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Thread: What was the couse with 2234H

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    Senior Member Niklas Nord's Avatar
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    What was the couse with 2234H

    What is the 2234H ment for? Subbas applications?
    Fast bass applications?

    is it a well performing driver in that range between 50 to 280hz ?
    better that 2235?

    A friend of mine has put the 2235H in 375liters box and
    ported to 21hz, and he says that he would not use it
    ower 55hz..

    im planning using 2235 in a subbas application, can i use
    the 2234 in between 50 to 280hz then?

    the difference between 2235 and 2234 ? weight? and then offcourse the FS...

    im planning to use the massring on the 2235 to 17HZ
    Best Regards
    .Niklas Nord, Stockholm Sweden
    Proud owner of the Project K2 s9500 system

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    "What is the 2234H ment for?"

    It was specifically designed for the 4435 Studio Monitor

    "Subbas applications?"

    Yes, when used in multiples and tuned much lower than "normal" to take advantage of low frequency mutual coupling.

    "is it a well performing driver in that range between 50 to 280hz ?"

    It's performance is excellent

    "better that 2235?"

    Between 50 and 280, arguably yes.

    "A friend of mine has put the 2235H in 375liters box and
    ported to 21hz, and he says that he would not use it
    ower 55hz.."


    In his specific application that may be the requirement. The transducer itself certainly doesn't have that kind of limitation.

    "im planning using 2235 in a subbas application, can i use
    the 2234 in between 50 to 280hz then?"


    Sure, but why when you can just duplicate the 4435 bottom end instead

    "the difference between 2235 and 2234 ? weight? and then offcourse the FS..."

    Yes, a 34 gram mass ring is the only difference between the two transducers. You can see the results of the mass ring by inspecting both transducer's TS parameters. The removal of the mass ring causes the Fs to shift up, Qts to shift down, reference efficiency to increase, usable frequency range to shift up, and high frequency response to become more ragged.

    One very interesting listening comparison is the 2235H with its mass concentrated at the apex of the cone versus the LE14H-1 with its mass distributed evenly over the entire surface of the cone.
    Last edited by 4313B; 04-19-2003 at 08:00 AM.

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    I have always been pleased with the overall low frequency response of the 4435's. In a studio I worked, for 4 years, we had the Westlake BBSM10's in the control room and Tannoy PB6.5 as well as NS10's.

    Main studio duty was JBL. 4412's and 4435's.

    The Westlakes had a rather physical low end but mostly below 50hZ. Output in the range of 65 to 110hZ did not "connect" as the 4435's displayed. The 4435's in stock form were equally physical throughout the entire bass range, without the boomy bloat of the Westlakes. It seemed the reactance VS resistance in the room was very well matched. I feel it is a great design in the stock approved enclosures. Very powerful and musical.

  4. #4
    Senior Member Niklas Nord's Avatar
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    ok

    Thank you Giskard!!
    Then i maybe will recone the empty baskets to 2234
    and have som fast bassdetail from 50 to 250hz ...

    is there a 2234 recone ?
    is there a 2235 recone ?

    what about the massring, can i buy these separately ?
    the 17FS massring for 2235 for example.

    is there any massring available for the 2245 sub ? 17FS ?
    Best Regards
    .Niklas Nord, Stockholm Sweden
    Proud owner of the Project K2 s9500 system

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    Hello,

    The 2234H and 2235H use the C8R2235 recone kit. Just have your reconer leave out the mass ring and have him give it to you in case you ever decide to use it.

    The mass ring is available separately.

    The 2245H already has the mass ring installed.

    -------------------------------------------------------------------------------------------------------------------------
    Ooops, my fault; looking at the 2245H, all the mass is in the cone assembly via aquaplas. No mass ring in the 2245H!
    -------------------------------------------------------------------------------------------------------------------------
    Last edited by 4313B; 04-20-2003 at 04:55 PM.

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    Originally posted by Giskard

    ...

    The mass ring is available separately.

    The 2245H already has the mass ring installed.
    Giskard,

    Do you know if there is a mass ring available for 2241H or 2242H?

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    -------------------------------------------------------------------------------------------------------------------------
    Ooops, my fault; looking at the 2245H, all the mass is in the cone assembly via aquaplas. No mass ring in the 2245H!
    -------------------------------------------------------------------------------------------------------------------------

    The 2241H and 2242H don't use mass rings and I couldn't say whether or not the 34 gram mass ring would fit. Installing it might impact Xmax or the suspensions might not be up to handling the added weight.

    Brief inspection of the published TS parameters for both transducers doesn't really fire up any enthusiasm for additional weight. I don't have time right now to work out the mathematics of the added mass ring but if you are REALLY interested I could possibly do so in the next few days.

