View Full Version : 4435, 4430, 4425 in Control Room help please!

08-27-2004, 10:58 AM
Please provide your opinions and suggestions regarding my in-process monitoring set up. I have collected 4) 4435's, 2) 4430's, and 6) 4425's. The room is private, brand spankin' new and is designed 5.1 so it's rather large (14400 cu ft) and built to specific ratios, absorption and diffusion coefficients. Speakers are flush mounted and isolated, RFZ and all that good stuff. The 4435's are front L,R and rear L,R. The 4430's were to be the center and maybe the .1 (if used) but volume vs. gain does not match the 4435's well. I'm looking for a 4435 I guess. A bridged Crown KI amp powers each speaker. The 4425's surround an Electronic drum kit so the drummer can hear and "feel" the kit - more like an acoustic set-up. Looks like he just got some 4430's for kick and snare. Problems....since I've had most of these speakers around for a while, some of the foam surrounds are less than perfect, but most are 'intact'. An "oop's at the board" blew a horn, a woofer or two and knocked my butt on the floor. Another 15 'cracks' sometimes. Swapping these out, I found a damaged crossover and horn. It sounded like something off a football field, and it only worked when the HF attn. was at an extreme (forget whether max or min). Sounded better with another known good horn, but not right. As I am not an expert on speakers and repairs, I lucked out when a friend told me about this forum. Obviously you folks know of availability, alternatives, solutions etc. I need a recommendation of someplace to send all of my components to for repair and/or general health ck. I assume all of the woofers have been reconed or refoamed before. These speakers are going to get a real workout in this facility, and past experience has shown that they are quite durable until abused by guys like me. Geesh....the crossover is NA from JBL, one recone now for both 2234H and 2235H, JBL recone/foam or aftermarket? What diaphram? These things need to be balanced L to R too. Again, please offer suggestions that you think will help me out (besides some good limiters!) If you got this far, Thanks!

08-27-2004, 11:22 AM

Tons of questions. But, with the endeavor you're undertaking, assuming it's the right speaker compliment :hmm:, you should send all repairs to JBL Pro. There's sufficient data to suggest there may be additional "damage" you've not yet heard, as the described events were obviously of large transient wave forms.

It doesn't matter if baskets have been "worked-on" before. But, with the work-load you describe, you'd do well to get everything back to spec.

Now, about that preamp. Oops - sorry, wrong Thread... :slink:

08-27-2004, 11:44 AM
so u have 12 of them amps? thats like 13000W into 8 ohm. bet it can do some damage if not used with caution.

08-27-2004, 11:50 AM
All but the 4425's are bridged K1. Only the 4435's saw the spike.

08-27-2004, 11:54 AM
welcome aboard...and go with Bo:s advice. (i allways do) :)

08-27-2004, 12:13 PM
Thanks for the welcome! Didn't know JBL serviced these anymore. I was hoping that a solution was less than a days drive away. Lots of parts to pack up and ship$$$$$$ Sounds like good advice. Probably more $ to fix and test at JBL, but right. True?

08-27-2004, 12:47 PM
Hey, Steve...

The main reason I suggested that, is from your description of planned use. Otherwise, if you were merely looking to resurround these yourself, and wanted to spend a few quality weekends sniffing MEK :spin: I would've suggested that. But, with so (apparently) much and the variety of damage, I'm not clear you'll really understand and get it right unless you go through the entire downstream of your studio. You are a higher-level user than many of us on the Forum.

Having said that, we try not suffer the sonic explosions you have! :rotfl:

Anyway, while the elements are off getting refurbished you (we...?) can spend time learning about your upstream gear...


btw - Terry has a "slapping" 15 on the B360 Thread, so you can see many are diagnosing similar symptoms.

08-27-2004, 01:47 PM
I do not want to do the surrounds myself because (1) I've never done any (2) got a zillion other fun things to do like miles of wiring, acoustical fine tuning, the list is huge. After doing 20 years of engine and fuel system development for the auto industry, the smell of solvents bother the **** out of me. Also, I need confidence the monitors are up to snuff, and that comes from someone who knows what their doing. FYI... console is an automated analog 28 ch Series 2 Neotek. New recorder will be IZ Radar S-nyquist @192 kHz. Tape costs WAY too much now, and latest 96k + digital recorders (a couple of them anyway) are finally sounding good. The only other component planned for upsteam signal path is a couple of dbx 480 driverack units or Klark Teknik equiv. They offer a host of features (like limiters, alignment, para eq, etc). Hopefully, the room won't require EQ - nor the 4435's, and it will be just limiters of some kind. Time will tell. Is my assumption correct that JBL can test a unit and bless it, or are there some residual black juju things that only go away after a full 'rebuild'?

08-27-2004, 04:57 PM
Originally posted by Steve Widman
a couple of dbx 480 driverack units or Klark Teknik equiv. I believe that qualifies as an oxymoron... ;)

Nice "rig", dood, and agree whole-heartedly about the newer 96k gear. Getting close(r)...

