Page 1 of 7 123 ... LastLast
Results 1 to 15 of 97

Thread: JBL 4355 clone with different woofers

  1. #1
    Senior Member
    Join Date
    Jan 2007
    Location
    Vicenza - Italy
    Posts
    114

    JBL 4355 clone with different woofers

    Hello to all the members of this beautiful forum. I have been an avid Italian fan of JBL products since the 1970s and I own many JBL professional series components. I want to make a clone of the JBL 4355, but I would like to use the JBL 2226H I already own instead of the JBL 2235H woofers (2202H, 2441H with lenses, 2405H are in my possession). I know that the JBL 2235H woofers have a lower frequency response than the JBL 2226H (stratospheric? Are they close, is it a small thing?), That I will have to recalculate the volume and the tuning tubes and many other things, problems that, however, I will be able to to solve. My only doubt lies only in the answer below; is it a little or a lot? I would like your opinion, thank you and good day to all
    Giuseppe

  2. #2
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    8,704
    Hello Giuseppe

    Why not try them out.

    The woofers in that system are used with a limited bandwidth up to 300Hz or so. With them being bi-amped the sensitivity difference will work in your favor and the power handling of the 2226's is better than the 2235. If you run them in a box program you can see immediately what the on paper differences will be. Just be flexible when you build your cabinets so you can change your port lengths if needed.

    In the real world the differences may not be as significant with music.

    There will be a difference in the first octave 20-40Hz but on many types of music you should be OK. You can also add some EQ if needed. You are going to have plenty of headroom available with a pair of 2226's. You could run them in an assisted alignment with a bump filter if it works out in the box simulators.

    If you are not happy then I would look for the 2235's.

    Rob
    "I could be arguing in my spare time"

  3. #3
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,995
    Quote Originally Posted by audiophile.1963 View Post
    Hello to all the members of this beautiful forum. I have been an avid Italian fan of JBL products since the 1970s and I own many JBL professional series components. I want to make a clone of the JBL 4355, but I would like to use the JBL 2226H I already own instead of the JBL 2235H woofers…
    Since you already own the 2226Hs, I guess you have little to lose. They do have different cabinet requirements though.

    Is building cabinets a simple task for you or is it a major effort? I ask because some people can bang out a set of cabinets in a weekend and others can take weeks, months, or more. If you are in the second category, I would suggest building the cabinets to the required 10 cu. ft. spec and place bricks, place mini boxes, or some other devices inside to bring the volume down to the required 8 cu. ft. for the 2226Hs.

    You should plan on changing the port tuning to 40 Hz for the 2226Hs. These ports can be swapped out and replaced with ~28-30Hz ports if you decide to change your woofers at a later date. If the 2226Hs don’t work out for you, you pull out the bricks and have your 10 cu. ft. enclosures ready for 2235Hs.

    Alternatively you might consider upgrading to a pair of 2216Nd. These woofers are available to buy new, and are a superior design to the 2235Hs and are intended for similar applications. These should work well as a drop in replacement for the 2235Hs.


    Widget

  4. #4
    Senior Member
    Join Date
    Jan 2007
    Location
    Vicenza - Italy
    Posts
    114
    “Is building cabinets a simple task for you or is it a major effort? I ask because some people can bang out a set of cabinets in a weekend and others can take weeks, months, or more. If you are in the second category, I would suggest building the cabinets to the required 10 cu. ft. spec and place bricks, place mini boxes, or some other devices inside to bring the volume down to the required 8 cu. ft. for the 2226Hs.”

    I have no problem to built a prototype of the cabinet and my idea is what you suggest. Using an EQ, do you think that I could obtain a lower response (closer to 2235)?
    Giuseppe

  5. #5
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    Hi Giuseppe,

    RE" is it a little or a lot?"

    4355 LF chamber internal volume is 265 L (9.5 cu.ft) and the box is tuned to 32hz (spec sheet). It doesn't specify if that LF volume is actually gross, or net after subtracting space taken by drivers, bracing, etc.

    The 2235 is modeled by JBL using a 140 L (5 cu.ft.) box tuned at 30 hz with flat response (spec sheet)

    The 2226 is modeled by JBL using a 140 L (5 cu.ft) box tuned at 40 hz but having a little droop in LF response (spec sheet), that's a small flag

    In the JBL Enclosure Guide the 2235 is specified for 5 cu.ft. box (140 L) tuned to 30 hz

    In the same Enclosure Guide the 2226 is specified (single) for 4 cu.ft. (113 L) tuned to 40 hz, and for double woofer 8 cu.ft. box (227 L) also tuned to 40 hz, that's another flag

    The message here is 2235 is consistent in JBL's box data but 2226 cab size is not. I think there's some marketing in the 2226 5 cu.ft. enclosure. The explanation isn't new, 2226 is a sound reinforcement optimized driver where efficiency is king, that shows in the maximized sensitivity rating (97 db) at the expense of some lower bass capability. Whereas the 2235 was engineered more along the lines of a Hi-Fi woofer for VLF bass reproduction, however as expected at a lower sensitivity level (93 db). That 4 db difference may seem like a little but in reality, for the same type of system, its a lot and implies compromises had to be made to get to that higher sensitivity number. 2226 is not really a 30 hz driver, more likely a 40 hz one.

