So I have arrived at the Crossover design portion of a speaker... my first ground up build. I am planning to use the Z19 XO because it is highly regarded among the forum. But then I started asking why is is better than another? I have rebuilt several crossovers with upgraded parts in the past but just went off the manufacturer schematic to know how to wire it up without any study as to why. I have a basic understanding of what caps, resistors and inductors do... but not a general understanding of how they work together and how to optimize a XO for a specific speaker.
I want to understand why you would opt for the Z19 XO over a 2nd Order Butterworth XO designed to crossover at 1200hz? Why are they so many extra parts in the Z19 and significantly different cap values??? I've always been a fan of the simplest solution, but I've read enough of the Z19 forums to know that it seems to work better.
I know the answer, I need to read up. So my real question is if there is a better place than the Z10 Forums scattered across several sites to learn this information?
2nd Order Butterworth 1200 Hertz
Stock Z19 Design
I want to understand why you would opt for the Z19 XO over a 2nd Order Butterworth XO designed to crossover at 1200hz? Why are they so many extra parts in the Z19 and significantly different cap values??? I've always been a fan of the simplest solution, but I've read enough of the Z19 forums to know that it seems to work better.
I know the answer, I need to read up. So my real question is if there is a better place than the Z10 Forums scattered across several sites to learn this information?
2nd Order Butterworth 1200 Hertz
| Parts List Capacitors C1 = 11.72 uF C2 = 11.72 uF Inductors L1 = 1.5 mH L2 = 1.5 mH |
Stock Z19 Design
my speaker project is the garden variety Valencia'ish build. I have Altec 811b horns, 808 8a's and 421a woofers that I plan to put in 612c style cabinet. I would like the crossover point to be in the 1200hz to 1500hz region. I plan to dial that in with an active crossover. But once I have the crossover point figured out I want to hardwire the XO and enjoy.
That's the first time I've ever heard of the "Z19" crossover.
What's supposed to be so special about it?
What's supposed to be so special about it?
the Z19 is a modified Model 19 crossover. I've read so much about it I guess I overestimated it's popularity.
But, the stock model 19 crossover could be substituted in as it also has a very different layout than the BW 2nd Order XO.
But, the stock model 19 crossover could be substituted in as it also has a very different layout than the BW 2nd Order XO.
Well, the calculated Butterworth crossover doesn't count in the electroacoustic transfer function of the loudspeaker. That is nowhere near linear. So you won't end up with a linear response. That is why calculated values don't work in speaker design. This Z19 design actually looks like a crossover that has been designed around a real world transfer function.
Doesn't make a lot of sense. If more people were comfortable with designing crossovers then they'd be making their own... A crossover is not a 'one size fits all' proposition.
However I see that this one is adjustable. There's nothing wrong with that, although a complete crossover should not need to be adjustable. However for experimental purposes, or for suiting different speaker options it might be wanted. It would certainly add to the popularity because some can get closer to what they want this way even if it isn't the best option.
Analyzing...
The original crossover (Z19) shows a 'regular' 2nd order LP. Why the difference between the calculated (1.8 mH and 11 uF) and the real one, 2.7/21? Probably for allowing for BSC \ Baffle step compensation.
The tweeter section employs a 3rd order crossover, quite common for compression drivers, and in general in P. A.
There are two equalization stages after the HP. The first (RC, with variable R) to compensate for HF loss from horn profile. The second is a RLC(a notch) for other purposes, still with variable resistance to modify something...
Don't want to over-analyze...
The original crossover (Z19) shows a 'regular' 2nd order LP. Why the difference between the calculated (1.8 mH and 11 uF) and the real one, 2.7/21? Probably for allowing for BSC \ Baffle step compensation.
The tweeter section employs a 3rd order crossover, quite common for compression drivers, and in general in P. A.
There are two equalization stages after the HP. The first (RC, with variable R) to compensate for HF loss from horn profile. The second is a RLC(a notch) for other purposes, still with variable resistance to modify something...
Don't want to over-analyze...
This makes a lot of sense since I first learned about the Z19 while reading numerous and very long threads over the years of people doing a project similar to mine, which to some degree, is a frankenstein Atec Model 19 or Valencia. Same basic parts with differing cabinets and crossovers. Lots of discussions on which altec crossover to use but the Z19 comes up in a lot of these conversations as an "improved" xo for such builds. So while the speaker builds are most definitely different across the various projects... they are the same in parts and relative cabinet size. I would not have thought to use the Z19 were I doing a different project not based on the Model 19.