Yes, JBL will fully test their rebuilds. John Nebel's had a few things redone at Northridge, and is very pleased with the results. And he's mighty picky. Here's his listening room: Blue vs Black (http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=2311&highlight=black+vs+blue) Thread.

But, maybe some other more informed Forumites will chime-in here. There's great depth on this bench... :yes:

scott fitlin
08-27-2004, 06:10 PM
I might tend to look at how your using those crown K1,s! Do you really need that MUCH power? A K1 is 1100w@8 ohms bridge mono, 1500w@4 ohms bridge mono!

Headroom is one thing, but you have enough power to continuosly do serious damage, even with limiters!

This is just my opinion, but I think you might look at running the K1,s in stereo, which considering the amount of speakers you have, should give you enough sound and coverage, and be much safer to operate!

scott fitlin
08-27-2004, 06:16 PM
I fully recommend JBL for servicing and rebuilding your speakers! Its worth whatever you have to go through to get this done, the speakers will come back brand new!

08-28-2004, 04:53 PM
According to the specs of the K1, they are rated 350W/ch. into 8 ohms/1100W bridged. The 4435's are rated to continuous 375W. JBL suggested going to the higher level because of what I'm doing to them - besides just plain monitoring/mixing. They also monitor electronic drums, 2 guitars, keyboards and maybe something else - simultaneously - while recording all signals direct. I'm thinkin' that makes an easy continuous 375W. No other amps are used. Bass is reserved for the rear 4435's. This is why the extra headroom was suggested. Sorry it wasn't shared earlier, my posts can get a bit long. FYI I did hook them up in stereo and for plain monitoring/mixing it's was fine. They may run unbridged now! The 4435's may not be the coolest thing for pure far field monitoring/listening today, but I do not know of anything else that could do all this without spending LOTS of $. They sound plenty good to me, and a few 40K Genelec guys raise an eyebrow or two as well. I've used JBL stuff for years, L100's, 11's,12's, little control 5's, etc. For me, the 44 series are the best. Instant PA in a pinch, a keyboard monitor, outdoor bon-fires, whatever.

Anyway...surfing around this forum the last few days has been quite an education! You guys have developed one of the best forums around. Lot's of reading to do....hope you all don't mind a lot more questions. Thank you for your comments

BTW...what should a guy expect to pay for a recone at JBL? Hmmm....quantity discount?

Seems to me that a few of you guys could fix em' up just fine!

scott fitlin
08-28-2004, 05:50 PM
Did JBl actually specify using two Crown K1,s in bridge mono? Having more power than the 375 watt rating to me means 500 watts per speaker, possibly double the power rating, which is 750 watts per speaker, and you have practically triple the rated power! Not to mention the peak output voltage those Crowns can swing!

08-29-2004, 09:13 AM
It was a process of elimination. No fans allowed. Also wanted to keep the amps local to the speakers so bridged was the only solution. They said K1 was the best way to go - but......watch the volume at the amp. I did, but a goofup with the automation is what caused me all the grief. While powering up the console a CD was being fed to a couple channels. Metering pegged at the console, as it defaulted to max gain. The amps were about halfway up. I figure they saw +20 of CD along with some square wave from the console. The automation is fixed now (i.e configured like it should have been) so won't default like that again. Fortunately(?) only one pair of 4435's got hit. BTW.... with no attenuation and bridged, the ears start to hurt with main console outputs at 3. Overkill indeed. Lookin' back, K2's (@500w ch.), and a bunch wire would have been better. Wait a minute.....didn't that JBL guy suggest that option too? Live and learn

08-30-2004, 08:21 PM
Geez, when you get it dialed in, invite me up for a listen!!! How far is Milford from, say, Toledo?

08-31-2004, 12:10 AM
It is 150 miles from Lima Oh. to Milford Mi.

08-31-2004, 06:44 AM
All of you guys that are willing to drive here are welcome. Milford is just over 1 hour from Toledo. It's gonna be a little while yet.... $$$$, but a good beating by some critical ear types could be helpful. The vinyl freaks will need to BYO gear. I'll have the red pop's.

08-31-2004, 07:45 PM
Maybe Giskard will want to ride up with me one day and check it out................let us kow when you're ready for guests! Could be fun!!

09-01-2004, 09:14 AM
Anybody have any tips for useful crossover mods while apart for repair? Has anybody tried an external 3-way crossover or? Thanks!

09-01-2004, 09:17 AM
Originally posted by Steve Widman
Has anybody tried an external 3-way crossover ...? :yes: Nice!


09-01-2004, 11:07 AM
I'm confused as to how the existing crossover works to begin with. Biamp/triamp to me means no internal crossover, period. So if you biamp these the crossover is still in the loop? Is this so that the 2234 sees 100 Hz or something and below? Some high-pass set up? So what are they..... 2 1/2 ways then? Ignorance is on full throttle today

09-01-2004, 11:15 AM
Well, your post suggested you were going somewhere else...

The series you mention are all two-way. And, the 4430-4435 can be a bit tricky due to the equalization issues, but can be bi-amped (from the brochure).


