View Full Version : Technical Ref Threads for 434x monitors

05-29-2007, 06:27 AM
Giskard had said (probably kiddingly) that he was waiting for more threads like the 4341 TechRef thread i did a few weeks back.


The helpful thing about the 4341s was I had a pair of them on hand, and had been collecting info on them for about 8 months before I bought them. But I'm not as well funded or schooled on the other big 4 way pro monitors of that series - I need some help and tips from the owners of those speakers to do it properly. As in the other thread I will give credit when I quote other folks thoughts and use images of their speakers.

I'm thing of doing separate threads (linked to the pre-existing threads on crossover upgrades and such, of course) for the Model 4343 and Model 4345 - maybe something for the 4344s, and because of the recent interest, probably a thread for the Model 4315 as well.

Comments, thoughts? PM me and let me know what you'd like to see!
Like the other thread - I plan to accumulate links and info, then build the index thread over a weekend ...

I know there are other JBL 4-ways that are quite nice (the 250TI series for instance) but the 250ti is a consumer model and I only have so much time ... so, I'll be staying with the 4-way Pro Monitors, at least for now.

05-29-2007, 06:50 AM
Giskard had said (probably kiddingly) that he was waiting for more threads like the 4341 TechRef thread i did a few weeks back.I wasn't kidding.

Thanks Heather.

05-30-2007, 06:23 AM
I wasn't kidding.

Thanks Heather.

Thank you!
I'd forgotten the significance of the 4315s until I read the L250 profile ...

I got a good start on the 4315 thread yesterday-
then went home and made some screencaps of the recent ebay auction ...
and merged them into the thread.

4315 Ref Thread - http://audioheritage.org/vbulletin/showthread.php?t=16926

I tried to follow the model I used for the previous thread:
4340/4341 Ref Thread - http://audioheritage.org/vbulletin/showthread.php?t=16493

I'd love to hear from owners of the Model 4343 and Model 4345 - it'd be nice to get some pictures of them from other than the usual posters (Bo maybe?) Anyway - the 4343 and 4345 threads will take a while longer to really do them justice, there are so many existing threads and posts to link to.

On another tangent - I really don't know much about the 4344 model(s).
I have heard of the 4344 MkII - apparently quite big in Japan, but were there any US 4344 versions? Can't say I've seen any pictures here - other than the homebrew variations ...

On that note, after all the recent interest in the 250 series, someone should build a similar thread on those 250TI consumer speakers. They had a long production run with a number of variants - and a lot of differences in crossover design, from what I recall ...

Maybe later this summer, eh?

05-31-2007, 12:23 PM
I am absolutely thrilled with your endeavor. :yes:

As Mr. Widget has also mentioned, this is outstanding!

08-29-2007, 06:50 AM
Yesterday I wound up taking another conversation off-topic ("What is an Audiophile (http://audioheritage.org/vbulletin/showthread.php?t=18114)"), but the resulting information seemed so good that I wanted to put it here where it belongs.

As Bo says, the 434x Studio Monitors weren't made for living room use - they were designed to be used in a studio setting where the sound engineer
would put them in place, then calibrate the audio system with an analyzer and use an equalizer or comparable gear to pre-adjust the source-audio and compensate for speaker and room conditions so it would result in flat sound response within the listening environment. That just makes perfect sense!

To me, "audiophile" conjurs the image of a high-end stereo buff - a person with very discerning taste, and who deploys costly gear and trunk-line sized cabling and all-too-often loves cabinets with multiple mid-bass drivers, no sub and limited cabinet volume.

Most commonly, to my chagrin, they will not acknowledge the importance of signal-path EQ to optimize for room response. A few have allowed me to insert an EQ and tune to the room - with vastly improved response - but they devoutly prefer the purist approach.
... They get the mid-bass and HF fine, but most typically there is a great deal of LF missing in their approach.

Not trying to be combative, but further enlightenment would be welcomed.
I had thought that unless you were above a certain price-point with EQ (an active component) you ran the risk of degrading the sound with noise while adjusting the spectrum to match the room response. What kind of EQ is suitable - Behringer? Rane? White? Something else?

