So, I own both the NAD viso 50 headphones and the Bowers and Wilkins P7s as my personal headphones. As a caveate to anything after this everyone should know I work in an audio store (part time) in Wisconsin which I have done so for about 15 years My main career is teaching at the University level in the field of Education. I purchased the NAD headphones without hearing them after hearing the PSB M4U headphones which I loved. In the store I work in we sell headpnones by B&W, NAD, PSB, Grado and Audioquest. I do not own any other B&W speakers but have spent extensive time listening to them. We picked up the PSB headphones on my recommendation. I spend most of my audio budget on my home system and do most of my listening through moddified Magnipan speakers with subs through a McIntosh system. I say all this as to say that I claim no headphone expertise. I am a casual listener of headphones but I am serious about my sound. I like musical sound over excessive analytical sound but I need the combination of resolution with musicality. I have two headphone amps, a little tube amp I got from Parts express on the cheap but good category and a Parasound z dac headphone amp which I am using at work mostly driving computer speakers rather than headphones.
I have not intentionally A/B compared these two headphones but my impressions thus far are that they both are good musical headphones with a warm characteristic that I like. The NAD headphones are lightly veiled and definitely not the most revealing headphones in the market. My buddy has a pair of grado headphones that he modded out with wood cups and other changes with better cables that sound way faster and more detailed than the NAD headphones. The difference in detail and resolution was so startling that I almost sold them but instead kept them and when not in comparison they are none the less very enjoyable and musical. I have perceived them to be fairly balanced top and bottom but perhaps a little recessed on the top.
Similarly, the P7s to me are relaxed but I think they have better detail and resolution than the NAD, I think they are faster sounding as well which I guess to me means that they express transient changes and detail better than the NAD. I think they are balanced and instruments sound like instruments. I think the B&Ws may require more break in but the materials and construction are top notch. I think they are a headphone that could perhaps last a life time. I love the way the cord is integrated into the design of the cup. If you remove the ear cup where the cable connects you will see the restraining boot is completely encapsulated or integrated into the ear cup which will makes it difficult to break and completely replaceable without have to break out a soldering iron. I tend to think of them as audiophile jewelry that sounds good.
Having said all of this, these are first but perhaps extended impressions. I will do an A/B comparison this week and share my thoughts on the matter and I will also see if I can get my buddy to listen and weigh in as well. Lastly I'll say that my very first pair of audiophile headphones were Beyer dynamic DT 990s which I purchased in the 80's and owned for ten years or so. This was before the headphone market blossomed. I don't think either of these headphones beat that pair of Beyers in sound quality but I think the NAD and B&W both sound very good and musical.
