Carson Sirens FAQ

Q: What is an Auxiliary Input?

The Auxiliary Input is a wiring input that may be connected to the vehicles horn ring or other switching device during installation. It provides the driver with "hands-free" operation. When connected, the vehicle's horn works like the Siren button if the siren has only one momentary override button or your choice of Air Horn or Manual/Phaser if the siren has two momentary override buttons. When the Auxiliary Input is connected, you may also choose to replace the Auxiliary Input function by activating the Horn Ring Cycler (HRC) or Horn Ring Cycler 2 (HRC2) function.

Q: What are the Horn Ring Cycler (HRC) and Horn Ring Cycler 2 (HRC2)?

With the Auxiliary Input connected and the Horn Ring Cycler (HRC) or Horn Ring Cycler 2 (HRC2) option selected, then the driver may scroll through wail, yelp and phaser tones by tapping the vehicles horn for "hands-free" control when the siren selector is in the Standby position. Pressing and holding the vehicles horn produces an Air Horn override tone without changing the basic tone selection. Pressing twice in succession will turn it off.

Q: What is Siren Cutout?

Also referred to as the Park Kill function, the Siren Cutout input is connected to the driver's side door switch and turns off any siren tone when the door is opened. The siren tone remains off even when the door is closed and will not resume normal function until a siren switch or input is activated.

Q: What is Instant On?

Instant On is a feature that allows the unit to be powered up without using an on/off switch. Selecting any function in normal use operation activates the unit.

Q: What does the Output Indicator do?

The Output Indicator is a sensor that lights up when it senses the siren sending out a signal to the speaker(s). This provides a quick and easy diagnostic feature to help pinpoint problems between a siren, speaker(s) and speaker wiring.

Q: What is DIP switch programmability and Face programmability with User Lock-out?

DIP switch programmability is an improved method for selecting how a unit will function over traditional jumpers. A DIP switch allows the installer to easily turn on or off select functions to semi-customize the unit for the desired environment. Face programmability with User Lock-out allows the installer to completely customize the unit for their specific needs through a push of the buttons and then they can lockout users from re-programming in the field.

Q: What is Dual Tone?

Dual Tone is when a siren produces two tones at the same time. It sounds like two sirens in one. Carson developed and perfected the dual tone technology over 15 years ago with the development of the independent 2-channel amplifier. The SA-441 MagForce is the original dual tone siren.

Q: How does the independent 2-channel amplifier work?

The independent 2-channel amplifier is basically two 100-watt amplifiers encased in one unit. When in single tone mode, the two amplifiers work in unison, but they work separately when switched to the dual tone mode.

Q: How do the short circuit, high voltage and reverse polarity protection systems work?

These systems are all incorporated into the circuit board to protect the amplifier from damage. The short circuit protection system protects the amplifier from a shorted or blown speaker. It senses when a short occurs in a speaker and blows the fuse to keep the amplifier components from overloading.

The high voltage protection system protects the speaker from the amplifier when spikes in input voltage occur. The high voltage sensors detect when the input level rises above 16 volts and kills the sirens output. The siren automatically resets when voltage levels drop back down to normal levels.

The reverse polarity protection system protects the amplifier by blowing the fuse if the power input connections are improperly connected. For example, if the positive wire is attached to the negative connector, the fuse will blow.

Q: What does a single lead connection mean on the remote sirens?

This patented design allows for all of the exchange of information between the control head and the amplifier to travel through a single #22 gauge wire. That means that during installation, the installer must only string one wire from the control head, through the vehicle and back to the amplifier rather than stringing as many as 10 wires back through the vehicle to the amplifier.

Q: What does the Master Switch do on the switch box?

The Master Switch allows the SB-008 Phantom switch box to function like it had a slide switch. When programming the switch box, you can group different switches together to be controlled by a Master Switch. When the Master Switch is activated, all of the switches in the group are activated like when a slide switch is in the 3rd position. The driver may then de-activate individual switches within the group to back-down the number of lights activated like when moving back to position 1 or 2 on a slide switch.

Q: What common additional options are available?

Carson has detachable microphones and 28-volt versions for large vehicle installations available for all siren models. In addition on our remote sirens, we offer amplifier or control head only packages for component replacement and FX extended detachable microphones for remote microphone mounting. Our SC-550 Stealth has a 15' extension cable for the hand-held control head.

