I've had the Monster Turbine Pro Gold (MTPG) for over a month, and have given them extensive use during that time. I put about 300 hours on them with burn-in, and listened to them every day for weeks. I liked them right out of the box without burn-in, but they did open up and become more transparent over time. I couldn't decide whether to rate them here at EarphoneSolutions as a 5 for being an excellent value, or a 4 when considered in comparison to the best out there which would be a 5. I'll let you decide from the review, but in their price range they are one of the best, coming in only behind the more costly Westone 3 and UM3X and being tied with the Westone 2 in some areas but not all.

FEATURES: These came with a nice number of pack-ins, including two small storage cases for carrying them in your pocket, a 1/4" adapter, and numerous tips. The MTPG came with the larger of two sizes of "super tips" pre-installed, but I had to use the smaller ones included for a good seal. These feel like a gel-filled silicone tip to me - they're springy and fun to play with in your fingers, and almost function like a modified silicone tip with a squishy foam tip underneath it (a popular tip mod posted online for Sennheiser IE8). I had more difficulty getting a good seal with normal silicone tips, and once I tried the super tips I didn't feel like trying any of the others (triple flange or foam).

One of the things I noticed was that if I try to deeply push them into my ear canals too quickly, that I can create a vacuum or pressurize the ear canal that binds up the driver and mutes the sound, until I wiggle the earphone enough to let the pressure equalize between the outside and my ear canal. I have seen this with several other closed dynamic driver IEM and earphones, so it's not unique to the MTPG. In regards to keeping the sound tubes clean, the TPG have a metal screen covering the sound tube opening. I don't think these need much cleaning, but I suppose if you get ear wax covering the screen that you could use a small pin to clear the tiny holes of ear wax, or invert the sound tube's exit so it is facing down and then wipe it down with a Q-tip dipped in hydrogen peroxide. Monster may be able to provide other suggestions for this as well, but I haven't checked. I have very clean ears so it isn't a problem for me.

GEAR USED: I compared the MTPG to several other IEM and earphones including Westone 2, Westone 3, Ultimate Ears Triple.fi 10 Pro, HiFiMan RE252, Denon AH-C700 and some modified Altec Lansing IM716 with 47 ohm resistor pod. I used several DAC/amps with my Macbook Pro to audition the MTPG, including iBasso D4 with an opamp upgrade, CEntrance DACport, Nuforce HDP, and Headamp Pico DAC with RSA P-51 Mustang amplifier. I also used my iPhone 3GS to listen to them unamped. I found that they do scale up well and the better your source and amplifier are, the better they sound; but they still work well un-amplified. My favorite amp for them was the Nuforce Icon HDP DAC/amp. The P-51 amplifier is also a little more sparkly on the top and and was a little better match for them, although they worked well with all the amps.

MUSIC USED: I listened to a wide variety of lossless music, including selections from Diana Krall "Live in Paris", Eva Cassidy "Live at Blues Alley", Kathleen Edwards "Back to Me", Nancy Bryan "Neon Angel", Norah Jones "Not Too Late", Sarah K. "Hobo", Ottmar Liebert "Up Close", Esbjorn Svensson Trio "From Gagarin's Point Of View", Fourplay "Between the Sheets", Herbie Hancock "River", Peter Asplund Quartet "As Knights Concur", Shota Osabe Piano Trio "Happy Coat", Infected Mushroom "B.P. Empire", Grateful Dead "Skull & Roses", The Beatles "Love", Led Zeppelin "Mothership", Nils Lofgren "Acoustic Live", Beck "Sea Change", Jack Johnson "In Between Dreams", Arvo Part "Tabula Rasa", and Bella Sonus "Enamoured", among others.

OVERALL IMPRESSIONS: In general I find the MTPG to be a very nice earphone or in-ear-monitor (IEM), and well worth the asking price (mid-high $200's last I checked). They're actually just a little more neutral IEM than my Westone 3, unless I'm using my Westone UM56 custom fitted tips with the W3. But they are also a less dynamic IEM than the W3, with less impact and presence. The soundstage of the Westone 3 is also a bit deeper and spacious. Lest you think I don't like the MTPG, nothing could be farther from the truth, as this is more of a testimony to how much I enjoy the W3. And many of the well respected universal IEM that come in below the Westone 3 and UM3X do have something to fear from the Monsters. The MTPG have a more balanced frequency response than Triple.fi 10 Pro and Denon C700, which I feel have recessed mids in comparison to the bass and highs. The C700 sometimes sounds like the bass and treble are tipped up for use with older iPods (I bought them for $199 back in early 2007). With the wrong tips the Westone 3 can have a similar issue with tipped up bass levels above the mids; but the W3's mids seem to be in line with it's treble levels and are not recessed. When I owned the Sennheiser IE8 I felt like the mids and the treble were both recessed in relation to the bass levels. But the MTPG don't leave me with any complaints about their balance between bass, midrange, and treble levels; and I don't feel that there are troublesome peaks or troughs in the response curve that will bother people or cause problems.

The Monsters work well with a wide variety of amps and iPods, and they're not too difficult to drive without an amp. I found that the RE252 and IM716 are much harder to drive than the MTPG which are more sensitive. The Monster's sound is close to the W2 in quality, but with slightly more bass and warmth, and not as bright with the wrong amp. I had previously discovered that the W2 don't like an amp with high output impedance or in-line resistor like a P-to-S adapter; otherwise the W2 can get a little bass-lite with the sound tipped up on the mids and highs. In particular, I had that issue with the Nuforce HDP prototype that I was testing, and they updated the final production version to where it became a great match for the W2. However, the TPG performed fine on the prototype HDP unlike the W2, and even after the amp updates the TPG sounded good with the HDP's amp.

