Why datasheets beat vibes
Marketing copy says “tight bass.” The datasheet gives Fs, Vas, Qts (and friends) so you can pick a box alignment that isn’t fantasy.
The big three (plain English)
### Fs — free-air resonance The frequency where the cone likes to bounce with no box. Lower Fs often means more low-end *potential*, not automatic deep bass in a tiny sealed cube. ### Vas — equivalent compliance volume How “springy” the suspension is, expressed as a volume of air. Large Vas usually wants a larger box for the same alignment family. ### Qts — total Q Damping from suspension + motor. Rough garage heuristic (not law):
- Lower Qts → often happier in vented / larger alignments
- Higher Qts → often more sealed-friendly
Always check the manufacturer’s recommended alignments and your net volume after bracing.
Other lines worth reading
| Spec | Use | |------|-----| | Sensitivity (dB @ 2.83V/1m) | Amp power planning | | Xmax | How hard you can push bass | | Re / Le | Crossover / amp matching clues | | Sd | Displacement math with Xmax |
On the bench workflow
- Pull datasheet PDF — not a reseller one-liner.
- Note Fs / Vas / Qts / Xmax / sensitivity.
- Pick sealed vs vented intent.
- Model or use published alignments; subtract displacements for net volume.
- Build → seal test → measure (REW basics).
If the sheet is incomplete, treat the driver as a science project, not a kit.
Related
Parts & kits hub · Enclosure mistakes that kill DIY speakers · DSP for DIY speakers — where to start · REW basics Browse DIY builds. Merchant SKUs stay affiliate-disclosed when Commerce wires real carts — see disclosure.