• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Z19 Crossover

jackgiff said:
Did you guys notice the name in the upper left hand corner?

Is wiredbecker up to something?
Click to expand...

Soon to be offered from the ZilchLab?

Jack, the nomenclature on the board for connections, would you explain? I assume it's the biamp option ... what's the T and W? T is HF amp out and W for LF amp out? Is there a jumper for conventional amping?
 
skywave-rider said:
Soon to be offered from the ZilchLab?

Jack, the nomenclature on the board for connections, would you explain? I assume it's the biamp option ... what's the T and W? T is HF amp out and W for LF amp out? Is there a jumper for conventional amping?
Click to expand...


T+ and T- are the tweeter outputs, and W+ and W- are for the woofer. Jumpers can be installed between adjacent pins to hook the HF- and LF- together, as well as the HF+ and LF+. Or with no jumpers, they can be bi-amped. Not wire jumpers, but purpose made jumpers from the barrier strip manufacturer. Typical Zilch class.
 
Last edited:
dc270 said:
If by chance you are making more boards PLEASE put me on the list!!! I am a huge Z19 builder/ user!

GREAT looking work!!
DC
Click to expand...

Me too guys!! Stuffing PCBs is a lot easier than building a point to point following a circuit diagram.

I am hopeful this crossover will work for the first set of speakers I ever built under Zilch's patient guidance. You can read more about them here. They use BMS 4555 compression driver connected to a JBL PT-D95HF horn. The woofers are JBL 127H-1. Zilch's adjustable bridged T HF comp filter is already installed in the Heath AS-10 cabinets. Am using a Behringer active crossover now, but would like to build a passive crossover so I can use the speakers in a single amp system.

Can I use Zilch's "Econowave Altec Crossover for Altec 414Z and BMS 4555 on JBL PT-F95HF Waveguide" with the JBL 127H-1 woofer? Or do some adjustments need to be made for the LF?

attachment.php
 
Last edited:
BmWr75 said:
Can I use Zilch's "Econowave Altec Crossover for Altec 414Z and BMS 4555 on JBL PT-F95HF Waveguide" with the JBL 127H-1 woofer? Or do some adjustments need to be made for the LF?
Click to expand...

Go back to post # 2 of this this thread. Somewhere in there (5th graphic) are curves of the 4555 on the F95HF using the the Z19 with the spike killer. You might want to consider that. Not much adjustment range and you still need to work up the LF section.
 
I saw Zilch's spike killer graph and this comment: [W/BMS spike-killer notch across the driver = 0.15mH, 0.47uF, 2R7.]

What does 2R7 mean? I think it means 2 R7 resistors. R7 is a 3 ohm in the LHF forum post. Does 2 mean 2 in parallel?

I'm a newb at crossover design. How do I go about figuring out the LF circuit other than trial and error?
 
BmWr75 said:
What does 2R7 mean? I think it means 2 R7 resistors. R7 is a 3 ohm in the LHF forum post. Does 2 mean 2 in parallel?

I'm a newb at crossover design. How do I go about figuring out the LF circuit other than trial and error?
Click to expand...

I know almost nothing about crossovers except what I've learned messing with the ewaves.

Looking at the crossover for the altec/4555/D95HF I see L5 = 0.1 mH, C6 = 0.68 uF, and R5 = 3.3 ohms which is pretty close to 0.15 mH, 0.47, and 3.5 ohms. I would assume 2R7 means 2 7 ohm resistors in parallel = 3.5 ohms.

As far as the LF section goes, brute force trail and error is one solution. If you have a something to measure frequency response it may not be so bad. Modelling is another option but that requires frequency response and impedance curves for your drivers...usually from measuring them yourself. A third option is to try to find a design where the woofer crosses over close to your target. What JBLs used the 127H-1 in a 2-way? Find the spec sheets and see what JBL did. At least that would give you a better starting point for trial and error testing.
 
BmWr75 said:
...

Can I use Zilch's "Econowave Altec Crossover for Altec 414Z and BMS 4555 on JBL PT-F95HF Waveguide" with the JBL 127H-1 woofer? Or do some adjustments need to be made for the LF?

attachment.php
Click to expand...

That appears to be an optimized HF section for your waveguide/driver. It may sound better than the Z-19, which still has a peak (or three!) with that combo.

For the LF though, since the Zobel is designed for the 414Z, and it is a first order filter, I'd start with the Z-19 LF section,

(Just L1 & C1 here: http://www.audiokarma.org/forums/attachment.php?attachmentid=107459&d=1220817080)

which is second order at 1.6KHz, IIRC.
 
