Measuring impedance with multimeter

This is an area of interest for me too.  A close friend's church had lots of PA gear stolen.  I'll be doing the installation and don't want to be attaching a new power amp before testing the long speaker cables.  Strangely another friend's church needs work on their 70v system with 8 speakers in the ceiling.   I've been running sound for churches for decades, not doing installations.  So I need to purchase something reliable. 

There are relatively inexpensive devices available that will test AC impedance for audio applications--not DC resistance. 
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=speaker+impedance+meter&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=impedance+meter

The more expensive ones will test impedance at various frequencies.  Some will also calculate "watts" for those testing a larger number of ceiling speakers running on a commercial 70v system, etc.  
http://www.gold-line.com/zm1.htm

There is a software based app that has lots of bells and whistles.  The package is very pricey due to the required $500 audio interface plus the app
https://www.studiosixdigital.com/audiotools-modules-2/speaker-test-modules/impedance-meter--sweep.ht...

The inexpensive  Chinese impedance meters only test at 1khz.  
https://www.ebay.com/itm/Digital-Audio-Impedance-Tester-LCD-Display-Speakers-System-Resistance-Ohmme...

The choice of 1khz seems strange to me.  My understanding is that the standard frequency for testing woofer impedance is 400hz. 

You can see why 400hz is more suitable for testing speakers since impedance varies greatly according to frequency!
https://www.studiosixdigital.com/_Media/impsw5.png 

Dayton Audio DATS is the only answer to this question.

Erik, thank you very much for the information on the DATS system.  It seems to be excellent for my situation and a good option for Recluse's situation.  I will likely purchase it. 

Do I understand correctly that it will not calculate the watts in a 70v system as some of the high-end hardware units do?
http://www.gold-line.com/zm1.htm

However I don't see any reason why DATS is "the only answer" to Recluse's question.   Some people may prefer the convenience of a very portable, small, dedicated piece of hardware.   A sound tech on a ladder troubleshooting a problem with ceiling speakers would appreciate the convenience of a small battery powered hardware tester rather than a laptop computer.  

Of course it is not "the only answer" but I wanted to avoid endless hackery and half baked solutions propping up here.
DATS is pretty comprehensive, allowing the measurement of drivers, entire crossovers and every component thereof. 
It is inexpensive, USB driven and pretty accurate. Certainly accurate enough for Magico to use (but not of course alone).