Damn, I forgot what was in this thread completely.

I have a Samson S1000 and have measured with a voltmeter to determine how much power my subs handling while playing a CD with a 20Hz sine wave. It is rated in the owners manual 545w rms into 4ohms. I measure 43.9v at 20Hz, obviously less current availible to provide the full output. Still, plenty of oumph for my $125 a piece drivers. In room response of about 120dB (+/-4dB) from 16Hz up to 100Hz for far less money than you spent on your amp alone. but I have not idea what the true impedence of my drivers at 20Hz. I suppose I should check that out because impedence usualyl goes up as frequency goes down when talking about this octave of material.

My receiver is rated at 90Wx5 rinto 8ohms and my front mains and center channels are 4-ohm loads. Rear are 8-ohm. I've never measured how much voltage they actually take as my ears hurt way before I could take such a measurement.

High current can suck my nuts. You've been hangin out in too many HK shops. Yes, power (which is directly related to output or loudness given the efficiency and environment transfer gain) equals voltage times current. Everyone knows VI=P from high school physics. So, what good is high current if you don't have the voltage? What good is 40w of power with high low impedance current if it still only produces 95dB in room response at 20Hz. That is hardly enough to notice, let alone feel. Just an example, though. Gotta have both.

In reply to:

To me loudness and excursion mean nothing if it cant do 20hz.


Actually, the three are closely related, as Dave gave an example. It takes a certain amount of excursion to produce a specific volume level given the efficiency of a particular driver and its impedence playing such frequency. All a speaker does is move air. The more it moves, the louder it is. Very simple concept.

If this original Sunfire driver has about 2" of one way excursion (probably is 2-way,but benefit of the doubt), that still is not much compared to the list Dave gave earlier. This is by no means accurate, but the surface area is pi times the radius squared. for an 8" driver, 4^2*pi equals about 50 square inches. A 12" is 113 square inches and 176sqin for a 15" driver. Thus 3 8" drivers would not even have the output of a single 15" given the same excursion (and availible power). There are quite a few 12-15" drivers that have a little less excursion, but can easily output 108dB, and do it lower. As Dave has been trying to get through to you, the Sunfire in question has an F3 at 25Hz and 108dB in room. I hate in room responses because no one has the same room as the next person. I figure that means closer to 105dB at 25Hz, and more like 102dB at 20Hz. While it may be heard, a step into my room (or my brother's or thousands of other peoples and probably one of your neighbors) can far out produce that 20Hz response. I could easily do it when I had an old stereo receiver powering my subs, only 125w to each one.

One point I'd like to make is that may speakers can have a flat response down to 20Hz or lower, but if it either does not have the excursion and cannot take the power, it is uselss for reproducing a material in that frequency range.

Aaron