Tannoy B950 USER MANUAL
1. Introduction
The Tannoy B950 is a dedicated subwoofer designed for high definition sound reinforcement at low and ultra-low frequencies. It extends the power bandwidth of SuperDual sound reinforcement systems to below 30 Hz, making it ideal for effects in club, theatre, and concert sound reinforcement. For ultra-low frequency enhancement with increased system headroom and maximum impact, combined frequency overlap is possible with cabinets like the B400.
The B950 is intended for use on the ground and can be close stacked, while the main system is flown. This powerful loudspeaker delivers high sound pressure levels with extremely low distortion, maintaining a uniform frequency response throughout its dynamic range. This ensures consistent intelligibility and tonal quality at any listening level.
The B950 comprises two 18-inch high efficiency bass units housed in a heavily braced, optimally vented enclosure. Constructed from multiple-ply hardwood, the B950 features carrying handles and inserts for castors.
2. Unpacking
Every Tannoy product is carefully inspected before packing. After unpacking your B950, inspect for any exterior physical damage. Save the carton and relevant packaging materials in case the loudspeaker requires packing and shipping again. In the event of damage sustained in transit, notify your dealer immediately.
3. Connectors/Cabling
The B950 is fitted with 4-pole Speakon™ connectors. Speakon offers advantages over EP and XLR connectors: all terminations are solderless, simplifying installation and field servicing. Contacts accept 6 sq. mm wire with an outside diameter up to 15mm and a current rating of 30 Amps. The pins of the two Speakon sockets (identified as input/output on the rear of the input panel) are paralleled within the enclosure. Tannoy uses the following wiring standard for all Superdual products:
| SPEAKON CONNECTOR | SIGNAL |
|---|---|
| Pin 1+ | Passive Full Range + Active Low/Mid + Low/Sub + |
| Pin 1- | Passive Full Range - Active Low/Mid - Low/Sub - |
| Pin 2+ | Active High + |
| Pin 2- | Active High - |
Should you encounter problems obtaining Speakon connectors, please contact Neutrik or its distributors directly:
UK: NEUTRIK MARKETING: 0171 792 8188
USA: NEUTRIK USA INC.: (201) 901 9488
For a worldwide list of distributors, please contact Neutrik AG: +41 7529666.
Cable Choice Guidance
Cable choice involves selecting the correct cross-sectional area relative to cable length and load impedance. A small cross-sectional area increases series resistance, inducing power loss and response variations (damping factor).
Connectors should be wired with a minimum of 2.5 sq. mm (12 gauge) cable for normal conditions. For very long cable runs, use a larger wire size. Refer to the following table for guidance:
| CABLE RUN (m) | C.S.A. OF EACH CONDUCTOR (mm) | CABLE RESISTANCE Ω | % POWER LOSS INTO 8Ω LOAD | % POWER LOSS INTO 4Ω LOAD |
|---|---|---|---|---|
| 10 | 2.5 | 0.14 | 1.7 | 3.5 |
| 4.0 | 0.09 | 1.1 | 2.2 | |
| 6.0 | 0.06 | 0.73 | 1.5 | |
| 25 | 2.5 | 0.35 | 4.3 | 8.6 |
| 4.0 | 0.22 | 2.7 | 5.4 | |
| 6.0 | 0.14 | 1.8 | 3.6 | |
| 50 | 2.5 | 0.69 | 8.6 | 17.0 |
| 4.0 | 0.43 | 5.4 | 11.0 | |
| 6.0 | 0.29 | 3.6 | 7.2 | |
| 100 | 2.5 | 1.38 | 17.0 | 35.0 |
| 4.0 | 0.86 | 11.0 | 22.0 | |
| 6.0 | 0.58 | 7.2 | 14.0 |
4. Polarity Checking
It is crucial to check wiring polarity before flying the speaker system. A simple method for LF units without a pulse-based polarity checker is as follows: Connect two wires to the +ve and -ve terminals of a PP3 battery. Apply the wire connected to the battery's +ve terminal to the speaker cable leg believed to be connected to pin 1+ of the speaker connector, and the -ve leg to pin 1-.
If wired correctly, the LF drive unit will move forward. Connect the +ve speaker lead to the +ve terminal on the amplifier and the -ve lead to the -ve terminal. If the LF driver moves backward, the input connections need to be inverted.
If problems arise, inspect the cable wiring first. Note that different amplifier manufacturers use different pin configurations and polarity conventions. If using amplifiers from multiple manufacturers, check polarity at both the amplifiers and the loudspeakers.
