4430 help!

[ricesinice]

I have been lurking around for a couple of weeks, and decided it was time to ask for some help. I have followed the 4430 quick and dirty thread but, it keeps going on tangents, and I have a couple of specific questions I would love to get answers for.

I have made a pair of 4430 type clones but, I used my own 12db/oct. 1khz crossover based on the dcr of the drivers, and a driverack to eq them. When playing at louder volumes, they seem to be a bit harsh. So, I am wondering if I should try to clone the 4430 crossover (is this a 18dB/oct. for the HP) to see if they play a bit smoother or just roll my own 3rd order and let the driverack do the rest? I would just bi-amp it but, that would require another amp which is not in the budget yet.

Thoughts to share?

Thanks

[Zilch]

Tangents? What tangents? :p

If you're using 2426H on 2344(A) horns, you need to clone the N3134 HP, at least, and the whole thing, HP & LP, if you're not biamping. Fortunately, that's easily accomplished.

There's more than just EQ in there. You won't get true 4430 character and performance without it, at least not so far as we have yet been able to achieve in the "Quick & Dirty" project.

I can only attribute it to "magic." Trust the Zilchster on this; it happens every time what I hook up using the factory crossover....

I can't tell you unequivocally it's better biamped, either. Having the passive crossover is essential to that appoach as well. Virtually all of those components remain in operation when biamping.

Your experience is well representative of that documented in the thread.

My guess is that the DR is pushing the 2426H too hard. Look at the published distortion curves of 4430, particularly how it's climbing exponentialy at the high end. Crank up the boost in that region, and it's gonna get outta hand mighty quick.

4430 operates at the limits of that 25-year-old technology, it seems. You have to stay within those limits for it to work. N3134 keeps you there and makes it happen in other ways, as well....

Nice lookin' stack you've put together there, BTW! :)

[Guido]

YEP!



Clone the 3134 and forget the driverack.

[4313B]

When playing at louder volumes, they seem to be a bit harsh.
I'm not sure just how loud you are playing them but the little 1" throat CD can be overdriven.

Ditto what Guido said. Bias them too if so inclined.

[ricesinice]

If I were to clone the n3134 are R210,202 available? Did I see somewhere the mid point values for these somewhere?
You are probably right about the Driverack, I used the speakers for a dance, and used it to eq the speakers flat...I was putting about 250 watts into each of these by the end of the night! The kids loved it but, I thought it sounded much better at about 3db less.

[Zilch]

R201 is a linear wirewound exposed porcelain rheostat. It's N/C past 30 Ohms (28, on one of two here). In other crossovers (e.g., 4425,) JBL used the P section of an L-Pad for this.


R202 is an 8-Ohm L-Pad. Center point is S=3.5, P=17.5. S=7 max., P=33 max. Non-standard?

4430 "0" is 3:00 on R101, range -6 (9:00) to +2 dB, 12:00 on R202, range -11 (7:30) to +4 dB.

You might be able to get the real things via JBL Pro Parts.

[Guido]

I was putting about 250 watts into each of these by the end of the night! The kids loved it but, I thought it sounded much better at about 3db less.

Sounds like a party
:dj-party:

[Uncle Paul]

R202 & R201 are in the miscellaneous parts list (N15-61390-1 & 54840). The inductors are still listed as well. Not sure if they are actually available, though.

Does anybody know the part number for the 5 pole 2 position rotary switch or know of a suitable substitute?

[ricesinice]

Well, sent mail to JBL parts to see if they have the pots, if so, I will try to go ahead and clone the crossover. I bid on one at ebay a couple of weeks ago but, it got too high for me oh well:banghead:

[Zilch]

While we say building N3134 is "easily accomplished," that's in theory. Nobody's ever put together a parts list with sources and costs here, that I'm aware of, even though several members have apparently made clones.

If the L-pad and pot aren't available from JBL parts, then standard parts could substitute, most likely. I don't think we care if the adjustment range comes out a bit different, and the "0" setting isn't at noon.

I looked at the costs at one time, and if I recall correctly, they came in a little over $100 for a pair, quite a bit less than the $565 each Pro Parts wants for them if they have them, which, when I last checked, they didn't....

[Robh3606]

The 3134's are no biggy to build. The replacement part JBL sells for the Rheostat is plain junk. Get the original or use a better potentiometer as a rheostat or run fixed values and switch them. Depending on how you want the back end of the curve to run you could drop in a fixed 4 ohm resistor as a start and just paralel up to drop the value. The inductor .04mh was available. I purchased a pair for my compensation units. That is the one inductor I would purchase from JBL to get the DCR right. Just get the pots from PE you should be fine.

Rob:)

[ricesinice]

Since I would probably order caps from Parts express I was wondering if you thought that PE lpad 260-255 would work for R202? And that sounds like a good idea just to use fixed value resistors for R201. Does anyone have the DCR's for the coils? I would like to roll my own, or reuse some of the ones I have sitting around in my basement....... can you say budget!

