Whelen HHS2200 second siren speaker question

[dockdoc]

Hi all - I have an HHS2200 which has had a single siren speaker for a while. I've found that I get inadequate warning with it so wanted to add some more power.

I purchased another siren speaker (Whelen SA315) to match the existing one. Followed the wiring diagram which has you tap it into the existing wire for the speaker, so both speakers come off the same wire from the HHS2200.

Is that all there is to it? I don't see anything in the manual about what the output should be, seems odd that you'd just add another 100W speaker tapped into the first one. Does this unit put out 200W that way?

I must say I don't notice much difference in volume with the second speaker, so just trying to make sure there's not something I'm missing...

 

[Jarred J.]

adding a second speaker adds 3 db of "loudness" see videos of 100 vs 200 watt setups...

 

[Brian209]

The reason that the 100 watt vs. 200 watt option is not a "setting" in the unit is that the electrical equations work it out.

If your speaker is 11 ohms of resistance, then the speaker driver will deliver the voltage waveform to the speaker circuit, and the amp draw will equal 100 watts.

If you add the second speaker, it's put in parallel to the first. The equivalent resistance of that circuit will be 5.5 ohms, or half of the resistance. You can use the formula (R1 * R2)/(R1+R2). Half the resistance means double the amperage. This equates to twice the power in watts.

If you hook two speakers up to a 100 watt siren, it will attempt to draw twice the current, and likely damage the amplifier output circuit.

There are some siren units that have two sets of speaker outputs, so that there are two separate 100 watt output circuits. These usually allow you to have one speaker play a slightly offset tone, so that it sounds like two separate vehicles.

 

[NoLimitSquads]

If you hook two speakers up to a 100 watt siren, it will attempt to draw twice the current, and likely damage the amplifier output circuit.

Fortunately the HHS was designed for this, so doing this won’t damage it.