MOBILE E.R.A.D. SYSTEM 2.0™ by E.R.A.D. Labs

Indemnification & Release

By purchasing this product, you expressly agree to release, indemnify, defend, and hold harmless E.R.A.D. Labs and its owners, agents, contractors, vendors, affiliates, family members, and associated businesses from any and all claims, actions, damages, injuries, losses, legal fees, or liabilities of any kind, whether arising from use, misuse, installation, training, testing, storage, or modification of this product.

You acknowledge that you assume all risks associated with ownership and use.

Design Updates & Product Variation Notice

E.R.A.D. Labs continuously refines and improves each production batch. By purchasing this product, you acknowledge that the unit you receive will be functionally equivalent to, or improved beyond, the version shown or described at the time of purchase.

Improvements may include (but are not limited to):

• Component upgrades

• Increased output or efficiency

• Minor changes to speaker orientation or mounting angles

• Cosmetic or layout refinements

No unit will be delivered with reduced capability or performance. Differences, if present, are intended solely to enhance reliability, output, or usability.

NO INTERNATIONAL SHIPPING

1. Acceptance of Terms

By purchasing, possessing, opening, installing, or using any product sold by E.R.A.D. Labs (“Product”), the purchaser and any subsequent user agree to be bound by these Terms & Conditions.

If you do not agree, do not complete the purchase and do not break the seal on the Product.

2. Lawful Use Requirement

All Products are sold strictly for:

Lawful training purposes

Educational and research applications

Animal deterrence use

Preparedness study

Products are not marketed, sold, or represented as weapons or enforcement tools.

The purchaser agrees to comply with all applicable local, state, and federal laws, including but not limited to noise ordinances and safety regulations.

Any unlawful, malicious, reckless, or criminal use is strictly prohibited and is the sole responsibility of the purchaser and user.

3. Assumption of Risk

The purchaser acknowledges that the Product is a high-output acoustic system capable of producing sound levels that may cause:

Hearing damage

Dizziness or disorientation

Physical discomfort

Property disturbance

The purchaser assumes all risks associated with:

Ownership

Installation

Setup

Power configuration

Operation

Storage

Transport

All use is at the sole risk of the purchaser and user.

4. Seal / Tag Acceptance

Each Mobile E.R.A.D. Unit™ includes a physical seal or tag outlining key use terms.

By cutting, removing, or breaking the seal or tag, the purchaser:

Acknowledges acceptance of these Terms & Conditions

Assumes full responsibility for lawful use

Accepts all risk associated with operation

Confirms understanding of the return and warranty policy

If the seal is cut, the Product is considered accepted.

5. Indemnification

The purchaser agrees to indemnify, defend, and hold harmless E.R.A.D. Labs, its owners, officers, agents, contractors, vendors, affiliates, family members, and associated businesses from and against any and all claims, demands, actions, damages, losses, liabilities, costs, or expenses (including reasonable attorneys’ fees) arising from or related to:

Purchase

Possession

Installation

Use or misuse

Modification

Resale or transfer

Violation of law

6. Limitation of Liability

To the fullest extent permitted by law, E.R.A.D. Labs shall not be liable for:

Personal injury

Hearing damage

Property damage

Consequential or incidental damages

Loss of use

Legal penalties resulting from misuse

Criminal misconduct

In no event shall liability exceed the original purchase price of the Product.

7. No Operational Advice

E.R.A.D. Labs provides setup and functional guidance only.

We do not provide tactical, enforcement, or operational deployment advice.

8. Custom-Built Product Notice

Products are individually hand-assembled in limited batches. Minor variations in configuration, layout, or component orientation may occur.

E.R.A.D. Labs reserves the right to improve or modify design without prior notice, provided functionality is not reduced.

9. Governing Law

These Terms & Conditions shall be governed by and construed in accordance with the laws of the State in which E.R.A.D. Labs operates, without regard to conflict-of-law principles. 

Cancelled orders incur a 20% fee - as these are all custom made and programmed.  

Explanation of the 4+1 Speaker Array Sound Waves

A flat-plane array of 4 speakers pointed outward at 90°, 180°, 270°, and 360° (0°) directions, with an additional speaker at 45°—creates a near-omnidirectional radiation pattern with a biased lobe, powered by a 600-watt amplifier (e.g., the Audio Systems R4002 Riot Series Class A/B amp) and the same electronics (noise filter/ground loop isolator). This setup is essentially a quadrupole-like radiator with an asymmetric tilt, designed for 360° coverage but with enhanced projection in one quadrant due to the 45° speaker. I'll break it down in detail, including wave propagation, interference, directivity, SPL distribution, and formulas, assuming standard horn speakers (e.g., 200W PA siren horns, 125–135 dB at 1m, 8 ohms, 1–5 kHz focus) wired to the amp for tones-only use.