[Zilch]

Yes, that part will work. Again, buy two of them and use the parallel section of the second one as R201.

L102 is 0.6 Ohms according to Giskard in the "Q&D" thread, if I recall. See PE# 255-434. I'm startin' a parts list here. :D


Does anybody know the part number for the 5 pole 2 position rotary switch or know of a suitable substitute?I did find a switch, Electroswich #C4D0604N-A, but it's $20. More research required, obviously.

http://www.electro-nc.com/rotaryus/c4.pdf

[ricesinice]

Boy, I think I am going to show my ignorance here! R202 wouldn't that require a stereo L pad?With the wiper connected and opposite ends of the resistor connected to ground? Also, I don't know what you mean to use a second one in parallel for R201. Shouldn't it be 30 ohm, or a couple of resistors totaling 30 ohm, and taking the feed off of the connection between the 2?
Simple minds want to know. This is one of the reasons I didn't try to tackle this sooner.. .but now with your exceedingly nice patience, and knowledge...:)

[Zilch]

I'm confusing you, apparently. You're gonna need four of those L-Pads, total, two in each crossover.

You'll wire one in each as R202 per the schematic.

Each L-Pad has two resistive elements in it. One, the "series" leg (because it's wired in series with the driver), between pins 3 and 2, varies between 0 and 8 Ohms as you rotate it CCW. The other, the "parallel" leg (because it's wired in parallel with the driver), between pins 2 and 1, concurrently varies between ~30 Ohms and 0.

So, to use the second L-Pad in each as R201, a rheostat, you'll just connect pins 2 and 1 only. Those PE units are 50 W L-Pads, and R201 is spec'd at 25 W. Should work just fine.

Look at 4425 crossover schematic. The same type L-Pad is used for both functions there.

The rotation is backwards, though; in 4425 it's wired as a shunt. Maximum HF attenuation will be at full clockwise in N3134. If so, we don't care....

Don't worry about the ignorance thing. I get smacked here all the time; it's the only way I learn.

My TRUE pals know to wait until the edit window is closed, so's it's here en perpetuity.... :p

[Robh3606]

This is a great post Ian made a while back. Should help clarify whats going on with the pots R201, R202. R201 can be set to a low initial value as this is where the "0" range lies.

Rob:)



I will need a great German Beer to quench my thirst when I finsh the explanation okay!

I recall explaining this on the earlier forums and Rob in certainly on the money.

Starting with the 4430/4435 sensitivity, the latter is 96 db and the former is 93 db.

Thus the horn on axis response must match these levels and within the design of the overall network offer a degree of mid band level shift boost (in the case of the 4430) and cut.

Looking at the schematics, R5 effectively sets the overall sensitivity of the horn driver.

As you can see R5 is shunted across the driver and forms a voltage divider with the series resister R4 and the bandpass Eq contour network defined by R201, C9/10 and L1.

The bandpass filter provides an inverse of the mass rolloff response of the 2425/6 driver and associated 2344 bi radial horn.

The effect of the variation in values for the C9/10 in either network reflects the low pass time constant of the filter and the resulting response shape. The larger value of c9/10 in the 3135 provides more voltage peaking of the filter and resulting output in the 1-5 kertz range.

The effect of R201 is to raise lower the Hf extension by varying the Q of the filter.

The effect of R 202 is to provide boost/cut in th 2 khertz area which is attenuated to a preset level by R4.

The crossover values are different in either network to allow for summation of the drivers with the all pass 2 nd order filter, the crossover points are identical.

Because the drivers are in phase, the networks function is to cancel the resulting peak/null at the crossover point. The effect of horizontal displacement is critical for a smooth response.
The 2234/2235 may have different acoustic centres at this frequency hence the chosen values.

I hope this explanation helps.....time for a beer.

Ian
Attached Imageshttp://www.audioheritage.org/vbulletin/attachment.php?attachmentid=1484&stc=1

[Zilch]

So, R201 is not merely attenuation, it concurrently varies the time constant (and thus the slope, or Q) of the RCL filter R201-C9-L1.

I read that before, but didn't get that part until just now. Cool. Giskard's beautiful Sim is here:

http://audioheritage.org/vbulletin/showthread.php?t=3838&page=7&p=43075

[We're talkin' the yellow part.]

I think I'd rather have R201 be variable so's I could play all that stuff. :D

Note: We've got another lead on a switch through member Tom Loizeaux, looks like....

[Earl K]

Rob,

- Have you done the math that would support Ians' contentions and your assumptions ?

- In particular, the characterisation about which of the two legs ( in the HiPass Section ) is the "bandpass" circuit seems flipped from my perspective .

