# Single Mid Channel Package

Everything needed to run **one midrange driver** on its own (bench testing, a mid module, or the mid leg of the 3-way).

Uses the same **LM3886** topology as `lm3886-poweramp/` (gain = 21 / 26 dB, 8 Ω, ±25 V) and the **midrange LR4 bandpass** from the active crossover (300 Hz – 3 kHz).

## What’s here

| Path | Purpose |
|------|---------|
| [`docs/BOM.csv`](docs/BOM.csv) | Mid-only amp + sealed box hardware |
| [`docs/wiring.md`](docs/wiring.md) | Signal path for single-mid setup |
| [`spice/single_mid_chain.cir`](spice/single_mid_chain.cir) | Bandpass → gain stage AC/TRAN check |
| [`kicad/`](kicad/) | Pointer to reuse LM3886 + mid crossover sheets |
| Sealed box diagrams | See [`../enclosure/diagrams/`](../enclosure/diagrams/) |

## Quick start

```bash
# Mid bandpass values / full 3-way tables
python3 ../active-crossover/calculator/calculator.py 300 3000 --channel mid

# Simulate mid filter + amp gain idea
ngspice -b spice/single_mid_chain.cir
```

## Signal chain (single mid)

```
Source → LR4 HP@300 ×2 → LR4 LP@3000 ×2 → LM3886 (G=21) → Mid driver in sealed ~8 L box
```

Power: crossover ±15 V; amp ±25 V. Keep grounds star-connected at the PSU.

## Enclosure

Use the **single mid sealed box** drawings:

- PNG: [`../enclosure/diagrams/speaker-box-single-mid.png`](../enclosure/diagrams/speaker-box-single-mid.png)  
- SVG: [`../enclosure/diagrams/single-mid-box.svg`](../enclosure/diagrams/single-mid-box.svg)

Or the mid chamber inside the full tower cutaway.

**VERIFY** driver cutout and Vb against the midrange datasheet before cutting.