2-driver build · Ported1 warning
Shared speaker build
2× Scan-Speak 18W/8531G00 + Seas 27TBFC/G H1212-06
A guided SpeakerForge build — the parts, the enclosure and crossover, and a compatibility check run server-side by the same engine that powers the builder. Published Thiele/Small specs are nominal; verify by measurement before building.
Drivers
Amplifier
Generic Stereo Integrated 2×100100 W/ch · min 4 Ω · Class ABrated 8 Ω · 2 ch
- Enclosure
- Ported
- Box volume
- 60.0 L
- Tuning Fb
- 30.0 Hz
- Crossover
- 2-way LR 4th2200.0 Hz
- Est. parts
- $110
- excl. drivers
Compatibility
1 warningWarningSensitivity mismatch: Seas 27TBFC/G H1212-06 (91.5 dB) is 3.5 dB more sensitive than Scan-Speak 18W/8531G00 (88.0 dB). Pad the louder driver with an L-pad so the two levels match.
L-pad calculator — attenuate Seas 27TBFC/G H1212-06 by ≈ 3.5 dB. Open the crossover designer →
NotePorted box for Scan-Speak 18W/8531G00: no port dimensions set, so port velocity / chuffing can't be checked. Add the port shape and size.
Enclosure designer — define the port. Open the enclosure designer →
NoteDirectivity match (modeled): crossing Scan-Speak 18W/8531G00 and Seas 27TBFC/G H1212-06 near 1.19 kHz gives the woofer ka ≈ 1.50 (good match — the woofer is not yet beaming). This is a modeled estimate from T/S; it improves with measured off-axis data.
Crossover designer — directivity-matched crossover point. Open the crossover designer →
NoteRemember baffle-step: a real cabinet loses ~3–6 dB of bass/midbass as output transitions from half-space to full-space. Budget baffle-step compensation (BSC) in the crossover, or expect a thinner-than-flat balance.
Baffle-step compensation calculator. Open the crossover designer →
Estimated parts cost excludes the drivers (their price varies by retailer); open the build to see buy links and the full parts list.