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Thread: 2231/2235 driver dilemma

  1. #1
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    2231/2235 driver dilemma

    I have been looking for 2231 drivers without much success.
    I have 8 cu ft cabinets to use them in.
    I have found some LE15s reconed as 2235 and was wondering what is the difference other than a slightly higher free air resonance and incidental differences in Thiel/Small specs that I can compensate for in the port tuning as opposed to the 2231?
    Is the LE15 basket/magnet the same as the 2235 or is this an abortion with unknown specs?
    Ceramic magnet LE15.
    Does anybody have facts or opinions?
    Or has anybody tried both drivers in a home stereo situation?
    I will use a 2121 mid an Altec 808-8A driver on a constant directivity horn all tri- amped with Bryston amps and electronic crossovers.
    Right now I have 2220s and 808-8As on 811B horns and have too little bass and way too much midrange.
    It's like starting a funny car in a 1 car garage.










    Thanks
    Bloys Dekker
    Kawasakitech

  2. #2
    Senior Member HCSGuy's Avatar
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    A 2235 Cone in a LE15 frame is an abortion - the 2235 is a long excursion, overhung voicecoil design, while the LE15 is underhung - stay away from that one, as the results are a complete unknown, but probably bad.

    For home use, a 2235 should get you much more first octave than a 2220, but any bass woofer will be at least 10db less efficient than your horn. If you have lots of space, you could try a bass horn or a scoop on your 2220 (it still won't go below 40hz or so). What is your goal; extension or bass slam?

    Lastly, what's the appeal of a 2231a (alnico) or 2231h (ceramic), other than period authenticity?
    That the internet contains a blog documenting your life does not constitute proof that your existence is valid. Sorry.

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    Clarification

    Hi

    Thanks for the info.
    I thought that a 2231 would give good low bass extension as it has a very low free air resonance (16HZ) in an 8 cuft cabinet.
    I put the 2220's in the large cabinets and fudged the alignments but have now come to realize that doesn't really work as the response will droop off at too high a frequency.
    I have tried a bass booster supplied with a Cerwin Vega speaker (6th order alignment) and a SAE parametric EQ but it's not what I'm looking for.
    The 2235 resonance is higher at 20HZ.
    I am looking for good low bass extension as well as a realistic sound.
    I want a drum kit to sound like a drum kit with all the immediacy and impact but not necessarily at a true volume level, maybe a bit less as a drum kit in a small living room can be a bit much.
    I was under the understanding that the 2220 was designed for midrange efficiency and not low bass extension.
    I also find that it has too much midrange, a product I believe comes from the beaming effect of a large diameter driver at higher frequencies.
    That is why I plan to use the 2121 10" as a mid, crossover points 300z and 1.2KHZ.
    I can set the levels as I want/need as the system uses tri-amp with active crossovers and all power amps have level controls.
    I normally drive the 2220 at less than 1 watt at normal listening levels, quite loud and thought that the 2231 or 2235 could easily handle the extra power required to produce the same volume levels.
    I have also considered building folded horns as per Bill Fitzmaurice using 2225 drivers that I also have.
    Vancouver Audio Speaker Clinic's David Lee said that a horn would not integrate well with the 2121 mid.

    Thanks

    Bloys

  4. #4
    Senior Member 1audiohack's Avatar
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    Were it me, I would use the 2220's in between the bass horns and the 2121's. That will get you the dynamic drum kit sound I'll bet. I love the 2220-2123 combination. Which one of Bill's horn plans are you looking at? What goes above the 2121?
    If we knew what the hell we were doing, we wouldn't call it research would we.

  5. #5
    Dang. Amateur speakerdave's Avatar
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    The 2231 cone kit has been out of production for quite some time (decades?), replaced by JBL in its parts catalogue with the 2235, and originals are highly prized by restorers who want period authenticity. Finding a usable pair would be a remarkable stroke of luck.

    The 2235 gets low enough for music. The question I have is whether one on each side would be enough. In the JBL legacy it may be that the 4350/4355 is closest to the kind of sound you are looking for. It uses the 2235 in pairs, all the necessary parts are obtainable and the crossover has been adapted to an auto-transformerless version you could build.

    The 2121 is the least preferable 10" unless you are locked into using the crossover from the 4343. The 2122, 2123 and 2012 would all be better, and in the 4350/55 the 12" 2202 might bring you closest to your drum kit sound.

    Also, the proposed direction you have described reminds me of the Drew Daniels Ancient Audiophile system. He used 18" woofers, 2220's from 80 to 300, the 2123, a large format horn at 1200 Hz and a supertweeter. However, the enthusiasm sparked by his narrative makes it easy to gloss over the fact that he resorted to custom frequency response tailoring in his amps and used some very sophisticated and expensive equipment for final set up. Without those things it could sound really horrible.

