I recently purchased a DATS V3 to measure some drivers I have lying around and each free air measurement is wildly different than the other (for the same driver). I'm getting QTS swings of 0.6 or more and the frequency curves look completely different each time. Anyone have any advice on this? I appreciate it!
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Make sure Windows device settings are configured properly, as spelled out in the quick start guide:
https://www.daytonaudio.com/images/resources/dats v3 quick start.pdf
For drivers with vented motors, make sure you are elevating them to keep the vent free when measuring, placing these drivers face up on a desk will not provide good results as you will block the vent.
Make sure Windows device settings are configured properly, as spelled out in the quick start guide:
https://www.daytonaudio.com/images/resources/dats v3 quick start.pdf
For drivers with vented motors, make sure you are elevating them to keep the vent free when measuring, placing these drivers face up on a desk will not provide good results as you will block the vent.
Placing the driver on/near any rigid boundary or surface is likely to give inconsistent results. The best data I've had from any 'ghetto style' electrical impedance measurement is from suspending the driver in the middle of the biggest room I have access to. In one case, that was from the ceiling light fitting by one of the driver's mounting bolt holes, and tying the opposite bolt hole to something heavy (like a nice, thick textbook) placed on the floor below. Probably not a good idea for anything larger than a couple of inches, mind! You could also try using a g-clamp to hold the driver to something sturdy and upright, by the magnet?
Don't forget a pre-conditioning period helps as well. No need for silly time periods or high power drive levels, but playing some pink noise at a reasonable level is a good shout.
Another thing to consider is how you're going to add a suitable, known mass if you're not fortunate enough to have a bunch of sealed test enclosures for the second part of the process. Josh Ricci at data-bass.com switched me onto the idea of using small, circular magnets placed at the dust cap. Luckily those are cheap enough from China these days, and strong enough to hold themselves in place even if the driver is mounted sideways.
As a general rule, it's also a good idea to take a bunch of measurements in succession and make an average, whatever you're testing.