Re: Article: Stair Cardioid
Sebastian,
In your article you wrote:
"It’s very important to note that in both traces only sub 1 is working. The only change made was placing sub 2 (turned off) in front of sub 1, just like in a cardioid configuration. In this special case, the only purpose of sub 2 is to act as a passive obstacle... Results were very significant, we even saw 5 dB attenuation at some frequencies."
"Just like in a cardioid situation" would require the sub to be driven by an amplifier, but it appears from your text it was not in this case.
You did not mention if the "obstacle" sub was shorted out at the cabinet input terminals, or connected to an amplifier (turned off or on). Each of those three cases would result in a different frequency response, assuming the amp disconnects it's load when turned off.
A cabinet shorted out at the input terminals acoustically appears pretty much like a box, the other two possibilities turn the obstacle sub in to various versions of "bass traps", which may largely be responsible for the measured frequency response deviations.
Which of the three options was the test case?
If the cabinet was not shorted, what is the resistance measured at the cabinet end when the amp is "off" or "on"?
Art
