As stated earlier, the TDK STi710 features a very Solo Beats like design aesthetic. This design choice was obviously an attempt by TDK to try to tap into the Solo Beats headphone market and attract potential Solo Beats buyers. As far as build quality goes, I was pleased to see that the STi710's have ear cups that are constructed out of some type of durable metal, presumably aluminum. Aside from the ear cups/ driver housings, the rest of the construction is a matte black plastic material. For the $200 dollar price point, I was a bit disappointed with the cable, which is a non detachable Y-cable design. For headphones that are competing directly with the Beats Solo HD's, the STi710's really should have a single detachable cable. This fact is a detractor for many people that have been eyeing the STi710's as a Beats Solo HD alternative. Furthermore the cable insulation on the TDK STi710's is extremely rubbery and non malleable. Overall I would say that the build is better than the STi710's primary competitors, but for $200 dollars I would have hoped for a better cable design. There is also little in the way of accessories included with the TDK STi710's. Thankfully they came with a carrying pouch, but that was the only accessory included in the box. It should also be noted that the TDK STi1710's do fold up to make the compact, in the exact same fashion that the Beats Solo HD's do.
As far as comfort is concerned, the STi710's pretty much fit in with many other similar on ear headphones. They are reasonably comfortable for about a two hour listening session but become increasingly uncomfortable after that time. I have never been a fan of on ear headphones, but I can say that their are few on ears more comfortable than the STi710's and many more that are more uncomfortable. I would have liked to see a bit thicker padding on the headband, but if you have a head full of hair like me this does not prove to be a comfort issue. The ear pads themselves are a pleather like material (synthetic leather) and can result in ear sweat during long listening sessions but the discomfort that occurs from the pressure of the headphones after a few hours of listening will likely hit before the ear sweat issue does. I would say that the clamping force is just a tad too tight but nothing ridiculous (I am looking at you, Sennheiser HD 280 Pro's!). Like I said, I am not, never have and likely never will be a fan of on ear headphones. My head size and shape and my ears just don't mix well with any on ear headphone that I have ever listened to in terms of comfort, so take my comfort complaints with a grain of salt.
The sound of the TDK STi710's can best be described as having a heavy emphasis on the bass and mid range. In fact, the STi710's are an extremely warm, almost dark sounding headphone. The TDK STi710's are predictably designed for use with portable devices and gain little by amplification. However, I was impressed at the loud the volumes that the STi710's were able to achieve with minimal power input and also the lack of distortion at higher volume levels. Honestly, you will blow an ear drum before the STi710's even begin distorting. The bass is one of the two main focal points of the STi710's sound signature. It extends into the relatively deep ranges without significant roll off and provides much impact but is also a tad bit sluggish and becomes muddy in the extreme low ranges. The mid range blends nicely with the lower ranges and is relatively forward and engaging. With so much bass and mid range emphasis, the STi710's treble response leaves some to be desired, although I will state that the treble is relatively crisp and accurate, it's just too recessed for my tastes and really seems to be in the foreground in comparison to the bass and mid range. Sound stage is extremely limited. There is little in the way of instrument separation and three dimensional sound is not a phrase that I would use to describe these headphones. I typically prefer headphones with a warmer sound signature and the TDK STi710's will definitely add a lot of warmth to your tracks.
In conclusion, the TDK STi710's perform reasonably well, but I feel that the price to performance ratio really isn't up to par. While I would still say that in terms of purely sound and build quality, they are a good alternative to Beats Solo HD's, other headphones such as the Audio Technica ATH-WS77's outperform the TDK STi710's sound quality wise for $50 dollars less, although I will note that the ATH-WS77's do not have an inline iDevice compatible remote and microphone. In this price range choosing an on ear headphone really comes down to trade offs between comfort, sound, build quality and features. As far as sound quality goes, the TDK STi710's didnt necessarily disappoint, they where however disappointing for the price.
CLICK HERE for TDK STi710 Product Page