Integrated Match to Focal Spora No. 2

Hi Toneranger,

I’ve done a lot of analysis on older Focal crossovers. They were "discerning" only due to a gimmicked crossover which reduced the minimum impedance by about 2 Ohms. I can’t tell if the Sopra is gimmicked the same way or not, but the impedance curve sure looks familiar. If it is, in the crossover you’ll find 2 large electrolytic caps, that go to 4 power resistors each in the bass. Remove the smaller of the two caps and they become very easy to drive, with almost no change to the frequency response or phase matching.

Erik, I've searched extensively for info on Focal X-Over's with little success. Any info you've got would be appreciated before I discect my Sopras to see what's inside. 
I don't seem to have any difficulty with their impedance using my 700i amp. It barely gets warm driving them to 93db peaks in my room. 

Anyone with Sopra's remove the tweeter cover yet?  I'm waiting until I get everything dialed in before I try removing them on my Sopra2's. 

Hi Stevizzy!

I've not looked at the Sopra crossovers, but the curve looks familiar to me. Take a look at this analysis for the Focal Profile crossover. Scroll down to "Bogus Woofer Cap" and look at the schematic there.  See if you have something similar. 

You may not! :) but if you find an array or two of power resistors, my guess is the same kind of trickery is going on.

Best,


Erik

Erik, thanks for the info. It's interesting to say the least how part cost plays into the design of fairly expensive speakers. 
Although it's beyond my technical skills to attempt any modifications to my Sopra speaker crossover, it's good to know what's possible in the future for my speakers if the mods become available by professionals in the industry. 
PS:. Does Magico really use the best parts available as they love to advertise?

Hi Stevizzy,

I am a huge fan of Scanspeak, and that is who they have sourced their drivers from. They now use custom driver materials though. Also, I have toured their factory. They use the highest grade Mundorf crossovers. Or rather, they match the crossovers to the speakers. The top grade speakers get the top grade Mundorf parts. This is not something a lot of speaker makers do.

Sound Stage network just released the measurements for the S1 MK II. The crossover and frequency response measurements are really very good, and could only be achieved with very good parts, though compression figures were disappointing, especially in the treble.

Having said that, are they the best? That’s debatable. If I absolutely had to buy speakers and could not build my own, I’d probably want to hear Gryphon’s and anything with the latest Accuton cell drivers like the Marten Coltrane.

Having listened to Magico’s, B&W’s, Wilsons and Focal’s, among those brands I would rather listen to a Magico all day long, but not for $100k. :)

Best,

Erik