Milestones Speaker project

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As I'm impressed by the Avalon Opus Ceramique speakers, I took the challenge to make look-a-like speakers. It is not my intention to replicate the Avalon speakers, I respect the intellectual property of the original designers.

The status of the speakers is that they have been built (with great help of Gydotron and Luc), and are playing music. I'm currently iterating on the crossover filter design (which is a huge challenge :h_ache: ).

I've created some documentation which describes their status so-far (for my own reference), which I think might be useful for others as well, so I've posted it on my homepage:

Milestones pdf files
Looking forward to your feedback, suggestions and ideas! :idea:


PS: This forum also had some previous discussions about Avalon look-a-likes:

Other related web pages: inleiding.htm

Some pictures of the current result:


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(sorry for my english)
Hi Marche,
Very interesting work. I have read the documentation and your passion for speakers is evidence.
I found much interesting on the other forum some particulars about
Avalon , Charles Hansen and JonMarsh.
I like your list of CDs too!
I hope your next steps with x-overs will get you full satisfaction but,
(if I can) I think 90% of result is..... x-over and room treatment so,.........good luck!! ;)

If possible, the design and documentation of the project is even more impressive than the speakers themselves. That says a lot, considering the quality of your speaker design and construction.

I also think the list of CDs is really interesting and useful. I'm going to go CD shopping.
Personally, I hope the Milestones speakers are more "impressive" ;)

I'm happy to see that my list inspires people. But be carefull with the expectations around my list of CDs. Most of it is "just music", and if you're looking for "audiophile" recordings, there might be better alternatives. I chose the music because of its variety, and because non-hifi records should also satisfy on the speakers. For that part, I would strongly suggest to select your own music as well!

David Gatti said:
Beautiful work Marche. A credit to your dedication & talent.
Care to discuss how they sound?
Are they everything you imagined or expected relative to the real thing?
Do you hear any areas where they could be better? There's always something isn't there?

Hi David,

Some of my impressions have been described at:

"The sound characteristics of the filter are good. It has a homogenous, integrated sound. It is the first filter that shows energy in the fundamental range (100-300Hz). There is plenty of bass and mid, giving a lot of energy to every note, but never becoming overly warm. Treble is smooth, and brilliant. The spatial image is impressively deep and wide.

The filter misses some texture, or what others would call an "airy sound". It could also be a bit more exciting, have more "micro dynamics", a bit more dramatic and/or romantic. The bass is also a bit "oinky", which can be explained by the Q of the filter. This also hints at fixes required for the tweeter circuit. "


"adding a bit of voicing and provide a bit more spatial imaging"

There are quite some plans to investigate what potentials are still out there:

So, to be continued! :snail:

Here a couple of pictures of a quick-and-dirty test setup for the crossover.

The passive crossover is as recommended by Joachim.
The active uses a prototype board we have for general active crossovers for 2 channels of 2x Sallen Keys.
Opamps (OPA2604) are used as followers for now, but we have an adapter board (DIP8) for 2x 2SK2145 wired as JFET followers.

All worked first time.




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