5. Amplification & Power Handling
Loudspeaker power handling is a function of voice coil thermal capacity. Avoid running the amplifier into clip (clipping occurs when an amplifier is overdriven), as this can damage the loudspeaker if sustained. Allow at least 3dB of headroom. When evaluating an amplifier, consider its behavior under low impedance load conditions, as loudspeaker systems can be highly reactive and demand more current than their nominal impedance suggests.
A higher power amplifier running without distortion is less damaging than a lower power amplifier that is continually clipping. A high-powered amplifier running below 90% of its output power generally sounds better than a lower-powered amplifier at 100%. An amplifier with insufficient drive capability will limit the loudspeaker's performance.
When using amplifiers from different manufacturers in a single installation, ensure their gains are closely matched (variation less than +/- 0.5dB). This is important for overall system balance, especially when using a single active crossover with multiple cabinets. It is recommended to use the same amplifiers throughout.
6. Crossovers
The Tannoy Professional contractor product range can be used with the B950, utilizing TX1, TX2, & TX3 crossover/controllers (refer to product literature for correct TX controller). For active operation, the TDX1 digital loudspeaker management system is also available. If using an alternative system (e.g., BSS™, Klark Teknik™, XTA™), contact Tannoy for correct parameter settings or refer to the recommended crossover points in the technical specifications section.
7. Equalisation
The B950 loudspeaker is designed to require no equalization or correction to overcome system limitations. Equalization is primarily needed to compensate for difficult acoustic environments.
Over-equalization can reduce system headroom and introduce phase distortion, potentially causing more problems than it solves. If equalization is required, apply it gently and smoothly. Aggressive equalization will be detrimental to overall sound quality.
8. Positioning
When a bass loudspeaker is used near boundary surfaces, its placement affects its frequency response. Understanding these effects allows for their use to enhance sound quality without additional amplification.
Consider the diagram below:
Boundary Effects Diagram Description
The diagram illustrates how sound pressure level (SPL) increases with proximity to reflective surfaces:
- (A) Free-field: In an anechoic environment, SPL is measured at distance D, serving as the reference level (0 dB SPL).
- (B) Half-space: Placing the loudspeaker near one large reflective surface (wall, ceiling, floor) causes sound reflection. The SPL can increase by up to 3 dB (effectively doubling amplifier power) as the loudspeaker radiates into half the space.
- (C) Quarter-space: Placement near two boundaries (e.g., a corner) can increase SPL by an additional 3 dB (total +6 dB).
- (D) Eighth-space: Placement near three boundaries (e.g., a corner) can increase SPL by up to 9 dB.
These effects vary with frequency; loudspeakers are omnidirectional at low frequencies (long wavelengths) but more directional at high frequencies. Positioning full-range loudspeakers near a boundary can boost lower frequencies while leaving highs unaffected. Coupling, or placing bass cabinets together, also increases bass output.
9. Dimensions
The Tannoy B950 subwoofer has the following physical dimensions:
- Height: 1110.0 mm (43.7 inches)
- Width: 576.0 mm (22.7 inches)
- Depth: 650.0 mm (25.6 inches)
The unit features two carrying handles on each end and has inserts for castors.
10. Performance Data
Anechoic Frequency Response
The anechoic frequency response, measured at 2.83V at 1 metre, indicates a relatively flat output from approximately 20 Hz up to around 200 Hz. A peak is observed near 200 Hz, followed by a gradual roll-off at higher frequencies. The SPL is around 90 dB at 20 Hz, rising to over 100 dB between 100 Hz and 200 Hz.
Impedance
The impedance curve shows a primary resonance peak around 50 Hz, reaching approximately 28 ohms. The impedance then decreases to a minimum of around 4 ohms between 100 Hz and 200 Hz, before increasing again at higher frequencies.
11. Technical Specifications
| Frequency response (1) +/- 3dB | 28Hz -240 Hz |
| Recommended Amplifier Power | 800 - 2000 watt / 4 ohm |
| Power Handling | Average(2): 600 watt | Programme: 1200 watt | Peak (10ms): 2400 watt |
| Sensitivity (1) 2.83 volt @ 1m | 101 dB |
| Maximum SPL (3) @ 1m | RMS: 129 dB | Peak: 135 dB |
| Impedance | Nominal: 4 ohm | Minimum: 3.9 ohm |
| Distortion (0.1 Full Power) | 100 Hz: 0.20% (2nd Harmonic), 0.12% (3rd Harmonic) | 250 Hz: 0.14% (2nd Harmonic), 0.10% (3rd Harmonic) |
| Distortion (0.01 Full Power) | 100 Hz: 0.18% (2nd Harmonic), 0.09% (3rd Harmonic) | 250 Hz: 0.12% (2nd Harmonic), 0.10% (3rd Harmonic) |
| Driver Compliment | 2 x 18" High efficiency Bass Units. Type Number 4501 |
| Crossover Point | Active: Recommended points 70 - 240 Hz, 24dB/octave, Linkwitz - Riley (dependant on application) |
| Enclosure | 337.5 litre (11.914cu.ft.) vented, 18mm multi-ply birch plywood |
| Finish | Textured black/grey paint |
| Protective Grille | Perforated steel, black with 50% free air flow |
| Connectors | 2 x Speakon NL4MPR IN/OUT |
| Rigging/Fittings | 4 x Recessed carrying handles, Inserts for castors |
| Dimensions | 576mm(H) x 1110mm(W) x 650mm(D) | 22.7ins(H) x 43.7ins(W) x 25.6ins(D) |
| Weight | 76 Kg (167.2 lbs) |
NOTES:
- (1) Average over stated bandwidth. Measured at 1m on axis using, in an anechoic chamber.