09-01-2004, 11:42 AM
Thank you.
Yea, was going somewhere else, but I'm back now. Thinkin' to eliminate the crossover entirely, but wait... thought std crossover may have some kinda woofer split of it's own. Then one amp ch. could feed both woofers. I guess not, so if triamps the only way to go, are their lingering EQ issues referred to in the JBL data to contend with? Those cards mentioned....available?

09-01-2004, 11:52 AM
Call it "Quasi 4-Way," if you like, the second 2234 woofer kicks in to augment the bass response via mutual coupling below 100 Hz.

The mid/high crossover cleverly splits the frequencies and attenuates them separately, as described above. That circuitry is not bypassed when biamping.

Looks like the mighty Giskard is on it, and we'll have the full scoop soon.... :D

09-01-2004, 11:53 AM
Thank you.
Yea, was going somewhere else, but I'm back now. Thinkin' to eliminate the crossover entirely, but wait... thought std crossover may have some kinda woofer split of it's own. Then one amp ch. could feed both woofers. I guess not, so if triamps the only way to go, are their lingering EQ issues referred to in the JBL data to contend with? Those cards mentioned....available?

09-01-2004, 01:36 PM
Originally posted by Steve Widman
... thought std crossover may have some kinda woofer split of it's own. The 4435 has a low-pass filter on one of the LF's...

And, indeed - I too hope Giskard finds time to post a Network Primer, tonight (or tomorrow, or the next...). :banana:

09-01-2004, 03:53 PM
First of all I want to thank you guys for the info.

Ok, lets see if I got a grip on all this so far...... The unavailable biamp network card works in conjunction with the unavailable existing unit to retain some freq compensation feature that can't be duplicated via aftermarket x/over. So it's run my stocker in repaired form and maybe beg, borrow, steal or create a biamp card. Both of these units can be improved upon. It is worth the grief to biamp.

If all this is true....
(1) How could you triamp then?
(2) Where does a guy start in the search for x/over repairs, mods and creation of such cool-guy devices.
(3) Are correct or equiv parts available to fix/build these?
(4) Will JBL fix/mod/create without service parts?

As you can tell I'm not a electron wizard, but have friends that think they are close. Given schematics (with mods?) and a primer on the special bits, we may be able to stumble though.

Gee.. for a minute I thought I'd get off lucky - if spraying $ to fix is lucky - and just use a 3 way. Thanks again....

09-01-2004, 05:13 PM
1) Rehab the drivers, check the crossovers, run them passive. They'll work fine.

2) If you are COMPELLED to mess, buy 5234A and the requisite cards when they come available on eBay or elsewhere (once or twice a year, typically, for the cards, the crossover more frequently,) and biamp them.

3) Several forum users HAVE biampped 4430's. Perhaps they'll post whether the improvement warrants the effort....

4) WHO started this, anyway? :bash:

ps: I've got dibs on Paul D's crossover if Figge don't want it....

09-01-2004, 08:34 PM
Nice work, Giskard, as always - thanks. :thmbsup:

And, Steve:
Maybe best is simplest here, and you should go back to first principles. There are simply too many solutions with too many variables. :nutz:

Going back to where this started, get the transducers reconed as needed, and then for the networks you know are toast, source a replacement either on eBay or here, using some DIY sweat-and-love.

The elements of your rig are too highly engineered to try a moonshot - IMO, you'd be happier and better off trying to re-establish Ground Zero.

09-02-2004, 05:13 AM
Giskard, I will contact you via PM regarding persuasion. Thanks

09-02-2004, 09:32 AM
Originally posted by Giskard
I might be persuaded to do the recones and the networks. Lucky Boy, Steve!! :yes:

Quality of work = Best of Class. Period.

09-02-2004, 11:08 AM
Indeed.... and considering some posts I've read about 4430's.....

Regards to all, Steve

09-02-2004, 12:34 PM
Ummmm, that would be these I believe.........

"sounds best submerged in 20 feet of murky lake water"

"They're junk"

"good money after bad"

"Cut your losses"

"vain attempt to make them sound listenable"

"woofer clamps for $20"

"sell those pesky little 4430's"

"hack 4430's"

09-02-2004, 12:52 PM
Over and out.....Later

09-03-2004, 12:18 PM
Remembered the discussion on this and saw this on Ebay


The model number on this unit is 5234. It is a stereo frequency dividing network with a fixed crossover point of 80 cycles. The crossover point can be changed by substituting the proper resistors and I believe info and parts are still available from JBL. Input and output jacks are RCAs so unit is very suitable for home as well as professional use. Has variable high frequency gain controls for each channel. It is rack mountable.

Unit is in typical used condition, but is not beat up. Front panel is clean and all lettering is good.

09-03-2004, 12:37 PM
"sounds best submerged in 20 feet of murky lake water"

Ah....sounds like the Techbot waxing poetic.......classic stuff!


09-03-2004, 12:40 PM
hes just trying to keep the 4430 prices down on ebay.

i think we all should try it! :)

4430:s? naw man get tlx8:s instead 4430 sucks! :)

09-03-2004, 12:43 PM
"Ah....sounds like the Techbot waxing poetic.......classic stuff!"

Bot Gone Wild!

:rockon2: :rockon1: :rockon2: