Originally posted by dgwojo
Hopefully this wasn't posted before but I see MCM is selling some new Pyle horns for cheap, model# PH612, they run $9.45 if you use source code 8SC208 in the shopping cart, Dave.
MCM 53-970
Dave, I went to the Pyle Audio site, and they show the same pics, and list size as 6.4" hi by 11.9" long. Virtually identical to the JBL waveguide. I ordered a pair of them from MCM, since I needed 4 each 100 ohm 20 watt resistors. I will check them out.
Originally posted by Zilch
It surprises me that you're using separate filter frequencies with CX3400 for two-way, though thinking about it, that's clearly possible by using it in three-way mode. I just use it conventionally, two-way, with a single frequency set by the one knob, 24 dB/octave, and dial the frequency within a desired range for the optimum tradeoff between HF and LF capabilities.
Yes, that is exactly how I did it. Since we wanted two separate crossover frequencies (or thought we did), it seemed intuitive to use the CX-3400 in three way mode where two xover frequencies can be controlled. I didn't realize that that wouldn't work when the driving impedance becomes essentially zero ohms. Changes things, doesn't it?
Originally posted by Zilch
Additionally, active, there are parametrics, graphic, and AutoEQ available in the DEQ2496 to assist with the task....
Yeah, but then we aren't really talking Econo anymore. Even adding just the CX-3400 removes the Econo tag from the description for me.
Originally posted by Zilch
It's the same rules, actually. Recall that we used the higher filter frequency on the HF as part of its passive compensation. With the active approach, that's not part of the scheme, is all; the frequency and slope are fixed.
Maybe it is only semantics, but things are different between passive and active. Passive accomplishes the roll off of fixed amplitude signal by using variable impedance frequency sensitive devices which drive the speaker through their combined impedance. Active drives the speakers with a variable amplitude signal at essentially zero ohms impedance.
Putting a fixed voltage of 1 volt across a 1 ohm resistor yields a current of 1 ampere. Putting a constant current source of 1 ampere through a 1 ohm resistor yields a voltage of 1 volt. Both situations seem identical as is, but change the resistor value in the former, and the current will change. In the latter, the voltage will change. Ohms law is at work in both cases, but using a constant current source is quite different than using a constant voltage source. Different rules?? Or maybe just semantics? You see it one way, I see it another way. We can disagree, can't we?
Edit: As noted above, I ordered 4 each 100 Ohm resistors to put across the 2214H's in the final version, which will be an EconoWave, meaning passive crossovers. In the Bi-Amped version, the 100 Ohm resistors should have absolutely no effect, since the woofer is driven with a zero ohm source. Adding them will only require a little more current out of the amplifier, which it will provide, no sweat. Also the Wayne Parham HF compensation technique should be changed to one resistor in series with the tweeter, since adding the second resistor to lower the effective impedance back to the original value will no longer be necessary. The effective impedance value in the active configuration is essentially zero ohms. Hard to change that be adding 25 ohms across it, isn't it?
Tweeter compensation filters that are added in parallel with the tweeter will not be effective due to the zero ohm driving impedance, but those used in series should still work. Using the resistor in series with the tweeter may provide enough impedance for parallel filters to work, but the resistor is not frequency sensitive like a passive crossover. HMMMM... Different rules?
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