Acoustic Zen Crescendo speaker crossover capacitors ... who makes them?

Owners of this fine speaker I have some news for you. After only 24 hours of consistent playing with the upgrades I can hardly believe what I am hearing. As music lovers and audiophiles every once in a while we experience an upgrade that just causes you to rest deeply into recordings you know very well hearing them seemingly for the first time. This is happening as I type.

It’s as if someone placed a monster tube amp with the finesse of the finest SET amp and the scale, control, and swelling stage of the best tube amp beast in my system without me knowing. I keep looking at my rack thinking something must have awakened and changed my Crescendo speaker. No, no changes other than the crossover. The change is nothing short of extraordinary. Here are some short thoughts running through my mind based on this afternoons listening session.

- never heard the music grow and swell with this kind of beauty and control as I turn it up.
- wonderful layering and waves of musical experience with the speakers being lost, meaning the sound is not coming from drivers here or there...
- new levels of impact and dynamic impact
- where is the noise I thought was never there in the first place? No kidding. I think those old sand cast resistors were causing the less refined sound I never knew was less refined.
- Improved resolution is easy to hear, but it is served up in a completely natural and meaty way. I love the beauty of the mids and highs.

The problem is is I can’t tell you what exactly is causing this remarkable improvement. Is it the new caps? Which ones? The new resistors? The aggregate of all the improvements? Most likely.

l replace the forest of sand cast resistors with a mix of these;

- All 20 watt sand cast replaced by two Mills MRA 12 in parallel.
- All 10 watt sand cast replaced by both Duelund standard and Duelund CAST.

Each of these resistors has has its own strengths and a mix seems to work very well indeed. I matched all part values within 1%

I am sure the original metalized poly caps do not sound as good as the paper, foil, and wax caps now in place.

I spent about $800 on the upgrade and improved the speaker in very real and important ways for me.

Keep in mind mine are MKl, not MKll. I am not sure if the newer version has any real changes in the crossover. If you see a sea of white sand cast resistors and AZ labeled poly caps, then you have opportunity.

So so why not build these with better parts upfront and change for a plus version? They should. It is a job to do it after, but possible.

Ok, I will keep posting as the hours build.

I purchased the Duelund resistors at Parts Connextion over 50% off the retail price. The caps were also on sale. I saved a good amount of money for this job.

I suppose the price for the Crescendo with upgraded crossover parts would be pretty high with additional builder and dealer margins etc... Perhaps $2500? Maybe more.

Anyway, I will report back middle of the week. I suppose the burn in process could take things south for a season. 

Hi Bill,

It was great that Robert Lee replied to your emails. What insight did he give for upgrading the crossover?

Can you give an executive summary of the sonic differences between: Harbeth 40.1, stock AZ Cresendo and the modified AZ Crescendo?

Bill,
Congratulations on your sucessful Cresendo modification project. I know that you have much experience doing numerous upgrade modifications over the years but I can tell you are especially pleased with this particular one.

There are certain speaker brands that offer upgraded/superior parts as a package. Daedalus and Kaiser (Kawero model) are 2 that come to mind, certainly there are others.

There’s no question that better quality parts can and do improve sound quality, I don’t know why some people are so resistant to this fact. My background isn’t as extensive and hands on as yours. In my experience capacitors, resistors, wire,fuses, etc. They all make a difference and I’ve heard it as plain as day.

Bill, you’ve taken a very fine speaker and have improved it to your satisfaction.
Charles

Thanks Charles!