What Is EBP? Sealed vs Ported (Fs ÷ Qes)
Subwoofer glossary — sealed vs. ported
EBP (Efficiency Bandwidth Product) is a quick figure that suggests whether a subwoofer is better suited to a sealed or a ported enclosure. It is calculated by dividing the driver's resonant frequency (Fs) by its electrical Q factor (Qes): EBP = Fs ÷ Qes.
In one line: EBP = Fs ÷ Qes. Low EBP leans sealed, high EBP leans ported.
Reading the number
- Below 50 — the driver generally favors a sealed enclosure.
- 80 to 90 — the driver works well in either a sealed or a ported enclosure.
- Above 90 — the driver generally favors a ported enclosure.
What EBP does and doesn't tell you
EBP is a starting point, not the final word. It points you toward an alignment, but the right enclosure still depends on your goals, your available space, and the driver's other Thiele-Small parameters. A high-EBP driver can still be run sealed for a tighter, more compact sound-quality build — you simply give up some efficiency. EBP narrows the options; enclosure design finishes the job.
How Audio Intensity uses EBP
EBP analysis is part of every Proline X enclosure recommendation. Run your driver's numbers through the EBP Calculator, then explore the Subwoofer Box Calculator Suite to size the enclosure itself.