So either this data is junk or Dayton woofers are REALLY off spec. I am inclined to believe either as I've both messed up measurements and had Dayton woofers that measured no where close to their specs.
I took impedence measurements of 3 of woofers (should have been 4 but one arrived damaged). They all measured nearly identically. I measured these exactly the same as I have measured every other woofer I have ever used. Unless I royally screwed something up. I'll even zip the impedence measurements and toss them on here.
The one spec I find the most concerning is the MMS. They have listed 24.17 grams. I show 16.27 grams. Way off. I used 12.08 grams of blue tack and added that to the cone for my measurement. That should have been half of the MMS. If the MMS is actually 24.17 grams.
Can anyone see errors in my measurements here? Or is this just what it is?
I might just buy a DATS V3 just so I can always be sure. Thoughts on how good those units are? Pretty reliable?
I took impedence measurements of 3 of woofers (should have been 4 but one arrived damaged). They all measured nearly identically. I measured these exactly the same as I have measured every other woofer I have ever used. Unless I royally screwed something up. I'll even zip the impedence measurements and toss them on here.
The one spec I find the most concerning is the MMS. They have listed 24.17 grams. I show 16.27 grams. Way off. I used 12.08 grams of blue tack and added that to the cone for my measurement. That should have been half of the MMS. If the MMS is actually 24.17 grams.
Can anyone see errors in my measurements here? Or is this just what it is?
I might just buy a DATS V3 just so I can always be sure. Thoughts on how good those units are? Pretty reliable?
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Measurements usually give a conistent set of parameters that will provide very similar enclosure simulations to data sheet or other measurements, even if the parameters themseves vary. That's usually no problem.
Did you loosen up the suspension prior to measurement?
Have a look at this driver test and the (apparent) parameter deviation:
https://hificompass.com/en/reviews/seas-excel-6-w18nx003-e0096-08-midwoofer-review
Make sure to click on the hidden paragraph "Broken-in and measurements of Thiele-Small parameters by other manufacturers"!
Did you loosen up the suspension prior to measurement?
Have a look at this driver test and the (apparent) parameter deviation:
https://hificompass.com/en/reviews/seas-excel-6-w18nx003-e0096-08-midwoofer-review
Make sure to click on the hidden paragraph "Broken-in and measurements of Thiele-Small parameters by other manufacturers"!
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Joined 2003
The measurements are quite noisy, that could be one source of error in T/S determination. Added mass is barely managing 25% drop in Fs, I would use a bit more added mass personally. You should also start your measurement sweep at 0Hz, not 20Hz, there's a lot of missing information that REW is trying to fill in with a curve fitting algorithm.
Comparison to datasheet is inconsequential - datasheets are often wrong. Comparison to actual result when the driver is placed in a cabinet is what matters.
Comparison to datasheet is inconsequential - datasheets are often wrong. Comparison to actual result when the driver is placed in a cabinet is what matters.
I did notice that. I looked through some of my old measurements and found that a decent portion of my ZMA measurements are quite noisy. They didn't effect the TS measurements like this but agreed, not great measurements. Hence me considering just buying the DATS.