JBL Array 2235 Be project

Discussion in 'DIY Discussion' started by cooky1257, Sep 17, 2009.

  1. cooky1257

    cooky1257

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    I think it pretty obvious that I have a passion for the Tannoy DC in all its guises(with the exception of the FSM which is a snarling dog imo!) what hasn't been clear is my secret passion for the JBL monitor sound. There's nothing quite like them and probably not a speaker built that rocks like a JBL can.
    A while ago I picked up some tired and jaded TM1 clones that had a bit of history being the monitors from Pluto sound studios in Stockport where they'd been on monitor duty for both (part of)the Smiths first album and Bankrobber by the Clash.
    This project came about after realising that my largish end terrace just wasn't big enough for some Westlake TM1 clones and Tannoy 215 clonesbut it may be for some of the newer JBL monitors like the excellent 4338's http://www.jbl.com/home/products/pr...age=ENG&Country=US,US&Region=&cat=BFS&ser=LSR
    JBL publish Tech sheets with xover schematics/driver compliments, part numbers etc and it became clear that both JBL Pro and Consumer were using the same drivers across the top of the range models with the drivers having different model numbers in each area.
    The mid/hf is a relatively new neo magnet 3" compression driver 435 Be/2435 HPL or 435 Al/2431H and the UHF either a 045Be or the 045ti. http://www.jbl.com/home/technology3c.aspx?Language=ENG&Country=HA&Region=
    The consumer variant mid/hf is 'dusted' with Aquaplas, a damping compound used widely by JBL in its flagship models.
    What these units aren't is cheap-the mids alone retail at $1300 each with new dias a stonking $600.
    Another problem is sourcing horns that can work with these units-they need to go low-around 7-800 hz only cloned H9800 are available as JBl wont sell.
    In each case I got very lucky-though that did dictate the type of flagship model I was attempting to copy.
    As a variant of the horn used in the 4338-the 4338H forms the basis of the SAM1HF horn as used in the new Array series and is rotated 90'.
    These are SOTA Bi Radials molded in Sonoglass an acoustically inert resin and are far removed from bi-radials of old.
    The pro version of the mid hf can sometimes be sourced via eBay for a not unreasonable $300-400 but you do need to give them a good gap clean, recharge the ferrofluid and if you've the bottle dust them with Aquaplas.The UHF can only be sourced from JBL with the Be version $900 a pair-I opted for the ti(titanium) version a more modest $400.
    Anyway heres where I got lucky, I managed to source some perfect 2435HPL drivers via eBay and best of all a pair of very slightly dinged SAM1 HF horn flares free of charge from a JBL tech on the Lansing forum.
    So I was going to build a variant of the 1400 Array using the beryllium version mid/hf and the stock 045 titanium UHF driver on SAM 1HF horns mated to because I had 4 kicking around, the ubiquitous 2235 bass driver.
    The set up will be active bass rolled off at 750 hz and the passive network from the Array crossing at 750/8k. The stock network has been tweaked to get the best from these drivers so I'm cloning it.
    Over the next few days I'll post all the stuff I have so lets start with reconing the old and (arrrgghhhh)front refoamed AlNiCo 2231a to 2235:
     

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    cooky1257, Sep 17, 2009
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  2. cooky1257

    cooky1257

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    cooky1257, Sep 17, 2009
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  3. cooky1257

    cooky1257

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    You have to be very careful to line up the lead out wires with the frame terminals and also to get an even and smooth spread of glue around the frame/surround.
    After checking there's no fouling of the vc leave over night to fix. The scariest bit is gluing the dome as it's so easy to get glue all over the place and also to place it off centre-I made a lining up jig from masking tape so Bob's your aunty job done.
    The cost of these recone kits is such, shocking european prices, that I'd recommend using a JBL service centre as JBL will not guarantee the kits unless professionally installed and it is easy to cock it up.
     
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    cooky1257, Sep 17, 2009
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  4. cooky1257

    joel Shaman of Signals

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    Great fun to watch someone else do, but far too scary ever to contemplate doing myself. Seems a shame not sprinkle some Aquaplas foo next...
    Highly rated on the LH forum as you well know.
    Sadly, JBL Pro don't use Aquaplas or a paper cone on their 3-way studio monitor. I guess that would be for cost savings.
     
    joel, Sep 18, 2009
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  5. cooky1257

    andyoz

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    Nice one Cooky.

    I will never have the guts to attept any re-cones....:eek:
     
    andyoz, Sep 18, 2009
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  6. cooky1257

    cooky1257

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    Designing and building the enclosures

    s.
     
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    cooky1257, Sep 18, 2009
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  7. cooky1257

    Dev Moderator

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    I'm getting very excited, no good will come of it :D.
     
