beyerdynamic DT-770 M

Looking for affordable monitoring headphones ("cans") for studio tracking, I compared Superlux HD660, Superlux HD665, t.bone HD 990D, Vic Firth SiH2 and Beyerdynamic DT-770M to each other and to my DT-770 pro 80. I know, not a really fair reference, but my idea was to seek for a series of cans that would not cost more, indeed preferably less than my DT-770 and still would have proper, useful sound quality. From the models selected, you can guess that acoustic isolation was also a desirable feature, to prevent the sound from the cans bleeding into e.g. a singer's mic and thus saving me time cleaning up tracks from this bleed. That is why I also searched among headphones dedicated to drummers. I will review all of the models mentioned, each in their own product page. Here we go for the DT-770M

Although a little more expensive than the DT-770 pro, I felt I had to incorporate the "M" into my comparison, as it is recommended as headphones for drummers with high acoustic isolation - remember my desire for bleeding prevention. From Beyerdynamic I expect quality construction and high comfort of wearing - and that is both what you get from the "M", too. From an earlier comparison I did a few years ago in store at Thomann's in Treppendorf (great experience by the way!), I already knew that the "M" sounds dull compared to its "pro" counterpart (see their specs also), so that was no surprise for me, but also compared to the HD665 that I tested this time together with the "M" and other models mentioned. Although its claimed isolation of 35dBA was the highest I could find in the specs of the models tested (or actually any model), in real life I found the "M" to be it just a little bit quieter than the DT-770 and other models tested, and by far not as quiet as the HD665. Add to that its higher price and you can guess that I consider the "M" not suitable for my purpose.