SMD-DD-1 Distortion Detector
Distortion Detector – The purpose of this tool is to enable the installer to set the gain of an audio amplifier to match the source unit’s output level, accurately and quickly. It can also be useful for detecting distortion in the audio signal caused by poorly designed or malfunctioning audio equipment.
Features
About the Design
When you pick up the DD-1, know that you are holding a precision piece of equipment. If treated as such it should provide you with many years of reliable service. We have chosen a 9V battery as a power source for a few reasons:
- They are readily available
- Isolating the DD-1 from the vehicle’s electrical system for power, guarantees that it will only measure what it is supposed to measure; distortion in the audio signal, not noise in the charging system
We also chose an RCA input connector for a few reasons:
- It makes it pretty easy to measure the output of a headunit directly, if you choose to do so
- Should the harness become damaged it is easily replaceable or repairable in the field
Specification
- The Distortion Detector’s circuitry is 100% analog
- Distortion Detection trigger level > 1.0% Harmonic Distortion
- Guaranteed operating range of input signal is 1.2Vrms – 125Vrms. (15,000 Watts at 1 ohm) Autoranging
- Signal Present LED trigger voltage 750mVrms
- Low Battery LED trigger battery voltage < 5.6Vdc
- Auto-shut off timer 8 – 10 minutes after ON button is pressed
Overview
The SMD DD-1+ is a professional-grade audio diagnostic tool designed by Steve Meade Designs to set amplifier gain and detect signal distortion. It evolved from the original SMD DD-1 by adding a digital microcontroller, a built-in voltmeter, and advanced gain overlap adjustment capabilities
Specification
Input Signal Range1.2Vrms to 200Vrms
Distortion Trigger > 1.0% Total Harmonic Distortion
Signal Detection Integrated Signal Present LED (triggers at 750mVrms)Power Source Single 9V Battery (isolated from vehicle noise)
Voltmeter Type Built-in Quasi-RMS AC Voltmeter
Compatibility
The DD-1+ can be used at every stage of the audio signal chain to identify distortion: [1]-Head Units: Compatible with aftermarket and factory (OEM) head units. For factory units without RCAs, use the included harness to probe the speaker outputs directly-Amplifiers: Supports all amplifier types (Mono, Multi-channel, Class D, Class A/B) and is capable of handling up to 40,000 Watts at 1 ohm (200Vrms).-Signal Processors: Works with DSPs and equalizers to set maximum clean output voltage before the signal reaches the amplifier.
Key features
Detects distortion at 1% Total Harmonic Distortion.
Operates with input signals from 1.2Vrms to 125Vrms (up to 15,000 Watts at 1 ohm).
Features continuously variable gain overlap (0.0–15.0dB in 0.1dB steps) for precise tuning.