Hello again, here I am with questions once again.
So, first, would you recommend that I send one or both of my RST28F-4 back and get new ones?
Attached you can see the free-air impedance measurements and one of them has a completely different curve than the other. One of them has 20% lower impedance at Fs and a prominent peak at 2.8kHz, which I guess would affect a lot the crossover design, and I am not very inclined in having each speaker have its own crossover. Also, they both do not pass the rub and buzz test although the software somehow is not calculating Fs correctly (it just takes the first slight bump of the curve instead of the main peak).
Seconly, after measuring my RS225-8, I got thiele parameters differing a bit from the listed ones, specially Fs which I got for both drivers that I bought 31.8 Hz instead of 28 Hz. And I wonder one thing: I always heard that speakers need to be broken in. Do the Thiele small parameters change a lot after several hours of use (for example Fs, as the suspension (surround?) becomes more ductile I guess Fs would decrease). If yes, does this mean that the data provided by dayton audio pertains to broken in drivers or new? How does one takes this into account in their design?
I ask this because the parameters I measured change quite a bit the best box and the response’s F3 quite a bit.
Lastly, if I would like to measure the z-offset, I should mount them in a test box. I gather that at least the x,y positions of the drivers should be the same as in my final design, but I wonder if I need to make the test with a box, or could I for example just mount them on the front baffle of my final design and measure their response without a box. Because I could in principle build a box like the final one, but then I would need to figure out how to mount the crossover inside (I guess I could use the hole of the RS225, but that sounds annoying). Its not simple for me at the moment to build three boxes, and I would like to see if I could leave it at building only 2 final boxes.
I am sorry for being so annoying with all this questions.
