Lt Cdr Data... he knows one thing or two about speakers...

Discussion in 'Hi-Fi and General Audio' started by BerylliumDust, May 24, 2005.

  1. BerylliumDust

    BerylliumDust WATCH OUT!!!

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    Shock horror... I've came across this comments by Lt Cdr Data:

    https://www.audio-forums.com/as-rediect/showthread.php?t=8670

    just to realize that those speakers use metal cones (magnesium) and... you wouldn't believe (!)... DNM like internal cables:

    "The advance tweeter makes other demands on the cable. To ensure a natural reproduction of even the most delicate harmonics, it is very important to have as low as a capacitive reactance as possible. This has been achieved with another newly developed cable type, the Jamo High Resolution Frequency Control OFC Flat Cable. This cable has a sectional area of 1.5(mm2) and large separation between the two conductors."

    http://www.progressive-av.co.uk/product_pdfs/speakers/jamo_concert_d830_manual.pdf

    And then I just found this:

    https://www.audio-forums.com/as-rediect/showthread.php?t=6919&page=2&pp=15

    and this...

    https://www.audio-forums.com/as-rediect/showthread.php?t=6837

    and... "Oops, I forgot. Only speakers with all metal cones can sound good ":

    https://www.audio-forums.com/as-rediect/showthread.php?t=7080


    I really think Jamo did a nice Job with those... even without listening...


    PS: Anybody knows the crossover order of the D830s?
     
    BerylliumDust, May 24, 2005
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  2. BerylliumDust

    Lt Cdr Data om

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    3rd order electrical on tweeter, 2nd order on bass, you can take the woofer off to have a look,you need to remove the xover with a socket set.
    its got a strange resistor network tho on the bass.
    they are great eh?
     
    Lt Cdr Data, May 24, 2005
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  3. BerylliumDust

    BerylliumDust WATCH OUT!!!

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    Are you sure? Where I can find the schematics?
     
    BerylliumDust, May 25, 2005
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  4. BerylliumDust

    Lt Cdr Data om

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    your right, he does know a thing or two, not quite enough, but then again a little knowledge is a very dangerous thing, know a thing or two about valve and transistor amps, been studying them all for years, again not enuff for pro level design tho :D

    I assume you are talking about the jamos?
    I looked inside, and had to take the xover out to trace and draw it.no-where on the web I am afraid afaik

    the yams
    are all 2nd order electrical.
     
    Lt Cdr Data, May 25, 2005
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  5. BerylliumDust

    BerylliumDust WATCH OUT!!!

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    Lt Cdr Data,

    I was just trying to call your attention to the benefit of using DNM like speaker cables... which is one of the reasons - and a very important one, as pointed out by Jamo - why you like those Jamos so much... Did you know about that, or I'm just being tiresome?

    Yes...

    Was it too much if I ask you to share your drawing?... Please!

    That I know, because I took the crossover out...
     
    BerylliumDust, May 25, 2005
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  6. BerylliumDust

    Lt Cdr Data om

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    don't know if I have it any more, but will have a look over the next few days, I also used to have all living voice xover drawings and mostly all proacs, I know stuart tylers tricks... :)
    and I know a thing or two about Tom Evans designs too, he uses application notes from linear technology and analog devices an-107.
     
    Lt Cdr Data, May 25, 2005
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  7. BerylliumDust

    BerylliumDust WATCH OUT!!!

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    Appreciated... thank you!

    But at least, you can call those Jamos accurate or low distortion designs...

    And, as you have all heard it a million times... metal cones and DNM like cables are the culprits.

    Not sure about that crossover combination though... trying to know...
     
    BerylliumDust, May 25, 2005
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  8. BerylliumDust

    Markus S Trade

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    Dear BD, take a look at this page and maybe you'll find life is not so simple after all.
     
    Markus S, May 25, 2005
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  9. BerylliumDust

    BerylliumDust WATCH OUT!!!

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    The problem is people like to complicate what is indeed simple...

    But in a way I agree with you, it is complicated to make things simple...

    "It should be apparent by now why stored energy and non-linear distortion are such important driver parameters. Stored energy is difficult to equalize for and non-linear distortion cannot be corrected. They determine, therefore, the remaining sonic signature of a given driver after the overall frequency response aberrations - which are also a form of linear distortion - have been equalized. Since accuracy of reproduction is my goal a driver should not noticeably contribute its own sound. "

    1) Stored energy or resonances can be damped by means of the xover: low crossover point (in this case 2500Hz) with high order slope for the low-pass filter (also in this case, 12dB/oct.) followed by an equalization network ("a strange resistor network", as Lt Cdr Data puted it). But, the W18EX001 has "no cone breakup below 3 kHz (...) with its rigid metal cone" which leads us to point 2)...

    2) Non-linear distortion CANNOT BE CORRECTED (as stated above) and... "A most remarkable driver is the SEAS W18EX001 because of its excellent linearity".

    An last, but not the least, "It would be interesting to know the audible difference between a Scan Speak and Seas equipped PHOENIX, but I have no plans to determine which crossover/eq modifications are necessary and build a second pair of speakers to run this comparison."... Enough said?!
     
    BerylliumDust, May 25, 2005
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  10. BerylliumDust

    Lt Cdr Data om

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    hi BD, sadly I don't have the xover schematic, I have searched for you and its not there, it probably wasn't remarkable.

    Only option I am afraid is for you to remove and have a look yourself, you have to take the woofer off to do so, and a few nuts on the xover, be careful if you do.
     
    Lt Cdr Data, May 26, 2005
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