@georgelofi
Sorry, was drunk flaming again. :)
No, stereophile’s charts are reasonably reliable. However, the deep impedance drop in the Profile series and the Sopra is too much alike so it makes me suspicious of more French Fraudulence.
I thoroughly analyzed the Profile 918 crossover and the speaker drivers in a way no reviewer would have dared....hahahah...and found that the impedance dip was deliberate and unnecessary. It makes the speakers seem more discerning, more exclusive. "Oh my god, my speakers can really tell the difference between a $10,000 amp and a $500 amp! I’ll take them!"
For a thorough explanation of what I"m talking about, please see the woofer section in this blog posting.
http://pqltd.blogspot.com/2016/01/focal-profile-918-ultimate-upgrade-guide.html
There is a pair of C/R circuits in the woofer section that caused this. For about $35 in parts, the impedance could be brought up to around 4 ohms and exactly matched the original response. However, a smaller tweak was to remove one of the two C/R circuits causing the impedance droop.
I have not analyzed these, but the circuit is easy to spot. Look for large electrolytic caps, around 120uF or more, with 4 or more power resistors to ground in the woofer section. If you see it, you’ll know what the problem is.
Best,
Erik
Sorry, was drunk flaming again. :)
No, stereophile’s charts are reasonably reliable. However, the deep impedance drop in the Profile series and the Sopra is too much alike so it makes me suspicious of more French Fraudulence.
I thoroughly analyzed the Profile 918 crossover and the speaker drivers in a way no reviewer would have dared....hahahah...and found that the impedance dip was deliberate and unnecessary. It makes the speakers seem more discerning, more exclusive. "Oh my god, my speakers can really tell the difference between a $10,000 amp and a $500 amp! I’ll take them!"
For a thorough explanation of what I"m talking about, please see the woofer section in this blog posting.
http://pqltd.blogspot.com/2016/01/focal-profile-918-ultimate-upgrade-guide.html
There is a pair of C/R circuits in the woofer section that caused this. For about $35 in parts, the impedance could be brought up to around 4 ohms and exactly matched the original response. However, a smaller tweak was to remove one of the two C/R circuits causing the impedance droop.
I have not analyzed these, but the circuit is easy to spot. Look for large electrolytic caps, around 120uF or more, with 4 or more power resistors to ground in the woofer section. If you see it, you’ll know what the problem is.
Best,
Erik