note, within both Alpha & AlphaE cabinet families a fuse is fitted to protect the internal passive filter network in the event of a voice coil failure. This fuse is located on the filter network, which is attached to the input panel of the following cabinets.
PAGE 19/37 TECHNICAL SPECIFICATIONS T ECHNICAL SPECIFICATIONS Alpha S2 SYSTEM SPECS Frequency Response [a] Usable Range @6dB [a] Sensitivity 1W @ 1m [b] Peak SPL @ 1m [b] Nominal Impedance Recommended Amplifiers FEATURES ALPHA S2 with Sub TDcontroller 32 Hz – 64 Hz ± 3 dB 29 Hz – 180 Hz 105 dB SPL 140 dB Peak 3 ohms (2.7 min) 1800 to 2400 Watts into 3 ohms ALPHA S2 Components 2 x 18’’ (46cm) long excursion 6 ohms drivers, high efficiency acoustic load.
PAGE 20/37 TECHNICAL SPECIFICATIONS Alpha B1-15 / B1-18 SYSTEM SPECS Frequency Response [a] Usable Range @6dB [a] Sensitivity 1W @ 1m [b] Peak SPL @ 1m [b] Nominal Impedance Recommended Amplifiers FEATURES Components Height x Width x Depth Shape Weight: Net Connectors ALPHA B1-15 ALPHA B1-18 Wideband: 42 Hz – 180 Hz ± 3 dB Xover: 80 Hz – 190 Hz ± 3 dB 40 Hz – 230 Hz ± 3 dB 39 Hz – 600 Hz 38 Hz – 600 Hz 106 dB SPL 107 dB SPL Nominal 140 dB Peak 142 dB Peak 6 ohms (5.2 mini) 6 ohms (4.
PAGE 21/37 TECHNICAL SPECIFICATIONS Alpha M3 / M8 SYSTEM SPECS Frequency Response [a] Usable Range @6dB [a] Sensitivity 1W @ 1m [b] Peak SPL @ 1m [b] Dispersion [c] Directivity: Q & DI [c] Nominal Impedance Recommended Amplifiers FEATURES Components Height x Width x Depth Shape Weight: Net Connectors Construction Handles ALPHA M3 ALPHA M8 190 Hz – 19 kHz ± 3 dB 190 Hz – 19 kHz ± 3 dB 150 Hz – 20 kHz 150 Hz – 20 kHz 110 dB SPL 108 dB SPL 145 dB Peak 143 dB Peak 35° x 35° 75° x 45° (HF Horn Rot
PAGE 22/37 TECHNICAL SPECIFICATIONS Alpha EM / EF SYSTEM SPECS Frequency Response [a] Usable Range @6dB [a] Sensitivity 1W @ 1m [b] Peak SPL @ 1m [b] Dispersion [c] Directivity: Q & DI [c] Cross-Over Frequency Nominal Impedance Recommended Amplifiers FEATURES ALPHA EM ALPHA EF 220 Hz – 19 kHz ± 3 dB 40 Hz – 19 kHz ± 3 dB 180 Hz – 20 kHz ± 6 dB 38 Hz – 20 kHz ± 6 dB 107 dB SPL 107 dB SPL 140 dB Peak LF: 142 dB Peak MF/HF: 140 dB Peak 75° x 30° 75° x 30° Q = 25 – DI = 14 dB (Nominal f > 630 Hz)
PAGE 23/37 TECHNICAL SPECIFICATIONS Directivity Tables Off-Axis Attenuation from On-Axis Frequency Response (dB) 125 Hz Angle / dB 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 B1+M3 hor 0.0 0.5 1.3 2.0 2.5 3.5 4.3 4.5 5.0 4.8 6.0 6.0 6.5 6.8 6.3 7.0 6.3 B1+M3 vert 0.0 0.3 0.5 1.5 2.0 2.8 3.5 4.3 4.8 5.5 6.0 6.8 6.8 6.0 7.0 6.5 6.0 5.8 5.5 5.5 5.5 5.5 B1+M8 hor 0.0 0.5 1.3 2.0 2.5 3.5 4.3 4.5 5.0 4.8 6.0 6.0 6.5 6.
PAGE 24/37 CURVES CURVES Alpha S2 On Axis Response Alpha S2 With SubTD Controller (dB) Impedance Alpha S2 (Ohm) 10.000 50 0.0 -10.00 10 -20.00 -30.00 30 100 1k 10k 20k 2 10 • Figure 1: Frequency Response with Sub TDcontroller (dB) 100 1k 10k • Figure 2: Impedance (Ohms) Alpha B1-18 On Axis Response Alpha B1-18 With AlphaETD Controller (dB) Impedance Alpha B1-18 (Ohm) 10.000 50 0.0 -10.00 10 -20.00 -30.
