Crossover caps

[audio39]

I'm getting ready to have the capacitors in my Yamaha NS-1000M's replaced and upgraded. In speaking with 2 different sellers of capacitors the suggestion has been to use good caps in the mid and tweeter path particularly, but to use one very good cap paired up with the others so that the quality of the better cap will be picked up.

The recommendation for the mid is to use a 20uf cap of good quality and a 1uf cap of excellent quality to arrive at the necessary 21uf value required. This I'm told will realize the sound quality of the higher price cap while keeping the costs down.

Thoughts?

 

[SY]

Someone is trying to sell you something.

Use a good quality polyprop cap from a reputable manufacturer (the kind you find at Mouser or Digikey), avoid anything labeled "audiophile," and use the money you save to go to a couple of concerts.

 

[SY]

Also, if the old caps had a high-ish ESR, you might want to put some small resistors in series with the new caps, otherwise the spectral balance can be affected (bright and edgy).

 

[xrk971]

Try motor run industrial caps. They are metalized poly film in oil. Sound excellent and very reasonably priced for a 20uF with 370v rating.

Do search for "motor run capacitor 20uf" to see what you can get. They are big but typically cost $10 to $15.

 

[fandersen]

You may want to check out Troels Gravesen's rebuild of the NS-1000 crossover.

Yamaha-NS1000

 

[Scottmoose]

A few general points to consider:

-A capacitor 'upgrade' is only an upgrade if you don't foul up the transfer functions. Simply replacing electrolytics with film types may do just that, as the ESR of the original caps will have been factored into the XO design. In such cases, you will either have to replace like-with-like, or possibly add a small series resistor as noted above.

-Watch out for the logical fallacy that series components are more critical than shunt components. As far as the crossover is concerned, shunt components are just as much in the signal path as series components. With that said, as far as a 3-way like the NS1000M is concerned, it does make sense to concentrate on optimising the HF & midrange; the bass leg is usually a little less so given our falling hearing acuity as frequency decreases.

-If you want to mix & match caps to save money, as I recall, the recommendation of several respected designers has been to make about 1/3 - 1/2 of the total value out of whatever higher quality type you want to use (PIO or film & foil), and the rest of a cheaper MKP type, which they feel gives most of the performance at reduced cost. Does it make any difference? Pass. On paper, it may; in practice -YMMV, as always.