a question to all 4430 and 2344A owners

[Jakob]

Hi!

I finally got some 2344 horns with 2426H drivers to hook up to my 4430 networks I got off ebay. I think the sound is really impressive and with the attenuators set at +-0 I dont feel any need for an additional tweeter. What I foud however, was that when I turned up the volume (rather high, party-level-like) they began to sound harsh. I think I read somewhere on the forum that the narrow throat can be cause to this, but I guess there are several possible root causes. Not properly installed diaphragms, faulty diaphragms etc.
I know a lot of people here use this horn, so I thought it would be interesting to hear any experiences on this matter. This weekend, I will take the drivers apart and check out the dias.

Thank you for any input on this.

Kind regards,


Jakob

[4313B]

What I foud however, was that when I turned up the volume (rather high, party-level-like) they began to sound harsh.My 4430's didn't like a thorough beating either. They couldn't take the juice that my 4331B's or 4333B's could take but they sure sounded better at normal volume.

[pos]

I think this has more to do with the CD compensation than with the slot area

[Mr. Widget]

I think this has more to do with the CD compensation than with the slot areaI agree... I have also experienced this and my guess is that the driver is driven harder for a given SPL than it would be on a non compensated constant directivity horn.


Widget

[1audiohack]

All the one inch stuff I have begins to sound just plain unpleasant when leaned on pretty hard. I usually run a 2404 or 2405 on top of most everything so that makes me really wonder about how much the C.D. comp. thing adds to the problem although I reckon it does.

I have 2342's and 2344's, and they both behave the same way meaning when I listen loud, there are parts in tracks I am familliar with that I just turn it down. The diffraction slot is one inch wide in the 2342 and 5/8 inch wide in the 2344 if that is a contributing factor or not I do not know. I do not experience this unpleasantry with any of my two inch stuff including my 2360's or 2365's.

As for the unpleasant characteristic I have different hypothesis. If I understand correctly, 194 dB SPL is about the limit of our standard atmosphere to transmit an acoustic or sonic event grossly undistorted before the rarefaction force causes the momentary seperation of the medium, a vacuum between two pressure fronts like a rip or tear that crashes back together.

I am not a math wiz but what is the SPL in the slits of the phase plug that is about one tenth (10 to 1 compression ratio) of the radiating area of the diaphragm in a compression driver that is capable of 118 dB SPL at 1 mW into a plane wave tube? I would bet when you are asking it do deliver 105 or 110 dB SPL at 1 meter or more it's getting pretty crazy in the restricted area. Figure a one inch comp. driver with a 1.75" diaphragm has about 2.4"² of diaphragm radiating area compared to the 12.5"² of a two inch driver with a four inch diaphragm. I think the "unpleasant noise" comes from the inability of the air to transmit the pressure wave into the throat of the horn undistorted when when that limit is reached and you get there much faster with the small stuff.

My one inch stuff now resides in the bedrooms and office.

[4313B]

My one inch stuff now resides in the bedrooms and office.You win. The 1.75-inch and 3-inch drivers simply aren't 4-inch drivers. It isn't compensation because even the 3-inch beryllium drivers can be stressed in systems such as the K2-S9800 and SK2-1000 and that's straight from the designer.

With the 4430 and 4435 though a 2-inch exit driver wouldn't yield the same power response at high frequencies due to the larger aperture. One would probably have to add a UHF to maintain dispersion which would eff up the beauty of the system.

I think people will be pleasantly surprised when they start replacing those now-ancient aluminum and titanium diaphragms with the beryllium diaphragms in these systems. They might get lucky and only need to turn the L-Pads down a few numbers rather than have to tweak the networks. I guess we'll be finding out soon enough. :)

[Robh3606]

I noticed it as well when I was using them in my active set-up. Go up too loud and they could get unpleasant. Fortunately it was at levels I seldom went too and at any sane levels they sounded just fine. I crossed them over higher with steeper slopes than a 4430 so I can certainly understand you having the same experience. I think any of the 1" systems can "stress out" although I have not heard this in my 4344's?? Not sure why?? Maybe because the driver is more bandwidth limited crossed at 1.5 and 10K??

Rob:)

[toddalin]

Hi!

I finally got some 2344 horns with 2426H drivers to hook up to my 4430 networks I got off ebay. I think the sound is really impressive and with the attenuators set at +-0 I dont feel any need for an additional tweeter. What I foud however, was that when I turned up the volume (rather high, party-level-like) they began to sound harsh.
Jakob

Or maybe you just don't care for the sound of the titanium diaphragm when pushed to its limits. I also found it a bit harsh.

[4313B]

I think any of the 1" systems can "stress out" although I have not heard this in my 4344's?? Not sure why?? Maybe because the driver is more bandwidth limited crossed at 1.5 and 10K??I didn't notice any stress in the 4344/4345 either. Until I bolted a 4-inch in. There is an effortlessness with the 4-inch. One gets the feeling that there isn't a limit to it. Of course, we're talking normal listening rooms were those steep waveforms of explosive loudness don't have any place to go. I have definitely noticed the 1.75-inchers and 3-inchers reaching their limits on the waveguides, 2344A's, H9800's and H4338's but they're too loud at that point for any meaningful enjoyment. It is interesting though that the 1.75-inchers don't seem to exhibit the same level of raggedness at high volume with the old exponential horns. Maybe it's because the exponential horns sound so bad from the start that they can't get worse with increased volume? :rotfl: J/K! I'm not sure it's the slightly higher crossover in the 4-ways. The 4331 and L300/4333 didn't stress out like the 4430 or 4435 did. Oh, and that 4331 has pseudo compensation on it...

