This 4" Bass/mid-range is appropriate for a wide range of high-end audio systems, whether 2-way bookshelf speaker, a multi-driver floor standing speaker or a professional line array. A rigid, but light weight carbon fiber cone along with an edge wound copper voice coil, combine for excellent transient response and an extended and controlled top end roll-off. The frame is heavy duty, aluminum die cast with venting below the flat spider and through the center of the magnet structure to avoid air turbulence and noise. This is a premium, well-crafted speaker designed to bring music to life.
- Light weight, rigid carbon fiber cone with rubber surround
- 2.6 mm, Klippel verified minimum Xmax
- Vented, square cast aluminum basket
- 1" voice coil, edge-wound copper on Kapton form
- Wide frequency range, 60 to 12kHz
- 0.9 kg, (2.1 lb) net weight
Bold North Audio products are the most accurate, engineered audio transducers available. Each design requires Klippel vibrational test analyses to verify the key parts of optimal audio performance. While we rely heavily on objective science to lead us, we understand that most of all speakers need to tell the musical truth. Our engineers, musicians, and recording studio veterans are the final judges of when a design is worthy of the Bold North Audio brand.
All Bold North Audio products are assembled in Minnesota, with parts sourced from around the world to produce the highest combination of performance, consistency, and customer value.
| Model # | BMW-4001 |
|---|---|
| Speaker Type | Mid-Bass |
| Size, Nominal (inch & mm) | 4" |
| Shape of Speaker | Square |
| Application | High-End Audio and Home Theater, Home Audio, Indoor, Pro Sound |
| RoHS Compliant | Yes |
| Rated Impedance (Ω) | 8 |
| DC Resistance (Re) (Ω) | 6.4 |
| Rated Power IEC268-5 (W) | 25 Watts |
| Continuous Power (W) | 25 |
| Program Power (W) | 50 |
| Frequency Range (Hz) | 60 - 12,000 |
| Sensitivity (dB SPL) ¹ | 88 |
| Resonant Frequency (Fs) (Hz) | 68 |
| Nominal Impedance (Z) (Ω) | 8 |
| Voice Coil Inductance (Le) (mH) | 0.33 |
| Mechanical Q Factor (Qms) | 8.30 |
| Electrical Q Factor (Qes) | 0.34 |
| Total Q Factor (Qts) | 0.33 |
| Moving Mass (Mms) (gm) | 6.49 |
| Suspension Compliance (Cms) (mm/N) | 0.84 |
| Mechanical Resistance (Rms) (kg/s) | 0.34 |
| Surface Area of Diaphragm (Sd) (cm²) | 52.8 |
| Compliance Equivalent Volume (Vas) (L) | 3.31 |
| Motor Force Factor (BL) (T•M) | 7.23 |
| Efficiency (η₀) (%) | 0.30 |
| Efficiency Bandwidth Product (EBP) (Fs/Qes) | 200 |
| Basket Type | Cast aluminum |
| Voice Coil Diameter (mm) | 25.4 |
| Voice Coil Wire Material | Copper |
| Voice Coil Former Material | Kapton |
| Magnet Material | Ferrite |
| Cone Body Material | Carbon fiber |
| Cone Surround Material | Rubber |
| Spider Material | Cotton |
| Net Weight (kg) | 0.95 |
For all orders exceeding a value of 100USD shipping is offered for free.
Returns will be accepted for up to 10 days of Customer’s receipt or tracking number on unworn items. You, as a Customer, are obliged to inform us via email before you return the item.
Otherwise, standard shipping charges apply. Check out our delivery Terms & Conditions for more details.
