JBL 4430 Speakers

[Dave 2021]

Greetings,

I am a new member here and I wanted to apologize up front for posting something that has probably been discussed many times already. Seems that I can't quite get the hang of the search engine on this forum. Basically, I bought a pair of 4430's and really have been enjoying them. They are not perfect but do a lot of things right, almost to the point of being magical. I have made some minor tweaks that seemed to make a difference (deoxing the bi amp switch on the crossover board and replacing the speaker wire terminals with gold plated binding posts) and now am contemplating upgrading some of the internal crossover components. Would it be worth it to upgrade the iron core 2.5 mH inductor for the woofer with a good air core inductor? I was able to find the network diagram here on this forum but the diagram does not list the DCR for any of the inductors. Anyone here know those values? I have replaced iron core inductors with air core inductors on other speakers and there was not a gigantic difference. I just wonder since the 4430's cross over at 1000 Hz. Also, I was thinking about replacing the .01 uF bypass caps with some sonicaps. I really don't want to go the route of bi amping, charge coupling or using external crossovers. The sound to my ears is actually very good, I just wanted to try some relatively inexpensive but effective ways to get them sounding even better. The real question is that after I post this, will I be able to find the responses (if any) in the forum!

Thanks,

Dave

[BMWCCA]

Greetings,

I am a new member here and I wanted to apologize up front for posting something that has probably been discussed many times already. Seems that I can't quite get the hang of the search engine on this forum.

Welcome.

Basically, it is better to use Google Advanced Search using "audioheritage.org" as the search domain.

This thread might help you: http://www.audioheritage.org/vbullet...ecapping-4430s

[Dave 2021]

Toddalin, thank you for pointing that out. I have no experience with smaller value resistors and I am chomping at the bit to get all the parts to get this project going. I was not familiar with a Mega Ohm resistor and failed to get the right google which said mega was 1000 instead of 3 million!. Anyway, I am fortunate enough to have people like you who can set me straight on the right resistor. Thank you for that my friend! Also, Ian, I would be happy to supply you with a bottle of Knob Creek. You mentioned you visited Bardstown, Kentucky awhile back? I actually now live in Kentucky having relocated from a bigger city several years ago. I live out in the country in a small town that has no traffic signals and I have some land and room to breathe. Come to think of it, I have room to let my JBL's breathe and can hit 100 dB's continuous with 110 dB peaks without bothering any neighbors. It can go louder without any harshness but I am trying to preserve my hearing (and my marriage). I wanted to upload a picture of my rig with the 18" subwoofer and 4430's but go figure, I can't figure out how to do that either yet. I think I can handle the wiring now that I know it all goes back to one battery. However, I was thinking, since I am doing this, I will separate the woofer crossover from the horn crossover and bi amp using the four posts on my amps, unless that is not recommended. If I do this then I would need (2) 9 volt batteries for each speakers independent hi/low networks? I am all ears and if you think keeping it all as one network then that is the way I will go. Now comes the final decision of caps. I have used Solen's in the past with Polk Audio signature SDA's, Bozak B4000 modern symphonies and ESS AMT-4 speakers. All to good effect. But, Clarity caps keep coming up. And if I do Clarity caps bypassed with Auricaps then that adds additional work. Plus, I am assuming you don't add the bypass caps to the charge coupled 9v battery, just add to either end of the coupled series caps at the far ends. Whew, my head started spinning on that one. So bottom line, can I get a great result with the Solen's or should I soldier on through and do the Clarity caps with bypass? I am willing to spend the extra money if it will get me to the world class sound that eagerly awaits! Also, thanks for your patience with all my questions!

[Ian Mackenzie]

Hi Dave,

If your power amp had 4 binding posts per channel then l think you are referring to what is termed “Bi - Wiring. This is where the full passive crossover is used but separate wires lead back to the power amplifier for the input to each low and hi pass filters

I would only consider this a virtue if you have longer than 2 metre cables to the loudspeakers. Short stout loudspeaker cables and high quality binding posts and spades with large contact area are important in ensuring you have a low contact resistance with hi current transfer across the contact area. It’s also reliable.

On the capacitors l would go with the Solen 250V Fast Caps and Charge Couple. Use a single battery if you are using a common power amplifier to each loudspeaker. You will most likely be very happy. If that option is unavailable to you consider the Clarity Cap and the Auricap combo.

On the resisters to the battery anything from 2.2 meg ohms to 3.3 meg ohms will work fine.

The low dcr on the woofer inductor is a virtue and will make your outlay on the binding posts worthwhile.

[Dave 2021]

Thank you for kindly directing me to the relevant posts with very good information. Geez, I had no idea the 4430 had mylar caps. After reading, I have decided that the best route is to go ahead and make a new network a bit at a time and leave the stock one in in case I ever sell. The charged coupled crossover has me very interested and I will probably go that route. I believe I read somewhere that when charge coupling, you can get by with less expensive poly caps with good results. Dayton makes a 1 % tolerance poly cap that I have had good results with in the past. I guess Hovland's are no longer available and Sonicaps can get a bit expensive. Would it be correct to assume that bypass capacitors are not needed when charge coupling? And then there is still the question of the DC resistance for the inductors. Perhaps it is not a big deal but I remember reading an article by Gregg Timbers at this site discussing improving the network for the 4345 and he mentioned it would be best to match the DCR of the existing inductors if replacing. The same logic would apply to the 4430's. I am assuming someone has posted a network diagram with charge coupled caps somewhere and hopefully bypassing the L-pads.

