It probably has things in common, although I am not familiar with how exactly an lcr meter is programmed to perform measurements.
As a point of addition to that, an LR filter will give 50% of the voltage at Fc, whereas a Butterworth filter will give 70.8% of the voltage.
If you've got more money to throw at a solution a DATSv3 is accurate and easy to use:
Dayton Audio DATS V3 Computer Based Speaker & Audio Component Test System
Does accurate impedance sweeps too if you are a passive XO junkie or want to check drivers for consistency / issues.
Dayton Audio DATS V3 Computer Based Speaker & Audio Component Test System
Does accurate impedance sweeps too if you are a passive XO junkie or want to check drivers for consistency / issues.
It is not an"issue", it is a feature. Accuracy and resolution of measurements of every RLC meter are closely related to the measuring frequency. According to the Tenma manual, the best accuracy and resolution in the range of usual values of L and C found in the typical crossover is with 1 kHz measuring frequency. Only for a very small L value (below 0.2 mH) slightly better accuracy is with 10 kHz - but it is only academic, the real-life tolerance of L and C components are much worse than the accuracy of the RLC meter.
The main point is: every L or C measured at 1 kHz will have the same nominal value from 20 Hz to 20 kHz.
Sonce, I should have said, "my issue is". I just find it curious that quality manufacturers go on about carefully selecting components for tight tolerance and pair matching etc, yet the general advice here seems to be, don't worry about measurement discrepancies as the component tolerances are so wide...?
As a DIYer you have the luxury of choosing your level of precision and absolute quality. The thing with DIY is that you have access to the components and measuring ability that allows you to do so, so you can know what the actual parameters are with certainty. Whether absolute precision is of benefit - and to what extent - is a different discussion.
Shaun you are correct about DIYers, but I'm a DIYer trying to measure a manufactured product, with different equipment than that of the manufacturer. Anyway, there's no use me continuing to split hairs, I'll have to learn more by experience. That's the beauty of DIY! Cheers. Matt
Pair matching and tight tolerances in crossovers are very seldom used, exclusively for a high priced loudspeakers if at all. It demands driver matching also.
It's nice for doing sanity checks but for me exhibits inconsistencies, for example when measuring paralleled caps. Two identical caps usually display higher ESR than a single. The ESR of a 100 uF poly/oil goes up when paralleled with a 200 uF electrolytic. Two ASC x366 2 uF in parallel however improve ESR dramatically. No idea why.
In general polypropylene measures better than polyester, film better than electro, etc., as expected. Still a good tool to have around.
Probably so but not cheap. Nice impedance analyzers approach five digits quickly.
Hi alayn91. It's always a smaller impedance than either unless at a specific frequency if resonating. Even then, ESR is the real R of the complex impedance and doesn't resonate. Wouldn't the expectation be the real part of the parallel measurement is always less than the real part of Z1 or Z2? DATS often shows paralleling increases R at 120 Hz, 1 kHz and 10 kHz.