Combo unit with extra external speaker cab question

[lopxtc]

Hey all ...

I apologize if this has been answered before, I have a question about amps if someone can help me.

I currently play through an Ashdown 400 watt 1x15 combo unit. It has an output for adding another speaker cab, but its rated at 8 ohms. I was thinking of someday adding a 400 watt 2x10 (also 8 ohms) cab to it but wondering what effect this would have power wise to the whole setup. Would I still be putting out 400 watt, or would the power be reduced and by how much?

Thanks ...

Aaron

 

[fdeck]

I am not finding technical info on this amp. However, if this is a typical combo, it is likely that the internal speaker is 8 Ohms, and is being driven at somewhat above half of the rated power. Plugging in a second 8-Ohm speaker makes the overall impedance 4 Ohms, and also distributes half of the full power among the two speakers.

You get a double whammy. A 3 dB increase in amp power, and a 3 dB increase in sensitivity from using two speakers, for an overall 6 dB increase in volume.

Now I am generalizing. It is worth reading the owners manual carefully, related to instructions on connecting external speakers, to make sure what I am saying makes sense for this particular map.

 

[Mcrelly]

your amp can put out more total power AND it will sound louder.