FWIW : & just for this one example , assume the ac impedance of the 2425/6 at higher frequencies is 7.5 ohm ,,,, parallel a 7.5 resistor with that,,, the new working ac impedance becomes 3.75 ohms ( not accurate , but will suffice in this example ).
- 1.8uf times 3.75 ohms gives 6.75 ( I've excluded the DCR of L1 ). ( 1.8 is an approximate product derived from 20uf in series with 2uf ).
- Divide 6.75 into 159000 ,, the answer is 23555 (hz ). Divide 8 into 159000 ( likely a more accurate approximation when dcr values are included along with accurate ac driver/horn impedances ) and the answer is @ 20,000 hz.
- These answers/products are the Fc points for C9/C10 in series with C7 ( in biamp mode ).

- Say the working impedance around the driver / R5 area is 4 ohms. Then 159 times 4 = 636 . 636 divided by .04 (mh) = 15900 hz. ( this would be the so called 16K shelving circuit built into the N3134 )

- This circuit is best built step by step & then measured along the way as a hands-on educational tool .

:o:

[Zilch]

Rob,

L1 and L2 are apparently NLA at JBL. Can you get us DCR's on those two, please?

I hate to tear into my factory crossovers to get them, but I will if I have to.... :(

Maybe Giskard knows, too....

[Guido]

Rob,

L1 and L2 are apparently NLA at JBL. Can you get us DCR's on those two, please?

I hate to tear into my factory crossovers to get them, but I will if I have to.... :(

Maybe Giskard knows, too....

L102 = 0.45 ohms
L1 = 0.15 ohms
L2 = 0.38 ohms

Posted earlier from subwoof :applaud:

[Robh3606]

Rob,

- Have you done the math that would support Ians' contentions and your assumptions ?

No, this supposed to be fun:p . Earl you kind of lost me in your example. Where did the 159000 come from??? I run that band pass leg without the 20uf cap and it seems to work as described. That R201 changes the contour on the top end of the range. If I am missing something please poke me in the eye:blink:

Rob:)

[Zilch]

Finding the damn resistors is the hardest part. There's only three of them (2 values, actually,) but if we want truly non-inductive, that's hard to come by.

Wirewounds are inherently inductive, but there's a non-inductive winding method (Aryton-Perry) that would be suitable. That's used in Dale type NH, but I can't find them. The Vishay Dale website is impossible.

Also, there's power thick films, inherently non-inductive, in TO-220 packages, but proper heat-sinking's not part of our typical "screw on a piece of plywood" assembly technology here.

Maybe just use the aluminum chassis-mount type RH. The two values we need are available in 25-Watt for under 3 bucks each. :blah:

Using those, the total's below for each, including the expensive switch:

http://home.att.net/~i_am_zilch/N3134_Partslist.jpg

Any crossover builders out there have resistor options or other better choices? The spreadsheet's an image I can update....

[Earl K]

- I'd suggest that one simply & fully disconnect R202 to discover what frequency information is being carried within that "leg" of the circuit.



Where did 159000 come from ?

- I realize that electronics' math isn't "fun" :( - so here's where that formula originates.

- It's from a normalized scaling applied to the standard formula for finding capacitance :
" C = 1/(2<pi> * f * Xc ) "
( * is my short hand for the multipier sign )
f = desired crossover frequency
Xc= capacitance reactance at the crossover frequency

- This standard formula results in capacitance values in Farads, which isn't entirely useful.

Normalized and scaled to deliver an answer in microfarads ( uf ) the formula becomes ;

" C = 159000/( f*Rr ) "
f = desired crossover frequency
Rr= impedance of the tweeter ( AC ohms at the crossover point )


:blink:

[4313B]

Dayton Film and Foils with Dayton Metallized Polypropylenes taste bad. Use the AudioCap Theta Film and Foils with the Dayton Metallized Polypropylenes. Also, the non-inductive resistors PE sells are perfectly fine. I'd skip the biamp switches myself.

Try biased passive, it's funner.


Finding the damn resistors is the hardest part. There's only three of them (2 values, actually,) but if we want truly non-inductive, that's hard to come by.


Wirewounds are inherently inductive, but there's a non-inductive winding method (Aryton-Perry) that would be suitable. That's used in Dale type NH, but I can't find them. The Vishay Dale website is impossible.

Also, there's power thick films, inherently non-inductive, in TO-220 packages, but proper heat-sinking's not part of our typical "screw on a piece of plywood" assembly technology here.

Maybe just use the aluminum chassis-mount type RH. The two values we need are available in 25-Watt for under 3 bucks each. :blah:

Using those, the total's below for each, including the expensive switch:

http://home.att.net/~i_am_zilch/N3134_Partslist.jpg

Any crossover builders out there have resistor options or other better choices? The spreadsheet's an image I can update....

