General Crossover Capacitors Question

AudioMan612
AudioMan612 Posts: 11
edited July 2012 in DIY, Mods & Tweaks
Hey,

So I recently got a pair of Acoustic Research PS2052's for $40 that I'm going to sell to a friend of mine. I have to say, for the money, they are really good speakers. They do however, have room for upgrade as the capacitors in the crossovers are electrolytics. Unfortunately, they used unusual values (7.4uF and 34uF), so I will have to use series/parallel combinations to match these values. I'm thinking of using ClarityCap What are the best combinations for this? For example, for the 34uF one, I can get a 35uF and a 1uF and wire them in series, or a 16uF and 18uF and wire them in parallel. The 7.4uF might be a bit trickier to find a good combination...
Post edited by AudioMan612 on
· Share on FacebookShare on Twitter

Comments

  • Outfitter03
    Outfitter03 Posts: 563
    edited July 2012
    What's your budget? This will dictate the quality of capacitors that you are able to use. Within 5 % of capacitance value is great and within 10% is good. If you are splitting capacitance, you really need to use two of the same value such as two 17uF to make a 34uF.

    To get some ideas on cost of clarity caps check out these two vendors: http://www.madisoundspeakerstore.com/esa-cap-630vdc/ http://www.partsconnexion.com/
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,653
    edited July 2012
    The original price was $49.99! I'd suggest not putting another penny into them.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

    · Share on FacebookShare on Twitter
  • zingo
    zingo Posts: 11,258
    edited July 2012
    I agree that unless you want to invest money in them for sentimental value, you are not going to be able to recoup anything when you sell them.
    Jake
    · Share on FacebookShare on Twitter
  • AudioMan612
    AudioMan612 Posts: 11
    edited July 2012
    Oh my friend would pay for the upgrades as they're going to be his speakers. I'm not looking to make a profit here. I got them because they were a good deal and my friend didn't have the money at the time. They retailed for $150 (obviously more than what anyone would pay). They really don't sound bad, but I like to get the best out of everything.

    So putting 16 and 18 in parallel could cause problems? Mathematically, it's the same as two 17's in parallel, but I don't know much beyond the calculations...
    · Share on FacebookShare on Twitter
  • arny
    arny Posts: 37
    edited July 2012
    AudioMan612 wrote: »
    So putting 16 and 18 in parallel could cause problems? Mathematically, it's the same as two 17's in parallel, but I don't know much beyond the calculations...

    When it comes to paralleling capacitors, simple summing gives you accurate results.

    What kind of capacitors are the existing parts? If they are film capacitors, changing them out will probably have zero benefits.

    Please remember that it is not unusual for speaker designers to factor stable capacitor properties such as effective series resistance and inductance into their design.
    · Share on FacebookShare on Twitter
  • AudioMan612
    AudioMan612 Posts: 11
    edited July 2012
    The capacitors are electrolytic. I don't remember if there was a brand name on them or not. I'll have to look again sometime. Considering series resistance, I'm guessing that it's a better idea to use smaller capacitors in parallel than larger ones in series?
    · Share on FacebookShare on Twitter
  • cristo
    cristo Posts: 231
    edited July 2012
    AudioMan612 wrote: »
    Hey,

    So I recently got a pair of Acoustic Research PS2052's for $40 that I'm going to sell to a friend of mine. I have to say, for the money, they are really good speakers. They do however, have room for upgrade as the capacitors in the crossovers are electrolytics. Unfortunately, they used unusual values (7.4uF and 34uF), so I will have to use series/parallel combinations to match these values. I'm thinking of using ClarityCap What are the best combinations for this? For example, for the 34uF one, I can get a 35uF and a 1uF and wire them in series, or a 16uF and 18uF and wire them in parallel. The 7.4uF might be a bit trickier to find a good combination...
    A 35uF and 1uF in series would give you 0.975uF. 16 + 18 in parallel would do fine for 34uF.
    Two 15uF in series would give you 7.5uF which should be damn close to the 7.4uF value.
    cristo

    NAD C 545BEE cd player, Philips AF877 turntable / Shure V15V-MR with JICO SAS stylus,
    Tascam 122 mkIII cassette deck, Harman Kardon 3480 receiver, Terk FM-50 antenna in the attic,
    Soundcraftsmen SE550 stereo equalizer, Polk Monitor 10a speakers
    (with Sonicraft/Solen/Mills crossover rebuild)
    · Share on FacebookShare on Twitter
  • AudioMan612
    AudioMan612 Posts: 11
    edited July 2012
    Yeah, I realized I did the math totally wrong for the series combination last night. I was really tired and not thinking. I've taken electrical engineering classes, so you would think I'd be better than that :P. I wonder if there's anyway to have the caps measured before I get them to find a combination that gets exactly 7.4...
    · Share on FacebookShare on Twitter
  • AudioMan612
    AudioMan612 Posts: 11
    edited July 2012
    Yeah I was thinking that as well. I'll see if whatever website I order them from can test them before they ship them to get values as close to what I want as possible.
    · Share on FacebookShare on Twitter