On a punt , someone recommended to me a pair of Ollo S4x’s at a discount price , Never heard of them , checked out a couple of reviews online , checked out the website and all reviews were glowing so i thought i would give them ago .
Ordered Wednesday at 4pm from Slovenia and they were on my doorstep Friday morning in the UK ,(outstanding service ) .
Opened the box and there was a hand signed frequency reference chart signed by the testing engineer .
These hand made walnut reference headphones certainly looked the part , very very well built , they look fantastic and they feel so comfortable to wear .
So testing , they recommend to leave them burning in for a week ( the longest time ive ever had to burn something in ) but i was keen to see what all the reviewers were raving about . Plugged them in and the immediate impression was " right … wellllll ummmmmmm " .These things were as flat as a pancake so i spent 6 hours on and off with them , leaving them playing in between and the more my ears got used to how critical they are with no bass bumps ,no hi end boost the more they grew on me .
Well , 2 days of burning in and all i can say is Woooowww , im blown away , they take a little time to get used to as they are so flat responded but the detail is incredible , they seem to unfinish a mix so you can here even the smallest of errors .tales of the revrbs ,delays ,flanges are all there , Bad mixes sound incredible bad , reference tracks sound absolutely how they should , beautiful .
I had a little problem because they are so flat and clinical thinking they are really bass shy , not good for EMD/D+B styles so i put on a track that sorts the men from the boys (LSG Netherworld (kids loop remix ) and they just blew me away , the lowend on these ? one word … incredible , the kick drum was full the sub was so tight and fast and full of depth i was in complete ore .
So i tried a couple of my tracks and instantly i could hear exactly where i have been going wrong so i attempted a quick home remaster through these and the difference was incredible ,my 350hz cleared up , the 3500hz range is now less congested , they are in the very short space of time working wonders and importantly , with no ear fatigue .
Still 5 days of burning in to go but they already have started opening up , can wait to see what they sound like after this time .
So all i can say is if your like me and have neighbours and can’t mix late of a night then these are really the new kids on the block they are incredible ,from the delivery , to the packing , hands signed reference chart for BOTH matched speakers , the quality build and then the sound , well as you may guess im in danger of being a fanboy but i don’t care 
30 day trial so you have nothing to loose but im pretty sure ,you wouldn’t be sending them back if you need critical headphones