Altec Lansing 6 x 9-4A
Best box: 68.0 L bass reflex tuned to 39.8 Hz · F3 45.5 Hz
Open and tweak this box live ↗
Will it fit your requirements?
Check the Altec Lansing 6 x 9-4A against your space and targets — instant, no sign-up.
Free, no sign-up to simulate · a free account saves your design
Comparable 6.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Altec Lansing 6 x 9-4A does not fit your target box volume or tuning. Each entry links to its full enclosure design and Thiele/Small parameters.
⚠️ Engineering Notice for Builders
- Limited linear excursion (Xmax: 2.032 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 68.0 Liters |
| Tuning Frequency (Fb) | 39.8 Hz |
| F3 (-3 dB Cutoff) | 45.5 Hz |
| F6 / F10 Extension | 35.0 Hz / 30.2 Hz |
| Port Inner Diameter | Ø 6.8 cm |
| Port Physical Length | 5.2 cm |
| First Pipe Resonance | 3280.0 Hz |
| Estimated MOL @ F3 | 100.9 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 84.1 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 65.6 Hz |
| F3 (-3 dB Cutoff) | 66.4 Hz |
| F6 / F10 Extension | 50.2 Hz / 38.0 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 56.8 Hz |
| Total Q (Qts) | 0.57 |
| Electrical Q (Qes) | 0.691 |
| Mechanical Q (Qms) | 3.25 |
| Equivalent Volume (Vas) | 45.3 Liters |
| Diaphragm Area (Sd) | 185.5 cm² |
| DC Resistance (Re) | 2.6 Ω |
| Efficiency Bandwidth Product (EBP) | 82.2 |
| Linear Excursion (Xmax) | 2.0 mm |
| Thermal Power (Pe) | N/A W |
| Nominal Diameter | 6.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Altec Lansing 6 x 9-4A?
Load Forge's calculated alignment puts Altec Lansing 6 x 9-4A in a 68.0 liter vented enclosure tuned to 39.8 Hz, reaching an F3 cutoff of approximately 45.5 Hz.
Can Altec Lansing 6 x 9-4A be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 84.1 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 66.4 Hz.
What port dimensions should be used for Altec Lansing 6 x 9-4A to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 6.8 cm with a length of 5.2 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
Embed this design card on DIYAudio, AVSForum, Reddit, or Facebook. It shows the calculated F3, MOL (when the power rating is published) and box parameters.
Not sure if 6 x 9-4A fits your physical space?
Don't force a driver into the wrong box. Use Bass Match to calculate which of 8,000+ catalog drivers delivers the highest SPL, lowest F3, and cleanest port air velocity for your exact trunk or room dimensions.
Run Bass Match for Your Space