Hello, I've got a question to some of you concerning decibels. If you have two dB values...for example, 70 dB's and 75 dB's and both values combine, you don't get a 6 dB maximum improvement. If we are talking about subwoofers and dB's, I've been told that if you add two identical figures, like 70 dB's + 70 dB's (and the sub's are in phase) that the result would be a 6 dB improvement. But I've also been told that if two levels are different, that both will not combine to provide with that same 6 dB advantage. So I would like to know from the experienced posters here, why is it that equal levels between both provide an advantage if summed over the dissimilar levels. Or am I wrong ? I'm not sure so I'm asking anyway.