Replacement capacitors in a speaker crossover

I have some nice 40 year old McIntosh xr19 speakers that I want to replace the capacitors.
They originally have Sprague 439p film 8uf 120vac caps in them but I can’t find any, I know you can take two or more caps and put them in parallel to get the proper value needed but is it a good option or should I keep looking

If you have the physical room to accomodate paralleled capacitors it is actually preferable to do so.


I used to sell that model. I would definitely update the caps with higher quality film ones. Solen makes an 8mf 400v that will drop in at Solen 8 mfd Fast Cap 400V. Or you can step up with a ClarityCap 8.2mF PUR series at ClarityCap PUR 8.2 MFD 250VDC.
I don’t remember the crossover circuit to be able to tell in which driver circuit it is used.


I would go with the 8.2uf clarity cap, you could even pay a little extra to have them measure a few with a lower uf closer to 8uf. I needed a 5.8 uf cap and could only find a 5.6uf but the retailer just measured a bunch and sold me some that measured closer to 5.8uf.

You should actually measure the caps you are removing to insure that you do not hear a change in sound due to value change rather than change in the construction of the caps. I use an HP capacitance meter to do my alterations.


In my experience, capacitors have a big impact on the sound. To achieve a specific value, it is recommended to create combinations of different values. A small, high quality bypass capacitor in parallel with the main capacitor can significantly improve performance. It is important that the components of both speakers have almost the same value. My capacitors are the same pair. This increases the imaging and spatial representation. Tight tolerances are always good.

Duelund pp Caps are fine and not so expensive

Grüße Andreas

I was actually just looking at the clarity pur
How much better than the clarity csa are they, are the worth double?

I don’t know the Pure ones yet, but they’re supposed to be good. I used Clarity SA in a broadband project and was disappointed. The SA lacks clarity and was absolutely unsuitable as a tweeter capacitor. Mundorf delivers quite good performance for the price. The duelund pure foil types play in their own class. The new duelund Cast PP is an affordable entry into the duelund sound world. The sound should be full and natural. I have ordered Miflex KPCU which will be delivered tomorrow. I want to mix these in the midrange. The capacitor for the treble is the most important in terms of sound. I have a duelund JDM CU/SN there that sounds fantastically natural. A small, high-quality bypass can do wonders. Duelund JDM CU/SN and silver as a bypass are excellent.

Read Humbolt Captest to see what properties the capacitors have. Ask yourself the question. What it currently sounds like and which direction you should go in order to find a capacitor to your taste. I don’t know the capacitor currently installed. You can’t go wrong with a Jantzen Superior z-cap. A Mundorf Supreme is nice too. A cheap alternative might be a Mundorf EVO Oil, not too expensive and quite compact in size. If appropriate, you can also mix to achieve a specific value and sound.

I have 8uf &12uf 439P Sprague 120vac caps on the crossover but don’t know what would be comparable or better, can’t really find any good info on them
If anyone knows I would appreciate any information

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All crossover parts can have a tremendous effect on a speaker. The quality of hook-up wires, inductors, capacitors, and resisters all play a major role on the sound of a speaker. That said, on capcitors, don’t skimp on cost. Go for Mundorf Gold Silver Oil Supremes, Duelunds, or V-Caps. They are the most neutral and disappearing caps that do not dull and make the sound lifeless caps in my experience.

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From the school of everything matters, I can attest to the efficacy of the Mundorf Gold SilverOil Supremes in my Pure Audio Project Trio 15 Classic speakers. For example they offer a naturalness to piano, no glaare no harshness, easily conveying the after-tones and harmonics of the instrument.

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Resistors also make a lot of difference and are cheaper than capacitors and inductors. Read about capacitors bri Toni Gee humbolt cap test. He also tested a Sprague. He is the man who knows best about the properties of capacitors. He’s so good at this that he can also offer speaker upgrades. Mundorf supreme silver oil could also be interesting for B&W. Google it. I saw these on Ebay, 3.9 uF in a double or four pack is quite cheap. My recommendation. Prices ranged from €140 to just over €200 for the set. The duelund cast PP should also deliver very good performance for its price. If you don’t want it to be too expensive, a Mundorf Supreme or an EVO Oil, Jantzen Superior z-cap.