[Zilch]

Thanks, Giskard. Thetas it will be.

Maybe I look a little more for the Dale NH resistors before doubling up using PE's.

Any suggestions on the inductors, or are they "close enough?"

L1 should be 20 or 22 Ga., looks like, but PE don't offer that.

Shall I hunt more for the 14 and 6 uF MPP capacitors?

A 10 anna 4 for 14 and a 2 anna 4 for the 6, maybe?

Biased passives gonna be another list. :p

[Robh3606]

"I'd suggest that one simply & fully disconnect R202 to discover what frequency information is being carried within that "leg" of the circuit."

I did I opened up one of the CC networks and cut the leg and the 1.2K-4k response just dropped out by several dB.

Rob???

[4313B]

What about http://www.partsconnexion.com/catalog/resistors.html? Anything there you like? Also maybe something here? http://www.percyaudio.com/

I'd get as close to the schematic values as possible. Buy inductors one size larger and unwind to spec.

Why are you doubling the resistor power handling over stock? The Mills 12 W aren't enough?

[Earl K]

Nice Work Zilch !

Good List :) I too would recommend "DC-Biasing" as a significant "step-up" that will give better sonic results.

- If money is an issue because of DC biasing, I'd still spend the money on the extra caps ( at least in the horn circuit ) while delaying ( or cutting back ) spending in the UHF contour circuit. ie; I'd build the UHF circuit without R201 ( and possibly L1 ) . If it turned out there really was too much UHF information present ( from a 2426 ? ), then at that time I'd spend the money on those parts.

:cheers:

[Earl K]

I did, I opened up one of the CC networks and cut the leg and the 1.2K-4k response just dropped out by several dB.

Thanks Rob for demonstrating that the "purpose" for that circuit leg ( in which R202 is located ) - is to "restore balance" to the horns' lower midrange frequencies. This particular frequency range has been severely depressed in the other ( UHF contour ) circuit leg.

Of course, if a person knew their own preference for "midrange balance' - then R202 could be omitted & replaced by either 2 or 3 resistors ( depending on if a person wanted an Lpad or Tpad ).


:cheers:

[Zilch]

Why are you doubling the resistor power handling over stock? The Mills 12 W aren't enough?Because me STOOPID yesterday. :banghead:

Factory board uses 10 Watt el-cheapos. Percy Audio DOES have the Dale chassis mount ones I was lookin' for, tho....

I've updated the parts list to reflect forum recommendations. Hit "ctrl + refresh" if your cache still says $88.34 total. Giskard spent our money on better stuff. Biased version wouldn't be much more, probably, since it wouldn't require them expensive bypass caps (though it looks like Rob used 'em anyway from his pic, above).

Right click the spreadsheet and hit "Print Picture" for a working hard copy.

I also independently confirmed DCR measurements of the inductors using 3-point resistance measurement at 400 mA.

L1 = 0.143 Ohms
L2 = 0.429 Ohms
L102 = 0.507 Ohms

Subwoof's numbers are good! :p

I'd say the parts list is good to purchase. Parts Express doesn't list the 7.5 Ohm Mills resistors, but they may have them. If not, go to Parts Connection for both them and the 20 Ohms.

Building for just biamp cuts the cost in half, or if you can do without the biamp option, knock out the switch, C7, and C8 to cut it by a third.

The only item in question is L1 with too low DCR. Maybe put a resistor in series with it, 0.06 Ohms? I do find them in surface-mount metal strip and wirewound versions, about $1.50. That's more like a fuse, actually.

We're lookin' for similar for the AM crossover in the "Q&D" thread, so if anybody has a lead to smaller-wire low vaue inductors, please post it.

I think I'll build these for the updated constant directivity L200's, maybe. I'll have to change the diaphragms in the LE 85's; they likely need it, anyway. I maybe use the aluminum C8R2421, though they're kinda "dear."

Here's what the board actually looks like, including the cheap switch. It's downright silly how these few components make such a HUGE difference. These are revision "E", 1989, from what it says on 'em. Missing components would convert them to N3135 for 4435 :D :

[Guido]

I prefer this style :D

Actually its a 3135 clone!
I think it looks more "reliable" than the originals.

[Guido]

The only item in question is L1 with too low DCR. Maybe put a resistor in series with it, 0.06 Ohms? I do find them in surface-mount metal strip and wirewound versions, about $1.50. That's more like a fuse, actually. :

Yeah! series resistor will do it. Or just forget about that as you anyway have the rheostat in series.

[Zilch]

Goodo JOB, Guido. You set a standard for the rest of us. :p

I have some fiberglass Vectorboard here, so I may build like Rob did. Just gotta find the pins....

Point being, nobody who can handle a soldering iron should feel intimidated about building these themselves.


