Turbosound TMS-4 – 3-Way Bi-Amped Loudspeaker System

The Turbosound TMS-4 is a classic 3-way bi-amped loudspeaker designed for high-output professional sound reinforcement. Known for its powerful projection and distinctive voicing, it’s ideal for medium to large venues and touring systems.

Acoustic Design

• Configuration: 3-way bi-amplified system
• Drivers:
  • 1 × 18″ horn-loaded bass driver (TurboBass™)
  • 1 × 10″ midrange driver on a TurboMid™ horn
  • 1 × 1″ high-frequency compression driver
• Crossover:
  • Active crossover between bass and mid/high at ~250 Hz
  • Passive crossover between mid and high around 2.8 kHz
  • Mid driver typically phase-inverted (polarity flipped) in original design
  • Recommended mid delay of ~3.9 ms to align with LF

Performance

• Frequency Response: ~40 Hz – 17 kHz
• Sensitivity: ~105 dB SPL (1 W / 1 m)
• Max SPL: Up to ~135 dB peak
• Nominal Impedance:
  • LF: 8 Ω
  • Mid/High: 16 Ω (combined via passive crossover)

Power Handling (approximate)

• Bass (18″ driver): 300 W RMS / 600 W program
• Midrange (10″ driver): 250 W RMS
• High Frequency (1″ driver): 50 W RMS

Construction & Dimensions

• Cabinet: Heavy-duty birch plywood with black textured paint
• Grille: Steel, backed with foam
• Handles: Side-mounted recessed handles for lifting
• Stacking/Arraying: Designed for horizontal array use in clusters
• Dimensions (H × W × D): Approx. 114 cm × 50 cm × 73 cm
• Weight: ~75 kg (165 lb)

Connectivity

• Dual 4-pole speaker connectors (usually EP or NL4 depending on version)
• Internal passive network handles mid/high crossover
• External bi-amp control required for LF and MF/HF separation
• Can be rewired for full tri-amp use with external DSP if desired

Ideal Applications

• Live music venues and touring rigs
• Mid-to-large club sound systems
• Outdoor festivals or fixed installations requiring punchy vintage tone
• Often used with complementary subwoofers for full-range performance