Ivan, i agree with you, but he is looking to replace 2 TSW218 with 4 TH118, which brings me to a conclusion that he needs a lot more spl in the sub region.
Wile you are correct that you don't need to operate them full tilt, people usually do just that.
If you get 4 TH118 and run them at half power, surely there are more compact offerings that can do the same. Isn't there?
My comment was more about using the amp at 2 ohm on a regular basis then the power that it will give to the subs.
Regards
Of course "half power" is only 3dB down. When you start looking at what is happening down around 30Hz, it can get interesting.
And then you have to consider what do you want-Do you want a sub that is "crusing along at "half power"-or one that is run at its maximum and on the edge of blowing up.
And then you also have to consider what happens to the distortion when you apply more power. As a general rule-the lower the power (in relation to the maximum the driver can handle) the lower the distortion.
So a driver that is run at half power is going to have less distortion than one run at full power.
I would agree and disagree that people run cabinets at full power. Some do-some don't. When you look at the overall sound reinforcement scene-I would say that most people/systems do not run anywhere near the max output.
If you look at the club scene-then it would probably be quite the opposite.
it all depends on the particular application/situation.