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View Full Version : My 4430 crossover: properly split?



Russellc
12-23-2007, 11:02 AM
This is the crossover I have come up with for my 4430 project. It basically came from the JBL 4430 schematic and Zilches info on the "4430 HELP!" thread, and the parts list there.

My plan is to split the high frequency circuit from the low frequency circuit and use double binding posts for Bi wire/Biamp, and jumpers for single wire use.

I am not the most crossover savvy person in the world, but can follow a "recipe" fairly well. Just wanted to make sure this is as simple as it looks and I am not overlooking something that will prevent it from working as intended. Also, it will allow me to eliminate the switch that Zilch used, as I cant figure out how to wire it anyway! Any feedback much appreciated here.

Russellc

Russellc
12-23-2007, 11:42 AM
I am particularly proud of these NOS, (still in plastic,original box, mounting screws,paperwork,etc) 2344 horns. Much thanks to OldBlindJim!

Russellc

Zilch
12-23-2007, 11:49 AM
Looks right, yes, and I've built several of these, including charge-coupled versions. The switched version is certainly the most difficult.

Terminal 2 of an L-Pad is the common wiper connection, where you have the dot on the double-ended arrow, not the end of the resistive element. You've just drawn the connection to the wrong place on R202, is all.

For R201, I just use the series element of a 16-Ohm L-Pad, terminals 2 and 3. An 8-Ohm one also works fine is most cases, as the typical setting is in the 0 - 4 Ohm range, in my experience. I'm saying there's no necessity to hunt down a wirewound pot used as rheostat in that location.

If somebody knows something about that I don't know, I'd be pleased to be "corrected" here.

C11 is 6.2 uF in the version below; use a pair of 3 uF or a 3.3uF and 2.7uF in parallel, if you want to be more exact.

C5 is 12 uF plus 2 uF in parallel here.

I don't use bypass caps with Solens.

I removed 2 turns from ERSE Super-Q 2.7 mH for 2.6 mH, 7 turns from Jantzen 18 Ga 1.7 mH for 1.6 mH, and about 20 turns from Jantzen 20 Ga 0.1 mH for 0.04 mH. You'll have to measure to get that one accurate. Unwinding from the Jantzen 18 Ga 0.05 mH is fine, too; I just didn't write it down the last time I used that option.

You actually need only a 4-wire cable going to the L-Pads. I was stupid about that the day I built this one.

You can't see it, but the Zobel resistor is tucked down between the Super-Q and the two 12 uF caps there.

This layout is economical of space; it's just a 6" x 6" board as shown. Split N3134 is a moderately easy build, and DIY 4430 an especially rewarding project.

Beautiful butt-cheeks you've got there.... :thmbsup:

Russellc
12-24-2007, 05:22 AM
Whoops, yes I see where I misconnected the R202 wiring.....I had planned on using the PE part for both R201 and R202 as per your parts list in "4430 Help!"
thread. Seems to have worked well for you. Now I just need to have the 2225Hs reconed to 2235Hs, and decide on boxes....

Still sort of up in the air as to whether to just copy the 4430 box, or just do a subwoofer box like your thread, perching the 2344 on top. This would allow me to later add a small box between them for my 2123H mid ranges. Leaning towards copying the 4430, then later building the larger box to contain all three. Hate to leave the 2123Hs unused.

Russellc

Ian Mackenzie
12-24-2007, 05:29 AM
Russell,

Been there and done that..so has Rob.

Enjoy the journey.

Ian

Russellc
12-24-2007, 01:42 PM
Russell,

Been there and done that..so has Rob.

Enjoy the journey.

Ian

Thanks, I guess we all enjoy the journey, except the sore hands and empty
wallet part! I know very well that as soon as I have built a nice pair of 4430, then the three way, I will find a great deal on a pair of slot drivers, and will be forced to "journey" to 4 way land! Hopefully the 4430 will blow me away so that I wont see the need....but those poor 2123Hs, NOS still in the box...sort of sad. Have already gotten much info from Rob, as well as others. Thanks Rob! (and everybody)

Cheers,
Russellc

Russellc
12-24-2007, 01:46 PM
Zilch, is the charge coupled version much of an upgrade in this particular application? I know it is in general, so I imagine it is here as well. What
caps did you use in the charge coupled version, solens?

russellc

Ian Mackenzie
12-24-2007, 01:52 PM
Attempting to use the slot with the 4430 will spoil the overall result.

Best you find an aquaplas diaphragm DR82425 and a 2420 driver.

The diy system might not look as nice but is works:).

Zilch
12-24-2007, 04:32 PM
Zilch, is the charge coupled version much of an upgrade in this particular application? I know it is in general, so I imagine it is here as well. What caps did you use in the charge coupled version, solens?Solens, yes. I've never A/B's the two, actually.... :dont-know

Same deal, more caps. You can see the Zobel resistor tucked in there.

Two batteries are required if you're actually going to biamp, to isolate the LF/HF commons.

I've got the 4-wire cable on the L-Pads in this one.... :p

http://audioheritage.org/vbulletin/attachment.php?attachmentid=21501&stc=1&d=1166588174

Russellc
12-25-2007, 08:32 AM
Attempting to use the slot with the 4430 will spoil the overall result.

Best you find an aquaplas diaphragm DR82425 and a 2420 driver.

The diy system might not look as nice but is works:).

Nice speakers you have there, as usual! By using the slot, I didnt mean that I would add it to the 4430, but after I try it(4430), then with 3 way (adding 2123H, different box), then finally get the slots and build a 4344 clone, of course the 2344 would not be used on this.....I'll be lucky to get to the 3 way stage! I think the 4430 will be to my liking, having lived with the 2-way Altecs so long. The "smaller" size of it, compared to the 828G A7 boxes would be welcome!

As to aquaplas, I would very much like to try this, and have had an offer of help to do so. I have a few DR2428 diaphragms but only the 2425H motor. I'll search around a little to see why the 2420 driver is advisable, or is the 2425H fine as well?

I really like your 3 way there, wouldnt mind doing something like that, except with the 2235H bass driver. It would use all my drivers and the 2344 as well!

russellc

Russellc
12-25-2007, 08:38 AM
Attempting to use the slot with the 4430 will spoil the overall result.

Best you find an aquaplas diaphragm DR82425 and a 2420 driver.

The diy system might not look as nice but is works:).

By the by Ian, what are you using for a crossover in the DIY 3 way? I realize you have a larger woofer, but a little crossover tweaking should allow the 2235H's use when I go three way.

cheers,
Russellc

Ian Mackenzie
12-25-2007, 03:16 PM
Ah,

I made my own passive and biamp crossovers. Yes you will have to mess with it. I recommend you biamp the woofer and use the JBL 3135 filter and passive Eq as a starting point.

That is long gone and transformed into a JBL 4345 some 3 years now.

Rob did a 3 way similar to what you are thinking of.

Ian