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jandregg
06-24-2003, 02:14 PM
Several people have 4343 monitors. The pictures I've seen never quite show the detail of the crossover settings. I am trying to understand much about this crossover and speakers. Can anyone tell me what the markings are on the knob surrounds and where the flat (0 decibel) setting is. ie markings go from 7 oclock to 5 oclock with 0 dec at 12 oclock, or some such description. Or a picture that shows the detail.
Thanks

Tom Loizeaux
06-24-2003, 05:34 PM
I would say that, generally, mid position, (in this case 12 O'clock) is what JBL considered a normal setting. In some other models they even used the words "flat" or "lab standard" when you choose that position on switched attenuators. The pots are there so you can balance the upper drivers to your tastes, or room. I would start with them at 12 O'clock and see how you like the balance.
Just today I was listening to my 4343s and realized that because I was running these in the bi-amp mode and had left all the level control pots set on mid position, that I was "burning off" power from my high frequency amp unnecessarily. I turned them all up to max and turned down the high frequency level control on my active crossover, reducing the signal to my high freq. amp. As long as I am using the bi-amp mode, why not turn up these L pads to get more power to the speakers with less pushing of the amp? Of course if any needed to be turned down realtive to the others, I would turn them down at the L pads to achieve the best balance. When driving these in the INTERNAL mode these pots are the only way to balance the mid and upper frequency drivers relative to the woofer level.
One of the problems with level and EQ controls at the preamp, seperate level controls at the active crossover, level controls on the seperate power amps, and level controls for each section on the speakers as well - is that this gives you many places to screw up your music!

Tom

jandregg
06-25-2003, 05:39 AM
Thank you.

Ken Schwarz
06-26-2003, 10:07 AM
My 4344mk2 pots oxidize over the course of about a week, and are noticibly improved by a couple of rotations and reset to 0.

Before I realized this, I was very confused by the results of possible adjustments. I periodically became dissatisfied with the sound, and get up and move speakers around, fiddle with controls, and experiment with covers on and off, only to settle back right where I started. Even a hair turn of the pots seemed to make a difference, but the results were not reproducible! The reason, of course, was that the levels were fine, but the pots needed cleaning.

Now I clean the pots regularly and all is well.

IDF
06-27-2003, 12:44 AM
I would say IMHO "O" setting mean nothing as the speakers are calibrated in hemispherical free-field conditions, which does not wholly correspond to a "domestic use".
I personaly don't like the sound of 4343s when set up to 0. I find it hard, no musical at all. A Harman tech gave me the tip a long time ago : 2405 pot set up to max,
2121 and 2420 pots lowered about -1/-2dB.
Then comes a great speaker with an incredible sound stage holophonic if electronics are up to par.

:)

PSS AUDIO
06-27-2003, 04:54 AM
Originally posted by IDF
A Harman tech gave me the tip a long time ago : 2405 pot set up to max,
2121 and 2420 pots lowered about -1/-2dB.
Then comes a great speaker with an incredible sound stage holophonic if electronics are up to par.

:)

I am glad reading such a post!

It means that your amplifier has, as lot of them do, hard mids and makes all speakers with horns sound quite aggressive and not smooth and mild!

This is what I am working on since several years now and I managed to improve the mids and get them less aggressive (I personally use melting pot of 4350/55 – 2 x 2231H baskets one with its original cone one with a 2235H cone, a 2441 driver and a 12dB 250Hz network with a 300W amplifier) with an AB class amplifier.

I also naturally enhanced the bottom notes and a lot of “sounds” sounds now milder than before.

That is why I posted several days a go a thread about amplifiers and numbers …

IDF
06-27-2003, 05:56 AM
"I am glad reading such a post!
It means that your amplifier has, as lot of them do, hard mids and makes all speakers with horns sound quite aggressive and not smooth and mild!"

The amplifiers are McIntosh 7270 or 7200.
I know of no one that ever heard these amps sound aggressive.

Regards

Ken Schwarz
06-27-2003, 06:30 AM
I lived in Japan for many years. These big JBL monitors were very popular and are still aggressively marketed there.

It has always amazed me how poorly they are demonstrated, though. I've seen the adjustments set up apparently willy-nilly. There are folk-remedies to misbalance floating around, including removing the diffusion lens of the high-frequency unit and dialing it down by a couple db to compensate. Stereo Sound, that big glossy Japanese audio magazine, had a in-depth story where the reviewer made pretty gross adjustments and concluded that the speaker was colored. Well, duh.

Try adjusting the toe-in to get rid of some of that hardness. The off-axis response of the high and ultra-high drivers don't match perfectly, so there is a sweetspot where I find the best balance.

I have heard 4344s sound just excellent on class-A transistor amps (Accuphase 50W) and on my home tube amps (50W pp and 10W set). I have heard them sound aggressive and unlistenable with big transistor AB amps. They are sensitive, so they don't need a whole lot of juice. They really let you hear how nice a good class A amp can be.

PSS AUDIO
06-27-2003, 07:44 AM
Originally posted by Ken Schwarz


I have heard 4344s sound just excellent on class-A transistor amps ... . I have heard them sound aggressive and unlistenable with big transistor AB amps.

Once again I am dam glad reading your opinion!

It means that an amplifier is as important than a speaker and today’s amplifier are just making some noise, perhaps some music, but not playing good music.

It reminds me that someone wrote: Think different.

I am about to write: Sound different.

It is quite easy to have a great sound with an AB amplifier, but one must work a lot on it before putting his hands on the good setting.

Major brands prefer to pay one or several engineers to build an amplifier with the greatest numbers then the sellers think that they will easily sell it as it carries the greatest numbers ever provided…

Listening at some techno, dance, scratch or what ever you want; it is needless having good speakers and amplifiers as you are just listening a flat sound (no dynamic, no melody). That is why after 5 minutes your ear is tired and you need more raw power to increase the sound level and so on.

I do prefer a T-bone steak to a hamburger!