Poor sounding 4320's....pull the trigger as a project ?

[Goldjazz]

I recently inspected/listened to a pair of 4320's that I'm considering buying. I've never heard 4320's or any large JBL monitors for that matter. Pairs I owned are 4311's, L110's, L65's. So I went there ready to be impressed and....I was NOT impressed. They were seriously lacking in bass and quite lacking in detail. I mean 15" drivers should have been much better.

Ok so I'm sure that's not what healthy 4320's should sound like, I should have been blown away right? Now the guy had them set up on the floor was driving them with the biggest, most insane looking Audio research tube amp I have ever seen. So I don't think the issue was with the source, or anything further up the chain. I could only stand a couple feet away from them cause the room was crowded with stuff, so placement wasn't good, but there was something else going on.

Their history: the guy has owned them for four years, hasn't touched them. Interestingly the guy has also owned the 3 way version and admitted that they sounded much better.

Now I am thinking of getting these guys as a project to clean up the cabinets and do the 3 way conversion and I don't mind getting down and dirty and doing some work. So my question: Is the problem most likely something fixable i.e.caps needing replacement. Or could it be something more terminal and this is a bad idea to pick them up as a project? Oh and they won't be going cheap.

Thanks.

[Mostlydiy]

Doesnt seem to be the original woofer. The original should be rippled (2215?). I dont recognise the suspension at all, might not even be a jbl cone? The cone looks like 2220 though, but the 2220 doesnt have that kind of suspension(2220 has dual role, hade to see if its dual role on the image). weird woofer.

/Mostly

[Goldjazz]

Yeah, well spotted that cone is not rippled. So most likely a non jbl recone or they're not the original 2215s. Thats not cool.

[Goldjazz]

I dont think it has a dual roll. Looks more like the cloth type surrounds I have on the 12" s on my 4311s. I wonder if theres another 15" driver that also used that and these and were reconed with that. The guy did mention they weren't the originak surrounds and that could be the reason for the less bass.

[Goldjazz]

Ok so I have got more info. The woofers are definetley 2215A's and are marked as such. So I assume that means a non 2215a and possibly non JBL recone job has been done I guess.

[Mr. Widget]

A stock S7 load is just OK by today's standards in my far from humble opinion. ;) They can be turned into something pretty cool, but blown away? I suppose it's all relative.

All that aside, those cones make the woofers reconeable cores... turning them into true LE15A/2215s is costly and only worthwhile if you are into vintage for the sake of vintage.

If you can get these at a fair price, I'd go for a 2235H and new crossover... and probably add the slot to turn them into 4333s.


Widget

[4343]

A stock S7 load is just OK by today's standards in my far from humble opinion. ;) They can be turned into something pretty cool, but blown away? I suppose it's all relative.

All that aside, those cones make the woofers reconeable cores... turning them into true LE15A/2215s is costly and only worthwhile if you are into vintage for the sake of vintage.

If you can get these at a fair price, I'd go for a 2235H and new crossover... and probably add the slot to turn them into 4333s.


Widget

+1

The crossover should be the 3122 or 3122A. IRC there was a mandatory update for the 3122 to address some diaphragm failures in the tweeter.

I've had a set of the top half of 4320 since the '70's when someone parted them out. I learned never to use the passive XO for anything more than low-level stuff, as the iron-core inductors saturate easily. Active crossover worked/sounded fine...

The 2307 horn is run a little too far down with the 3122 also, I ended up adding a 10" mid to give it some relief, and added the slot. I eventually removed the 10" and built the Nelson Pass L300 passive, now it's back to 3-way using a 2225H in a pole-mount box. I use a sub when the 2225H is not enough. 2235H would be better, but the box would not be a candidate for pole-mounting...

BTW, that suspension looks like a K 130 Triple Roll to me. Maybe it's a K-130 cone with a paper dome.

[martin2395]

As Mr Widget stated - you should either recone the 2215 or replace it with 2235H (best option imo), add a 2405 slot and recap/replace the stock networks.

[Goldjazz]

Thanks for the reply. Yeah Blown away for me = significantly better than those jbls ive listed at the top which are my reference point. I would have expected deeper bass, that nice clear horn sound and more detail. The upgrades you mention sound interesting but its sounding like a big project to get them sounding good, theyre prob not cheap enough to allow for that. Though id enjoy the challenge



A stock S7 load is just OK by today's standards in my far from humble opinion. ;) They can be turned into something pretty cool, but blown away? I suppose it's all relative.

All that aside, those cones make the woofers reconeable cores... turning them into true LE15A/2215s is costly and only worthwhile if you are into vintage for the sake of vintage.

If you can get these at a fair price, I'd go for a 2235H and new crossover... and probably add the slot to turn them into 4333s.


Widget

[subwoof]

say WHAT???

The triple roll suspension is CORRECT for the 2215B ( NOT the *A* as found with the lansaloy surround in the older high-end home systems ) and IS the factory correct woofer for that cabinet/load combination...1970 - the very first year of the "pro" division at JBL.

