I started to take the newest (3rd one I've tried) MX Sport hunting today but it's too dang hot, so I opted to try it on some surface targets in the driveway.
The results are not wholly acceptable to me but until and unless White's receives enough pressure from MX Sport owners or decides that they are not going to sell enough units until they fix its problems, I think this is where we all stand.
I placed all sorts of targets on the ground. Nickel, clad dime, silver dime, buckle size brass plate, rusted square nail, ihp, clad quarter, minie ball, brass flat button.
Using the supplied headphones, I tried the various functions while in Prospecting, C&J, Relic, and Hi-Trash programs.
At first I thought VCO and Audio Modulation were not working at all. What I found after further testing is that they do affect the operation of the detector. JUST NOT IN A GOOD WAY!
Audio Modulation (option) is supposed to change the volume of the target signal proportional to the distance between the coil and target. Closer, louder; farther away, softer.
What it does on this particular unit, is that as you raise the coil away from the target while swinging over it, a point is reached where the tone goes from a fixed volume and clear to a splattered tone of nearly muted volume. It is not a gradual change with distance. It is an abrupt change at a specific distance. A perfect example, one might say, of how NOT to implement audio modulation in a metal detector. A user of this machine in its present state has one clear choice: DO NOT implement Audio Modulation. It's not just worthless; it is actually detrimental to the operation of this particular MX Sport.
VCO (option); Voltage Controlled Oscillator/Oscillation/(change in pitch) of the signal produced by the target as the distance between the coil and target changes. Closer, higher pitch (frequency); farther away, lower pitch (frequency).
What I describe here is pretty much what everyone familiar with VCO expects in a detector so equipped. My findings, with this MX Sport, is that the actual tone does not change. Rather, there is an accompanying sound, call it a tail or tail out that changes in pitch, but the tail/tail out has a buzzy/noisy aspect to it that could affect one's comprehension of the actual target tone. Again, I have to say that this seems to be a terrible implementation of VCO.
Iron Grunt (option) is suppose to confirm iron targets as iron. I'm still not quite sure how it is suppose to work so I honestly cannot say if it works or not. If it's as bad as Audio Modulation and VCO is on this machine, I may never be able to tell if it does anything or not.
While cycling through the options, I noticed a slight hum in the headphones and traced it to the backlight. When the backlight is on, its circuitry emits a hum that can be heard in the headphones. Only position/selection 5 under the backlight option stops the hum.
If you turn on the backlight while detecting (by tapping the power button), the hum returns and continues until the button is tapped again to turn off the backlight.
Pinpoint function. There is not a lot of frequency range to the pinpoint tone, nor is there a lot of spacial range either. It doesn't reach out and grab the target like some machines/coils do. You pretty much have to get the center bar of the stock coil (that runs from nose to tail) directly over the target for it to pinpoint. Most of the length (from front to back) of that bar is max pinpoint volume, but move the coil left or right just an inch and the target pretty much disappears. This is for targets laying on the ground. It may respond somewhat differently to in-ground targets.
Having said all of the above, I am not convinced that this specific unit has been updated. Mary in Customer Service sounded a bit frazzled when I talked with her last evening. Maybe White's record keeping (or not) is getting the best of her.
If this machine has been updated, it still has issues. My dealer let me listen over the phone last week to a demo unit he had as he tried out the VCO and Audio Modulation functions, and his machine sounded like it was working much better than the machine I just received.
So, it seems there MAY be some machines that check out perfectly fine. The problem, as it appears to me, is that (1) White's can't tell a good machine from a bad one, so you may get a good one or you may get a bad one. Or, (2) White's knows which machines are good and which are bad, but they send them all out, hoping many of the bad machines won't ever come back to them. Personally, I thinks it's some of both.
I'm going to try to speak directly with someone at White's who repairs MX Sports and tell them how the VCO and Audio Modulation sounds on this machine, and mention the hum from the backlight, and see if they can tell me that yes, they CAN and WILL fix the issues if I return the machine to them.
Knowing what I know now, would I repeat my decision to buy an MX Sport? That's a really tough question to answer because I think the MX Sport has a lot to offer, but I think I'd try to wait 6 months to a year and hope some of the known issues are resolved. Will they be? Who knows?
Wayne