Q: I've noticed that your sirens don’t have rows of holes punched into the case like many other sirens. How do you keep them from overheating? - Mike in California

Those holes that you find on many sirens play a very important role. When a siren is producing warning tones, it is also producing heat. The holes in the cover and chassis provide ventilation to keep the amplifier components from overheating. Sirens have differing power consumption efficiencies when producing tones. The more inefficient a siren is, the faster it produces heat. The faster it produces heat, the more inefficient it becomes. This snowballing effect eventually leads to overheating and shortens the sirens life.

Carson sirens do not need ventilation holes because we use a patented design that increases efficiencies and slows down the heat production rate avoiding that snowball effect. Additionally, since the siren has no ventilation holes, it is better protected against outside contaminants like dust and liquids. That's part of what "Tough to the Core" is all about.

Q: What makes your membrane switches like on the SC-550 Stealth and SB-008 Phantom more durable than traditional rockers and other push-button switches? - Bob in Ohio

Carson’s new enclosed membrane push-button switches provide improved durability over other switch options because they are completely enclosed and utilize metal dome technology within the switch. There has been great strides made in increasing the integrity of membrane switches with the inception of metal domes. However in the environment that a siren is used i.e. inside a vehicle, the primary factor that increases the switch and unit’s durability is that our membrane switches are covered with a rubber overlay to keep liquids out. Let’s face it, liquids kill electronics. And a siren or a switchbox is nothing more than a box full of electronics. Traditional switches with exposed perimeters function like a funnel anytime there is a spill. But since our switches are enclosed, the points of entry for outside elements into the circuitry are significantly reduced.

Q: What is the difference between your Siren Cutout feature and what other manufacturers’ usually call the Park Kill feature? - Ron in Indiana

Both systems work off the same theory to re-activate the siren using an electronic signal. The difference is how the features are triggered. The Park Kill feature was intended to attach to the gear-shift of the vehicle. When the driver shifted into Park, a signal would be sent that would shut off the siren output. However, there are potential problematic side-effects that could result from tapping into a vehicles transmission system. Rather than using the gear shift to deactivate the siren, we looked for an alternative trigger source to send the signal back to the siren. The best system we found for connecting the trigger was the driver’s side door switch. It offers much easier access during installation and avoids the risk associated with tampering with one of a vehicle’s main systems. To distinguish between the two installation practices, we gave our feature a different name, calling it “Siren Cutout.”

Q: When there is no sound or the siren is blowing fuses, how can you tell if it’s the siren or speaker that is causing the problem? - Jerry

First you need to isolate the problem. Do this by disconnecting the speaker leads at the siren amplifier, replacing any blown fuses and turn the siren on to the yelp position and follow the below steps. If either the siren amplifier or speaker(s) fails one of the steps, contact the distributor or manufacturer’s service department: 1. If the replaced fuse blows quickly, check for proper power lead polarity to the amplifier. If the wiring is correct, the amplifier is probably damaged.

2. If the fuse does not blow, listen for the yelp tone faintly coming from the amplifier box. If you do not hear the yelp, the amplifier may be damaged.

3. If you can faintly hear the siren tone the amplifier is functioning properly, check the resistance across the leads to the speaker with an ohmmeter. Siren speakers typically measure about 4 ohms. If the ohmmeter reads zero ohms or an open circuit, the speaker leads or the speaker is damaged or disconnected.

Q: I just finished installing my siren, but the unit has no power. What am I doing wrong? -Tony

The first check you should make when experiencing this problem is to ensure that the enable lead is connected to positive power. The enable lead can be identified as an orange wire, as in the SA-360, SA-361 and SA-380, or as a terminal connection for the SC-409, SC-1002 and SC-1012. This lead must be connected in order for your siren to power up. There are exceptions to this rule,so please consult your installation manual for more information on enable wire installation and the connection exceptions. For additional questions related to this or other service/installation issues, contact our Service Department at

Q: What is the sound called that is used in the European Emergency services? Does Carson Sirens have that?

The typical sound that comes to mind when you think of emergency services in Europe is called the HI-Lo tone. The siren tone is two tones at certain frequencies that bounce back and forth. One is higher than the other. Hince the name Hi-Lo. Most Carson Sirens have this tone. Some may require you to change the settings on the siren to activate the sound. Have questions, call us at 1-800-646-1086!