[Ian Mackenzie]

Thank you for kindly directing me to the relevant posts with very good information. Geez, I had no idea the 4430 had mylar caps. After reading, I have decided that the best route is to go ahead and make a new network a bit at a time and leave the stock one in in case I ever sell. The charged coupled crossover has me very interested and I will probably go that route. I believe I read somewhere that when charge coupling, you can get by with less expensive poly caps with good results. Dayton makes a 1 % tolerance poly cap that I have had good results with in the past. I guess Hovland's are no longer available and Sonicaps can get a bit expensive. Would it be correct to assume that bypass capacitors are not needed when charge coupling? And then there is still the question of the DC resistance for the inductors. Perhaps it is not a big deal but I remember reading an article by Gregg Timbers at this site discussing improving the network for the 4345 and he mentioned it would be best to match the DCR of the existing inductors if replacing. The same logic would apply to the 4430's. I am assuming someone has posted a network diagram with charge coupled caps somewhere and hopefully bypassing the L-pads.

https://audiokarma.org/forums/index....pgrade.537606/

Jbl don’t bypass the Solen 250v Fast Caps in the charge coupled crossovers. I would not recommend other caps without experimentation.

The woofer coil dcr is 0.5 ohms or less.
The horn crossover coil is 0.5 ohms. The small coil is 0.2 ohms.

I recommend you use air core inductor.

The Lpads are required for adjustment of the horn midrange level and HT is extension.

Simply double the capacitors values and wire them in series for charge coupled operation. Use 3 Meg ohm resistor from the junction of the two capacitors to a 9 volt battery and return the crossover ground to the negative terminal of the battery.

I have used Hovland capacitors quite successfully in this design. The caveat is your power amplifier, preamp and source need to be of premium quality such as a Parasound to experience the benefits of these capacitors.



There are other modifications such as removing the 2235H mass ring and re optimising the passive network for improved midrange clarity and some electrical bass boost at 30 hertz. The mass ring as the name suggests adds mass to the cone of about 35 grams to optimise the bass performance in small enclosures. However this impacts on the midrange clarity above 500 hertz. It’s quite audible wh we n compared to the larger 4435 which used the 2234H driver variant without the mass ring.

[Dave 2021]

I love my JBL 4430 speakers. All I wanted to do is try to improve them if possible. All the post about charge coupled crossovers or anything are really just arguments. Really hard to discern if there is any useful information to be found here. If anything, I asked just one question if anyone here knew the DCR of a 2.6 mH iron core inductor in a 4430 crossover (revision H), and nobody responded or nobody cares or nobody knows. I guess this information is proprietary or something and you have to go to an outside source to get suggestions on what works or not. Or I guess that the 4430's are subpar to the whole JBL crowd. Thanks again for all your help.

[Mr. Widget]

..and nobody responded or nobody cares or nobody knows.

There are probably folks here that do know or could find out, but unfortunately the two folks who would have had that info burned into their brains are no longer posting, one passed away and the other has moved on to other interests.

Be patient and perhaps someone else will be able to step up.


Widget

[Earl K]

Some regulars might not even see this thread > since it's so misplaced and visually buried down in the roll-call .

Normally when one owns the actual part needing a spec ( like the 2.6mH coil in question here ) it's best to simply measure it for ones-self ( un-solder one end first to take it out of the circuit ).

[Mr. Widget]

Some regulars might not even see this thread > since it's so misplaced and visually buried down in the roll-call .

Good point... I didn't even pay attention to that. I'll move it.


Widget

[Dave 2021]

Hi Ian (Master Yoda),

My beloved tripod droid was not able to project the holographic image of the plans as when I clicked on the attachment, I just received a picture of a paperclip. Then CP3O was babbling something in the best English accent his A.I self was able to muster but alas, I could not get to the projections. I will be sending some wupiupi or perhaps nova crystal your way and perhaps that will unlock the secret plans. I will most likely require some additional instructions as the l-pad instructions through me for a bit of a loop. Something that is readily available at parts express? And then there is that electrolytic cap somewhere in the mix. I am taking a deep breath and calling on the force for patience and determination! But the force has told me to trust, and that I will do so be on the lookout for the wupiupi.

Thank you,

David Mark

[Riley Casey]

The crossover schematic displays for me. Perhaps check your user settings on the forum or maybe a different browser. BTW, great inductor symbols Ian. What software is that?

