+ Reply to Thread
Page 1 of 5 123 ... LastLast
Results 1 to 10 of 42

Thread: renewing yamaha ns 20 speakers

  1. #1
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default renewing yamaha ns 20 speakers

    hi

    i started in this NS (natural sound) world just 2 months ago with a pair of a ns230, just choose them because my grado headphones are sort of open box (is this the correct definition ?) and i love them so i thought what about an open box speakers ?

    bought the ns230, they were afordable and happen to be good but with some troubles that i could solve easily by cleaning, fixing some loose screws, and adding a new strap adhesive perimetral sponge band, did not replaced capacitors and resistors, but will look on this later

    IMG_2033.jpg

    in the mean time a pair of huge ns20 popped up in the radar and simply i have to had them.

    if the profound bass is what makes the ns great just imagine a 800x600 mm sized bass driver in the ns20

    see the 230 in black grille cloth compared to the ns20 in light brown

    20181202_105054.jpg

  2. #2
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default

    When recived, i checked tha sound was good but found some differences between them. So i wanted to take a look at the interior,

    started the dissasembly,...

    BTW, i have seen that even being ns20 there are slight differences between these speakers (seen the photos in the internet) some have two coils, mine, only one, some have a fixed panel for the medium and tweeter, mines have those dirvers hanging with the front cover grille

  3. #3
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default

    this is a picture of my setup
    20181101_191805.jpg

    first i removed the front to find no absorbent material in the walls and moreover no sign of staples or eny fixing glue, my guess is that these came with no absorbent, is this possible ?

    20181202_182601.jpg

    ok, front panel with drivers medium and high

    20181202_163734.jpg

    removed the woofer, it is really huge, it has its own suspension with rubbers, separators and washers

    20181202_163900.jpg

    the empty shell with new absorbent installed

    20181202_163843.jpg

  4. #4
    Macca's Avatar
    Macca is offline Moderator and lover of technical papers
    Join Date: Aug 2009

    Location: Staffordshire, England

    Posts: 24,450
    I'm Martin.

    Default

    New one to me. Open baffle, but bass fires backwards and tweeter fires forward?
    Martin



    Current Lash Up:

    Technics SLP1200 CD Player * Nelson Pass DCB1 Pre amp / Krell KSA50S Power amp * JM Lab Electra 926 loudspeakers *


    'You fool! To think that your ape-brain could contain the full knowledge of the Krell!'

  5. #5
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 39,376
    I'm Geoff.

    Default

    I remember the old NS range with the big expanded polystyrene diaphragms. I saw and heard them at audio shows in the early seventies and thought they sounded pretty good. I still see the occasional set for sale and it's interesting that they have survived this long in decent condition, they must have been very well made.

    I think the lack of damping material was because they were a doublet design and relied on front and rear output.

  6. #6
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default

    actually i need some help



    as one of my medium drivers is not original and it sounds not perfect i am considering going the route of swapping both medium and tweeters (both 8 Ohm rated) with a 5 Ohm rated Saba Greencones (greencones are known for working well in open box configuration)



    here is my question:



    can I directly replace a 8 Ohm rated driver with a 5 Ohm rated driver ? or should i add a resistor to this 5 Ohm rated to make the equivalent of the 8 Ohm previous driver ?



    if that is the case which kind of resistor should i use ?



    forgive me for this question if you feel is too obvious, but i have no idea what to do



    regards

  7. #7
    Macca's Avatar
    Macca is offline Moderator and lover of technical papers
    Join Date: Aug 2009

    Location: Staffordshire, England

    Posts: 24,450
    I'm Martin.

    Default

    Should be fine, no driver is exactly one resistance anyway. Try without the resistor first.
    Martin



    Current Lash Up:

    Technics SLP1200 CD Player * Nelson Pass DCB1 Pre amp / Krell KSA50S Power amp * JM Lab Electra 926 loudspeakers *


    'You fool! To think that your ape-brain could contain the full knowledge of the Krell!'

  8. #8
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 39,376
    I'm Geoff.

    Default

    I think your proposed mid driver change may not be a great idea. A 5 ohm driver with series resistor will give unpredictable results with the existing crossover.

    The Saba green cone units may be favoured by some, but are not necessarily ideal

    Although marked Yamaha, I suspect the original mid units may actually have been sourced from a reputable Japanese maker of the time, like Coral, Foster or Crysler. It may be best to look for something similar. Many used drivers of this sort appear on ebay US listings, it could be worth keeping an eye on those.

  9. #9
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default

    Quote Originally Posted by Macca View Post
    Should be fine, no driver is exactly one resistance anyway. Try without the resistor first.
    Quote Originally Posted by walpurgis View Post
    I think your proposed mid driver change may not be a great idea. A 5 ohm driver with series resistor will give unpredictable results with the existing crossover.

    The Saba green cone units may be favoured by some, but are not necessarily ideal

    Although marked Yamaha, I suspect the original mid units may actually have been sourced from a reputable Japanese maker of the time, like Coral, Foster or Crysler. It may be best to look for something similar. Many used drivers of this sort appear on ebay US listings, it could be worth keeping an eye on those.
    thank you for responding, both approaches might be sound

    i have tried to source the mid drivers, very rare in europe, might have a chance in US and AUS, and of course JPN but that market is almost impossible to access,

    first thing will be to refresh crossovers,

    meanwhile will check different approaches and will report here

    regards

  10. #10
    Join Date: Dec 2018

    Location: bilbao

    Posts: 49
    I'm arsenico.

    Default

    started the process:







    first big surprise (but i had heard the difference before) was to find two different circuits for the crossovers



+ Reply to Thread
Page 1 of 5 123 ... LastLast



 

Posting Permissions

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