Hello Rick,
There is a lot of talk about the Purify 6 1/2 inch woofer in the pages lately.
There appears to be an distortion issue identified at 380hZ.
This distortion peak shows up even in the Purifi factory data.
As these woofers are not inexpensive, I can certainly understand concerns over their performance. That said, it is important to understand the conditions under which any measurements have been done. Given this, here are my findings:
- I cannot reproduce Amir's results under any conditions.
- I tried measurements with both SPK5 and Directiva r1 and did not get consistent results. I will stress conditions matter greatly. The SPK5 is vented with a crossover mounted internally and the Directiva has a PR in a different. Would expect a Sointuva to have yet another set of results.
- In the end, also looked at EAC's and hificompass's test of the driver and found no evidence of a major issue.
Here is the hificompass measure at 2.83 V and 20 mm...
If you go to the site, you can try higher voltage levels and all are pretty good.
My takeaway is that the Sointuva measures are unique and could be an isolated driver/speaker issue and has some contributing factor for a distortion issue. If Lars was evasive, he may have been avoiding a long, drawn-out discussion. I do not see any repeatable reason for concern at this point.
Hope this helps!
Rick