But, obviously, we all need to get back in the room with these systems and give them another listen side by side before writing anything in stone.

Or maybe you just don't care for the sound of the titanium diaphragm when pushed to its limits. I also found it a bit harsh.Yeah, instead of suddenly shattering into a bunch of smaller pieces they give you fair warning with rapidly degrading sound quality. "It's a feature!"

[subwoof]

I have yet to be satisfied with extended listening and/or high SPL with the smaller 1.75 dia's, even if coated. Even way back in the PA's I had in the early 80's I kept replacing the 1" drivers with 2" when I could afford it.

The network "push" on the 4430 works fine ( as noticed by others ) at low to medium volume but is just harsh after that. Of course it didn't help when my pre teens played early MP3 hiphop crappola through them.

When I got my first pair of 4 ways to rebuild I installed the 2440/2311 instead of the one inch and was much happier and so was the person who bought them away...

Recently I had a few 2430/31/35 drivers to play with and while they are very attractive in size and weight when compared to the others, nothing *yet* has topped the 2450SL / 2452SL for high output and clarity.

BUT as soon as the 4" Be's come along I am sure to try them and probably will incorporate them into the 4345 clones I plan to make this summer if I can ever get the time...sigh....

[toddalin]

Yeah, instead of suddenly shattering into a bunch of smaller pieces they give you fair warning with rapidly degrading sound quality. "It's a feature!"


I don't listen anywhere near loud enough to shatter these things. But one doesn't need to push them that hard before they start to get a bit harsh. Everyones sensitivity is different.

[Mr. Widget]

I don't listen anywhere near loud enough to shatter these things. But one doesn't need to push them that hard before they start to get a bit harsh. Everyones sensitivity is different.It was a joke... ;)

Not to say that it isn't impossible to shatter a TAD or Yamaha beryllium diaphragm, they are quite brittle and will shatter if seriously abused. The JBL and Truextent Be foil diaphragms are not prone to shattering, they bend.


Widget

[Jakob]

Thank you all for your input. So I guess it's not a faulty diaphragm-problem then. Too bad really, I sure enjoy them at normal listening levels. Maybe can use them as surround speakers in a HT-setup...

Once more, thank you all for precious input!

[pos]

you should check your diaphragmrs anyway, and make sure they are properly aligned with some sine waves

[DavidF]

You're scaring me, guys. OK, so the 4430 (or quasi 4430 in this case) is not a fill-in for a PA system so don't take it to a rave. Got it. But it can't go louder than normal levels in a normal room? Maybe relegate it to surround? Exactly how loud is too loud for 4430s that some are throwing out here? (holding my ears thinking about it)

Thank you all for your input. So I guess it's not a faulty diaphragm-problem then. Too bad really, I sure enjoy them at normal listening levels. Maybe can use them as surround speakers in a HT-setup...
Once more, thank you all for precious input!

[Mr. Widget]

Exactly how loud is too loud for 4430s that some are throwing out here? (holding my ears thinking about it)I think it is subjective. For me I think they sound fine with peaks around 95dB... louder than that they can sound harsh depending on the musical content. That said, I think we all have our own perception of harsh... some folks may think they sound fine at 110dB.


Widget

[4343]

You're scaring me, guys. OK, so the 4430 (or quasi 4430 in this case) is not a fill-in for a PA system so don't take it to a rave. Got it. But it can't go louder than normal levels in a normal room? Maybe relegate it to surround? Exactly how loud is too loud for 4430s that some are throwing out here? (holding my ears thinking about it)

My thoughts exactly. I saw some 4425's on the soundstage at Universal Studios a few years back that went _almost_ to stupid loud that sounded just fine. From 40 feet. In a huge space. Not to say that up close in a small room they couldn't be shown to get harsh at some as yet undetermined level. Maybe the program material I heard was the inverse of harshness or something... But, yeah, how loud is loud here?

Full disclosure, I tried undamped Ti diaphragms in my 2446/2334 setup and ended up back at the Aluminum that they came to me with.

I still think the CD comp is pushing the HF a bit too hard. But then, I grew up with 4330's and kind of like the rolloff to happen before the breakup mode that just adds distortion. That is what I consider to be the harshness everyone talks about.

110dB is what, about 1W or so?

[4313B]

I still think the CD comp is pushing the HF a bit too hard.It isn't. It's all strategically arranged passive cut filters. There isn't any pushing going on.

What is happening is a whole chunk of midrange sensitivity is getting cut to bring it in line with the high frequency sensitivity. The other option is to do it all actively with cut or boost filters strategically manipulated to maintain a reasonably flat response curve until high end roll-off exceeds 6 dB/octave. These older horns and compression drivers are outstanding candidates for passive high frequency compensation because they are so well behaved.