    There are pitfalls associated with wanting to go too low with a woofer (in point form): risk tuning below Fs; QB3 LF alignment here, not a C4 which is a different story; down tuning puts more strain on woofer, VLF reproduced at a lower level; lower tuning than normal has unwanted consequence on driver output capability higher in the spectrum, displacement overload possibility (excursion); etc.

    As for box volume reduction, i'd use old books instead or pieces of lumber (2X4, 3X3 or 4X4") as filling material placed at bottom back of cab, about a cubic foot+ in each. Books are lighter, easy to handle and to find. You can buy few stacks of cheap books at a flea market for little money, the story they tell doesn't matter here... Regards,

    * Last minute reply to post # 4: EQ won't change the 2226 capability, it won't make it a 2235. On the other hand the EQ you have in mind would imply EQing below driver Fs and box Fb, this is risky business for woofer health. For my part and taste 40hz bass is quite acceptable, i live with that very well.

    Richard

    P.S. Regarding your initial question, charts/graphs exist where one can get an idea of proper volume cab and tuning frequency (even F3), without having to input and model data in speaker design software, just a little elementary math with Fs, Qts and Vas driver parameters. Its not Keele's Approximate Vented Box Design using the same driver parameters (have this also), its much simpler than that having to locate and multiply two numbers only in each of the three charts/graphs (Vb, Fb, F3). The drawbacks are it gives maximally flat LF alignments only, and its copyrighted material i can't reproduce...

    Here's the results i got using this simplified quick modeling method for 2226 and 2235.

    One 2226: optimum Vb 87.5 L (3.1 cu.ft.), tuning 48 hz, multiply Vb by two for double woofers

    One 2235: optimum Vb 92-115 L (3.25 - 4 cu.ft.), tuning 29 hz, multiply Vb by two for double woofers. Graph resolution for this multiplier number wasn't great, using .20 or .25 as multiplier (the most likely) made a notable Vb difference in this case. So tolerance is a little larger here, i think 100 L or so Vb would be about correct (max flat).

    Remember these are valid for maximally flat response only, typical users Vb would be somewhat larger, not everyone is seeking max flat, nor every project requires that either. Still gives an idea regarding "a little or a lot" for Vb. Based on the above, i think you will need less Vb using 2226 vs 2235, hence the 4355 box filling mentioned in case you change your mind about driver, and personnaly i wouldn't try to tune that 2226 cab below 40hz.

  6. #6
    Senior Member
    Join Date
    Jan 2007
    Location
    Vicenza - Italy
    Posts
    114
    ... I don't know if it is important, my 2226 is the version HPL
    Giuseppe

  7. #7
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    The info i have and gave you is for the "G, H, J" versions...

  8. #8
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,995
    Quote Originally Posted by audiophile.1963 View Post
    I have no problem to built a prototype of the cabinet and my idea is what you suggest.
    Great, that is the right approach.

    Quote Originally Posted by audiophile.1963 View Post
    Using an EQ, do you think that I could obtain a lower response (closer to 2235)?
    Giuseppe
    Yes, but with limited max SPL output.


    Widget

  9. #9
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,995
    Quote Originally Posted by audiophile.1963 View Post
    ... I don't know if it is important, my 2226 is the version HPL
    Giuseppe
    This is the standard H version but without the rubber tire around the magnet. It is essentially a lower cost version that JBL used in their own cabinets as opposed to direct sale version of the driver sold as individual raw drivers.


    Widget

  10. #10
    Senior Member
    Join Date
    Jan 2007
    Location
    Vicenza - Italy
    Posts
    114
    What do you think about this project?
    https://mainkas.tripod.com/page/audi...ngen_sub2r.htm
    Giuseppe

  11. #11
    Senior Member
    Join Date
    Aug 2017
    Location
    WDC USA
    Posts
    182
    I'm currently listening to a system with a single 2226H in an enclosure originally designed for a JBL1500F subwoofer driver tuned to 25h. I use an Ashly 4.24D DSP unit to provide step down equalization and crossover functions. The system works well down to 30hz and is high passed at 25hz. This is powered by pair of 60 watt amp channels in mono for a small living room area and crosses over into a pair of JBL 4828 speakers. For a larger area or higher listening levels than I can reasonably run in my townhouse I could easily go to a 300 watt amplifier without exceeding the power capacity of the 2226.


