Comprehensive Guide: Live Audio & Two-Tone Detect Setup

This guide helps teams determine what equipment, what configuration, and what limitations apply when setting up Live Audio and Two-Tone Detect in IamResponding. It is written for users who may be brand new to the concepts.

1. Determine Whether Two-Tone Detect Already Exists

1.1 Does the agency already have Two-Tone Detect?

• Yes, at the county/regional level: Excellent — we can often use the existing equipment for Live Audio as well.

• Yes, but at the individual station level: We can still likely use that infrastructure.

• No: Proceed to determining live audio needs only.

2. Identify Existing Hardware Compatibility

2.1 Check the device running Two-Tone Detect or live audio

Supported minimum hardware:

❗ Note: Anything older than Pi 4B or older than Windows 10 must be upgraded.

3. Identify Radio System & Audio Source Requirements

3.1 What kind of radio system is the agency using?

Look at the frequencies:

• ~150 MHz: VHF

• ~400 MHz: UHF

• ~700 MHz: 700 MHz

• ~800 MHz: 800 MHz

3.2 Are they using a conventional or trunked system?

• Conventional: Standard scanners work (VHF/UHF/700/800 depending on frequency).

• Trunked: Requires a trunking-capable scanner.

• Encrypted: Requires a dedicated encrypted radio with the key unless the ECC can provide an analog audio-out feed.

3.3 Radio Integration for Audio Source

If an agency chooses to utilize a radio as their primary audio source, they should consult with their radio service provider to determine the most effective method for extracting an analog audio output. The physical configuration will vary based on the hardware:

1. Portable Radios

Ensure you have the correct manufacturer-approved adapter or connector for the accessory/headpiece output. This adapter must bridge the connection from the radio’s proprietary or earpiece port to the USB Sound Adapter.

2. Mobile or Base Stations

Work with your radio service provider to configure the appropriate accessory pin-out (typically located on the rear of the unit). This ensures an analog 3.5 mm audio jack can be properly interfaced from the radio to the USB Sound Adapter.

Pro Tip: When configuring these outputs, ask your provider if the audio is "Fixed" or "Variable." Fixed level is generally preferred so that changing the volume knob on the radio doesn't accidentally break your recording or streaming levels.

4. Determine Channel Requirements

4.1 Do they want Live Audio on the same channel as Two-Tone Detect?

If yes:

• No additional scanners or radios needed.

• The same device can support both Two-Tone Detect and Live Audio simultaneously.

4.2 Do they want Live Audio on additional channels?

If yes, each additional channel requires:

• 1 scanner or radio (or audio-out feed)

• 1 USB sound card

• 1 audio cable

• 1 RF filter

Example: If they want to stream 5 channels → they need 5 full setups.

(Note: Two-Tone Detect counts as one “channel” of equipment.)

5. Special Considerations

5.1 ECC Audio-Out Option

If the 911 center is willing to provide an analog audio-out on the channel AND a location to host the device, then no scanner or radio is needed. This option can bypass encryption and trunking issues.

5.2 P25 Paging Systems

Two-Tone Detect has special handling available. Live Audio works the same, as long as the audio source can hear the dispatch channel.

6. Hardware Planning Example

Scenario: Agency wants Two-Tone Detect on VHF and Live Audio on three channels (VHF Paging, 800 MHz Ops, and 700 MHz Dispatch).

Required:

• 1 Raspberry Pi 5 (recommended)

• Channel 1: TTD + Live Audio (shares hardware)

• Channel 2: 800 MHz scanner/radio + USB sound card + RF filter + cable

• Channel 3: 700 MHz scanner/radio + USB sound card + RF filter + cable

7. Configuration Steps Summary

1. Confirm existing Two-Tone Detect & hardware compatibility.

2. Identify radio frequency type.

3. Determine whether channels are Conventional, Trunked, or Encrypted.

4. If using a radio source: Consult provider for "Fixed" analog output.

5. Confirm if ECC can provide audio-out (optional).

6. Count total desired Live Audio channels.

7. Buy required equipment (Scanners, USB Sound Cards, RF Filters) per channel.

8. Label sound cards to match each channel.

9. Configure Live Audio & Two-Tone Detect in IamResponding.

8. Comprehensive “Will This Work?” Compatibility Checklist

8.1 Hardware & Radio Source

8.2 Radio System Type

8.3 Channel Count

9. Ultra-Fast 10-Second Lightning Check

If they answer YES to these 5 things, it will almost always work:

1. Do you have a Pi 4B+ or Windows 10+ device?

2. Do you know your radio frequencies and system type?

3. Is the channel unencrypted (or can you use an encrypted radio with analog out)?

4. Do you have a scanner or a radio configured for Fixed Analog Output?

5. Do you understand that each channel needs its own audio source and USB sound card?