Hi Ian (Master Yoda),

My beloved tripod droid was not able to project the holographic image of the plans as when I clicked on the attachment, I just received a picture of a paperclip. ...
David Mark

[toddalin]

Hi Ian (Master Yoda),

My beloved tripod droid was not able to project the holographic image of the plans as when I clicked on the attachment, I just received a picture of a paperclip. Then CP3O was babbling something in the best English accent his A.I self was able to muster but alas, I could not get to the projections. I will be sending some wupiupi or perhaps nova crystal your way and perhaps that will unlock the secret plans. I will most likely require some additional instructions as the l-pad instructions through me for a bit of a loop. Something that is readily available at parts express? And then there is that electrolytic cap somewhere in the mix. I am taking a deep breath and calling on the force for patience and determination! But the force has told me to trust, and that I will do so be on the lookout for the wupiupi.

Thank you,

David Mark

Try this...,

On the picture of the paperclip. "right click" your mouse and select "open image in a new tab" and do so. This is what I have to do to see my pictures when posting JBL Heritage images in the AudioKarma forum.

[Dave 2021]

Ian, thanks again for correcting me. Yes, big difference between bi wiring and bi amping. My mom always used to tell me that I wasn't the brightest bulb in the pack and not the sharpest tool in the shed but if I said please and thank you enough, people would take pity on me and help me . Seriously though, I feel like I am a young Luke Skywalker and you are Yoda and we are at the swampy lake trying to raise the X-Wing Falcon out of the muck. Except this time, the young Luke might have a chance. Much thanks Master for your help and patience. I did indeed order inductors as you suggested and especially the Erse Super Q's for the 2.5 oHm values. I got all inductors for under $100 from Parts Express. I guess the Super Q's are on backorder but were supposed to be in today on 11/5. Who knows, I thought Erse were made in the U.S. so probably not held up somewhere on a dock or slow boat from China? And now I know that Solen's are the way to go so I am going to look into ordering direct from Solen. Probably off topic here but I wanted to mention that I have found a bit of upper base extension by blocking off one port of the 4430's. Had my wife crochet a 4" round web around some acousta stuff. Very subtle but seems to make a difference. Also, I wanted to mention that these speakers achieved the WAF because I don't just listen to them loud, I can listen to them at sub 70 dB levels at night and they still retain their definition and detail. At one point I was going to sell them and my wife said, no, why don't you hold on to them. Ha, that says a lot! Anyway, so where do I deliver the Knob Creek? You have deserved it! Or if you are up for it, how about a phone call? Finally I clicked on a link of the pictures of the JBL speaker Hall of Fame from your posts. Holy Crap, I thought I was at the Kendrick website. Man, if I ever win the lottery, I will buy all of them! Are all those your speakers? I am greatly humbled and awed at the same time. Cheers!

[Ian Mackenzie]

Hello young Skywalker,

Below is a drafted up schematic that should take your 4430 system well past light speed!

Don’t tell anyone l told you so because they might feel precious over their stock 4430’s.

Some notes for your mission should you choose to accept it.

1. The variable resisters are in fact two separate mono 8 ohm Lpads.

The 30R variable resister is the parallel arm of an 8R Lpad. See the terminal numbers for correct connection. Not it is wired as a variable 30R resister. I suggest you use a multi meter to verify you have the correct terminals on the Lpads. Many Star Troopers have fallen foul of incorrect Lpad wiring.

2. The 8R variable resister is wired up as a constant impedance 8R Lpad. See the terminal numbers for correct connection.

3. You will need to order 4 mono 8R Lpads,

4. The drivers are wired up in phase (electrical). The original network was designed by David Smith. After much experimentation this network was chosen as it offers some midrange (presence) level adjustment around 2,000 hertz and a high frequency (brilliance) extension adjustment above 10,000 hertz.

5. The charge coupled caps are simply wired in series. The +Ve connection of the 2.2 meg ohm resisters goes to the +Ve terminal of a nine volt battery. The -Ve terminal of the 9 volt battery is connected to the -ve / ground connection of both the low and high pass filters. If you can’t get 4uF used 3.9uF. This is perfectly acceptable. If you have problems ask for help.

6. Allow 15 minutes for the connection of the 9 volt battery to take full effect.

7. The conjugate network is to flatten the rising electrical impedance of the woofer past the crossover point. The capacitor can be a non polarised electrolyte type to reduce cost.

The resisters should be wire wound ceramic types or Mills power resisters with a minimum power rating as shown. I suggest you use Mills resisters in the high frequency network as they are lauded to have superior subjective characteristics.

8. General Construction Notes:

I suggest once you get all the parts to lay them out on an A3 sheet of paper just like the schematic.

Then mark up the paper sheet with the position of the parts. Cut a sheet of plywood or Mdf with your powers to size and use the paper outline as a template for mounting the parts. I suggest you use both 5 mm zip ties and hot melt glue to fasten the parts to the crossover boards. Mount the ERSE Super Q inductor well away from the air core inductors to avoid cross talk. Use tag strips to terminate the parts with flying leads. Use 7.5 amp stranded copper wire. Use spaghetti heat shrink tube to insulate exposed connections to avoid short circuits. I recommend a 60 watt soldering iron for this work to heat the joins quickly enough and to avoid dry joints. A 25 watt iron is not going to work properly.

David Smith designed the 4430-4435 networks and went on to design a number of loudspeaker systems including those for Snell Acoustics. The 4430-4435 were largely the work of John Eargle and Don Keele. Greg Timber’s later designed the JBL 4425 monitor.