A few years ago I was a big fan of the Shuttle Barebone SFF PCs for LAN party gaming. I also was a big fan of surround audio for gaming. I had a soundblaster that days. But the graphics cards grew bigger and bigger and suddenly there was no space left for an internal soundcard and the onboard sound that Shuttle provided was kinda meh.... it was then when Asus decided to enter the game of PC sound with its Xonar line. Luckily for me they came with an external solution in form of the Xonar USB or later called U1. This small device was my little sound magician for some years. But someday the grafic cards like the Radeon HD 5700 just needed too much power from the little Shuttle barebone and also the heat inside the box increased so much that I needed a big PC box again. Inside this one the Xonar STX found its place. It was a better solution for music and a slightly better solution for gaming and movies over the Xonar USB. But the Big PC was sold with the STX and I went for a gaming laptop with my Xonar USB again. As I said good for gaming and video, but definitely not audiophile regarding music reproduction. But it is a very small device. I loved Dolby headphone on both the STX and the U1/USB but never for music.
Now ASUS comes with a feture and hardware packed device that has all I need (external and audiophile) but with Dolby Home Theater v4 instead my beloved Dolby headphone. The DHT v4 has been said to be not on par with DH for positional cues in FPS gaming. Oh oh, that is not good for me ... Wrote a mail to Dolby customer service and got a good response:

Here is my request:

As a long time user of Dolby Headphone technology from Asus Xonar soundcards, I am concerned that the new Dolby® Home Theater v4 headphone implementation found on the Xonar U7 might be inferior to the classical Dolby Headphone. Please clarify that for me.
Thanks
Peter

Here is the answer I got fro Dolby:

Hi Peter-

I apologize for the delay in responding to your email, the team was attending E3 last week. The algorithms between Dolby Headphone and Dolby Home Theater v4 for headphone virtualization are the same, so there shouldn’t be any difference. You may be hearing a difference because DHT v4 features things like volume leveling, dialogue enhancement, etc.

I hope this helps.

Best-
The Dolby Game Team

I had the Asus Xonar U7 on hand some days before I got this response, so I knew already that this was true. The device is a pretty good DAC, a decent headphone amp and a powerfull virtual surround device for headphones. Beside that it can run your 7.1 home theater system with ease and also simulate 7.1 on two speakers. But I am only using the headphone part of this.


•]Disclaimer: All of the statements I make are only for headphone use.Headphones used: Ultrasone Signature PRO / DJ AKG K 702. OS : Windows 7 64 bit
•I had the Xonar STX before still have the Xonar U1/ USB.
•for me the external USB card is better because I have two PCs to use the card for gaming. A classic PC and a good gaming laptop.
•It is the best sounding sound card I had so far. For me even better than the STX.
•it has no audible hiss and seems to be absolute neutral to me.
•it has a very dark background
•Very good controlled bass.
•Very good and big sound stage.
•I use them without the Dolby Theater V4 for my ITunes collection. AAC 320 VBR most. Dolby sounds also well, but it alters the sound signature as expected and I do not prefer that for stereo recordings.
•For gaming the Dolby standard gaming setting produces a very good surround sound for me, good directional cues in Crysis 3 /COD Black Ops so far.
•Movies: LOTR DVD version. same as for gaming, very well implemented Dolby Theater V4.

Had some hassle on driver installation. The driver on the CD that came with the U7 did not install the Dolby feature at all. Downloaded the only available beta driver from ASUS and all was fine Dolby was available.



In other words:

Highly Recommended.