Multiple-Input Adapter (Crab Box)

Last Updated: 13 December 2019 at 11:59


In the past, multiple-input adapters were provided in many meetinghouses. The information below is helpful if you have one of these devices. Buildings with new or recently replaced sound systems will have connectivity native to the system, eliminating the need for the adapter. In these cases, the multiple-input adapter is not provided. Because of its many cables, the box is sometimes referred to as a crab box.

The multiple-input adapter box has a variety of cables and connections (RCA, XLR, and 1/4-inch and 1/8-inch phone jacks) that allow connections to be made from almost any electronic audio source (laptop computer; tablet; cell phone; DVD, VCR, CD, or MP3 player; mixer; and so on) to the house sound system (the XLR mic-level input of the typical chapel and cultural hall). However, the adapter box cannot be used with mic-level audio sources (for example, a microphone). Mic-level sources may be connected directly to one of the sound system’s microphone inputs.

The crab box comes in two models: EJ-10 (gray case) or EJ-8 (black case). Unlike the EJ-8, the EJ-10 can connect to telephone lines, so it can be used to either transmit or receive audio through a wired phone line. One use of this capability is to back up the audio of a broadcast if the satellite or internet stream fails.

Older meetinghouse sound systems do not have a line-level input (such as an RCA jack). Where this is the case, the EJ-8 and EJ-10 allow the connection of any non-mic-level signal into the building sound system. Since the EJ-8 and the EJ-10 each have a volume control, various input devices, such as a DVD player with soft audio, can be adjusted for appropriate sound levels.

Both boxes have a hum switch, which can help reduce unwanted noise in the system. The Church issues at least one audio adapter box to each building. It is usually stored in the library.

To learn more, visit the following links:

EJ-2Plus Information
EJ-8 Information 
EJ-10 Information