Last edited:
@4343 - if i use the HF section of the Econowave Altec crossover for BMS 4555/414Z, is Zilch's "Adjustable bridged-T HF comp filter", which I already have installed in this speaker, still needed?

attachment.php


I apologize in advance for being such a dumbass.
 
Last edited:
BmWr75 said:
@4343 - if i use the HF section of the Econowave Altec crossover for BMS 4555/414Z, is Zilch's "Adjustable bridged-T HF comp filter", which I already have installed in this speaker, still needed?
Click to expand...

No, those components are lifted right from the Z-19 crossover schematic on page 1 of this thread. Just the HF compensation portion, actually.

You have about a third of the Z-19 HF section there. You are missing the adjustable MF section, since you have a level control on the active crossover, it would have been redundant. Also the actual high pass circuit, since the active XO does that as well.

Add the rest of the circuit and you could compare the Z-19 to the Ewave XO you posted above...
 
Guys hi
My name is Harel and just now got me a pair of Altec 19 Boxes and drivers.. Obviously, i need a pair of crossovers and while looking i encountered this interesting forum...
I used a bi-amp system to check the sound prior to building crossovers. i found that 1200~1500Hz is the most pleasant region
To my calculation on Zilchs' (MHRIP) design on the Woofer cutover point show 680Hz rather than the original N1201 Cross which suppose to cut over at 1200Hz? am i wrong here? My 416 and Tweeter are both 8Ohms BTW..
Thanks Harel
 
The Z19 is pretty close to a 1200 Hz crossover point. Look at the graph on post #24. That graph is not for the Altec Model 19 but the effect is similar. If you search over at the Lansing Heritage site you can find Zilch's development of the Z19 for the Altec. As always with Zilch, he provides lots of documentation.

Not sure how you calculated the crossover point put that can be tricky business as impedance of drivers is not constant over their frequency ranges. The woofer may also have a rising response which would make the acoustic crossover point much different than the electrical crossover.
 
Last edited:
I have build probably a dozen of these Z19 networks- they are xover pretty close to 1200 for sure! A much improved network over stock.
DC
 
Since this thread is going again, I thought I'd post this drawing a super-cool member made earlier. (Last time I checked, it seemed to be gone, but luckily I'd saved it to my hard drive.) I can't remember whether we finally confirmed its accuracy, although I think it's right. Best to double-check before relying upon it. Some of the cap values (like maybe the 8 uF?) may need to be split up into two parallel caps because the full value is hard to find in a single cap.

Z19drawing.png
 

Attachments

  • Z19 drawing.png
    Z19 drawing.png
    57.6 KB · Views: 499
Last edited:
Zilch Labs Z19 crossover board field testing

Finally the planets and stars aligned on this day after many months of deliberation - WiredBecker could bring the Zilch Labs Z19 crossover boards for testing over at my place.

We started out listening to the M19s with the original crossovers in so everyone could familiarize with the original sound. After a more than a couple of beers and bbq, we were ready to swap out the original x'over boards. Some pics below

Original Crossover ready to be ripped out

DSC_0397.JPG



Shoehorning the Z19 Crossover board

DSC_0399.JPG


Ready to fire up the amp :


DSC_0398.JPG


Eureka moment - it worked in the first try !! Mighty relieved that surgery was successful without blowing anything (even after all the beer consumption!:beer:) And there was glorious sound emanating from the Altecs.

WiredBecker celebrating with a Melon Ice Cream Bar !
DSC_0402.JPG


The Rig :

DSC_0410.JPG



Clearly, the Z19s made a vast improvement over the original crossovers as many of the Altec users who upgraded the crossovers can attest. The sound was more balanced top to bottom letting all the nuances pass thru the drivers.

Much thanks for Chris (WiredBecker) for bringing over the Z19 proto boards so we could test these out in my stock Model 19s and hanging in there thru the sweltering heat this summer Saturday. Thanks to jackgiff for designing the boards based on Zilch's design and making it available for testing.

Last but not all the least, these Z19 boards are truly a tribute to Zilch.


Whereever you are, Mr Zilch - Thank you ! Thank you ! Thank you !
 
Last edited:
I guess I better drag the parts out and build mine. I'm just going to put the HF portion together so I can try out some of the leftovers from my e-wave builds. (I still have not tried the odd shaped JBL waveguide Zilch talked me into buying. Not the Dr. Suess, but sort of tapered on the sides.)

Well, my parts bin has all the parts, but it also has a set of parts for a CC XO for my recently acquired XPL-140A's and the second one of the JBL 3110A I built today. Tapped Inductors, fun!:thmbsp:
 
tablaloops,
Looks like a good time.
The rig looks sweet.
I'm happy to see Chris and Jack are getting those boards ready for the masses.
:thmbsp:
 
You must log in or register to reply here.
Back
Top Bottom