"When I read the 12/1/99 TTOTD another question occurred to me that might interest inSync readers. When you lower the load impedance on your power amp by connecting speakers in parallel and the output power doubles, what does the volume from the speakers do? My educated guess says that in an ideal world it increases by 3 dB SPL. Is this correct? Would it be noticeably louder in a club?"

Let's try an example. Say you have one 8-ohm speaker on one side of an amp. The amp puts out a maximum of 100 watts at 8-ohms. Now, you add a second 8-ohm speaker in parallel. The amp now sees a 4-ohm load. If the amp does indeed double its power in this situation (many do not) you are now putting a maximum of 200 watts into two speakers. That's 100 watts per speaker. This leaves you right where you started in terms of the power for each speaker. However it does double the output power of the amp overall (+3dBm). Yes, in ideal circumstances this translates to a 3dB SPL increase. Of course, circumstances are never ideal and you'll never see (hear) the full 3 dB. I would characterize a 3dB increase as "just noticeably louder." It's not a big difference. The good news is if you stay at the same volume, you now have 3dB more headroom on your PA. In most circumstances this is far more beneficial than trying to actually be louder. It means less clipping, distortion, wear on the PA, and wear on the audience's ears.