Your post date stamped December 29, 2007 10:03AM indicated that the X-Terra had a 10.5-inch coil and the MXT had a 6.9 coil. And you indicate that it seems unfair to compare two detectors with different sized coils. When you refer to it as a 6.9 coil, it would appear that there was a substantial difference in the sizes of the two coils. However, the post that you copied and pasted later indicates that the Whites coil was the Whites 6 X 10 inch coil. For you and others not familiar with the 6 X 10 White's Elliptical DD Eclipse coil, it is an oval shaped coil (elliptical) that measures approximately 6 inches wide and 10 inches long. The Minelab coil 10.5-inch DD coil is round. And from front to back, (where the target is detected) measures only one-half inch longer than the White's. Honestly, one-half inch difference is about as close as you will ever get when comparing coils from different manufacturers.
Although Whites describes the MXT as a detector that has three completely separate operating modes, (coin/jewelry, relic and prospecting) the frequency does not change. It will always run at 14 kHz. The X-30 operates at 7.5 kHz, the X-50 operates at either 7.5 kHz or 18.75 kHz. and the X-70 can operate at 3 kHz, 7.5 kHz or 18.75 kHz. Even though ANY of these three frequencies will find goodies, we all have our preferences as to which one to use at specific sites. Due to design characteristics, DD coil perform better than concentric coils in soils with mineralization levels considered to be "above moderate". With my X-70, I consider that level to require a GB of 28 or a smaller number. In the detecting world, lower frequencies are best suited for targets of higher conductivity, such as silver and copper. In the case of the X-Terra, lower frequency (compared the the 14 kHz MXT) would be either the 3 kHz or the 7.5 kHz coils. By comparing the 9-inch concentrics at these two frequencies, I have not been able to determine any differences in depth of detection on silver or copper coins. However, I prefer the 3 kHz coil for hunting around iron infested sites. In my opinion, the lower audio sounds produced by iron targets have a more distinct sound with the 3 kHZ than the 7.5 khz. Higher frequencies are designed to provide optimum performance on lower conductive targets such as gold. That is why most of the folks using their X-Terra for prospecting are touting the performance of the 18.75 kHz coils.
In comparing the MXT and the X-Terra.... there are many design differences. Feature wise, you are comparing two different generations of technology. In a nutshell, they are both marketed as detectors capable of finding coins/jewelry, relics and prospecting for gold. Understanding the fact that different frequencies respond differently to targets of varying conductivity, it should be clear that the capability of the X-70 to use all three frequencies makes it a truly universal platform. A detector with the capability to adapt to almost any hunting situation by simply switching out the coil. Another big difference between the two detectors is the manner in which they accept and reject specific targets. The MXT has a variable discrimination system. That means that when you set the discrimination to a certain level, it will reject everything below that setting. Granted, it does have one preset notch for pulltabs. It is activated with the trigger mounted under the meter. But it is preset and not adjustible. With the full range notch discrimination circuitry of the X-Terra, you can pick and chose which notch segments you want to either accept or reject. For example, if you set your MXT to reject pulltabs, you will also reject anything with a conductivity lower than pulltabs. With the X-Terra, you simply reject the notch segment representing the pulltab, and continue to accept targets with lower or higher conductivity readings. These differences don't make the MXT a bad detector. Just a totally different concept in metal detecting technology. I have an MXT and the X-Terras. (and an Advantage, and an XLPro, and an Explorer etc etc) Although I use the X-Terra much of the time, I still have situations where I use other detector/coil combinations.
I'm not sure what your intent was by posting those 4 negative reviews on the X-Terra Forum? There are over 12,000 posts on this forum that pretty well examine the pros and cons of the X-Terra and it's functionality. Regardless, I've visited those review sites myself and frankly, don't hold a lot of stock in reading reviews from people that I don't know if they even used the detector they are reviewing. The thing that I find suspicious about the reviews on those sites is that some "reviewers" post similar comments about numerous detectors. One guy posted (on 4 different makes and models) that the specific detector being reviewed was the best thing he ever used. Interestingly enough, that same person has a website who's address that includes a certain manufacturers brand name. Tough to take someone like that very serious. In the four reviews you listed, I did note that two commented on the slow reset speed. That statement alone tells me that they are not familiar with the X-Terra, compared to nearly every other detector in the industry. Amongst the top line detectors available today, the reset speed of the X-Terra ranks among the fastest. The comment that struck me as the funniest was the guy who said he has been buying and selling detectors for 25 years. My initial reaction to his comments is that he should spend less time buying and selling, and more time learning how to use a detector properly. With his comments about "dialing out iron" and setting the sensitivity to a "median", it is obvious he knew nothing about the X-Terra. One comment that could have been an honest review was from the person stating the inability to find hammered coins. What I noticed about this review is that it was made prior to the release of most of the accessory coils. Posters to this forum have attested to their success on hammered coins (as well as ancient artifacts) by using their X-Terra and the DD coils, higher frequency coils and the 6-inch coils.
As to whether or not White's is using Minelab technology......White
