4344's Up and running

[Robh3606]

Finally got them up today. Been listening to them all afternoon. They were well worth the time to build. Really smooth and dynamic I can see why you don't see them for sale that often. Get in the sweet spot and they image real well, better than I thought they would. I always figured the lenses would mess things up but they seem to be OK. Those are Ians crossovers up top. Thanks again bud!:D Still have to get them squared away indside. They are biamped with a JBL M552 24DB L/R at about 300hz. Amps are 2 Crown 150 series 2 strapped so 300 watts for the 2235's and a PS-200 on top so about 100 watts for the rest.


Rob :)

[Ken Pachkowsky]

Looks good bud...

Enjoy!

Ken

[Ian Mackenzie]

Nicely presented Robert,

You could always mount the crossovers on the back?

Ian:)

[4313B]

Outstanding! :cheers:

I especially like the mini serpentines :yes:

[johnaec]

Are those the same size as factory 4344s? 'Looks like you need some of Bo's JBL Blue. 'Looking good! :yes:

John

[boputnam]

Originally posted by Robh3606
Those are Ians crossovers up top. Superb, Rob...

Ian actually offered to leave those hear (sic), since we were outa time during his visit to work with them. I declined, knowing they were intended for points east. Glad to know they're as good as can be. I'm still hopin' for the oft-promised Ver. 2.0 - the wait is holding-up my swapping-in some brand spankin' new 2245H's.

Oh, and I've got that tin of JBL Bleu packed and ready to ship - pm me the particulars, if you're interested.

[Ian Mackenzie]

I recall Robert plans to stick with the black baffles to suit the decor in his JBL bunker.

He is one lucky guy, the 4344, 2344 4 way bi radial and diy XP and they all sound very nice....well done Robert.

Ian:cheers:

[boputnam]

Originally posted by Ian Mackenzie
I recall Robert plans to stick with the black baffles to suit the decor in his JBL bunker. Doh!

That's what grill cloths are for... ;)

[Don C]

Wow, Nice!:thmbsup:

[Regis]

Those speakers are very, very nice. I like! The color is fine. No use chasing after the fabled JBL blue, as cool as it looks. BTW, anyone ever notice how close that shade of blue is to Ford's Grabber Blue from 1970? Some of the Mach 1's, Boss 302's and Boss 429's came in that particular color and it just oozes power!

[Guido]

WoW

Congratulations Rob!

:cheers:

[Robh3606]

Thanks guys!

Well would you beleive I finally get them going and one of the reconned 2235's has a low level buzz after a few hours!! So out it comes and back to the reconner. Damn! The cabinets are not stock size they are about 4 inches narrower and the tunned box size is 5 cu ft. Bo about the blue I will PM you. Never know what the future will hold so I figure it can't hurt to have some available.
Those will stay black and I like my drivers in the buff:D
I will have to wait till I get the woofer back to really set them up right.

Rob :)

[herve M]

Hello Rob, have you compared lens serpentine with 2344 for the new system ?:)

[Robh3606]

Hello Herve

Well this is preliminary as I have not had enough time listenning to them yet. I really need to get the 4344's set up better. Both set-ups are running as flat I can get them. Looking on axis on the RTA they measure the same except for the expected roll off using the 2344. The 4344 could be dialed right in thanks to Ian's excellent crossovers and Giskards multitap inductor solution. The presentation is different between the two. Obviously the 2344 is rolled off up top a bit. Even with direct comparison it is not objectionable. They seems to be some loss of detail but its subtle. The 2307/H94 077 combo is very smooth and I was really surprised at how well it images. They don't image the same either. The 2344 seems to be more up front and presise image wise while the 2307 seems to have more depth but it's not as presise as the 2344. The sound from both are a little different too. This sounds contradictory but the 4344 is more in your face even though the imaging is not. By in your face I don't mean it in a bad way but it's hard to describe. They seem to have an "immediacy" to them but they are not at all harsh. Basically I very much enjoy both and to choose between them would be tuff indeed. I still lean towards the 2344 a bit but time will tell that could change. Now the problem I have is the speakers are in the same room but in very different locations. The main set-up is at a disadvantage as far as imaging because of asymetrical placement and the right speaker being in a corner. The 4344 are out in free space. When I had my XPL's in the same positions they were the image champs which is what I expected. This is definately a preference issue between the two. They both sound great and there are diferences but they are less than I thought they would be. At least for now have to get more time listenning. Hey Ian what was your impression with the 4435/4343 shot out you did with John??

Rob:)

[Ian Mackenzie]

Robert,

We need to archive your post, its sums up the properties of both arrangements perfectly!

Your comments mirror my impressions when I compared the 2307/08 with the 2344 using the 2122 mid.

I was playing my own system last night to the wee hours and the transient detail, immediacy and depth shows.

My recollections of Johns 4343/4435 were similar but yet another derivative as the 2344 crosses over the the 2234 woofer.

Ian

[Audiobeer]

Just beautiful Ian! Wish I owned them!! :banghead:

[Ian Mackenzie]

Well HP has taken on making up proper drawings as understand it so I expect we can all share this model sooner or later.

Ian

[Hofmannhp]

Originally posted by Ian Mackenzie
Well HP has taken on making up proper drawings as understand it so I expect we can all share this model sooner or later.

Ian

thats right Ian..... I haven't forget it......a little problem the last weeks with my pay work.....have to travel a lot....next week to Moskow.
c ya

HP

[Michael]

Nice work! I'm curious though why you opted for a sealed enclosure and not the original ported design?

[Ian Mackenzie]

Michael,

Its rear vented as I recall .

Ian

[Michael]

Ah thanks Ian, quite interesting.

[Robh3606]

The ports are on the removeable back top panel. 2 3" approx. 5" long cabinet tuned to 30Hz.