The woofer is in NO way equal to the later foam-surround models with VERY different magnets / coil depth / gap depth / etc etc etc...

And it's the stock - original 2 way GP network ( 3110 ) which WAS installed on this model.

3+ years later the first gen 4000 series started the dedicated network versions - I have some original 4331 and 4341's from 1974. AND the newer pro speaker ( 2230 / 135A ) that became the 2231 then 2235......

And if the diaphrams and caps are original from 1970 don't you think they've aged a little also??

At the time these were the most massive and professional monitor they offered - intended to get the infamous altec 604C a run for the money in the new studio large format market..and the succeeded by a huge margin within a few years..

That was then, this is now. These are vintage, limited bandwith / output speakers that have been eclipsed so know what you're getting into before you pull the trigger.

sub

*edit* - the suspension is correct but the smooth cone is not so it's a frankenwoofer with questionable pedigree..:)

[Mostlydiy]

JBL doesnt have that many 15" with smooth cones without an alu dustcap. And definitely no one with this kind of suspentions. The cone is wack

/Mostly

[Goldjazz]

Yeah decided not to go for this in the end


JBL doesnt have that many 15" with smooth cones without an alu dustcap. And definitely no one with this kind of suspentions. The cone is wack

/Mostly

[Goldjazz]

Thanks for your advice everyone, as mentioned I din't go for these in the end. Perhaps my expectations of these early generation monitors was too high, or perhaps they were not sounding as intended due to the non original cone and surrounds or caps or a combination of several things. Anyway I'll be holding out for a better pair of these or some other large JBL studio monitors so thanks again.

[Mostlydiy]

How about these ones? :)

http://www.ebay.com/itm/JBL-4350-Legendary-Studio-Monitor-Speaker-Pair-/121284836438?pt=AU_Hi_Fi_Speakers&hash=item1c3d23bc56

/Mostly

[Goldjazz]

Ha yeah I did see these babies pop up,...i wish :)



How about these ones? :)

http://www.ebay.com/itm/JBL-4350-Legendary-Studio-Monitor-Speaker-Pair-/121284836438?pt=AU_Hi_Fi_Speakers&hash=item1c3d23bc56

/Mostly

[Steve Schell]

Hi everyone,

Now I don't know much about these newfangled 4320 monitors, as I am stuck firmly in the pre-1950 era, JBL-wise. A friend with a professional recording studio located at his home has been working on an early pair of 4320s, trying to decide if he can use them for playback in his studio's well damped big room. He had refoamed the woofers himself (very nice job), and borrowed a pair of 2405H tweeters to try them as a three way. Echoing Goldjazz' thread starter comments, he mainly objected to them having "no bass." He invited me over for a listen, and had just installed an Allen Organ Co. PP 6L6 stereo tube amp I lent him for evaluation.

The 4320s were on high stands that placed the mid horns at ear level when standing, and they were at least 3' in along the rear wall from the room corners. At my suggestion he moved them close to the corners and we began to hear some bass, though humble. Standing close, it seemed to me that the woofers were simply being outshouted by the horns and possibly the tweeters. He turned down the tweeters but that didn't help much. Though the crossovers had multi-position attenuation for the horn driver set to minimum, they were still shouting. I asked my friend if he had pairs of small value resistors. He was able to put these in series with the driver due to the wire connections on the crossover in back. We tried 4 ohm (slight improvement), then 8, then 12, finally making it to about 20 ohms before I was satisfied with the balance. Now there was plenty of accurate sounding descriptive bass, fine for sorting Fender bass lines from kick drum and etc., but not in Snoop Dog territory. As I have had to learn over and over, too much highs equals too little lows!

Does anyone here have experience with similar problems with these early JBLs? I have understood that some early JBL monitors had been given a goosed-up upper midrange to emulate the Altec 604 and gain traction in the recording studios. Is this what is happening here? We probably knocked the horn response down a good 3 or 4 dB before it sounded reasonable. An iPhone spectrum analyzer app showed a pretty good response to pink noise after the adjustments, though it still looked a couple dB hot to me in the horn's range.

[Mr. Widget]

I assume these 4320s have LE15As and LE85s with an LX5 network plus tweeters. My very first JBLs were S7s and I wasn't happy with the balance until I built my own networks... I wasn't able to tame the mid horn with the LX5's three position switch... and wasn't thrilled with the 500Hz crossover point either.


Widget

[martin2395]

A quick advice - don't power big 15's with tube amps, they very much prefer transistor amps like Crown DC300A for example.

[rusty jefferson]

I see on the specs page of the manual for these the minimum impedance is 12.5 ohms. Does your tube amp have a 4/8/16 ohm taps? Fixed output impedance?

http://www.jblpro.com/pub/obsolete/4320.pdf


A quick advice - don't power big 15's with tube amps, they very much prefer transistor amps like Crown DC300A for example.

I'm not a fan of transistor amps with a lot of feedback, however I'd consider trying one next.