Yeah! series resistor will do it. Or just forget about that as you anyway have the rheostat in series.That's what I thought at first, too. But, I looked again, and the rheostat and inductor are separated by the capacitor, so it's not the same.

Best answer is the proper smaller-wire inductor (22 Ga. air core, looks like), of course, but for now, I'll order some of them tiny resistors....

[Edit: Spreadsheet again updated, parts ordered. All in stock except 1.80 mH coil, B/O. I bought the PE 260-274 dual faceplate with 260-252 L-Pads instead, tho, for a little upgrade. :p ]

Who knows a source for these 0.04 mH inductors? This is the laminate-core version, 20 Ga.:

[Note proprietary "Gob o' Snot" mounting methodology.... :D ]

[Zilch]

In the context of what these are selling for, DIY is not the most economical route.

BUT, ours're gonna be better! :p

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=61377&item=5762120683&rd=1

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=79840&item=5757445158&rd=1

Who the Hell is parting out 4435's? Sheesh!!!

I'm not ignoring everyones' suggestions to do the biased version. Just wanna see how doing it straight works, first.... :)

[Mr. Widget]

"Point being, nobody who can handle a soldering iron should feel intimidated about building these themselves."

Sorry to bring it up, but I inferred from your post on the 2403 thread that you can't handle a soldering iron....;)

Widget

[Zilch]

Nope, soldering's not a problem. It's screwdrivers (and Sawzalls) that get me in trubble.... :D

These, too:

[Zilch]

$20 enclosed rotary switches are higher quality than used in factory crossovers. Actually 6-pole 4-position, simply moving the shaft stop converts them to the 2-position operation we need.

Rated 0.5 A switching and 15 A continuous, they should work fine in this application. That'd be 1800 W across 8 Ohms. It'd take 120 V to do it.

They could also be used to switch other options in and out, as well, though I can't think of any right now. :p

Our other lead on a switch turned out to be $119 each and a minimum $500 order. Nope.

Having the 6 poles, they could also serve N4333 (6 circuits) and possibly other int/ext switching needs as well.

1.5" across the terminals, 1/4" shaft with knob flat. Low value metal strip resistors, rear:

[Uncle Paul]

Thanks for dogging those rotary switches down :)

[ricesinice]

Well, thank you guys for getting me on the right path. I ordered a bunch of parts from Parts Express, and wound my own coils (almost to dcr specs!). Finished one and hooked it up, and the sound is better than my own homebrew crossover. I did notice that the speakers sounded, and measured best with pot R201 all the way over to about 1 ohm resistance. So, if you are having a hard time with that part you really might think about using a resistor in place of it.

Now on to building the second crossover!:applaud:

[4313B]

So, if you are having a hard time with that part you really might think about using a resistor in place of it.Good point. Those things have sufficient slop in them that a set of fixed 1% resistors might be a nice option. Something like how the straps are on the UHF of a 250Ti. Four levels set at 1 dB or 1/2 dB increments maybe. I believe the S9800 is 3/4 dB increments but I can't remember for sure. Whatever.

[Zilch]

I ordered a bunch of parts from Parts Express, and wound my own coils (almost to dcr specs!).How about providing us a little tutorial on winding our own inductors, with pics, of course, posted here?

Please also provide recomended types, sizes and sources of wire, coil forms or bobbins, etc. :D


I did notice that the speakers sounded, and measured best with pot R201 all the way over to about 1 ohm resistance.Yup, "0" is nearly full on....


Finished one and hooked it up, and the sound is better than my own homebrew crossover.You musta got the "magic" part right! :p

[We want PICS!]

:useless:

[Zilch]

Laying out my DIY N3134's, I have come up with additional options for the two surplus positions on the switch, which derive from work experimenting with various applications of it here:

#1: Passive per original.

#2: Biwire - splits the LF and HF sections without changing out any components. Good for separately driving the two sections with multiple amps. Zilch runs this way with Q=2 bump at 25 Hz on UltraCurve.

#3: Biamp per original. Use external 5235 crossover with 4430/35 cards or other, as desired. Zilchster preferred configuration using 5235 bump filter.

#4: Drivers only - well, not really. Leaves the 20 uF in series with the compression driver for protection against mishaps below 1 kHz (a Zilch exclusive). Bypasses the Zoebel in the LF, tho, per N3135. For users who just MUST exercise their parametric EQ's. :D

Anybody have other suggestions for this switched options upgrade?

[Ian Mackenzie]

Thanks Rob for demonstrating that the "purpose" for that circuit leg ( in which R202 is located ) - is to "restore balance" to the horns' lower midrange frequencies. This particular frequency range has been severely depressed in the other ( UHF contour ) circuit leg.

Of course, if a person knew their own preference for "midrange balance' - then R202 could be omitted & replaced by either 2 or 3 resistors ( depending on if a person wanted an Lpad or Tpad ).


