Wow I love hot topics like this!!!
I have used a Whites DFX for 2 years and I have used a Minelab Explorer II for 3 years now. Minelab wins hands down. I have used both and feel I know both very well. I have hunted with Steve Leheto when I used my DFX, and used the DSM program. I have also been posted on Whites web page 3 times and have also had stories in Western and Eastern Treasure Magazine. Now that being said you can take what I'm going to say to the bank. First off, forget air test as a way of determining depth of a detector. If your doing this, your wrong. Especially if you do this inside your house or building when doing the test. Electronic interference like TV, radios, microwaves electronic current will cause this test to be false one. Next what most people don't know is, the technology in Minelab Explorer, is different, and is the same as in the Whites DFX.( LOL). Whites used the duel frequency technology and had to pay MineLab on patent infringements. I know this will upset you DFX users but its true. Now lets get back to the depth issue. I have tested both in the outdoors side by side in a test garden. They were both tweaked to the best of there ability's for depth and Identification. (Yes the other detector was turned off while the other was being tested). The Whites DFX was ground balanced and the Minelab Explorer noise Cancel. The Whites DFX using the DSM and pre amp of 4 correlate, accept +94 to-40, and the Minelab Explorer II sens 28 manual, deep on, iron mask -16 and ferrous tones. The Minelab was able to pick up a dime at 10 inches no problem and The Whites DFX couldn't even hear it. Conditions, soft wet dark farm soil that a barber dime has been packed flat over 6 years now. Now, I will admit after I put the hot shot 12" coil on the DFX, I got a slightly broken low signal. This was especially upsetting to me, because I wondered how many times I passed up a good target with the DFX that made that noise. As with many avid metal detectorist, I like to hunt by tone ID. So this was really was upsetting. OK back to air testing. The reason an air test is nonsense is because, Minelab doesn't use ground balance to determine depth. They use what is termed a Time Domain and a computer to send and receive the signal of a known target. They also use Noise Cancel to block out all electromagnetic interference such as cell phone towers, telephone lines, and other detectors etc. This is the primary reason in mineralized ground conditions why the Minelab is deeper than the Whites DFX. It has the ability to block out the magnetic interference and mineralization.
The Whites DFX uses ground balancing, and in real bad soil stinks. The Explorer in Ferrous tones will make all your Iron targets sound low and all conductive targets like copper silver sound High. So in a nail and iron infested area or trashy area, the Minelab Explorer will out gun the whites DFX hands down. The Whites DFX will just null away on those nails. Here's what the strange part is,that I don't understand. The Whites DFX uses a convex coil.Meaning a cone shape pattern signal is emitted from the coil. Common knowledge is that this is supposed to go deeper than a DD coil that emits a straight line pattern. So why is this happening??? The answer is easy. Ground balancing in bad soil areas, or with any other type of interference is downfall of the Whites detectors!!! Seriously look at how many times you have to ground balance and in bad soil areas and have had a hard time doing So?? Sometimes it wont even do it. Thats my honest opinion on that issue.
The Mine lab Explorer II has the ability to change what the sound sounds like. Coins can be made to sound longer and wider while junk targets sound short and choppy. You can't do that with the DFX!!!. Also, you can control the strength of the signal response and separate the surface targets say 1-5 inches sound strong while the 6-12 sound a little fainter. Yes you can look at the depth indicator if you believe it, but thats not always accurate on the Whites DFX .By using this the Minelab Explorer lets you cherry pick sites for just the deep targets by hearing them rather than watching the screen. You cant do that with a DFX. What impressed me the most about the Explorer is the depth. You can honestly still hear the high pitch sound of silver when its deep say 10 -12 inches. It doesn't turn into a constant low sound like it does on the DFX. This is what makes the Minelab Explorer a better choice. I will be happy to show anyone this if they want. This is a fact. I hated this when I first found out. I couldn't believe the tone ID was really that bad on the DFX after 6 inches. Yeah the weight issue is a problem with the Explorer II, but the balance in the detector is pretty good for the average person. When you dig more deep targets your spending more time digging than swinging anyway so it's not an issue for me. Like others have said, if your going to dig 1-5 inches than get the DFX and be a clad farmer. If going to find deeper silver Indian head pennies and Barber dimes, Seated coins at 6- 12 inches, then get the Explorer from Minelab and a deep shovel. Oh one more thing, if your ever in Michigan look me up or PM me and I'll show you this is a fact, you might not like it, but I'll show you free of charge. I'll take you to some great hunting spots and you can see this for yourself. I know this will stir up the pot a little, but it's not about opinion, it's a fact. Your older finds will more than double.
Tom