ISI-HMAB-1

Battery Module and Stereo Microphones built into headphones

This portable headphone assembly has a built-in battery module, which utilizes its built-in microphones. It is extremely versatile because although it has high fidelity mics built in for stealthy recording, it also has a concealed built-in battery module for those high Sound Pressure Level (SPL) situations. This eliminates the need for an external battery module, making it much more convenient, while eliminating the need for additional bulky devices for various recording situations.

This device has two different switch settings. The first setting utilizes the built-in battery module along with the built-in mics, allowing you to use the line input of your recorder (for the cleanest recording) for use in moderately loud to very loud conditions. The second setting is used to by-pass the battery module, using only the built-in mics with the mic input of your recorder. This second setting will save battery life if you only need to use your mic input for your recording situation. Also, for you Sony lovers, this device has a level control option available built into the earpiece, enabling you to adjust levels on the fly.

This assembly uses lightweight Sony walkman-style headphones to house the built-in mics and battery module. The cabling is 4 feet in length, and terminated with a high quality, gold-plated, stereo mini connector. This device uses high quality built-in mics available with either omni-directional or uni-directional (cardioid) microphone elements. One microphone element is mounted within each earpiece on the headphones using the earpads as windscreens, thereby covering the microphone elements, as well as the build-in switches. Note: These headphones are equipped with a battery module and mic elements – NOT the actual speakers for listening as with standard headphones.

Level control option:
This option is available so you can conveniently control the output level with a knob discreetly mounted to the earpiece. This is extremely useful when using MiniDisc recorders that do not allow level adjustment while recording (most SONY MD recorders), or when using MiniDisc recorders that do not have microphone sensitivity settings (some SONY MD recorders). This feature adjusts the output of the microphone signal passing through the module, before going to the recorder, which will be reflected in your recorder’s level meters. Note: the level control option is designed to be used with the line input for on the fly adjustment.

Features:

• Flat frequency response
• Very convenient 2-in-1 device with mics and battery module contained in one unit
• Available with omni-directional or uni-directional (cardioid) mic elements
• Four different mic elements to choose from
• Optional built-in level control
• Can be used directly with any recorder that has a line input or a mic input with "plug-in-power"
• Very stealthy for inconspicuous recording
• Now available with Audio-Technica Premium "Slimline" microphones (AT 943 with interchangeable elements)

Microphones to choose from and Specifications:

Standard Low Sensitivity Omni-Directional:

• Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa
• Dynamic Range: 76dB without battery module, 91dB with battery module
• Frequency Response: 20 - 20,000 Hz
• Open Circuit Sensitivity: -42 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Standard High Sensitivity Omni-Directional (+7 dB):

• Signal To Noise Ratio: >62 dB, 1 kHz at 1 Pa
• Dynamic Range: 80dB without battery module, 95dB with battery module
• Frequency Response: 20 - 20,000 Hz
• Open Circuit Sensitivity: -35 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Standard Cardioid (Uni-Directional):

• Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa
• Dynamic Range: 76dB without battery module, 91dB with battery module
• Frequency Response: 80- 18,000 Hz
• Open Circuit Sensitivity: -51 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Deluxe Cardioid (Uni-Directional):

• Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa
• Dynamic Range: 76dB without battery module, 91dB with battery module
• Frequency Response: 50 - 20,000 Hz
• Open Circuit Sensitivity: -45 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB when powered by our battery module)

Premium Audio Technica Slimline Omni-Directional (AT943):

• Signal To Noise Ratio: >65 dB, 1 kHz at 1 Pa
• Dynamic Range: 83dB without battery module, 98dB with battery module
• Frequency Response: 20 - 20,000 Hz
• Open Circuit Sensitivity: -40 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level:
• Maximum Input Sound Level: 110 dB SPL, 1 kHz at 1% T.H.D. (125dB when powered by our battery module)

Premium Audio Technica Slimline Sub-Cardioid (AT943):

• Signal To Noise Ratio: >65 dB, 1 kHz at 1 Pa
• Dynamic Range: 83dB without battery module, 98dB with battery module
• Frequency Response: 20 - 20,000 Hz
• Open Circuit Sensitivity: -42 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 110 dB SPL, 1 kHz at 1% T.H.D. (125dB when powered by our battery module)

Premium Audio Technica Slimline Cardioid (AT943):

• Signal To Noise Ratio: >65 dB, 1 kHz at 1 Pa
• Dynamic Range: 83dB without battery module, 98dB with battery module
• Frequency Response: 30 - 20,000 Hz
• Open Circuit Sensitivity: -40 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 110 dB SPL, 1 kHz at 1% T.H.D. (125dB when powered by our battery module)

Premium Audio Technica Slimline Hyper-Cardioid (AT943):

• Signal To Noise Ratio: >65 dB, 1 kHz at 1 Pa
• Dynamic Range: 83dB without battery module, 98dB with battery module
• Frequency Response: 80 - 20,000 Hz
• Open Circuit Sensitivity: -30 dB (5.6 mV) re 1V at 1 Pa
• Maximum Input Sound Level: 110 dB SPL, 1 kHz at 1% T.H.D. (125dB when powered by our battery module)

Built-in battery module

• Normally used for louder recording situations using your recorders line input
• Runs approximately 20 hours on 3 coin cell batteries (included)