Thomas Dankowski's Metal Detecting Forum

El Nino....... good post/video.
Chris....... yes..... multi-freq has superior advantages if engineered properly. These tests displayed exactly that. (Unit sounds like a Minelab)! Those two different coil configurations AND different coil sizes can really skew the data (and invalidate the test); yet, comparable coil size/configuration may not always be available........ and ........ you have to test...what you have!

Mr. Dankowski-Tom ....you are right,,, work Concentric coil and *DD coil can work differently on the same iron objects...
I did a slightly different type of test where a detector is tested for discrimination of 12 different pieces of iron... and at the same time a test for unmasking a nickel coin under an "iron carpet"...

VERSA..23DD coil
https://youtu.be/lJ11-NSM0DU

TESORO MOJAVE- 6" CC coil.
https://youtube.com/shorts/NOXNrJUUJmc?feature=share

In this test, Tesoro Mojave had a problem with the discrimination of flat iron.. 2 pieces of iron gave a non-iron signal... but when separating a nickel coin under an iron carpet, it was able to give a partial signal or rather a hint of a signal on the coin.. I note with a really slow sweep with the coil ..

VERSA.. on the "multi-frequency" surprised me a little during this test, because even at the zero setting of the filters../Iron filter/ and /bottlecap filter/ ..it gave a non-ferrous signal only on 1 piece of iron,,and on the other piece of iron it was 50% iron signal/50% non-iron signal from a total of 12 pieces of iron... and at the same time it unmasked the coin quite well under the iron carpet from three sides of the coil sweep..

I did these tests in the spring of this year...and I included a few more...detectors...in the tests.

Vista Gold Gain 30 khz..
https://youtu.be/Iy8AixpvcPE

XP Deus1 74khz eliptic hf coil..
https://youtube.com/shorts/u4imKUG0HjU?feature=share

VERSA 1frequency 40 khz program Field..
https://youtube.com/shorts/WxFfPnERqvY?feature=share

From this test, you can see how effective you can be in detecting good targets vs. unsolicited targets in practical detection...

Very good tests. Especially..... all of the individual DIFFERENT types of ferrous/iron targets......,,,,,,....... to include flat iron. Flat iron is a achilles-heal to ALL detectors. Very few detectors give you any tool(s) to adjust/compensate/alter responses to flat iron.

Sometimes..... Single Frequency units "appear" to do better with certain iron; yet, at the compromise of unmasking.
Sometimes..... Multi Frequency units can 'false' on certain iron targets at a higher rate; yet, with a little bit of practice/skillset..... the operator can (fairly) easily discern between the 'falses'....... and ferrous/non-ferrous (co-locate) scenarios..... for enhanced unmasking capabilities.

If you dig deep into Manticore's tools/featureset....... you can easily unmask at a higher plateau.........next-Generation technological advancement/capability.