Ohmic Audio

🔧 INSTALLER LEVEL: Platform Comparison and Configuration

Selecting by System Architecture

Map your system before selecting a DSP:

Count inputs needed: - Stereo head unit with RCA: 1 stereo pair (2 inputs) - Factory head unit without RCA: use high-level input; count speaker pairs used (usually 2 pairs = 4 inputs) - Factory head unit with separate center/sub channel: may need 3 pairs

Count outputs needed: - Each individually driven speaker = 1 output channel - Tweeter (L, R) = 2 channels - Midrange (L, R) = 2 channels - Midbass woofer (L, R) = 2 channels - Subwoofer (mono) = 1 channel - Total 3-way + sub: 7 channels (requires 8-output DSP minimum)

Feature checklist:

Feature Why It Matters Min. Requirement
Parametric EQ per channel Room correction, driver response correction 6+ bands per channel
Crossover filter type Butterworth, Bessel, LR options LR12/24 minimum
Crossover filter order Steeper = better driver protection 24 dB/oct minimum
Time delay per channel Critical for imaging 0.01 ms resolution
High-level inputs Factory integration Required for factory HU
FIR filter support Phase-accurate crossovers Optional but premium
Software quality Stability, usability Mac/PC with active development

Configuring Input Signal Level

Test procedure:

  1. Play a 0 dBFS (full-scale) test tone from head unit
  2. Set head unit to reference volume (typically 75% of maximum)
  3. Open DSP software, observe input meters
  4. Input level should reach −1 to −3 dBFS on the DSP meter
  5. If below −10 dBFS: source level too low → increase head unit output or reduce DSP input attenuation
  6. If above −1 dBFS (clipping indicator): source level too high → reduce head unit output or increase DSP input attenuation

The goal: Use as much of the DSP's dynamic range as possible without clipping.