Crossover Upgrade for SDA 2a

CoachP
CoachP Posts: 8
edited July 2011 in Vintage Speakers
I purchased a pair of SDA 2a's in the mid 80's that are still going strong. I am thinking of replacing/upgrading the crossover. The reason I am thinking of upgrading the crossover is to increase/improve upon the sound quality of what is already is a great speaker. I have already replaced the original tweeters with the the RDO 194's.


I have a local dealer who is willing to do the labor if I can provide the crossover parts. I am hoping that the vintage fans that frequent this forum can provide me with suggestions for the best replacement parts and best source(s) to obtain

Your input or links to previous posts is greatly appreciated!!!:smile:

If there is nothing to gain sonically, I'd appreciate that input as well.

Thank you all.
Post edited by CoachP on
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Comments

  • CoachP
    CoachP Posts: 8
    edited July 2011
    I guess I should add that I have no knowledge of circuit boards, capacitors, resistors, or inductors so you are going to have to walk me through this.
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  • dorokusai
    dorokusai Posts: 25,577
    edited July 2011
    There's a number of solid threads to walk your eyes thru first, then come back with some specifics. Just do a search and check out some of that to start Coach.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • chandler9a
    chandler9a Posts: 878
    edited July 2011
    I think I have a link book marked on another computer on this, I will send it out if I can find it later Coach.

    Welcome to the Club!
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  • george daniel
    george daniel Posts: 12,096
    edited July 2011
    it's Chief guys.
    JC approves....he told me so. (F-1 nut)
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  • CoachP
    CoachP Posts: 8
    edited July 2011
    So I found the SDA 2a schematic thread. Based on that I'm attaching the following Excel spread sheet of possibilities for the capacitors and resistors. I confess I am totally lost with knowing what to look for with the inductors.

    Please look at what I've found and give me feedback.
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  • ben62670
    ben62670 Posts: 15,969
    edited July 2011
    Keep the inductors stock. It's the caps and resistors you want to change.
    Welcome to Club Polk
    Ben
    BTW I have done over 100 crossovers for Polkies if you need someone to do them. Please contact me by email. ben62670 @ yahoo.com
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • dorokusai
    dorokusai Posts: 25,577
    edited July 2011
    The inductors are an advanced upgrade...start simple as it's not a hard project. I'd suggest doing it yourself instead of sending them to anyone, get more familiar with the hobby and learn at the same time.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • ben62670
    ben62670 Posts: 15,969
    edited July 2011
    Learn to solder if you don't know how yet. Youtube has plenty of instructional videos.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • CoachP
    CoachP Posts: 8
    edited July 2011
    I have found Mills 2.7 ohm resistors at soniccraft. For the 12 uf capacitors I have found Soniccaps Generation I or Clarity Caps ESA or SA. For the 20 uf capacitors I have found Clarity Cap PX or SA and Soniccaps Generation 1. The only 130 uf capacitors I have found are Solens ($40+ a pop x 4).

    What do you suggest?
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  • dorokusai
    dorokusai Posts: 25,577
    edited July 2011
    Sonicap and Solen for the 130uf.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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