Ohmic Audio

🔧 INSTALLER LEVEL: Comparative Analysis

Amplifier Technology Comparison

Class AB vs. Class D for Full-Range:

When to choose Class AB:

Advantages: - Purest sound reproduction - Lowest distortion (<0.01% typical) - Widest frequency response - No switching artifacts - Audiophile preference

Disadvantages: - Lower efficiency (50-65%) - More heat generation - Larger size - Higher cost per watt

Best applications: - Front-stage amplification - Sound quality competitions - Audiophile systems - Unlimited space/cooling

When to choose Class D:

Advantages: - High efficiency (75-90%) - Minimal heat - Compact size - More power per dollar

Disadvantages: - Historically inferior sound quality (modern designs have closed gap) - Potential EMI issues - Requires output filtering - Some designs have limited bandwidth

Best applications: - Subwoofer amplification - High-power needs - Limited space - Daily drivers - Modern designs rival Class AB

Modern high-end Class D: - <0.1% THD - Flat 20 Hz - 20 kHz response - Minimal audible difference from Class AB - Examples: Hypex N-Core, TI Class D chips

Speaker Material Comparisons

Cone Materials: Performance Matrix

Material Stiffness Damping Weight Cost Best Use
Paper (treated) Medium High Medium Low Midrange, warm sound
Polypropylene Medium Good Light Low All-around, reliable
Kevlar High Good Light Medium Midrange, detail
Carbon Fiber Very High Low-Medium Very Light High Competition, transients
Aluminum Very High Low Light Medium Efficiency, bright sound
Glass Fiber High Good Light Medium Balance, versatility
Beryllium Extreme Low Very Light Very High Ultimate performance

Selection guide:

For warm, forgiving sound: - Treated paper midranges - Silk dome tweeters - Polypropylene woofers

For accuracy and detail: - Kevlar midranges - Titanium dome tweeters - Carbon fiber woofers

For efficiency/SPL: - Aluminum/titanium cones - Horn tweeters - High-sensitivity designs

For ultimate performance (cost no object): - Beryllium tweeters - Carbon fiber midranges - Composite woofers

Component Matching Principles

Impedance Matching:

Series connection (Z₁ + Z₂): Two 4Ω speakers in series = 8Ω total

Use cases: - Connecting two speakers to single amplifier channel - Increasing total impedance when amp can't handle lower

Example: Amplifier rated 2Ω minimum, want to run 3 speakers: - Wire two 4Ω speakers in series (8Ω) - Parallel with third 4Ω speaker - Total: 1/(1/8 + 1/4) = 2.67Ω ✓

Parallel connection (Z_total = 1/(1/Z₁ + 1/Z₂)): Two 4Ω speakers in parallel = 2Ω total

Use cases: - Multiple subwoofers on single amp - Decreasing impedance for more power (if amp can handle it)

Power matching:

Rule of thumb: Match amplifier RMS to speaker RMS within 80-120%

Why 80-120%?

Under-powered (60-80%): - Risk: User turns up gain too high causing clipping - Clipped signal has higher average power - Can damage speakers (even with less power!)

Properly powered (80-120%): - Amplifier operates in clean range - User satisfied with output - No clipping at normal use

Over-powered (120-200%): - Safe if user exercises restraint - Risk: Brief moment of excessive volume damages speaker - More headroom for dynamics

Way over-powered (200%+): - High risk of speaker damage - Only for experienced users - Professional competition use

Sensitivity matching:

Front speakers vs. subwoofer output needs balancing.

Example system: - Front components: 89 dB sensitivity - Subwoofer: 85 dB sensitivity - 4 dB difference

For equal output: - Subwoofer needs 2.5× power (10^(4/10)) - If fronts get 100W, sub needs 250W - Adjust with amplifier controls and crossovers