Rear Panel DIP Switches

Rear Panel DIP Switch Controls

The rear panel of the Hx1 and Hx2 chassis contain two banks of DIP switches labeled "Settings" and "Options."

Figure 2 - Rear panel DIP switches

Figure 2 - Rear panel DIP switches

The "Settings" switches (SW1) control the operational levels of various signal processing stages. The "Options" switches (SW2) are used to configure various features. The tables below explain the individual DIP switches:

Settings

Function

Bits 1 and 2

EQ LO, fixed dB gain adjustment

Bits 3 and 4

EQ HI, fixed dB gain adjustment

Bits 5 and 6

Ducking dB gain adjustment

Bits 7 and 8

AGC and Noise Gate settings

Options

Functions

Bits 1 and 2

DDEQ configuration

Bits 3 and 4

Auto-answer configuration

Bit 5

Send gain to phone

Bit 6

Hx2 internal mix-minus enable

Bit 7

Feedback Reduction enabled

Bit 8

Reserved

Dynamic Digital Equalization Configuration Settings

Options Bits 1 and 2 control the overall operation of the DDEQ processing function. Selections include OFF, Fixed EQ, Adaptive EQ, or Adaptive + Fixed EQ.  See the Digital Dynamic Equalization section for an explanation of each.

Bit 1

Bit 2

Setting Value

OFF

OFF

DDEQ  turned OFF

OFF

ON

DDEQ enabled in Fixed EQ mode (use SETTINGS Bits 1-4 to set levels)

ON

OFF

DDEQ enabled in Adaptive EQ mode (factory default setting)

ON

ON

DDEQ enabled in Adapt + EQ mode (use SETTINGS Bits 1-4 to set levels)

You can separately specify the level of adjustment in the EQ HI and EQ LO frequency bands when the DDEQ mode is configured for Fixed EQ mode. SETTINGS Bits #1 and #2 control the dB adjustment for the EQ HI band, and Bits #3 and #4 control the dB adjustment for the EQ LO band as follows:

SETTINGS

Bit 1

Bit 2

Setting Value

OFF

OFF

EQ LO, 0 dB adjustment (factory default setting)

OFF

ON

EQ LO, +2 dB adjustment

ON

OFF

EQ LO, +4 dB adjustment

ON

ON

EQ LO, +6 dB adjustment

SETTINGS

Bit 3

Bit 4

Setting Value

OFF

OFF

EQ HI, 0 dB adjustment (factory default setting)

OFF

ON

EQ HI, +2 dB adjustment

ON

OFF

EQ HI, +4 dB adjustment

ON

ON

EQ HI, +6 dB adjustment

We encourage you to try varying levels of EQ boost to make your telephone audio sound warmer and clearer. Our factory default settings should be considered a safe starting point, but because tastes and situations differ, we don’t presume to make those choices for you. Our testing does suggest that utilizing the full 6 db boost works well in most cases and dramatically enhances telephone audio, but we suggest that you set up your phones like you would any other audio processing device: Adjust, listen critically, and repeat the process until you’re satisfied.

Ducker Configuration Settings

SETTINGS Bits #5 and #6 control the overall operation of the Ducker processing function. See the Ducking system section for an explanation of each setting, including full-duplex (no ducking), -6 dB, -12 dB, or half-duplex (one way at a time).

SETTINGS

Bit 5

Bit 6

Setting Value

OFF

OFF

Full Duplex (no attenuation)

OFF

ON

-6 dB attenuation (factory default setting)

ON

OFF

-12 dB attenuation

ON

ON

Half Duplex

Receive AGC and Noise Gate Settings

SETTINGS Bits #7 and #8 jointly control the operation of the receive AGC and Noise Gate processing functions. You can select how aggressively low-level signals are brought up to the nominal (+4 dBu) level using the following bit settings:

SETTINGS

Bit 7

Bit 8

AGC Setting Value

Noise Gate Setting Value

OFF

OFF

Phone AGC = OFF

Noise Gate = OFF

OFF

ON

Phone AGC = 1/2 Full

Noise Gate = OFF

ON

OFF

Phone AGC = Full

Noise Gate = OFF (factory default setting)

ON

ON

Phone AGC = Full

Noise Gate = Normal

Auto-Answer Configuration Settings

OPTIONS Bits #3 and #4 jointly control the operation of the Auto-Answer feature of the hybrid. You can select between turning the feature off, or set the number of rings before the incoming call is answered and then placed on air as follows:

OPTIONS

Bit 3

Bit 4

Auto-Answer Setting Value

Ring Setting Value

OFF

OFF

Auto-answer = OFF

Disabled (factory default setting)

OFF

ON

Auto-answer = ON

Auto-answer after first ring

ON

OFF

Auto-answer = ON

Auto-answer after third ring

ON

ON

Auto-answer = ON

Auto-answer after eighth ring

Send Extra Gain to Caller Configuration Setting

The Hx1 and Hx2 hybrid units have been designed to send a -9 dBu average level to the telephone line in order to meet the USA’s FCC regulations. OPTION Bit #5 adds 3 dB of gain to the send level heard by the caller. This should only be used when the hybrid is connected to a PBX or in countries outside of the USA that permit a higher transmit level.

OPTIONS

Bit 5

Setting Value

OFF

No additional gain applied (factory default setting)

ON

+3 dB additional gain applied to audio sent to the caller

Hx2 Internal Mix-Minus Configuration Setting

The Hx2 can operate as two independent hybrids or be configured to perform an internal mix- minus between the two hybrids.

Bit 6

Setting Value

OFF

Independent - Internal mix-minus disabled (factory default setting)

ON

Coupled - Internal mix-minus enabled

Feedback Reduction

The Hx 1 and Hx2 have an optional Acoustic Echo Canceler in the Studio send path. This can be used when there is acoustic coupling between a loudspeaker connected to the hybrid output and a microphone connected to the input. Enabling feedback reduction also causes the ducker to insert more loss into the announcer-to-caller direction when the caller is dominant.

Bit 7

Setting Value

OFF

Acoustic Echo Canceler disabled (factory default setting)

ON

Acoustic Echo Canceler enabled (use in "open speaker" situation)

Reserved Bit

OPTIONS Bit #8 is set aside as RESERVED for future use.

OPTIONS

Bit 8

Setting Value

OFF

Reserved for future use (factory default setting)

ON

Not recommended