    Quote Originally Posted by audiophile.1963 View Post
    What do you think about this project?
    https://mainkas.tripod.com/page/audi...ngen_sub2r.htm
    Giuseppe

  12. #12
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    Hi Riley,

    RE "to provide step down equalization" ; "The system works well down to 30hz"; "I could easily go to a 300 watt amplifier without exceeding the power capacity of the 2226." My observations about this.

    Power capacity is the driver's thermal limit (600W here), not the excursion limit which is what we're really interested in this case considering you're talking about a subwoofer cab.

    Your box size is not mentioned i took the 5 CF box indicated in the 2226 spec sheet and did some scenarios in speaker modeling software. If it was larger my results could be worst than shown here.

    In my view its very unlikely the 2226 could take 600 W, at 30 hz for example, or even somewhat higher, since my normal mode modeling, sort of a best case scenario, shows 300 W (just making it). And this using a more forgiving software program with RMS excursion measures (say sustained), instead of one using peak excursion values. With the latter the average music level would need to be notably lower to avoid exceding Xmax on musical peaks.

    Seems to me your 2226 VLF assessment is missing the driver excursion limitation in the octave or so above the tuning frequency imposed by down tuning (step down) of a woofer, which reduces a driver's output capability at some higher frequencies (EV, plus Eargle). That doesn't appear to be factored in the sub's performance. I have something in the works about this, hopefully i can finalize it soon and post it.

    Step down tuning is often described as half an octave or so below normal tuning, so for a normal Fb 40hz you'd do 30hz, yours is even lower at 25hz, which might put additional pressure on the woofer.

    At low power one may get away with it, but i remain skeptical at higher power levels. Didn't see yet 2226 30hz bass specified or approved by JBL either. I think what might be saving some 2226 users when using the driver as a subwoofer is the large excursion before damage (Xlim; 40 mm p-p), but at even higher distortion (Xmax= 10% dist).

    Richard

  13. #13
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    Half-space loading (2Pi) and standard QL 7 are already included in the following gaphs.

    1rst graph, 5 CF, tuned to 40hz, 300W input shown bottom left, red dotted line is Xmax and red solid is actual excursion, Xmax reached just before reaching 30hz, response about 3 db down @ 50 hz compared to mid-bass level, may be prone to sound mid-bassy.

    Name:  IMG_2528.jpg
Views: 649
Size:  94.7 KB

  14. #14
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    2nd graph, 5 CF, tuned to 48 hz, 300W, Xmax reached at about 35hz. Fb 48 hz here used for the sole reason of trying to get the bass level at about the same level as the rest of the response (less than 1 db bump). Btw in post # 5 for 2226 max flat alignment Fb was also at 48 hz, but using a smaller box volume. Interesting coincidence, not drawing any conclusion at this point.

    Name:  IMG_2532.jpg
Views: 633
Size:  99.3 KB

  15. #15
    Senior Member RMC's Avatar
    Join Date
    Feb 2017
    Location
    Canada
    Posts
    1,289
    3rd graph, 5 CF, tuned to 25hz, 200W can't take 300W here, Xmax reached close to 114 db at 20hz, very droopy LF response, down 10 db @ 30 hz or so. A usual B6 boost filter of +6 db with Q=2 would have some difficulty filling such a large gap in order to achieve flat response. NOTE: can't model B6 boost/cut filter in Winspeakerz software. Same for the 25hz HPF. However, for the latter since its located at the same frequency as Fb, i'm not sure it would change response, but might help for excursion? Not sure again, no filter data, you indicate the system works well down to 30hz.

    Name:  IMG_2534.jpg
Views: 637
Size:  87.8 KB

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. JBL 4355 clone with Ashly xr1001, 3120a and N8000
    By hiendcomponent in forum Lansing Product DIY Forum
    Replies: 2
    Last Post: 01-31-2017, 12:32 PM
  2. JBL 4355 (4344) clone with Ashly 4001
    By hiendcomponent in forum Lansing Product Technical Help
    Replies: 0
    Last Post: 01-16-2017, 10:00 PM
  3. 4355 clone
    By lasse in forum Lansing Product DIY Forum
    Replies: 13
    Last Post: 01-30-2012, 08:58 AM
  4. Widget's 4355 clone...
    By boputnam in forum Lansing Product DIY Forum
    Replies: 31
    Last Post: 05-11-2004, 11:36 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •