speaker capacitors-----leave alone or does it open pandora's box ?

It is amazing the level on sonic improvement that can be realized with smart cap, inductor and resistor upgrades in speakers. Most builders use run of the mill and “cheap” crossover parts in their $20,000 speakers. They do it to save money. That simple. 

This is something I’ve never quite accepted about high end audio. If the sonic improvement is “amazing” by flipping $1 caps for $40 caps, why wouldn’t the builder do that themselves? To fetch $20k for your speakers you gotta sound amazing; and the return on cost for being able to sell them in another tier should be huge. So why don’t they do it? The only answer I can come up with is that it doesn’t make a difference; or the difference it does make doesn’t fit the sound the builder is going for. 

If I can make my $10k speakers sound like $15k with $300 worth of parts... why didn’t the guy do that and sell them to me for $15k?

It’s more like flipping $12 caps for $150 caps. Jupiter copper foils etc... Flipping $.35 Resistors for $30 resistors. It adds up and after dealer mark up the end price of the speaker is increased substantially. I have performed $2000 crossover upgrades that would increase the price of a $15,000 speaker to $25,000 after dealer mark up etc... The mark-up can be immense on high end gear.

Also, not all designers buy into more expensive parts sound better. They miss opportunities for SQ improvement. Many designers and builders spend time designing and building and have little time or inclination to obcess over how various caps and resistors sound in their design. This tedious task of part rolling and carefully listening is a different body of study and knowledge.

Until and unless you try it for yourself and learn, I’m afraid you will always scratch your head and wonder. Knowledge in this area of audio tweaking takes a great deal of time and effort. No way around it. You have to educate yourself through hours of trial and error with much work and careful listening. It is different from pure design only interested in a part that adheres to spec. Many builders laugh at the notion of “boutique” parts as I have had those conversations. I don’t blame them because these parts can be expensive and they don’t have the time or personality for such tedious and “questionable” endeavors.

At the same time there are plenty of builders that do offer these boutique parts and simply charge for them. They buy into and understand parts make a difference beyond just meeting spec. So it is happening and being offered by builders who know Duelund and Juputer film/paper and foil caps, as well as others, sound better than Poly caps.

Lastly, it is possible to replace a $10 Solen Fast Cap with say a $60 Film & foil cap from Jantzen (Alumen Z) and improve the sound of a given HEA speaker. The speaker set may have 4-8 total caps to replace. Also, you can also improve SQ with $4 Mills MRA resistors over sandcast. The total cost of this moderately priced upgrade is say $400. Some builders after all the mark-ups would sell this upgraded speaker for $2000-$2500 more! This is a very competitive business and one that is hard for the manufacturers to make enough money to stay in business. Every dollar matters and they do watch costs.

I replaced the bottom of the line Solen caps and sandcast resistors in my $14,000 Dali Epicon 6 speakers with $600 worth of part upgrades in the crossover. The result was very pleasing to myself and family. The improvement in sound quality before and after burn in was easily discerned and appreciated. It made a very good set of speakers even more to our liking. The Solen caps sound more closed in and rough compared to the Jupiter film and foils I used. The sandcast resistors also sounded more ragged compared to the more nuanced and refined Path Audio resistors. Dali has a long standing relationship with Solen and they spec their parts. I seriously doubt Dali has listened to their Epicon speakers with the parts I used. They simply used the same approved vendor they have always used. They needed to hit a certain price point and therefore spec’d the part used for these reasons.

Us DIY guys know that nice SQ improvements can be realized with our skills and effort.

^^^^^ You ask a question I've also been wondering about. The tube preamp that I modified cost under $1K new and the cost of the capacitor upgrade was under $70 and took me under an hour to do. It would have probably been cheaper for the original builder buying them bulk. The sound improvement was significant. I don't get it either... 

@rwdawson - 

For parallels in cars, you cannot take a Yugo, put fancy tires on it and make it a Maserati, but there are certainly a number of performance tweaks available for most cars. 

There's also an issue of component cost to retail price. Using normal distribution chains, you need to charge 10x your component costs to make money. Adding $100 in capacitors needs to translate into $1,000 or more to be worthwhile making. 

I don't believe every speaker benefits from new caps, nor every tube preamp, nor do I necessarily believe all caps are worth their cost. I do however think that there's an interesting place for the careful listener to tweak.

If you are truly interested, I encourage you to consider building your own speaker kit. There's a number of them available from Parts Express, Madisound and others. You can learn a great deal, and tweak to your heart's content. 


Best,

E