Thanks for this great site to give comment but so far it's working good. flatbed towing

I'll just give an update if there's some bad review about this product.

Excellent Bass & amazing Sound Stage.

Some annoying frequency response at some level. Notch Cutting

Exceptional sound quality. roofing contractors

Expensive and uncomfortable if used for long hours...

Sound remarkably spacious! Works very well with the majority of mainstream music. Rheed - Commercial/Residential Services

Just a little bit expensive.

Build quality is great! Cheapest planar magnetic headphone in the range.

All models look identical. ​HVAC Residential/Commercial

Hi: I have the 400i's which are an update of the 400's. The differences being the 400i's are more efficient at 93 db sensitivity and have updated planar drivers, cords, a more comfortable headband and new ear pads. They sound fantastic, amazing sound stage and detail yet very smooth. I'm using the line out of my Cary tube pre-amp then into a "BOSS" headphone amp to boost the signal. Depending on the material generally CD's have a higher output level than my vinyl ( Michell Gyro SE, RB 250 and Benz Wood medium output moving coil into a Graham Slee phono pre-amp ). As such the volume control on my Cary is generally between 10 and 2 o'clock to get good "drive" out of the phones. They're light weight for a rather large over ear open back phone but as such don't have much isolation to outside noise. Try them with whatever device you're using to make sure you can get good volume out of them, if not I believe the model under the 400i's are less expensive and a step down in fidelity but have a sensitivity of 98 db. I managed to find mine on sale for $349 Cdn ( list is $649 Cdn I believe ). These are by far the best phones I've had, I had a pair of Micro Seiki electrostatics years ago which had excellent detail but not much bass, the 400i's have amazingly tight well defined bass! The rest of the spectrum is never edgy with amazing sound-staging and detail really quite lovely. If you're looking for a great set of phones do yourself a favour and give them a listen I was able to try a "loaner" pair at home for a week before purchasing.

Other then getting used to the size of over ear phones for me I love them. To sum up: Being an audiophile and a professional musician I need phones that give me a very smooth response i.e. detailed but never edgy and are comfortable for long listening sessions so I can, besides listening for pure enjoyment, evaluate and compare recordings I've done with established "audiophile" standards in both pop, jazz and contemporary music. These are a well made and refined set of phones that won't break the bank and have no real "downside" you can't go wrong with the Hi Fi Man 400i's!