Okay headphone fans, it is time for some thoughts and impressions on the above sets of cans while I am still discovering them.
The Monoprice M1060C, despite being considerably cheaper than the HifiMan Sundara, comes in a far more luxurious box which includes a seriously solid, round carrying case, nice! Packaging for the Sundara was rather minimalist & functional. Also the Monoprice cable would appear to be quite reasonable - haven't tried swapping it around yet, that will be an exercise for another day.
Some reviewers have also criticised the headband & mount on the 1060C as being very basic (cheap). Which, to be fair, it is - but you can't have everything. I have no complaints about it (certainly not for the price) and the money will hopefully have been spent on the drivers and enclosure - the real-wood backs look really cool and give an up-market, solid-chic feel to the cans. They are also quite a lot heavier than the Sundara and have nice thick pads that surround the ears in a pleasing way. Sound isolation is pretty good - better than the German Maestro GMP 450 that was in place prior to these.
Soundwise: the Monolith starts off as dark and enveloping, reminding me of the rather laid-back AQ NightOwl. Big, fat, weighty bass and smooth mids really wrapping you in an audio experience. After about 10 hours burn-in the treble came up to be very detailed but never harsh. Then you realise that these are planar drivers with that airy, spacious, effortless detail and a beautifully-defined soundstage that is remarkably wide and -out-of-the-head for closed-back headphones.
Did a comparison playing JMJ's 'Equinoxe' (latest remaster, WAV ripped from CD) which the 1060C gave major Oomph to in the bass, 'Monolith' is a good name for these as the bottom end is like solid marble: heavy, subtly-defined and smooth.
Switching to the Sundara's the first thought is 'Where's the bass?"- but it is there, only differently presented. The Hifiman planars excite in another way with razor-sharp detail, massive space and airiness and a velvety enveloping sensation that lifts them into a higher level. Both are involving, exciting and penetrate to the heart of the music.
I did give the very detailed GMP 450 a go as well but even that, a highly-revealing studio monitor, sounded dull, anaemic and flabby when put alongside the Sundara.
Bottom line, for now. The Hifiman Sundara is a serious audiophile delight of space and detail. The Monolith M1060C is a truly satisfying closed-back that combines the rich darkness of the AQ NightOwl with the sharp, wide-screen definition of the GMP 450.