:cheers:

The actual theory of operation is quite intuitive, particularly if you have a chance to read the white paper on the 44xx published in the early 80's AES.

About two years ago now Robert Hamel an I reverse engineered and tweaked the arse out of these networks to get the desired results with the 2122H / 2123H mid cone , which I might add is impressive at least down in Robert's cellar I thought so! But then again all Robert's diy systems are Fab.

The attached files show my system and the resulting curve....I would love to tweak this network for a Tad 2001 some day. The curve here is that of the DR2425 dia used with the 2420 alinco driver. The network to the 2122H used 3135 crossover which is a special 2nd order filter with minimal group delay, the 2122H (or 2235 ) and the compression driver are " IN PHASE".

I recall publishing a number of graphics in PC paint to explain the action of the variable pots in one of the earlier forums. The effect of the Pad in the 2 khertz area is mid presence, I prefered it nearly up full most of the time, this gives nice holograhic centre image.

However, for those keen enough to build up clones you are best served with an analyser (Gated) to adjust the overall response for a flat curve extending to 16.5 khertz or so.

Ian

[Guido]

Nice calendar Ian ;)

I like the 2344 / 2122 Combo.
Ooops and the 2245 of course.

[Ian Mackenzie]

That's my darling Elle, our super model.

Ian

[Zilch]

Complete N3134 from parts list above fits neatly on 7" X 7" board, LP top, HP bottom. We're backordered on one inductor which goes at lower left. Won't get to hear them for 30 days, alas. :(

The requisite four input terminals will enter from the rear in the space along the left edge. Switch shaft extends out the rear panel as well. It's located where the action is to keep the leads short:

[Zilch]

Done. About 8 Hrs. apiece, incuding "figurin'" time. :) :

[JBLnsince1959]

Zilch:

looks very nice..... so, how does it sound? Also, do you have a stock crossover to compare this to ( if I missed that part excuse me)

[Mr. Widget]

Zilch:

looks very nice..... so, how does it sound? Also, do you have a stock crossover to compare this to ( if I missed that part excuse me)

He does, both in 4430s and extras that he bought. Which brings me to my question. Why did you build these? "( if I missed that part excuse me)" to.

Widget

[Zilch]

Zilch: So, how does it sound? Well, suffice it to say the "Magic" is there.

I haven't tuned L2 (P.E. Jantzen 1.8 mH vs. factory 1.6 mH) or L102 (2.7 mH vs factory 2.6 mH) yet, but they sound very much like factory originals.

Bottom line: if you want 4430 using 2344A, 2425/6/7, and 2235, you gotta build them crossovers, or at least those portions of them you intend to use.

I do have factory stock units I want to compare with them, before and after retuning, and the simple N200T3's I built at Giskard's suggestion, a more easily constructed "Suh-weet" substitute. We'll see over in the "Quick & Dirty 4430's" thread how they all measure up.



Why did you build these?
1) I'd have to reconfigure my factory crossovers to split them to play in the "Biwire" mode, which I use most often. That's all of the components in both the LF and HF sections, each running on separate amps, not an available option on the original crossovers. The six-pole switch I found permitted me to add it.

2) By the time I'd have also replaced the inductors with air cores, replaced the mylar caps with metalized polypropylenes, and upgraded the bypass caps to Thetas, all that would have been left was the el-cheapo resistors to change. It made NO sense to rework the factory ones. I could make better boards than the one-sided phenolic ones they used originally anyways.

3) I repeatedly found myself advising others doing DIY 4430's on the forum to build the crossovers, but had never done it myself. It's easy to say, but what are the contemporary parts and sources? HOW to assemble them? Will they sound as good? Will the 4430 "Signature Sound" be there? What do we use for the HF rheostat? Only one way to find out -- build 'em.

4) All the info is here, now, except the coil tuning, which I'll add after I do it. I can advise with confidence on this matter now.... :p

[Mr. Widget]

OK, so you built these to allow you to "upgrade" the components and facilitate bi-wire. I guess I would have wanted to replace one part at a time to see where and if any real improvements occurred. Should be an interesting comparison none the less.

Bi-wiring? You buy into that huh? I'm not convinced... what's that state's motto? Show me? ;)

Widget

[Zilch]

Bi-wiring? You buy into that huh? I'm not convinced... Well, it's not biwire in the conventional sense, although that's possible in this configuration as well. I'm running HF and LF on separate amps.

That's biamp, actually, but in the standard 4430 context, using the "ext" option, external crossovers and EQ are also required.

I think we can agree that "biwire" in this sense is a worthwhile option.

BTW, did you run tests on that 6260 I drug over there yet? :p

[That's my standard LF amp. Another nice one just came up on eBay last night. Don't need any more here, fortunately, or I'd be biddin'....]