BASS: In regards to the bass quantity, I would say the MTPG have a little less bass than my Westone 3, which will make some people happy if they thought the Westone 3 had too much bass. They also have less bass than the Sennheiser IE8 which I sold because I though those had a little too much. The MTPG have a similar bass quantity to the Triple.fi 10 Pro (and as I recall the UM3X), which is usually just a little more bass than the Westone 2. To me the MTPG bass level is very good and where it should be, and I would never say the MTPG have too little. Nor do I think many will complain that it needs more, even though there are other IEM out there with more bass where it isn't felt to be too much. As a matter of fact, the MTPG have noticeably more bass than the HiFiMan RE252 or IM716 with 47 ohm pod, which do have good midrange and treble. The RE252 and IM716 don't feel like they are too lacking in the bass until you compare them to the MTPG, W2, W3 and Triple.fi, and then they leave you wishing for more. But the MTPG have enough bass to make classic rock from the 70's and 80's sound good to me, where sometimes the W2 are not the best choice for that genre.

The MTPG bass quality is also good, with no bleeding over into the lower mids or any boomy mid-bass hump, and it extends deeply to 20Hz without effort, although with some roll-off below 30 Hz. When I compared the bass to the Denon C700, I thought that the C700 bass was of similar quantity, but the C700 bass can fall apart at times and become a little uncontrolled, while the MTPG bass remains poised and in better control. I find the Monster's bass speed to be nimble enough for most people's tastes as well, but the W2 beats the MTPG in this regard, with very fast and detailed bass that one comes to expect with a nice balanced armature earphone.

MIDS: Overall the MTPG mids are a little warmer sounding than the similarly priced W2; and as I mentioned before, the MTPG have fuller mids than W3 or Triple.fi which makes them more like the W2 or UM3X, but without making them sound too forward or losing soundstage depth. The forward mids of the HiFiMan RE252 can hurt their depth of stage vs the Monsters, although the width of stage may be wider than the MTPG, like the W2 and W3. I find the Monster's mids to be engaging with good timbre and tone, and without a lot of coloration but for the slightly warm tone. They are fairly transparent and open sounding with good timbre, detail and presentation, but not as wide open sounding as the W2 or W3. Vocals and strings are presented well, and acoustic music is also a pleasure with them.

HIGHS: The MTPG treble is defined and detailed enough, without sibilance or brightness, but with a slightly rounded or "analog" feel to the transients. They're not as fast as my favorite balanced armature IEM, but they get things done fast enough. The MTPG treble doesn't sound muted, but the highs are just not quite as present or strong as with the other IEM that I compared them too. This may be why they do such a good job hiding sibilance in recordings that have a problem with that (Live in Paris for example). Still, I would say the treble, while very slightly recessed, is extended to the 16 Khz limit of my 47 year old ears with just a little roll-off noticed past 12.5 Khz.

CONCLUSION: How do I rank them? Overall the TPG are a nicely balanced sounding IEM, but I prefer my Westone 3 with UM56 tips a little more than MTPG. After those I find myself using the MTPG about as much my Westone 2 or slightly more, but whether for the novelty of change or whether one is better I can't say. In reality these two are on a similar level of performance, but very different sounding - if I was hard pressed to qualify the difference I [I]might[/I] say the W2 would be more like listening to a 24/96 digital file and the TPG more like a 180g vinyl album. Sometimes I think the W2 are better depending on the amp and music, and sometimes I like the TPG more (classic rock for example sounds better with TPG). While the Monsters may not be the most detailed or speedy IEM, they are very musical and enjoyable to listen to with a wide variety of gear and genre of music. I would call the Monsters a very forgiving IEM, and I can use them with recorded material that I would normally not enjoy very much because of quality issues with the mastering.

I do prefer the TPG over my Triple.fi because of the improved mids and effortless reproduction, and more than the Denon AH-C700 because of the better balanced frequency response and lack of sibilance that the C700 can exacerbate, and more than the HiFiMan RE252 or IM716 for the extra warmth and bass impact that the MTPG offer. The MTPG also have much better dynamic range than the RE252 or IM716, and work better unamped because they are more efficient. I also prefer them more than the Sennheiser IE8 that I sold a few months ago, which were really only exceptional sounding with my ALO Amphora amp, but otherwise the IE8 had too much emphasis on the bass and not enough on the mids and highs for me. These MTPG are pretty darn good for the price. They are certainly a step above the original Turbine that I heard at CanJam 2009, which were okay but nothing special to me. As a dynamic earphone, this is what I think the IE8 should have been but never were for me. If I were to change anything about them I would want a little better extension in the bass and treble, a little more speed, and a little deeper soundstage.

I do want to stress just how important the gear you are using will influence the sound and thus the listener's impressions of these IEM. So many things need to be considered such as what tips are you using, what source and amp you are using, the quality of the music and what kind of music, i.e. classic rock with little bass, 128K MP3 vs 320K, or how the amp handles the impedance and sensitivity of one phone differently than another, etc. It's no wonder there are such widely disparate impressions posted out there about this or that product. With the gear I used in my testing, the MTPG didn't complain much or seem to be picky about source and amp, and that is a good thing to find in an IEM these days. I like to try out new gear these days more for the fun of trying something new and different, than for trying to find something better than I already have, and I am not sorry one bit for giving these a shot. It makes me even more eager to try out the Monster Turbine Pro Copper.