My experiences of the MG6Pro are that, contrary to the way almost every pundit in this thread has glowingly lavished praise upon it, the MG6Pro is not, in fact, an audiophile-oriented CIEM.
I'm not saying it isn't any good; I'm just pointing out that it isn't aimed at audiophile use. Out of respect to FS, I've remained quiet about this, but since no one else seems willing, or sufficiently aware, to discuss this publicly (not even FS themselves, in their own literature), this thread has become rather skewed in its appraisal of the MG6Pro, which can be misleading to potential audiophile-oriented purchasers.
Consequently, I've come to the conclusion that it's unfair of me to remain quiet any longer, as quite a few Head-fiers may experience disappointment if spending their hard-earned cash on what they have been led to believe by other Head-fiers is an audiophile CIEM.
I am not 'axe-grinding' here. If I wanted to 'axe-grind' I could have done that long before now, and I have enough life experience to know that putting negativity out into the world only begets negativity in return, one way or another. Please understand, therefore, that this post, whilst undoubtedly being contentious and potentially-unsettling to some, is coming from a sincere standpoint, not a negative one.
So...with that out of the way....
The design brief for the MG6Pro was very, very specific - namely, for HIGH-SPL stage use, and high-SPL stage use means that certain frequencies can rapidly become fatiguing to the user. Therefore, an experienced designer designing a CIEM for HIGH-SPL usage may choose to take this factor into account when designing an appropriately non-fatiguing frequency response. I am given to understand that such was the case when Marty designed the MG6Pro's drive unit.
However, at the time of this writing, on the FS website, the MG6 Pro is described thus:
The mg6pro™ are multi-driver & crossover free; delivering full range audio w/ natural hi-end sparkle, warm mids and a low-end frequency response no two, three, four or more way balanced armature earpiece can touch!
Whilst I acknowledge, in FS's defense, that they do not actively promote the MG6Pro to audiophiles, it nonetheless remains the case, as you can see from the above quote, that no mention is made of the frequency response of the MG6Pro having been deliberately tailored in the aforementioned manner.
If FS were up-front about this and/or permitted 'universal demo' units (I know they're flawed, but they're better than nothing) then there would be far less potential for audiophile-oriented customers to spend several hundred bucks on something they end up being disappointed with. The standard recommendation for potential MG6Pro customers to listen to the MG7-driver Atrios is misleading, in my view, since the MG7 driver's frequency response is not tailored the same as the MG6Pro.
All CIEMs have differing sonic characteristics, of course, but the issue with the MG6Pro is that the frequency response has been very specifically tailored to a purpose other than that traditionally sought by audiophiles (i.e. striving for as close to an even frequency response as reasonably practicable). Evidently, the MG6Pro still pleases some audiophiles, in spite of deviating from this, but, judging by personal PM conversations I've had, I am very definitely not alone in finding it less than satisfying. Anyone reading this Head-fi thread could much too easily arrive at the conclusion that the MG6Pro has a supremely balanced frequency response (a conclusion which, even in the absence of the glowing testimonies, is all the more tempting to arrive at, by virtue of the single, crossover-free, dynamic driver design). And, indeed, some owners may retort to my post that they do consider the MG6Pro to be 'supremely balanced', but I beg to differ.
Again, let me make it perfectly clear that I am not 'bashing' the MG6Pro - it is very effective in fulfilling its intended design brief, and it is a good quality CIEM overall. By comparison with Balanced Armature models, it is also notably robust, both in terms of ability to withstand inappropriate input signals, and in terms of shock resistance (if dropped onto the floor).
My only intention in contributing this post is to bring some balance to what has, up 'til now, remained an extraordinarily one-sided thread, so that potential Head-fi customers of the MG6Pro can hopefully make a somewhat more informed decision.
Please note that I will absolutely not be drawn into any debate regarding what I've said here. Such debates only ever end up becoming heated and therefore counter-productive. I've said what I've said, and I've said it sincerely, from a non-negative intention/standpoint. If you read my post and interpret it as a negative attack on the MG6Pro or on FS or anyone on their staff, then please take a deep breath, re-read, and realise that that's an inaccurate projection on your part. You do not need to 'counter attack', or 'defend' or whatever, because I'm not 'attacking' anything in the first place.
Put simply, if you are a potential customer of the MG6Pro and wish to discuss the specific intricacies of its design brief, then I recommend you contact FS by phone, and get all the details straight from the horses mouth, so-to-speak. As a potential customer, it will benefit both you and FS to discuss such matters prior to placing an order. If, having done so, you decide to go ahead and order the MG6Pro, I hope you enjoy it very much.
As with all CIEMs...
And @ David/Marty (yes, I know you keep an eye on this Head-fi thread), howsabout acknowledging on your website that the MG6Pro has a response specifically tailored for HIGH-SPL stage usage? It wouldn't lose you any of your pro customers and it would reduce hassle and potential disappointment for audiophile-oriented customers, which is in the best interests of both them and you.
Edited by Mython - 10/26/12 at 9:34pm