waxcalifornia
Member
If you are running an IR direct to PA and a power amp/cab from output 2, would you match the LF Resonance to the IR or the physical cab for best results?
That depends. What's more important to you: what the audience hears or what you hear?If you are running an IR direct to PA and a power amp/cab from output 2, would you match the LF Resonance to the IR or the physical cab for best results?
Then optimize it to sound best for your FOH signal. I'm thinking your cab sill sound pretty good, too.In this case, what the audience hears. Thank you for the quick reply.
The resonance Q is a bit more difficult to calculate. It is derived from the bandwidth at the points where the impedance "gain" is the square root of the resonance impedance gain. IOW, if the impedance is, say, 10 times the nominal impedance then the bandwidth is given by the frequencies where the response is 3.16 times the nominal impedance. For our example the resonance gain is 5 (40 / 8 = 5). So the bandwidth is the frequencies at which the impedance equals sqrt(5) * 8 = 18. From the graph this is approximately 75 Hz and 130 Hz. Q is defined as f0 / bw so our resulting Q is 100/60 = 1.67. Most speakers have a Q of around 2.0 or so. Again the exact value isn't overly critical and don't be afraid to try extreme settings (you can't break anything).
Here are the values:@FractalAudio
Please confirm my math:
144 ohm (resonance peak impedance).
96Hz (resonance frequency).
14 ohm (nominal impedance).
144/14 = 10.3
sqrt(10.3) * 14 = 45 ohm
At 45 ohm: 80Hz, 113Hz (from graph).
BW: 113 - 80 = 33
Q = Rf/BW = 96/33 = 2.9
That formula has been deprecated.Thank you.
So the math for Q in the first post is not correct? It's in the Wiki too.