Can such adjustment/room calibration be done by the end user with a Radio Shark db meter and some test tones/test record? Or is this something that needs calibrated gear and an ear for hire every time there is a major change in the system?

Good question. Of the three, the White would be best. Rane are OK for starters, too. Nothing Behringer I have tried is acceptible for me. dbx has a good model in the 1231, and Ashly, further up the cost curve with their GQX3102. All EQ's introduce phase distortion by their filters - so, less is more. Top shelf are parametrics, particularly the Meyer CP-10 if you can find and afford such - they are phase coherant and wonderful.

A dB meter has no application, here - that is merely a reading of loudness, not a measurement of response.

While a nice calibration set-up, comparing the reference and measurement signals, is ideal, a simple RTA can provide a great deal of information. Using Pink Noise, you should see a flat response across the frequency spectrum. Where you see peaks/bumps, you should reduce (notch) that frequency in the signal path (insert the EQ between the pre-amp and amps) - these are areas that are being excited either in the room or the cabinet (or could be transducer anomalies, too...) and are being over represented; same (reverse) for valleys, although most users try and notch, only.

There are some reasonable handheld RTA's out there - I think Phonic makes a good one (PAA2). Once you begin tweaking/optimizing your system response, your ears will learn and be more critical of unintended resonances.

Okay - just to get some dollar figures recorded and put Bo's comments in perspective (I am not advocating any particular brands, just trying to get a feel for the figure$)

A few quick googles show the Phonic PAA2 runs around $250 or so. It looks like a neat little unit - its handheld and has a built in mike - looks kind of like a Blackberry or PDA ...

I did some other quick searches - (as of Aug 28th, 2007)
I found a Meyer CP-10 used, selling for about $1500 (!)
Sweetwater has the Ashley GQX3102 for about $950
Sweetwater has the dbx 1231 unit - for around $350

So a dbx 1231 and a Phonic unit would be around $600 (new)
I could see buying an EQ if its in that kind of range, but it would be harder to justify buying the PAA if I couldn't do a few "tweak for hire" jobs to help pay for it ...

Yea, costs always awaken a dream...

The PAA2 you will get plenty of fun from - it has an SPL meter too, so you could do the stuff grumpy mentioned (in his now deleted post... :dont-know ). It is a great tool that has many applications. Once you get it, you'll wonder why you waited.

Yea, I know. I've got five of them - all were sent for full check-ups/refurbishing at Meyer (they do great work!) - and they have become my favorite. They've replaced GEQ's in my racks - I have grown to require/prefer the exactness of a parametric.

Check eBay for EQ's - stick with highly reputable sellers. I've had good luck.

In any event, your first results I am almost certain will be enjoyable. You might find your results "open" the sound, by the removal/lessening of resonance(s). You will also surely see how the LF rolls-off, and then we'll just have to start talking about 2245's... lol

And from another thread asking for a source of pink noise, test tones and such

"Can someone point me towards me a good Pink Noise file/cd rip?"

Helpful? http://www.burninwave.com (http://www.burninwave.com/) (A lot of stuff)

Ian Mackenzie
08-29-2007, 02:28 PM

That's not really the fully story and this aspect deserves a far more (qualified and) thorough, and deep coverage than a few side posts by some members who happen to be EQ fanatics. I felt the discussion was very lope sided and lacked fact and technical know how about core issues.

Serving up a buyers guide on Eq gives the wrong impression.

Most 4343-4344 that were manufactured were sold and ended up in audiophiles homes, noteably Japan. In comparison very few 4345 models were made because it was not a big seller but the 4345 had a far superior crossover network, compression driver and mid cone than the 4343-4341. These earlier descendents very bright and relatively harsh compared to the former. No amount of Eq will help that incidentally.