    For VLF or "subwoofer" applications the 2242H works best in 8 to 10 cubic feet tuned to 25 Hz. A 25 Hz auxillary filter (Q = 2) is optional and can benefit a single 2242H. A 20 Hz high pass filter is recommended. When used in multiples the concept of mutual coupling makes properly placed 2242H's extremely effective, especially when bandwidth limited to below ~ 80 Hz, and a 25 Hz auxillary filter (Q=2) becomes superfluous.
    Last edited by 4313B; 04-20-2003 at 05:05 PM.

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    Administrator Mr. Widget's Avatar
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    ""Subbas applications?"

    Yes, when used in multiples and tuned much lower than "normal" to take advantage of low frequency mutual coupling.

    "is it a well performing driver in that range between 50 to 280hz ?"

    It's performance is excellent

    "better that 2235?"

    Between 50 and 280, arguably yes."

    Hi Giskard,

    Isn't it true though to get the performance that JBL achieves from the dual 2234s in the 4435, they do some crossover gymnastics.

    In the 4355 they use a pair of 2235s in parallel, but with the 4435 to get the higher sensitivity and better transient response of the lighter cone assemblies doesn't the crossover in the 4435 filter out one of the woofers early and tweak the signal they see?

    Have you had an opportunity to compare the parallel 2235 to the twin 2234 in the 4435? I am curious as in my 4355 clone setup I get a very tight and deep bass. I can appreciate the theoretical advantage in the 4435. I would be interested in observations anyone might have who has had first hand experience with these two set ups.

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    It has been a long time but if I remember correctly, one of the woofers in the 4435 is allowed to go higher than the other and both go all the way down. I remember one of them (listening up close) had a very low crossover point.

    I could be mistaken, it has been a very long time since I used them regularly.

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    Originally posted by Giskard

    The 2241H and 2242H don't use mass rings and I couldn't say whether or not the 34 gram mass ring would fit. Installing it might impact Xmax or the suspensions might not be up to handling the added weight.

    Brief inspection of the published TS parameters for both transducers doesn't really fire up any enthusiasm for additional weight. I don't have time right now to work out the mathematics of the added mass ring but if you are REALLY interested I could possibly do so in the next few days.

    ...
    Giskard,

    Thanks for a very informative answer!!! Using a mass ring in a transducer like the 2242H (or the 2241H) is something that I've been wondering about for quite some time. The reason to this is mainly out of curiosity ...

    I you feel that you have time to work out the mathematics I would be VERY grateful! Would a mass ring yield a better low-end response of the 2242H? What happens to the T/S parameters besides lowering the fs?

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    Hi guys,

    Yes, the 4435 does employ an 18 mH inductor on one of the 2234H's to attenuate signals above ~ 100 Hz. That's so the other 2234H matches the 2344A at the 1 kHz crossover frequency. One shouldn't have both transducers covering the same bandwidth going up that high. Plus the limited bandwidth of the other 2234H results in the required VLF response. I thought the plan here was to use the 2234H to ~ 300 Hz.

    As for transient response, the 4435 is only marginally better because much of the "inherently better" transient character of the lighter moving mass of the 2234H is "killed off" by forcing it to go so low. Remember my post about the 2242H versus the 2245H. The 2242H will go as low as the 2245H but not with the same "punch" because forcing it to do so "kills off" much of it's inherently better transient character. Now, you pretty much have to A/B these things to get the picture because frankly, they all sound so very good and only an A/B will reveal the differences.

    Yes, I've had the opportunity to compare the parallel 2235 to the parallel 2234 in the 4435, several times in fact. In my opinion the stock 4435 setup is slightly superior to the stock 4355 setup. Personally though I prefer a custom dual 2235H solution wherein each 2235H is in it's own 5.0 cubic foot volume tuned to ~ 28 Hz instead of the smaller volume of the 4355 tuned slightly higher. I find the slight bass hump of the stock 4355 around 30-32 Hz makes it harder to integrate into typical rooms than the 4435, which integrates very well with typical rooms. Many people like that slight bass hump in the stock 4355 though. I think the custom 2235H solution I just mentioned also integrates a bit better with the typical room.

    If he bandwidth limits the 2234H from 50 to 280 it will inherently sound "better" than a 2235H covering the same specific range providing both transducers are optimally loaded and tuned. If greater efficiency is required in a slightly higher bandwidth then the 2234 is the ticket, if VLF extension is prefered then the 2235 is the ticket. There is no way an optimally loaded and tuned 2234 will produce deep bass as well as an optimally loaded and tuned 2235, it is physically impossible, conversely, there is no way an optimally loaded 2235 will exhibit the same efficiency and transient character as an optimally loaded 2234, it's physically impossible. Forcing a 2242 or 2234 to produce VLF in the same realm as the 2235 or 2245 will obviously "kill off" some of the former transducer's "inherently better" transient character. Can't have something for nothing.