    Dev, Sep 18, 2009
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  8. cooky1257

    cooky1257

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    Magic Dust

    Probably the most nerve racking thing I had to do was applying Aquaplas solution to extremely thin and expensive Beryllium diaphragms. Having heard the drivers in their raw pro guise and running the system full range as a 2 way they sounded incredibly detailed so I did have second thoughts. Getting the right consistency of the water soluble Aquaplas was difficult as was the correct thickness.
    I practiced on coke cans cut to reveal a rather handy alloy dome to learn on.
    Too thin a solution and the Aqua acts as a solvent on itself, pooling and failing to adhere, too thick and it wont brush.
    JBL spray it on but I carefully measured out 0.3g of Aqua paste and went for it with a sable chisel tipped artist brush:D
    [I
    The sound improvement/difference was not subtle, more focused, precise, inner details were/are clearer the slightly forward hash now gone these are very very smooth and detailed. Reseating the diaphrams may also have played a part here but what I hear is in keeping with the reported damping effect of Aquaplas.
    Note the patented diaphragm jig; 2 straight sided Guinness glasses.
     
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    cooky1257, Sep 18, 2009
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  9. cooky1257

    cooky1257

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    Hi Joel, Any of the monitors that use the 435Al or 435Be are Aquaplased
    What 3 way monitors don't use paper cones? The 1500AL is paper as is the 1500FE-with a rear cone treated with Aquaplas too.
     
    cooky1257, Sep 18, 2009
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  10. cooky1257

    andyoz

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    Yep, a great sounding driver. Not too OTT in terms of expense. More systems should use them to get efforless bass.

    One of Greg Timbers (JBL designer) favourite drivers apparently. He's particularly proud of how they sound in the wee S4600 which by all accounts sound much better than they deserve to (given the cost relative to the rest of that "S" range).
     
    andyoz, Sep 18, 2009
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  11. cooky1257

    cooky1257

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    Hi Andy, did I see an old post of yours with 2 LE14 drivers in boxes? Do you carry spares for your 250's?

    I've just mailed Giskard about Greg Timbers' 1500AL's-spotted the ad too late I think:(
     
    cooky1257, Sep 18, 2009
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  12. cooky1257

    andyoz

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    Yea, I have a spare pair of LE14H-1's boxed-up in the loft. They were taken out of the 250Ti's I bought 3 years ago. The surrounds were on the way out and I managed to pop them completely with a too hasty cable connection to my power amp one day.

    I couldn't get a re-cone kit for a decent price (they needed re-cone not just refoam) so bought brand new LE14H-3's from the Harmion dealer in the UK - paid about £300-350 for the pair. That was less than they were charging direct from the main Harmon dealer in France. the UK dealer went bust so I think there pricing was a bit weird.

    Anyway, no more foam surrounds to worry about :cool:

    Here's an old post with them shown.

    http://www.zerogain.com/forum/showpost.php?p=210967&postcount=164

    [​IMG]

    [​IMG]
     
    andyoz, Sep 18, 2009
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  13. cooky1257

    cooky1257

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    Wow that's a seriously good bargain.
     
    cooky1257, Sep 18, 2009
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  14. cooky1257

    andyoz

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    Just checked the invoice and they were £381 incl VAT. I ran them thru the busienss so tax deductible :D

    I think France wanted to charge about 40% more than that even before shipping was included...weird as I've heard all the Euro JBL stuff comes thru France. I know that when I sent the enquiry to Harmon in the US, they sent it back to Harmon in France who sent in the UK dealer I had never heard of. Some small dealer in Bristol or something. Harmon have made a complete mess of how their products are handled in the Eurozone from what I can see.
     
    andyoz, Sep 18, 2009
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  15. cooky1257

    cooky1257

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    Yeah agreed, just as they have some truly astonishing speakers to sell they seem to have fluffed it. The Euro zone pricing is also ridiculous and it isn't all down to import duty either.
     
    cooky1257, Sep 18, 2009
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  16. cooky1257

    joel Shaman of Signals

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    A *very* different beast, but reportedly very good:
    [​IMG]

    LSR6332

    Still really like the look of these:
    [​IMG]
    There's a s/h pair in chiba right now that could be had for less than 500,000 yen. Sadly, I don't have spare cash atm, but that's certainly in the ball park.
    And their overall footprint would be no more than the yams.
     
    joel, Sep 18, 2009
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  17. cooky1257

    cooky1257

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    Ah, I getcha.
    Those do look nice, the Yams are a tough act to follow though can't you use your birthday money?:D(many happy returns by the way!).
     
    cooky1257, Sep 19, 2009
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  18. cooky1257

    joel Shaman of Signals

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    Only another 499,950 yen to go :)
     
    joel, Sep 19, 2009
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  19. cooky1257

    andyoz

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    That's about £3,400. Still sounds a bit steep to me. What do they retail for in Japan then?

    S9800's fetch only twice that second hand over there don't they? A much more signifcant long term investment surely...
     
    andyoz, Sep 19, 2009
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  20. cooky1257

    andyoz

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    I read a technical review of the LSR6332 from a well regarded studio designer (Philip Newell).

    On every count, the LSR6332 performed incredibly well for a system that doesn't really cost the earth - about £2,500/pair. On-axis, Off-axis Frequency response, distortion, etc. Just shows you don't need a dome mid to produce good results. I think his general conclusion that the crossover is REALLY well sorted on them and whoever did it knew the drivers like the back of their hand.
     
    andyoz, Sep 19, 2009
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