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Thread: JBL 18 inch up to 300 Hz?

  1. #1
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    JBL 18 inch up to 300 Hz?

    Hi,

    I would like to use a driver between 40 Hz an 300 Hz in a domestic environment. I was thinking about an 18 inch (2241) just to keep the excursion to minimum.

    Is someone running such a large driver that high? How does it sound at the higher frequencies (300 Hz) compared to a smaller (15 inch) driver?

    Thank you,

    M
    Last edited by mefisto; 02-12-2007 at 05:19 AM. Reason: Correction

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    Administrator Robh3606's Avatar
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    Look at the 4345, uses the 2245 up to 300Hz with no problems at all.

    Rob

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    Just to play devils advocate, I believe, for home use, and for the range you specify..if you can find a 2231 (L136). you'll do better. If you can find an earlier alnico magnet model all the better. It can also be used in smaller enclosures (3-5 cu. ft is good) and will yeild reasonably flat response to 40Hz, and will sound better in the upper range. R

  4. #4
    Nightbrace
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    Earth narrows down your location .

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    Nightbrace
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    What about floating on an 11 dimensional membrane?

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    Generally, a design shouldn't require a cone driver to reproduce frequencies with wavelengths smaller than the cone diameter, so the driver can operate in pistonic mode over its' full bandwidth. For an 18", this is approx. 700Hz, for a 15" it's around 1100Hz.

    The main remaining issue is intermodulation distortion, which rears its' head when a driver has to deal with much more than 2 octaves.

    Also for consideration is the effect of having an XO point in the midst of the musical fundamental range, but that's an unavoidable issue in multi-way broadband systems.

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    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by mefisto View Post
    I would like to use a driver between 40 Hz an 300 Hz in a domestic environment. I was thinking about an 18 inch (2241) just to keep the excursion to minimum.
    I'd recommend the 2245 as it just sounds better to me... and to many others. I wouldn't worry about the excursion thing... unless you are you planning on SPLs of 120dB. If you are, use several of them.

    Is there a reason you want to bandwidth limit the system below 40Hz?

    Quote Originally Posted by Robh3606 View Post
    Look at the 4345, uses the 2245 up to 300Hz with no problems at all.
    Yes and no... I personally think the 4345 would sound even better if the crossover was around 150Hz or even lower. It isn't really possible with that driver compliment and the ~300Hz XO was the best option... it isn't terrible by any stretch, in fact the 4345 is one of my favorite JBL systems, but for ultimate resolution, that massive cone does seem to cloud a small portion of the music just a tad.


    Widget

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    Thank you all for your answer, although I have some difficulties deciphering Nightbrace's recommendations. ;-) But then again, I am not the smartest guy around.

    Dear Mr. Widget,

    The bandwidth is dictated at the upper frequency by the horn I will be crossing over to between 250-300Hz. On the lower frequency, in my room, room gain starts at about 60-70 Hz. So I was thinking that the roll-off of the driver will be compensated by the room gain.

    If there is a better driver for the intended puurpose, which will assure low distortion and high sensitivity please recommend it to me.

    Kindest regards,

    M

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    Moderator hjames's Avatar
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    Quote Originally Posted by mefisto View Post
    Thank you all for your answer, although I have some difficulties deciphering Nightbrace's recommendations. ;-) But then again, I am not the smartest guy around.
    Nah, NightB was jest diggin' at you for using the oblique "Location: Earth" in the user details you "shared" with us ...

    perhaps you'd bless us by a using a more specific point on the ol' globe ...
    2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
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    Actually, I am running 2245's 40-290Hz in my 4345's and it isn't bad at all. I plan to try substituting a pair of Alnico 2235's (easy to plug and play with Speakons, now ) and see if there is any difference.

    The only immediate downside is that I end up with a lot of large boxes in the listening room....

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    hjames wrote: "Nah, NightB was jest diggin' at you for using the oblique "Location: Earth" in the user details you "shared" with us ..."

    Sorry, I did not realize that - I noted that I was not too smart. However, in my case it is rather true because I spend a lot of time in different parts on the Earth. Currently, I am in Munich, Germany.

    Dear Chas,

    Why are you considering the change? Once you get any results, could you please share them?

    Thank you,

    M

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    More than 3-way

    Have you considered running one of several available JBL 10-inch drivers in between the big cone and the horn? Sub-enclosure requirements are minimal, so using a pair could be a possibility.

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    Hi, I actually was not contemplating a permanent change. I just thought I would give it a try for fun, since I have them kicking around.

    My 2235's are in pairs mounted vertically with two vents at the top and two at the bottom. This arrangement always sounded nice to me in the mid-bass. I think this was partly due to the actual woofers being higher off the floor compared to the 2245/4345's. I.E. less coupling with the floor to muddy things up. This is just a guess though, on my part.

    I recall that the articulation was outstanding with acoustic plucked bass on jazz recordings. I will post the results when I have time to do it.

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    Quote Originally Posted by whizzer View Post
    Have you considered running one of several available JBL 10-inch drivers in between the big cone and the horn? Sub-enclosure requirements are minimal, so using a pair could be a possibility.
    Nice idea . Any suggestions for drivers? I wasn't aware JBL still had any available.

  15. #15
    Moderator hjames's Avatar
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    Quote Originally Posted by Chas View Post
    Nice idea . Any suggestions for drivers? I wasn't aware JBL still had any available.
    Try a pair of 2123s. I got mine off ebay, but perhaps available as JBL B stock perhaps. I saw a pair go recently for under $200.
    ... 250 W continuous pink noise power capacity. 76 mm (3 in) edgewound aluminum ribbon voice coil. 80 Hz-6 kHz response ...
    http://www.jblpro.com/pub/obsolete/2123.pdf

    Still waiting for my 4 way crossovers so I can tie them in with my 4320s as pseudo 4343s
    2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
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