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Thread: Enclosure questions?

  1. #1
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    Enclosure questions?

    I am building an enclosure for a pair of 2235H's. I am building the enslosure at 9 cubic feet. If I remain at that enclosure volume I was told I could change the dimensions of the box as long as there is 9 cubic feet. Right?
    If the box is too shallow or too deep are there internal problems that would effect the bass response? Is there an ideal enclosure proportion?

    Thanx!?

  2. #2
    Administrator Mr. Widget's Avatar
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    9 cu ft?

    Why not build two separate enclosures... that gives you much more room placement control.

    Here is JBL's recommendation from the pro site:

    http://www.jblpro.com/pub/manuals/enclgde.pdf

    And here is Greg Timber's recommendation for use as a sub.

    http://www.lansingheritage.org/html/.../1983-subs.htm

    Widget

  3. #3
    Senior Member spkrman57's Avatar
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    How come I can't access those links?

    I get error msg's

    Ron
    JBL Pro for home use!

  4. #4
    Administrator Mr. Widget's Avatar
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    I fixed them.


    Widget

  5. #5
    Senior Member spkrman57's Avatar
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    Thanks Widget!

    Good reading on the 2nd one for sure!

    Ron
    JBL Pro for home use!

  6. #6
    Senior Member Steve Schell's Avatar
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    Spkrman57, are your DRD 300B amps the ones sold by Ron Welborne? My speaker company partner and I are about to demo at our third show in a row with Ron. We think Ron's electronics are some of the very best out there, and a steal at the price.

  7. #7
    Senior Member spkrman57's Avatar
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    Welborne DRD 300B

    Steve,

    You are correct. I had to decide between keeping my Yamamoto A-08(45 SET) stereo amp and the 300B monoblocks. I bought EML 45's for the Yamamoto and did a comparision of the 2 amps with the same source and speakers. The Yamamoto won by a very slight margin in the midrange detail, not by much. Stock RCA 45's would have been more detailed in the midrange. I ended up keeping the 300B's as the Yamamoto brought more $$$ in my pocket.

    The 300B's are a nice set of monoblocks! I also liked the huge iron for a 7 watt amp! Mine were built by a friend and sold to me after completion. They have the "silver wire" upgrad and SS rectification!

    Ron


    Quote Originally Posted by Steve Schell
    Spkrman57, are your DRD 300B amps the ones sold by Ron Welborne? My speaker company partner and I are about to demo at our third show in a row with Ron. We think Ron's electronics are some of the very best out there, and a steal at the price.
    JBL Pro for home use!

  8. #8
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    Questions

    Why do you not see bass reflex cabinets today that are not ported? Is it drivers that are designed differently? Is it a new way of thinking? Does it gaine a few more low notes at the expense of some efficiency?

    When they spec a box size for acoustic suspension I understand that (I think)
    When they spec a box size for ported or reflex or any other cabinet that uses or reuses the rear wave and returnes it, it also makes since that the dimensions could be important, perhaps even critical but for an infinite baffle why is there an upper limit given? Is it important or are they just saying that beyond that the gains are little if any.

    When being used as a sub woofer in an average living room can a pair of 2240's be made to work as well as a pair of 2245's? equalization is a given.

    Thom

  9. #9
    Senior Member spkrman57's Avatar
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    What is your requirements for sould levels?

    Quote Originally Posted by Thom
    When being used as a sub woofer in an average living room can a pair of 2240's be made to work as well as a pair of 2245's? equalization is a given.
    Thom
    If your needs are modest(less than concert level), I see no reason whey the 2240's could not provide decent LF resproduction.

    I'm going off memory here but I think 11 cubic ft cabinet would work for EBS alignment.

    I have a 2242 in a 9 cubic ft ported box, some folks use EQ to help out the bottom end. In my living room(12' x 16') I found EQ cut @25hz to work out well. But I prefer to use it without EQ for best sound results with my ears.

    Ron
    JBL Pro for home use!

  10. #10
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    Enclosures?

    Quote Originally Posted by Mr. Widget
    Why not build two separate enclosures... that gives you much more room placement control.

    Widget
    I was told that with a 9cu.ft. box that the LF could extend flat to 40hz rolling off at -3db@35hz. The single driver mounted in a 5cu. ft box, which was around 50 hz and then rolling off didn't seem to get down as efficiently. I am not sure what speaker simulation program was used. Sorry for such a delayed response to your response.

    CJNewbie

  11. #11
    RIP 2011 Zilch's Avatar
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    BB6P suggested tunings (maximally flat, typical) say the opposite:

    Dual 2235H in 9 cuft @26 Hz, black. Net volume is 8 cuft.

    Single 2235H in 5 cuft @25.5 Hz, red. Net volume is 4.5 cuft.

    Download WinISP for free and see what it says as you manipulate the variables.

    You REALLY need to do the calcs yourself and not rely upon what "Somebody" says....

    "Who told you that?"

    "Somebody on the Internet"

    "What's his name?"

    "Uhmmm, 'Zilch'"
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  12. #12
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by Zilch
    BB6P suggested tunings (maximally flat, typical) say the opposite...
    Not to mention that when you place a woofer in a box that is way under dampened, as in this case, transient response suffers. I'd definitely go with a pair of 5 cu ft boxes tuned to 30Hz.


    Widget

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