Yamaha ns-690ii recap

Discussion in 'Yamaha' started by elasticus, Sep 9, 2018.

  1. elasticus

    elasticus Member

    Messages:
    70
    I have a set of 690ii's in beautiful original condition however they don't deliver enough bass.
    I am prepared to spend about $250US on capacitors if anybody can help me with a shopping list and where to buy. I would prefer capacitors that fit easily however I will consider anything.
    Also does anybody know if they are a good match for my Yamaha ca-1000
     

     

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  2. clinic-audio

    clinic-audio all on YAMAHA untill 1990

    Messages:
    2,111
    Location:
    France
    Hello

    I am not convinced that bass frequencies will come back after spend 250,00 usd

    I read everywhere people making recap without serious reason , just to replace old components , even if they still good

    If you want to know if your speakers are working the way they should , use a spectrum analyseur and you will know the answer immediately

    It is a very good idea to ask the question before to spend money for nothing
     
  3. Jpete9

    Jpete9 Active Member

    Messages:
    396
    Location:
    Melbourne, Australia
    I recapped mine and it helped with clarity, but not bass. These arent too bad for bass, put them against the wall for more bass?
     
  4. DeltaB

    DeltaB Active Member

    Messages:
    158
    Location:
    Planet Earth
    If you were to look at the owner's manual, you would see that they fall off the lower end output fairly quickly below about 70hz. Caps won't fix this. Driver and cabinet design is your issue.
     
    Last edited: Sep 9, 2018
  5. FrostEOne

    FrostEOne Active Member

    Messages:
    299
    Location:
    Southeastern Iowa
    Food for thought, save your recap bucks and add a sub instead.
    Yamaha makes a nice sub for under your recap price,
    Yamaha NS-SW100 10" 100 Watt Powered Subwoofer
    Driver: 10" cone • Dynamic power: 100 watts (5 ohms) • Output power: 50 watts (100 Hz, 5 ohms, 10%THD) • Frequency response: 25 Hz – 180 Hz • Advanced YST: Yes • Twisted Flare Port: Yes • Dimensions: 13.88"W x 13.88"H x 16.13"D
     
    Last edited: Sep 9, 2018
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  6. elasticus

    elasticus Member

    Messages:
    70
    So would Yamaha just design these to be played loud. I wish I could change this as I love the look of them.
     

     

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  7. captouch

    captouch AK Subscriber Subscriber

    Messages:
    4,424
    Location:
    Bay Area, CA
    I had a pair - never thought they were too wimpy in bass, but it's true they were only designed to go so low.

    I second the sub recommendation if you want more bass.

    If you're still wanting to recap, just for peace of mind, you might use cheaper caps and see if any bass comes back. If it does, you could consider going higher end on the caps, but typically, higher end caps are lower uF values used for the tweeter and midrange drivers and the larger value caps used for the woofer are always electrolytic anyway due to the large values needed.
     
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  8. DeltaB

    DeltaB Active Member

    Messages:
    158
    Location:
    Planet Earth
    Inductors are used to roll off high frequency, caps to limit it's low frequency. You won't find caps being used on the woofer to limit it's low frequency. It won't help. Driver and tuned cabinet frequency is your limiting factor. The FS of driver limits you.
     
    Last edited: Sep 9, 2018
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  9. FrostEOne

    FrostEOne Active Member

    Messages:
    299
    Location:
    Southeastern Iowa
    Here's a crossover drawing that's easy to follow.
    [​IMG]
     
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  10. captouch

    captouch AK Subscriber Subscriber

    Messages:
    4,424
    Location:
    Bay Area, CA
    Thanks. I'm always eager to learn and this is a good opportunity.

    In the crossover schematic above, what is the 94uF (2 x 47uF in parallel) used for in the woofer circuit? I can see the signal doesn't go through it like it seems to for the mid (C2011) and tweet (C1011) caps, but it's in parallel to the driver.
     
  11. mbz

    mbz AK Subscriber Subscriber

    Messages:
    2,020
    Location:
    Melbourne, Victoria
    Yeah, the layout does not appear to match the circuit diagram. Caps in that position (in parallel to the driver) are used to shunt unwanted
    frequencies away from the driver by presenting a lower impedance path. I've posted elsewhere that such caps are not in the audio path
    so you should not spend big $$$'s on boutique items. Better to spend the $'s on upgrading any series components. Think yamaha used
    electorolytics in these shunt positions, ie, cheap and nasty BUT that's all that's required. Use budget PP for the shunt items.
     

     

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  12. DeltaB

    DeltaB Active Member

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    Location:
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    If in series it would limit its frequency. In parallel it adds capacitance to the load. It's effect is on the inductor.
     

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