The advantage I see in the DD over the 10" concentric coil is not potential added depth but the shape of the field which, in a side to side sweep, should better cover the area due to it not having a cone shaped magnetic field. Additionally, pinpointing is easier due to the narrower side to side field. Am I off base?
BTW, +1 on the DD. I LOVE mine, as well as the 4" coil!
When hunting large and wide open areas there is nothing better than using a big DD coil to cover them quickly and efficiently.
When I do I never get the feeling I am missing much because of that long scanning field and there are a few great targets I have found in these large areas I am convinced would still be laying in the dirt if I wasn't using the DD coil at the time.
I might indeed be missing some targets if I am not careful, but I never get the feeling that I am and that is important because the "what ifs" will kill me if I think that way.
Hunting in heavy trash, and I tend to aim for sites with unbelievable amounts of trash targets when looking for jewelry, I still prefer the small sniper concentrics because of that slightly smaller scanning field vs even a DD sniper.
I think target separation for me and the way I hunt seems a bit better because even with the small sniper DD's you still have a slightly larger chance of having more than one target under the coil at the same time.
I have some experience with a sniper DD and it works well, but I have more experience using the concentric snipers at this point so I am used to them.
As far as pinpointing when I first used the 10X12 DD coil on my Vaq I couldn't find the target at all, but after a few hunts and watching one video I learned some techniques that solved that problem and now I can pinpoint just as quickly and precisely with any DD coil as I can with a concentric so in that area for me now they are equal.
The only reason I am not a 100% died in the wool fan of DD coils 100% of the time is the disc on those are a bit more sloppy than the concentrics and they have that high tone pop top problem where they mimic dimes and quarters so well.
I have figured out ways of using them to tell the difference like rimming these problem targets that help immensely, but on my detectors the concentrics are just a little faster and a bit more accurate at giving me info about these hated types of trash.
I guess it wouldn't be a big issue in most sites that I hunt but there are a few very old park sites where there is a huge amount of these things, almost like a blanket of pop tops at all levels from shallow to deep that are a big drag for me to hunt using DD coils because they slow me down so much in these rarer but existing problem sites.
I have a new detector, the F70, and an 11" DD coil that goes super deep along with an extremely deep 5" DD and I plan on using these the bulk of the time this year so maybe my opinion will change a bit before the season comes to an end.