[4313B]

I guess I would have wanted to replace one part at a time to see where and if any real improvements occurred.There are three parts worth using in the stock 4430 or 4435 network and they would be the 30W ceramic rheostat, the 50W L-Pad and possibly the 0.04 mH air core inductor.

[Zilch]

We found what may be a good replacement for the 0.04 mH inductor, Jantzen #1806, 0.24 ohms, 0.50 mm wire.

P.E. can get them, but it's 8 to 10 week lead time.

Any forum members in Denmark near the Jantzen factory what can get us a pair of samples to test? PM me if so.

Guido's checkin' into availability direct, since we also need them for AM crossovers used with 2431H. Once we check 'em out, we'll likely order up a bunch here. :D

In the meantime, if anybody wants a pair of the precision 0.06 Ohm metal strip resistors I bought to use with the Jantzen 0.05 mH, 18 AWG, 0.09 Ohm inductors, PM me. I bought 10 to meet order minimums, only used 2 so far. See parts list above....

Edit - Two footnotes:

1) I ended up using the series section (between pins 2 and 3) of the second L-Pad as the HF rheostat R201. Since the original 30-Ohm rheo "0" is at very low resistance, adjustability between 0 and 8 Ohms is good enough, with better resolution. AND it cranks in the "right" direction. :p If you want more adjustability, use the series section of the also available (Parts Express) 16-Ohm version instead.

2) The two large inductors L2 and L102 are only 1-3/4" apart in this layout; best practice would be 3" or more. However, considering their functions in the circuit, it's apparent that any LF crosstalk between them is shunted to common. I also looked at contemporary JBL crossover layout practice and find that they violate this "rule of thumb" routinely. Finally, they are at right angles to each other to minimize inductive coupling. I'll measure them on the oscilloscope to verify my assumptions here....

[Guido]

Guido's checkin' into to availability direct, since we also need them for AM crossovers used with 2431H. Once we check 'em out, we'll likely order up a bunch here. :D

I'm currently fighting with Intertechnik as they ignored my inquiry. As I'm a very good customer of them I'm sure to bring them "back on track" soon :D

[Zilch]

I guess I would have wanted to replace one part at a time to see where and if any real improvements occurred. Should be an interesting comparison none the less.Once I get these tuned, we'll do a double-blind A/B/C test. I'll put them in a pair of 4430's, another pair with their factory crossovers, the upgraded L200's, and relays to switch the same amp and source among them.

Your place or mine? :p

[Zilch]

Some adjustment of all three inductors is required to bring them from stock Jantzen values purchased from parts list to schematic specifications. It's best to have an LCR meter to get them "spot on," but here's the adjustments that were required with these particular units:

1) L1 - removed 5 turns from outside to reduce Jantzen 0.05 mH to 0.04 mH.

2) L2 - removed 14 turns from outside to reduce Jantzen 1.8 mH tp 1.6 mH.

3) L102 - removed 6 turns from outside to reduce Jantzen 2.7 mH to 2.6 mH.

The resulting sonic character was "crisper," though playing them without the adjustements was fine, too. The change was not major.

Best tool I found for removing enamel from the cut ends to tin and solder: an emery board.

RTA measurements here:

http://audioheritage.org/vbulletin/showthread.php?t=3838&page=26&p=53444

[Zilch]

Two updates:

1) Jantzen #1318 seems like a better choice for L1 here, 0.047 mH, 0.17 ohms. Unwind down to 0.04 mH, and the resistance will be correct at 0.15 ohms without additional low-value series resistor. Probably available in Europe (made in Denmark), special order at Parts Express.

2) Crosstalk matters. Keep big L102 at least 3" away from the other inductors, and orient to minimize inductive coupling....

[Russellc]

Finding the damn resistors is the hardest part. There's only three of them (2 values, actually,) but if we want truly non-inductive, that's hard to come by.

Wirewounds are inherently inductive, but there's a non-inductive winding method (Aryton-Perry) that would be suitable. That's used in Dale type NH, but I can't find them. The Vishay Dale website is impossible.

Also, there's power thick films, inherently non-inductive, in TO-220 packages, but proper heat-sinking's not part of our typical "screw on a piece of plywood" assembly technology here.

Maybe just use the aluminum chassis-mount type RH. The two values we need are available in 25-Watt for under 3 bucks each. :blah:

Using those, the total's below for each, including the expensive switch:

http://home.att.net/%7Ei_am_zilch/N3134_Partslist.jpg

Any crossover builders out there have resistor options or other better choices? The spreadsheet's an image I can update....

