I myself use for traveling medium-priced closed headphones which already generate a relatively good sound in itself (but the sound it also deliberately falsify by ups and downs are slightly raised).
I have Apple's standard plugs through midprice About Ear Headphones (Sony, Sennheiser, AKG), expensive in-ears (Devil and Sennheiser) and very expensive high-end headphones just about anything through tested on an iPhone 5, Sony Xperia Z1, iPad 4 and iPad mini and finally arrive at my iPhone 6. In addition tests on my PC, but thanks to a Sound Blaster Zxr already has an outstanding issue - here, I have never achieved a significant improvement, but I had the not quite favorable soundcard yes also bought.
On iPhone / iPad Finally, I have heard with almost all types of headphones is no difference. But this is not in the pits, but for the average consumer now completely sufficient DSPs in the smartphones. Only at my (now no longer available) Sony high-end headphones for listening to the Super Audio CD - built material (with a frequency response 8-42000 Hz) I could really hear a difference. The is then but clearly and for each I gave the headphones also perceptible. The heights are much clearer, the depths of separated and the sound generally more transparent.
This does not help me now, unfortunately, nothing on the go, as my Super Audio headphones are too big and only intended for the couch. For my traveling mainly used Sony MDRZX600B I can not tell the difference - they are with or without beyerdynamic box to their performance limit. From in-ear plugs to mention.
In conclusion, this little box is therefore an absolute luxury purchase for those with true high-end equipment and relatively specific applications. For most users, the purchase is absolutely not worth it. Headphones which distorts the sound by itself (Beats ...) are also fundamentally the wrong target devices. Personally I keep the box because I often listen to music while working at your desk or at home on the sofa and can use my big headphones here. The small gain in transparency, I treat myself.
If you like spending money on this small and special gain for which the box is worth quite 5 star. In itself, it is very well made, and very easy to use. Supplied with its own leather case and all necessary cables are included. Who uses only "normal" headphones or must pay attention to the budget, but should better leave it alone and prefer to invest the money only once in better headphones.