I have never ever seen a Japanese audiophile use an EQ in their JBL systems. The more sophisticated audiophiles use elaborate room treatments just like studios to sort out the worst of the bass response and high frequencies issues. In any case it takes years of experience to use and equaliser effectively.

The issue locally is most people have fairly live listensing rooms with large hard flat walls. You can't EQ and make a live living room sound good with Eq alone after buying the old 4343 off Ebay. Its a myth. It may measure flat on your PA RTA and you will want to believe it sounds better but as posted by Pos in the audiophile thread it does nothing for the reverberation time and other serious issues such as early reflections, splash of walls and room modes.

Given the inherant blemishes in the earlier 4343-41 and a live room problems mentioned above its no wonder that using an EQ to tame the sound looks likes the right thing to do by the average Joe. But it won't solve the problem and is why we read posts about members winding the HF L pads well back on these systems and people posting dyer remarks about the 2307 horn/ 2308 lense.

This is why historically there has been a lot posted on the Lansing Heritage Forums about upgrading the 4343 components and the crossover.

It a no Brainer and should be done at the outset before considering a significant outlay on a fancy RTA/ Eq setup. Then think about your room.

You simply cant make a silk purse out of a sours ear!

Moving the loudspeaker around and finding the best location is the key in setting up but is seldom done as the WAF factor usually dictates the loudspeaker location. Most people such as yourself shove them up against a wall which causes a lot of your bass response issues. It is also the ruination of the imaging and many of aspects of sound reproduction.

Its a sin.

These 4 way systems need to have the L pads properly set up once you have positioned them in the best location in the listening room. There are some good articles on the internet about this. I've been over this dozens of times over the years and provided a method for the adjusting 4344-4345 L pads for a flat response based on the system voltage drives. From there the user has a base line for making very fine adjustments. 9/10 uses get the L pad set up totally wrong and goof it up further by incorrect use of a graphic EQ after reading utter crap about equalisers being the panacea..

Sorry to intrude on your thread but I am sure you can why I am making the above points.

At some stage it would be useful to write a home user guide to 4 way JBL Professional Series Monitors.


Heather: I will look at it when I get back from overseas.:)

08-29-2007, 03:09 PM
Excellent points, Ian, thanks!
Can you provide any links to the existing descriptions on the site so folks can get this info - its such a long process for the newcomer to use the search tools here and wade through all the posts on this site to find those posts that relate to setup instructions. There is a lot of off-tangent stuff in some of the threads, and a lot of things that wander around the point without hit specifics. Not in your posts of course, but - some of the other posts are a long read ...

09-01-2007, 08:36 AM

First of all thank you for all your work on the 43XX threads. Just to add to Ian's post, here is a link that pretty well describes equalizer use in laymans terms.



09-02-2007, 07:17 AM
Excellent points, Ian, thanks!
Can you provide any links to the existing descriptions on the site so folks can get this info...

Here is a link to Ian's description on setting the LPad levels. This method uses an Spl meter and is the most accurate method of setting LPads. To quote Ian "....using this technique (is) the only reliable and repeatable method of adjusting the relative balance of the drivers on a 4 way system."


09-02-2007, 10:04 AM
EXCELLENT! Thanks very much - I knew I had seen it once, but there's so much stuff here sometimes its hard to tell the signal from the noise floor!

Here is a link to Ian's description on setting the LPad levels.

09-11-2007, 05:23 AM
Chart showing relative size and weight of 43xx Monitors
(chart corrections/updates courtesy of grumpy!)

03-09-2009, 07:20 AM
Once again, because ya know it feels good!

4344 References Thread (http://audioheritage.org/vbulletin/showthread.php?t=17762)

4345 References Thread (http://audioheritage.org/vbulletin/showthread.php?t=16967&highlight=4345)

4343 References Thread (http://audioheritage.org/vbulletin/showthread.php?t=16951)

4341 References Thread (http://audioheritage.org/vbulletin/showthread.php?t=16493)

4315 References Thread (http://audioheritage.org/vbulletin/showthread.php?t=16926)

Please - PM me your ideas and images to go there ... thanks!