Just thought I would bump this up w/ a question for Zilch....I ran all these part numbers with the suppliers, the caps are still the same price, the coils have gone up, but are still available. Two parts gave me trouble. One, the rotary switch. Newark didnt show it under that part number, but when I searched the electroswitch factory part number, (on the Newark site) it came up under #06M4599. Problem is, it is described as a "3 PDT" while your original list calls it a "5 PDT".....will this make a difference? Next, the metal strip resistor by Vishay-dale. I think I found its new newark number as WSR2R0610FEK. It's a .061 ohm, 2 watt, series WSR, with package case 4527. Is this the same part? Thanks, If I can just source some 2344s I will be ready to proceed. Any idea on where to source two? Jammin jersey has some, but dont do pay pal or plastic for whatever reason.

Russellc

[Zilch]

If you look on the Newark catalog page, the switch is 6 poles, actually, a double stack of 3 poles, and you set the stop for anywhere between 2 and 4 positions. I used three positions, and 5 of the 6 poles, as I recall.

http://www.newark.com/jsp/level5/module.jsp?moduleId=en_US/5050.xml

So, the correct current Newark part# is 06M4599

You can forget about the Vishay-Dale resistor. Guido was right, it's not necessary, since the variable resistance makes up the difference, notwithstanding whether it comes before or after. If you want to use it anyway, PM me your mailing address, and I'll send you a couple.

[Russellc]

If you look on the Newark catalog page, the switch is 6 poles, actually, a double stack of 3 poles, and you set the stop for anywhere between 2 and 4 positions. I used three positions, and 5 of the 6 poles, as I recall.

http://www.newark.com/jsp/level5/module.jsp?moduleId=en_US/5050.xml

So, the correct current Newark part# is 06M4599

You can forget about the Vishay-Dale resistor. Guido was right, it's not necessary, since the variable resistance makes up the difference, notwithstanding whether it comes before or after. If you want to use it anyway, PM me your mailing address, and I'll send you a couple.

I sent you a PM, I may have another question about how to hook up these switches when I get them.

Thanks in advance,

Russellc

[JoMoCo]

Bump, to help make more accessible to those of us with applicable projects.

Note google search located it. :dancin:

LH search.... :blink:

[Zilch]

COOL!

Now, nearly five years later, I still use them.

In retrospect, asked to build them for someone else, I would force a decision as to whether an active, passive, or biwire version was desired and forgo the switching. I'd also use the ERSE "Hi-Q" laminate inductor for L102, as I have done many times since.... :thmbsup:

[Zonker92]

I'm startin' a parts list here.

Reviving this old thread, does anyone still have the parts list that apparently used to be here? I'm toying around with the idea of building some outboard biased 4430 (N3134) networks, split into LF and HF.

I have the caps, L pads and resistors figured out pretty well; those aren't rocket science. (From Parts Connexion I'd get Mills 7.5 ohm 12W (x 4) and 20 ohm (x 2) for the resistors, and from PE I'd be doubling up the numbers and capacitance of the 2, 6, 12 and 14 uF caps, and getting four 50W 8 phm L Pads (PE 260-252 or 260-255 L pads). Then I'd just need some 9V battery clips (PE 140-982; one for LF and one for HF) and some 3 (?) megohm resistors, for charging. I'm inclined to use Jantzen (metallized polypropylene) 400V Cross-Caps without bypasses for the capacitors; not too expensive.)

I also think I'm OK with L102 (2.6 mH; 0.507 ohms DCR) (Zilch suggests PE# 255-434 (Jantzen 2.7mH 15 AWG) - he removed 6 turns from the outside to reduce it 2.6 mH.)

But L1 and L2 seem a little problematic, so:

- As to L1, it should be 0.04 mH (0.143 ohms DCR) – The OEM part from an old 2001 parts list is 61014-0R04 ($11.19) --apparently it was listed under “miscellaneous” –- but does JBL still sell it? I guess I can ask them. Alternatively, Zilch said this coil should be 20 or 22 gauge - He suggested Jantzen #1318; 0.047 mH, 0.17 ohms. He said to unwind it down to 0.04 mH, and the resistance will be correct at 0.15 ohms. But I can't find this anywhere in the U.S. Maybe I should use PE 255-200 (Jantzen 0.05 mH 18 AWG (0.09 ohms DCR)) and add a small resistor in series?

- As to L2, it should be 1.6 mH (0.429 ohms DCR). I could opt for a Jantzen 1.8 mH and unwind it to 1.6, but which version: The 15 AWG (0.42 ohms) or 18 AWG (0.74 ohms)? (PE 255-264 or 255-428). (Zilch removed 14 turns from the outside to reduce the Jantzen 1.8 mH to 1.6 mH.)

- I guess a simpler question is whether after the I get the inductance correct on a coil, I can simply adjust (add up to) the DCR with a resistor in series and have it perform exactly the same as hitting it perfectly with the coil alone.

- Also, how much is an adequate multimeter that reads inductance? My cheapo does not.

- And is it worth springing for fancier caps like Audiocap Thetas, for the smaller values (2 and 6 uF; doubled up in value and number for biasing)? That could add some major expense.

Thanks!