- (2) Long term power handling capacity as defined in EIA standard RS - 426A.
- (3) Unweighted pink noise input, measured at 1m.
Tannoy operates a policy of continuous research and development. The introduction of new materials or manufacturing methods will always equal or exceed the published specifications, which Tannoy reserves the right to alter without prior notice. Please verify the latest specifications when dealing with critical applications.
12. Recommended Service Parts & Accessories
| Part Number | Description |
|---|---|
| 7900 0390 | Driver Kit - 4501 |
| 7900 0497 | Recone Kit - 4501 |
| 7900 0442 | Paint - Touch up Black-Grey |
| 7900 0400 | Padded protective transit cover |
| 8000 0717 | TannoyTX3 Active System Controller/2-way Stereo Crossover UK 220/240V |
| 8000 0718 | TannoyTX3 Active System Controller/2-way Stereo Crossover EUR 220/240V |
| 8000 0719 | TannoyTX3 Active System Controller/2-way Stereo Crossover AUS 220/240V |
| 8000 0720 | TannoyTX3 Active System Controller/2-way Stereo Crossover USA 100/120V |
| 8000 0721 | TannoyTX3 Active System Controller/2-way Stereo Crossover JAP 100/120V |
| 8000 0722 | TannoyTX3 Active System Controller/2-way Stereo Crossover HK 220/240V |
| 8000 0727 | Tannoy TDX1 Digital loudspeaker management system UK 220/240V |
| 8000 0728 | Tannoy TDX1 Digital loudspeaker management system EUR 220/240V |
| 8000 0729 | Tannoy TDX1 Digital loudspeaker management system AUS 220/240V |
| 8000 0730 | Tannoy TDX1 Digital loudspeaker management system USA 100/120V |
| 8000 0731 | Tannoy TDX1 Digital loudspeaker management system JAP 100/120V |
| 8000 0732 | Tannoy TDX1 Digital loudspeaker management system HK 220/240V |
13. Warranty
No maintenance of the B950 loudspeaker is necessary. All Tannoy professional loudspeaker products are covered by a 5-year warranty from the date of manufacture, subject to the absence of misuse, overload, or accidental damage. Claims will not be considered if the serial number has been altered or removed. Work under warranty should only be carried out by a Tannoy Professional dealer or service agent. This warranty does not affect your statutory rights.
For further information, contact your dealer or distributor. If you cannot locate your distributor, please contact Customer Services, Tannoy Ltd at the address below:
Customer Services Contact
Tannoy Ltd.
Rosehall Industrial Estate
Coatbridge
Strathclyde
ML5 4TF
Scotland
Telephone: 01236 420199 (National) | +44 1236 420199 (International)
Fax: 01236 428230 (National) | +44 1236 428230 (International)
E-Mail: prosales@tannoy.com
DO NOT SHIP ANY PRODUCT TO TANNOY WITHOUT PREVIOUS AUTHORISATION.
Tannoy's policy commits to incorporating improvements through continuous research and development. Please confirm current specifications for critical applications with your supplier. EASE™ Data for Tannoy Professional products is available on request.
14. Declaration of Conformity
The following apparatus is manufactured in the United Kingdom by Tannoy Ltd of Rosehall Industrial Estate, Coatbridge, Scotland, ML5 4TF and conforms to the protection requirements of the European Electromagnetic Compatibility Standards and Directives relevant to Domestic Electrical Equipment. The apparatus is designed and constructed such that electromagnetic disturbances generated do not exceed levels allowing radio and telecommunications equipment and other apparatus to operate as intended, and possesses adequate intrinsic immunity to electromagnetic disturbance.
Details of the Apparatus: Tannoy Contractor Loudspeaker, Model Number: B950
Associated Technical File: EMCB950
Applicable Standards: EN 50081-1 Emission, EN 50082-1 Immunity
Signed: [Signature Placeholder]
Position: Technical Manager, Tannoy Professional
Date: 16th July 1998