    All of the drivers mentioned require response compensation in h fi systems. You can provide this as Daniels did, in passive filter networks, or with external EQ, but it is probably impossible for most people to do any of those without the ability to do acoustic testing (i.e,, CLIO or the like). Therefore, you would almost certainly be more successful by replicating an engineered system, and the one which comes to mind, as I said above, is the 4350/55.

  6. #6
    Dang. Amateur speakerdave's Avatar
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    Some additional thoughts

    To improve things in the short term you could probably make your present set up more balanced with a couple of simple measures. If the 808-8A's have the original diaphragm, they are a PA diaphragm built for toughness and they have truncated HF response. Replacing those with the hi fi version would improve the highs.

    Also, if you are using your EQ to bring up the bass, I think that is the wrong idea. Use it to bring down the mids. i.e., put a broad watermelon smile across the whole scale. If you don't have a test set up, you will need to fiddle with it, maybe quite a bit, until you get a response you like, or maybe forever. You could start with published frequency response curves of the components you are using.

    Finally, if your 811 is not bolted to a cabinet, it's ringing, and that will definitely tire out a listener. It should be mounted to something or damped with duct seal or the like.

  7. #7
    RIP 2013 Rolf's Avatar
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    Hi. Are you saying that 2121H is not as good as the 2122H, 2123H? The 2123H does not match in the 4343B's at all.

    Rolf

    Quote Originally Posted by speakerdave View Post
    The 2231 cone kit has been out of production for quite some time (decades?), replaced by JBL in its parts catalogue with the 2235, and originals are highly prized by restorers who want period authenticity. Finding a usable pair would be a remarkable stroke of luck.

    The 2235 gets low enough for music. The question I have is whether one on each side would be enough. In the JBL legacy it may be that the 4350/4355 is closest to the kind of sound you are looking for. It uses the 2235 in pairs, all the necessary parts are obtainable and the crossover has been adapted to an auto-transformerless version you could build.

    The 2121 is the least preferable 10" unless you are locked into using the crossover from the 4343. The 2122, 2123 and 2012 would all be better, and in the 4350/55 the 12" 2202 might bring you closest to your drum kit sound.

    Also, the proposed direction you have described reminds me of the Drew Daniels Ancient Audiophile system. He used 18" woofers, 2220's from 80 to 300, the 2123, a large format horn at 1200 Hz and a supertweeter. However, the enthusiasm sparked by his narrative makes it easy to gloss over the fact that he resorted to custom frequency response tailoring in his amps and used some very sophisticated and expensive equipment for final set up. Without those things it could sound really horrible.

    All of the drivers mentioned require response compensation in h fi systems. You can provide this as Daniels did, in passive filter networks, or with external EQ, but it is probably impossible for most people to do any of those without the ability to do acoustic testing (i.e,, CLIO or the like). Therefore, you would almost certainly be more successful by replicating an engineered system, and the one which comes to mind, as I said above, is the 4350/55.

  8. #8
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    Quote Originally Posted by Rolf View Post
    Hi. Are you saying that 2121H is not as good as the 2122H, 2123H?
    The 2122 was developed specifically to improve upon the 2121.
    Quote Originally Posted by Rolf View Post
    The 2123H does not match in the 4343B's at all.
    No it doesn't. It is significantly more efficient than the 2121 and has a rising response that arguably needs taming.

    For what it's worth, I always liked the looks of the LE10A, PR10 and 2121A. I really liked that inverted dome look.

  9. #9
    RIP 2013 Rolf's Avatar
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    Me too.

    [QUOTE=4313B;331784For what it's worth, I always liked the looks of the LE10A, PR10 and 2121A. I really liked that inverted dome look.[/QUOTE]

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    Clarification

    Hi

    Thanks everyone that's providing info for thought, research or experimenting.
    I bought the 2121s off Dave at Vancouver Audio Speaker Clinic.
    I was phoning around for 2123s and he asked what are they for, stereo use in a small room I replied and he recommended the 2121.
    I was planning to keep the 2220 as you recommend but put it in a smaller cabinet, as per Thiel/Small.
    The 811B is mounted in a cabinet, flange siliconed to the wood damped with duct tape on the lips, damped with insulation foam inside the cabinet and the driver is solidly mounted in a saddle inside the cabinet.
    I have listened to it for 20 years and it sounds much better than most, the ringing is controlled as well as I can figure.
    The 808-8A driver has an aluminium diaphragm with a plastic surround, Symbiotic I think it's called, also from Dave at Vancouver Audio Speaker Clinic.
    I also have a couple of Motorola piezo horns per side, they seem to sound OK.
    I am planning to build Bill Fitzmaurice's Home Theatre Subs (Tuba 30") with 2225 drivers

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