The aluminums are going to sound better than the titaniums, that's just the way the cookie crumbles, and they are priced accordingly. Both materials can stand a dusting of aquaplas, they're metal... The berylliums will be an order of magnitude better than either, providing one has the hearing left to appreciate the difference. And these networks beg for charge coupled technology, if only on the horn/compression driver.

My updated 4430 system using the 1500AL and the H4338/476BE further proves that the whole concept is 100% viable. Granted the larger aperture of the 1.5" horn as compared to the 1" 2344 horn reduces high frequency power response... it's all based on what set of compromises one is willing to live with I guess.

Has anyone tried bi-amping their 4430's or 4435's with a nice electronic filter and perhaps a great sounding tube amp on the top end?

[Robh3606]

It isn't. It's all strategically arranged passive cut filters. There isn't any pushing going on.



Thanks you beat me to it.

Rob:)

[pos]

Well, that comes down to the same thing: by 15khz you are basically down to under 95dB/1w/1m sensitivity on a CD horn.

[4313B]

I didn't remember it being quite that low so I looked it up and you are right.

The 2344 has a sensitivity of 107 dB 1W, 1m. For some reason I thought it was more like 110 dB 1W, 1m.

[4313B]

But I have yet to meet anyone who runs the L-Pads full on so that further reduces the efficiency.

I guess at least we're all in agreement that they can sound harsh at high volumes. :dont-know:

If I still owned a pair of 4430's or 4435's I'd be pretty excited about the impending Be diaphragms.

[4313B]

Well, that comes down to the same thing: by 15khz you are basically down to under 95dB/1w/1m sensitivity on a CD horn.Here's the more modern 476Mg in the K2-S9900 for comparison. You can see the chunk of midrange sensitivity that is cut passively. And then the whole curve is further reduced by roughly 8 dB to meet the efficiency of the 1500AL-1. Obviously there is a bit more sensitivity to play with here than there was with the 2344A/2425H combo. I guess that's what a thirty year advance in horn/driver technology yields.

This is a 4" magnesium diaphragm (in a 1.5" exit core) which is very close in sonic performance to the beryllium diaphragm at a reduced cost. Both are "light years better" than either titanium or aluminum and I think it's great that Brush-Wellman saw fit to bring the beryllium diaphragms to market.

[pos]

I'd love to try this Mg diaphragm in 2452 cores!
The truextent diaphragms are really nice but they would certainly benefit from diamond surrounds to extend the HF extension (and maybe even remove that crash around 18khz)

[4313B]

I'd love to try this Mg diaphragm in 2452 cores!Further proof that JBL simply isn't the JBL we know and love anymore. JBL doesn't even bother to list a replacement diaphragm for the 476Mg or 476Be. They simply don't exist. If you blow a driver they send you a new driver (after you read off the serial number of your affected system to them).

[4343]

It isn't. It's all strategically arranged passive cut filters. There isn't any pushing going on.

What is happening is a whole chunk of midrange sensitivity is getting cut to bring it in line with the high frequency sensitivity. The other option is to do it all actively with cut or boost filters strategically manipulated to maintain a reasonably flat response curve until high end roll-off exceeds 6 dB/octave. These older horns and compression drivers are outstanding candidates for passive high frequency compensation because they are so well behaved.

The aluminums are going to sound better than the titaniums, that's just the way the cookie crumbles, and they are priced accordingly. Both materials can stand a dusting of aquaplas, they're metal... The berylliums will be an order of magnitude better than either, providing one has the hearing left to appreciate the difference. And these networks beg for charge coupled technology, if only on the horn/compression driver.

My updated 4430 system using the 1500AL and the H4338/476BE further proves that the whole concept is 100% viable. Granted the larger aperture of the 1.5" horn as compared to the 1" 2344 horn reduces high frequency power response... it's all based on what set of compromises one is willing to live with I guess.

Has anyone tried bi-amping their 4430's or 4435's with a nice electronic filter and perhaps a great sounding tube amp on the top end?

Great explanation! So I guess, after all the padding takes place, it's US that push them too far...

No tubes here, I just use a D45 or D60 for HF.

Also, good point about the L-pads, I couldn't take the sound with the HF up much above midway.

(Edit window closed, or I'd change that 4330 above to 4320. I can never remember that old model #...)

[Jakob]

Thank You all again for your input!

I took my drivers to my certified JBL-tech and all was fine with drivers and dias. When I got them back I moved the speakers to a somewhat larger room (4,8mx6,5m instead of 3,6mx4,8m) and the longer distance to the speakers made wonders on both percieved harshness, soundstage and all. They sound great. I don't own a good active filter so I couldn't take Giskard up on the tube amp on top thing. However I tried my Audio Research on the whole package and they sure sound sweeter that way. The ARC VT60SE's 50 watts is a bit too little though to drive these things at higher listening levels.

[grumpy]

I can vouch for the VT100mkII also sounding quite nice on the 4430's and
with sufficient 'oomph' for my own listening habits/levels.