Where do I begin? This article does show, with photos, how to rebuild a crossover. And it does show that new capacitors can be much larger than the original ones. That’s the good part.
Now come my complaints.
(1) SoniCap capacitors are hardly inexpensive. Compare prices of a 12 µF cap from SoniCap and two other well-known metalized polypropylene (MPP) types.
SoniCap 12 µF $22
Dayton 12 µF $4.81 (Parts Express)
Bennic 12 µF $4.90 (Madisound)
SoniCap is guilty, in my opinion, of selling well-made, but over-priced parts. They claim intangible and unverified benefits from using their products in speaker crossovers.
There is no evidence that expensive crossover parts, such as those caps sold by SoniCap, change crossover performance in any way. In fact there were efforts of several large groups of DIY speaker builders to verify this several years ago. I was one of the over 40 people present, and the unavoidable conclusion was that high-priced or exotic crossover capacitors made absolutely no audible difference when compared to cheaper MPP or non-polar electrolytic caps in properly designed speaker crossovers.
(2) Small amounts of data – false conclusions
Sample measurements of the components removed yielded some interesting results:
- 12 micro-Farads (treble leg) capacitor measured 13.7 micro-Farads
- 34 micro-Farads (bass leg) capacitor measured 36.8 micro-Farads
- poly-switches measured 1.3 and 1.7 Ohms
Not only was one capacitor outside its clearly marked +/- 10% tolerance, but the other had changed enough to materially affect crossover frequencies. It's also worth noting that all of the replacement components are manufactured to +/- 5% tolerances, so even if they do eventually drift in value, the delta will still be less than the components they replaced…
There is no evidence that these original caps ever drifted. The 12 µF cap that measured at 13.7 µF may have always been that much out of spec. The writer assumed they were originally in spec, and had drifted over time.
He further assumed he could hear a difference in sound. Because he did not do this in a blind test, his account is unconvincing. He then went on to claim, without any evidence, that the improved sound was due to the rebuilt crossover.
It is wrong to present articles like this that suggest, but provide no evidence at all, that replacing crossover capacitors with high-priced capacitors produces an audible improvement.
I expect better from AudioHolics.