I recently started the Zaph ZP5 thread, because I want a slim floorstander with good bass extension, but didn't want the tweeter he had chosen. Finding out how complicated it was to design a good crossover, I thanked everyone for the advice and began what I thought would be a long stint of reading.
So I was doing some research and found this nice link that provided a good primer on LR crossovers. Basically, saying that a LR4 crossover provides an ideal crossover, providing you can time align the HF and LF drivers. It was then that I vaguely remembered about a bi-amp feature of the Panasonic XR57: time delay. Basically, you tell the receiver the distance between the LF and HF drivers, entered in .5" increments, and it applies the proper time delay to get a phase correct response. Any thoughts about how useful this is? Is .5" increments enough? The older XR55 provides .36" increments, if that helps. Granted, I'd have to measure it, but theoretically? The XR57 obviously allows you to balance the SPL between the HF and LF, so I shouldn't need to add attenuation filters, either.
So basically, can I take a LR4 crossover at a good frequency for my drivers, add the right delay and LF/HF balance using the XR57, add the right Zobel filter for the LF, set up a decent baffle and then, build it, measure the response, and then correct the rest with notch filters, as necessary?
Also, another question. I was thinking about routing a inverted radius into the tweeter face plate to reduce the distance between the tweeter and woofer. This allows me to get a better vertical off-axis response at the crossover point, right?
Oh, one more question, how do you find the final nominal and minimum impedance of the speaker? Any way other than a measurement? I assume it's not a normal parallel impedance calculation, because that completely disregards the crossover network and would mean 2.6 ohms. :E
Here's a snapshot of the XR57 manual, describing the bi-amp options:
So I was doing some research and found this nice link that provided a good primer on LR crossovers. Basically, saying that a LR4 crossover provides an ideal crossover, providing you can time align the HF and LF drivers. It was then that I vaguely remembered about a bi-amp feature of the Panasonic XR57: time delay. Basically, you tell the receiver the distance between the LF and HF drivers, entered in .5" increments, and it applies the proper time delay to get a phase correct response. Any thoughts about how useful this is? Is .5" increments enough? The older XR55 provides .36" increments, if that helps. Granted, I'd have to measure it, but theoretically? The XR57 obviously allows you to balance the SPL between the HF and LF, so I shouldn't need to add attenuation filters, either.
So basically, can I take a LR4 crossover at a good frequency for my drivers, add the right delay and LF/HF balance using the XR57, add the right Zobel filter for the LF, set up a decent baffle and then, build it, measure the response, and then correct the rest with notch filters, as necessary?
Also, another question. I was thinking about routing a inverted radius into the tweeter face plate to reduce the distance between the tweeter and woofer. This allows me to get a better vertical off-axis response at the crossover point, right?
Oh, one more question, how do you find the final nominal and minimum impedance of the speaker? Any way other than a measurement? I assume it's not a normal parallel impedance calculation, because that completely disregards the crossover network and would mean 2.6 ohms. :E
Here's a snapshot of the XR57 manual, describing the bi-amp options:
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