Maybe the report will be helpful. He swapped the Sprague for Jantzen Standard Z-Cap and had an improvement. The Jantzen Standard Z cap is, alongside the Jantzen cross cap, the entry-level cap. The Jantzen standard z-cap are also used in finished high-end speakers such as the Steinheim Aluline five. For an additional charge of around €10,000 there is Jantzen Superior z-cap and in some places Mundorf EVO Oil, Supreme Alu oil and milflex kpcu as a bypass. If space and costs are crucial, the Jantzen or Mundorf EVO Oil can be interesting and a start that doesn’t cost too much. Then look at the resistances. Cement resistors have little detail. Mox, Supreme are better. A Mundorf Ultra or Powertron are currently the most permeable. But it should fit your speakers. Maybe take a photo of the crossover to see what’s on it.

Today I received my Milflex KPCU-03 with 0.1uF and immediately installed it as a bypass for the midrange. It seems that I got a better and more tangible soundstage. I have now combined the capacitance in series with the midrange from two EVO Oil 68 uF, one Jantzen Superior Z-cap 15 uF, two Supreme Silver Oil 0.68 uF, a Supreme silver gold Oil 0.1uF and a Milflex KPCU-03 0.1uF. In parallel I have a 10 uF Mundorf EVO Silver Gold Oil, two 1 uF Mundorf Supreme and a duelund JDM Silver 0.01 uF. For the tweeter I have a Mundorf Silver Gold Oil 4.7 uF with a duelund JDM Silver 0.01 uF as a bypass. The resistors are Mundorf Resist Ultra. The serial resistor is equipped with a duelund JDM Cu/Sn 0.47 uF as a bypass capacitor for an extended treble. For the bass I have Jantzen cross-cap and Audyn cap Plus.

.1 uf bypass on a midrange cap? I could see on a tweeter it having an audible effect but not so much on a midrange circuit.

A capacitor can also be heard as a bypass in the midrange. However, the treble is the most influential overall because it influences the overtones of all sounds, voices and instruments. The mid-tone range contains the frequencies that are most clearly perceived by our ears and which we are most sensitive to. Maybe the crossover frequency also matters. I think it makes sense that the upper midrange has a good connection to the treble so that it sounds like it’s made from a single piece. I’ve been trying out a lot of different small bypass capacitors lately. Some provide more separation, details but also the timbre can change and not always in the desired direction. Duelund JDM deliver the best results without disadvantages. (Silver more details, open, airy with a silky sound. Cu/SN a little darker, full and rich tones, very organic.) Röderstein KP 1832 open, good separation, not as organically liquid as the duelund or the Miflex. Somewhat sharp in the sound. Röderstein KP 1836 good separation without the partial harshness of the KP 1832. Audyn pure copper lots of air and very wide stage, bright sound without seeming cool. Vishay 1837 helps to clean things up a bit and sounds a little smoother, especially with cheap MKP capacitors. Mundorf Silver Oil brings depth and smoothness, very fluid sound. Mundorf Supreme Silver Gold Oil delivers a great stage with depth, very detailed and dynamic. But it can also be a bit too much. As a treble bypass, the coherence was a bit lacking, as if you were turning up the treble on the tone control. Maybe the 0.1 uF value didn’t fit well and was too large in the treble. 0.01 uF or even smaller is probably optimal as a bypass in the treble. Styroflex KS 160 V is characterized by improved separation of the instruments and rich sound. Milflex KPCU- 3 beautiful timbre, better separation and natural sounding. My conclusion: Milflex and the Duelund JDM capacitors do more of everything than the others I’ve tried, without the drawbacks of some others used as bypasses. They fit in well and it sounds like a whole, just better than without these little capacitors.

The bypass in the midrange makes a drum hit, for example, appear cleaner. Voices and instruments gain in realism.
A song I use for this is Hoist the Colors, from Pirates of the Caribbean
The song starts with drum roll. You should be able to hear individual beats. Individual voices can be heard in choirs. Instruments and voices become clearer separate towards the end.