1. Configuration Overview

Physical Layout: The 4 main speakers are mounted on a flat plane (e.g., a circular or square baffle ~12–18 inches diameter), each facing radially outward at 90° intervals—like the points of a compass (NE, NW, SW, SE). The fifth speaker is added, at 45°/IE 0° (e.g., North), either in-plane or slightly RECESSED for asymmetry.

Electronics Integration: The 600W amp (2-channel Class A/B, 2/4 ohm stable, high/low-pass crossovers) drives the array in bridged mono mode (~600W into 2–4 ohms total load). The ground loop isolator ensures clean signal (no 60Hz hum), minimizing waveform artifacts.

Wiring: For 5 speakers (8 ohms each):

Parallel 5 → ~1.6 ohms total (amp sees ~2 ohms safe if stable).

Power per speaker: ~120W RMS (tones burst-capable without distortion).

Assumed Frequency: Focus on 2–4 kHz tones (where hearing is sensitive and horns efficient) — wavelength λ ≈ 4.5–9 inches (c / f, c = 343 m/s).

This creates a multi-directional source with constructive/destructive interference, approximating omnidirectional coverage but with hotspots and nulls.

2. Sound Wave Production and Propagation

The sound waves are longitudinal pressure variations in air, generated by the horn diaphragms vibrating in response to the amp's signal. The amp's Class A/B topology adds slight even-order harmonics (warmth) to tones, while the isolator keeps the waveform pure (no low-freq noise modulation).

Individual Speaker Waves: Each horn produces a conical wavefront with high directivity. The beamwidth for a single horn is given by:

θ ≈ 70 × (λ / D) degrees (parabolic approximation for horn mouth, D = horn diameter ~4–6 inches).

At 3 kHz (λ ≈ 4.5 inches): θ ≈ 70 × 4.5 / 5 ≈ 63° per speaker.

Waves are high-pressure (125–135 dB at 1m), with fast attack/decay (compression driver characteristic) — sharp, impulsive transients for piercing tones.

Array Interference (4 Speakers at 90° Intervals): The 4 outward-pointing speakers form a quadrupole-like array, producing near-omnidirectional coverage through mutual cancellation and summation.

Radiation Pattern: In the far-field (r > λ/2π ≈ 1–2 ft for 3 kHz), the pattern is roughly toroidal (donut-shaped) in azimuth, with nulls along the plane axes if phases are identical.

The directivity index (DI) for such a symmetric array is ~3–6 dB (omnidirectional approximation DI ≈ 0 dB, but quadrature spacing adds ~3 dB gain in plane).

Interference: Waves from opposite speakers (180° apart) cancel on-axis but sum off-axis; adjacent (90°) sum constructively in quadrants.

Polar plot: Lobe maxima at ±45°/135°/225°/315° relative to each speaker, with ~6–10 dB variation across 360°.

Sound Pressure Level (SPL): Coherent summing gives ~ +6 dB gain in overlap zones (10 log₁₀(4) = 6 dB for 4 speakers, real-world ~4–5 dB due to phase losses).

At 200 ft: ~75–85 dB per direction (from 125 dB at 1m, -40 dB spherical loss over ~6 doublings).

Addition of the 45°/0° Speaker: This introduces asymmetry, tilting the overall pattern toward one quadrant (e.g., North if 45° is between 0° and 90°).

Wave Interaction: The 45° speaker adds a biased lobe, shifting the main beam ~20–30° toward 45°.

Interference formula: Total pressure p_total = Σ p_i e^{j k r_i cos φ} (array factor for point sources, k = 2π/λ, r_i = position, φ = angle).

Result: Enhanced SPL (+2–4 dB) in the 0–90° quadrant, with minor nulls elsewhere due to phase mismatch.

Pattern: Quasi-omnidirectional with a "hot spot" lobe ~40–60° wide at 45°, overall coverage 360° but with 6–12 dB variation.

Amp & Electronics Influence on Waves: The 600W Class A/B amp provides clean, high-current drive with slight even-harmonic warmth (2nd/4th order ~0.1–1% THD at mid-power). The isolator eliminates ground-loop hum (no 60Hz sidebands). Crossover (high-pass ~1–3 kHz) filters lows, keeping waves mid-high focused.

4. Overall Performance for Tones at 200 ft

SPL: ~80–95 dB in main directions (with hot spot ~5 dB higher at 45°).

Coverage: Near-360° with asymmetry — effective for sweeping alerts.

Perception: Piercing, multi-directional "surround" tone with directional bias for targeting.