    That said, the 4435 LF and VLF response is "still" very impressive, despite it's "non-optimal" configuration. Take those same transducers and tune them ~ 10 Hz higher in slightly smaller volumes and they will smack you right out of the room with their incredible punch but that will kill off the VLF. Same thing with the 2242, tune it ~ 10 Hz higher than the stock 4645C and it will kick you around the room forthwith at the expense of VLF. The 4435 was built using existing parts thereby keeping costs down. It's almost a fluke that the 2234 can be made from the 2235 with the result being a very viable transducer. Not all transducers react so favorably. I just have a hard time getting excited about using a single 2235H for VLF and crossing over to a 2234H for midbass. I don't think it is a good use of two 15" transducers. I can see a 2245H for VLF going to a 2234H for midbass. I can see using dual 2234H for VLF and midbass ala 4435 and I can see dual 2235H for VLF and midbass ala 4355. I just can't see using a 2234H for midbass and a 2235H for VLF. Now maybe dual 2235's for VLF crossing over to a single 2234 for midbass, THAT could be exciting...

    Anyway, just my view of the situation.
    Last edited by 4313B; 04-21-2003 at 06:32 AM.

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    Hello neriks,

    Installing the 51629 mass ring in the 2242H will result in the following TS shifts:

    Fs will drop from 35 Hz to ~ 31.75 Hz. Qms will increase from 5.0 to ~ 5.51. Qes will increase from 0.29 to ~ 0.32. Qts will increase from 0.28 to ~ 0.30. no will decrease from 4.0% to 2.73% resulting in an SPL drop from ~ 98.2 dB W/m to ~ 96.5 dB W/m. Mathematically, adding the mass ring looks to be a reasonably viable endeavor.

    A 2242H in the 4645C enclosure with the mass ring added will extend LF response from -3 dB at 35 Hz to -3 dB at 27 Hz. Group delay will increase a mere fraction of a ms. It should be noted that the drop in efficiency as specified above will only begin to occur above ~ 60 to 70 Hz in the 4645C enclosure.

    Again, I have to stress that I have no idea if the 2242 will actually physically take the 51629 mass ring but careful removal of the dust cap and inspection should tell the tale. I'm fairly sure the suspension can handle the additional weight but would like to verify first before committing.

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    Administrator Mr. Widget's Avatar
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    Thanks for the overview of the 2235, 2234, 2242, 2245 woofers. This info falls in line with the theoretical and agrees with my practical experience.

    I was under the impression that the 3135 was a bit more complicated in the low end, but it makes sense that simply rolling off the upper end of one driver would balance it.

    As I was reading your post I was starting to think about a 2245 2234 combo myself. I guess most people go the 2226 route due to it's ability to take more power, but it would be very interesting to try.

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    Giskard,

    Thanks again for a very informative answer! Very kind of you ...

    Based on your calculations I think it would be better to refrain from adding the mass ring to my 2242H's ... I'm very pleased with the performance of my 2242H's as it is. One thing I've noted though, is that the sound becomes a little bit more accurate if I use a hi-pass filter to keep the frequencies below ~25Hz out of the 2242H's. I thought that the idea of using the mass ring could result in a better performance of the 2242H's under 25Hz. Perhaps it's better to use my 2245H's for this purpose, instead of tweaking my 2242H's?

    Once again, thanks for answering my questions

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    Well I guess it all boils down to what you have on hand and what you want to accomplish. The 2226 shifts the bandwidth even higher than the 2234. I think if you want to cover 50 to 300 the 2234 is pretty hot. It definitely "fills in better" than the 2226 below ~100 Hz. The 2226 definitely handles the juice, especially above 80 Hz, and it really cranks out the SPLs. Personally, I really like the broader, flatter response of the older transducers for home but there is definitely a great argument for the lower distortion and power compression coupled with the tighter bandwidth and higher efficiency of the newer models. They are indeed SOTA.

    In the end, it's probably not a good idea to attempt to retrofit the newer drivers into the older designs but to start from scratch instead and exploit the "different" bandwidths of the newer transducers if you're going to use them. I just love the LE14H-1, 2235H, and 2245H for VLF work in the home whereas I can't imagine using a 2245H in place of a 2242H in SR anymore. It just wouldn't happen. The older designs simply can't compete with the newer designs for dedicated SR work these days. In the home the older designs are still, to this day, more than capable of maintaining their venerable legacy.

    The bottom line is, if someone is having a problem exploiting the potential of a 2235 or 2245 then they aren't using it properly. By design, there is nothing inherently "wrong" with the transducers. These aren't junk drivers. If someone is having a problem exploiting the potential of a 4645C with a 2242 or a 4648 with 2226's then they aren't using it properly. etc. etc.

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