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Z19 Crossover

Hey Guys - please keep posting.
I just updated the crossovers in a set of Valencia (Heathkit 101) to stock.
Old caps had drifted alot. Huge difference in sound.

Next step is going to be this upgrade. Took me a few weeks to find such good documentation. Thanks to everyone and Zilch especially. I nearly gave the whole thing up until I came across a keep on trying post from Zilch.

I am aquiring parts now (have most of the values for the Caps -) need resistors and chokes and a pair of L pads.

I am also adding to the drawing of Zilchs as new comments bring to light how to hook up and clear up any confusion.
 
:( Zilch is no longer with us. http://www.audiokarma.org/forums/showthread.php?t=350053

But I think his whole Z19 design can be summed up with these images:

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Z1920Board20Layout1.jpg

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Can anyone advise whether the Z19 could be adapted for use with other Altec systems but with a lower crossover? Specifically for use with a crossover at 500 for 288 or 299 with a horn that goes lower like an 805B.

Thanks for the help
 
Good question, but one that, unfortunately, probably can't be answered without a good bit of testing and re-design work. The CONCEPT could obviously work... but the values would have to be re-worked to do lower crossover points...

Regards,
Gordon.
 
Thanks Gordon. I was thinking about this crossover for the 2235 project I have contacted you about.

And I guess this is as good of a point as any to honestly admit that I really don't understand Zilch's design approach. I know it's not just a few notch filters for just one driver. It sounds like it's creating an equalization curve/profile that can be adjusted both in the shape of the curve and the amount of compensation. Kind of like CD compensation built into some active crossovers - but with ability to adjust more.

Is this right? Thanks again.
 
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WOW.. I can't believe this thread has been around as long as it has, and I haven't seen it until now... I just spent the last hour reading through it...

For those that were asking about other applications than Altec, I am WAY beyond happy with it in my barziwaves. Way back when, when I was designing my project, I asked Zilch about crossovers, and he suggested I try this... It was a large risk price wise for something I had no clue about, and he was just taking an educated guess it might work.

I am using mine on BMS 4555 drivers and AE's TD15M woofers, using the original design values... it was SPOT ON for my application... I can't stress enough, that if you are using higher end drivers for a 2 way build, this crossover is well worth considering, and tweaking to suit your needs.

I just wish I had a way to actually measure mine, but no one in this area is set up for measuring that I know of..

Anyway, here's mine that I built about a year ago..

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Here's the final mounting and wiring..

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Thanks. They turned out to be some pretty spectacular sounding speakers, and capable of intense ultra clean SPL levels..
 
I think Zilch's idea was to improve on the stock Altec Model 19 crossover, which had a form of such two-curve variable equalization. You can find a thread somewhere, where Zilch first started musing about the stock Model 19 design and wondered how it performed and how he could improve it. Ah, here it is:

http://www.audioheritage.org/vbullet...wrong.../page2 (Scroll down to post 26.)

History in the making ...
Click to expand...

Thanks Zonker, that post is a keeper - I've marked and printed it for multiple readings - it brings me a lot closer to understanding. Great of Zilch to stop and explain it for us mere mortals. (By the way I think it was post #46)

SR
 
You might want to take a look at another of Z's designs

Here This crossover was made for the 2235.

SR427 said:
Thanks Gordon. I was thinking about this crossover for the 2235 project I have contacted you about.

And I guess this is as good of a point as any to honestly admit that I really don't understand Zilch's design approach. I know it's not just a few notch filters for just one driver. It sounds like it's creating an equalization curve/profile that can be adjusted both in the shape of the curve and the amount of compensation. Kind of like CD compensation built into some active crossovers - but with ability to adjust more.

Is this right? Thanks again.
Click to expand...
 
SR427 said:
Thanks Zonker, that post is a keeper - I've marked and printed it for multiple readings - it brings me a lot closer to understanding. Great of Zilch to stop and explain it for us mere mortals. (By the way I think it was post #46)

SR
Click to expand...

I can't get that link for some reason but I certainly would like to hear about how the Z19 was developed.
I'm still amazed at how good my M19's sound.
 
What's the consensus on using a Z19 with the 2235H?

I know JBL doesn't recommend crossing that woofer over any higher than 1000hz, but the graphs for it don't look too much worse 1000-1200hz than they do for 800-1000hz.

Will the Z19's 1.2K crossover point be pushing it? Should I use Zilch's 4430 crossover interpretation instead?
 
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winters860 said:
What's the consensus on using a Z19 with the 2235H?

I know JBL doesn't recommend crossing that woofer over any higher than 1000hz, but the graphs for it don't look too much worse 1000-1200hz than they do for 800-1000hz.

Will the Z19's 1.2K crossover point be pushing it? Should I use Zilch's 4430 crossover interpretation instead?
Click to expand...

A couple folks have used the 2235 in ewaves witha 1600 Hz XO. Never heard them myself but they seem happy. I

I would look at the 4430 XO (what is XO point?) to at least see what was done for the LF XO section since the Z19 was designed for a particular Altec woofer. Of course the closer you get to cloning a 4430 instead of the Altec 19, the more I would look at the 4430.
 
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