Rob:)

[Michael]

Ah great idea! Easily adjustable port tuning and access to the horn driver.

[Robh3606]

How do you guys have your drivers balanced either 4344 or 4345?? I originally set them up flat but found I was getting burned out. They didn't sound hot just a little agressive and my ears fatigued after a while. I ended up backing them off a bit on the high end and they sound better to me. I am still very much on the learning curve with these so bare with me on this. It's a bit strange as they are rolled off a little level wise but more extended than the 2344 set-up. Trying to find a happy medium between the apparant detail with them flat and more laid back presentation with them set back a bit. I like the balance better with them off a bit when listenning for an extended period on time. I guess that's what I am used too compared with the 2344's.

Rob :)

[Michael]

Heres how we have ours set. We also run a custom active crossover, but that deals more with lower frequencies.

The camera wasnt really in focus.. at all, but this should give you an idea.

[Ian Mackenzie]

Robert,

Can I suggest this recipe, its a bit long winded but better than a hit and miss with 4 drivers. Not all these points need apply to your situation but others making the 4344 may find them useful.

1. Step 1 Calibration of faders.

Using a mic and test tone measure the output of each driver mid, horn and slot individually at near field say 600 hertz, 5 Khertz and 12 khertz with the fader up full. Mark that spot on a make shift Foil cal.

Then wind the fader back to -4 db for the Slot and horn, this is the 0 (zero) position, for the midrange -3db is the 0 (zero) position. Mark these points again on your Foil cal

Then mark spots for -1, -2, -3 , +1,+2, +3.

(the flatness of the drivers in the passband is arbitrary and only the absolute attenuation is relevant).

2. Step two make sure the crossover is wired correctly,

All the mid, high and UHF are wire out of phase with the woofer. (the polarity should be reversed after the faders).

If your compression driver for the horn is 8 ohms and not 16 ohms like mine, use a 2.2-2.7 ohms series resister after the 20 ohm resister shunted across the pad. (otherwise your horn will be 3 db too loud).

3. With all the pads in the zero position, adjust the enclosures for a very slight toe in , say 10-15 degrees only. The tweeters should be outermost. (Toeing in the enclosures too much or sitting in front of the speakers will sound too intense.)

Seated b/n the enclosures play some varied program material.

4. Subjective Evaluation.

The imaging should be dead centre and precise. The sound stage should be deep and will open up and expand when the level is increased. Some adjustment can now be made to the horn and slot depending on your listening room. I tend to run the slot +1 db and the horn 0 db or -1. In your scenario the woofer amp level can be adjusted independently for the right balance.

Alternatively, at this point you can use your RTA for a flat eq at the listener position (only) as the horns are non constant directivity.

5. Other observations...

Bo tended to use his nice RTA on this basis with good results. The Pads can to some extent assist with off axis adjustment but their action is a broad shelf remember and the dispersion of the horn is non linear in the passband, although I prefer its controlled pattern to the bi radial.

The presentation will be different to the others and most of your recordings will bare a more obvious individual recording signature, such is the price for a true precision monitor.

But I find the ones recorded on JBL's sound fabulous and its obvious, they just sound f&^%ing great, particularly earlier vinyl Jazz and some contemporary artists like Billy Joel's 52 nd Street.

This is a great test for the 4345's, 4343's and the 4344. The difference in resolving power b/n CD and vinyl on the 4344 is night and day. Hopefully the SACD recordings of yours can lay rest to that .

Your done...for now. Hey you were seen and Stereophile's HIFI Show in NY recently. Don't worry, you can run the JBL demo next year Robert!

Ian

[Robh3606]

Damn don't I look just awful!:eek:

I am wired up OK every thing passes the phase tests and all. I don't have the 20 ohm resistor across the pot. You don't have it hidden?? I didn't see it. Good quess about where I am with these location and distance wise. I am a little close and not on axis but with more toe in because I am close to them. I was listening to some Alan Parsons and was just awed by what was going on.

'Alternatively, at this point you can use your RTA for a flat eq at the listener position (only) as the horns are non constant directivity. "

That's what I was trying and it was not cutting it. That's why I backed them down a bit. Not alot a dB or 2 and dropped the slot the same amount. I have the bass and mid the same with the horn and slot down a bit in level.

Hey Bo can you measure your set-up with the pots at 0?? It looks like you have the mid down a bit looking at your photo's.

Thanks Michael for the photo of the trimmers.

Just wondering how they measure on axis with the pots at 0. JBL graphs are averaged over 30 degrees. I am not using the stock 2308 and I can see right down the throat thru the lense. I wonder a little about that I can see them being hot on axis and flatter off just wondering if this is indeed the case. I know the lenses lobe a bit and was afraid to go to far off axis.

Rob :) :banghead:

[Robh3606]

Stock Tag as a reference

[Robh3606]

4345 Tag

You can clearly see the level diferences

[boputnam]

Originally posted by Robh3606
Hey Bo can you measure your set-up with the pots at 0?? It looks like you have the mid down a bit looking at your photo's. Yea, man - I certainly can.

I'm really B-USY right now, looking for scotty... :rotfl: and with some gigs, :dancin: , but I can, if needed. Note that the L-pads are not presently where they are pictured (above) - they were adjusted after I re-diaphramed the 2421B's.

However, I really think this moot - the "ideal" setting, is that that pleases you. Flat is one thing, but tweaking that flat to your preference is great. Who amongst us don't tweak...?

[Ian Mackenzie]

Well you are the Knob Fmer Bo,

Robert,

The resister is across the other side of the Pad (speaker side).

Try toe then back out a bit say 10 degrees, then level the Pads.

The off axis listener postion does not matter and find the image forms better, I think you will like that better.

Ian