PAGE 25/37 CURVES Alpha M3 On Axis Response Alpha M3 With AlphaTD Controller (dB) Impedance Alpha M3 (Ohm) 10.000 50 0.0 10 -10.00 -20.00 -30.00 20 100 1k 10k 2 20 20k • Figure 7: Frequency Response with Alpha TDcontroller (dB) 100 1k 10k 20k • Figure 8: Impedance (Ohms) Black: MF, Grey: HF Directivity Index (dB) & Q Alpha M3 Coverage Angle Alpha M3 (Degree) 20.000 200 100 15.000 100 10.000 10 5.0000 1 0.
PAGE 26/37 CURVES Alpha M3 - Horizontal Directivity (5dB / div.
PAGE 27/37 CURVES Alpha M3 – Vertical Directivity (5dB / div.
PAGE 28/37 CURVES Alpha M8 On Axis Response Alpha M8 With AlphaTD Controller (dB) Impedance Alpha M8 (Ohm) 10.000 50 0.0 10 -10.00 -20.00 -30.00 20 100 1k 10k 2 20 20k • Figure 13: Frequency Response with Alpha TDcontroller (dB) 100 1k 10k 20k • Figure 14: Impedance (Ohms). Black: MF, Grey: HF Directivity Index (dB) & Q Alpha M8 Coverage Angle Alpha M8 (Degree) 20.000 200 100 15.000 100 10.000 10 5.0000 1 0.
PAGE 29/37 CURVES Alpha M8 – Horizontal Directivity (5dB / div.
PAGE 30/37 CURVES Alpha M8 Vertical Directivity (5dB / div.
PAGE 31/37 CURVES Alpha EM On Axis Response Alpha EM With AlphaETD Controller (dB) 10.000 Impedance Alpha EM (Ohm) 50 0.0 -10.00 10 -20.00 -30.00 30 100 1k 10k 20k 2 20 100 • Figure 19: Frequency Response with AlphaE TDcontroller (dB) 1k 10k 20k • Figure 20: Impedance (Ohms) Directivity Index (dB) & Q Alpha EM Coverage Angle Alpha EM (Degree) 20.000 200 100 15.000 100 10.000 10 5.0000 0.
PAGE 32/37 CURVES Alpha EM – Horizontal Directivity (5dB / div.
PAGE 33/37 CURVES Alpha EM – Vertical Directivity (5dB / div.
400 [15.74"] ALPHA SERIES USER MANUAL V1.0 DATE: 14/01/00 16:23 754 [29 11/16"] 762 [30"] 889 [35"] 754 [29 11/16"] 754 [29 11/16"] 1200 [47 1/4"] 22.5° 688.77 [27 1/8"] e 22.5° 688.77 [27 1/8"] e 762 [30"] 889 [35"] 762 [30"] 889 [35"] 754 [29 11/16"] 1200 [47 1/4"] 754 [29 11/16"] 600 [23 5/8"] 22.5° 688.77 [27 1/8"] 22.5° 688.77 [27 1/8"] 762 [30"] 889 [35"] 762 [30"] 889 [35"] 754 [29 11/16"] 600 [23 5/8"} 754 [29 11/16"] 800 [31.49"] 22.5° 688.77 [27 1/8"] 22.5° 688.
PAGE 35/37 TRANSPORT ALPHA SERIES USER MANUAL V1.
ALPHA SERIES USER MANUAL V1.
PAGE 37/37 CONNECTIONDIAGRAMS B1-18 B1-18 B1-18 S2 SP4 CABLE SP4 CABLE SP4 CABLE M3 / M8 SP8 CABLE M3 / M8 SP8 CABLE M3 / M8 SP8 CABLE S2 SP4 CABLE Recommended Amplifiers ALPHA M3 -HF 350 to 500 Watts into 12 ohms ALPHA M3 -MF 650 to 900 Watts into 12 ohms ALPHA B1-18 / B1-15 900 to 1400 Watts into 6 ohms NX241 TDcontroller NX241 TDcontroller SP4 CABLE ALPHA S2 1800 to 2400 Watts into 3 ohms SP4 CABLE SP4 CABLE M3 / M8 SP8 CABLE M3 / M8 SP8 CABLE M3 / M8 SP8 CABLE S2 SP4 CABLE SP
France NEXO S.A. 154 Allée des Erables ZAC de PARIS NORD II BP 50107 F-95950 ROISSY CDG CEDEX Tel: +33 1 48 63 19 14 Fax: +33 1 48 63 24 61 Email: info@nexo.fr USA UK FAR EAST NEXO USA Inc. NEXO limited NEXO Far East Ltd 7950 Redwood Drive Suite 3 Cotati CA 94931 Tel: +1 707 793 9300 Fax: +1 707 793 9310 Email: nexousa@aol.com 9 Lyon Road Walton-on-Thames Surrey KT12 3PU Tel: +44 1932 886 007 Fax: +44 1932 886 008 Email: info@nexo-sa.
