Finally, I moved on to Sennheiser RS160 and cannot be happier.
The sound was initially thin and dry for the first 3 days, but after that, the sound has become sweet and rich. Bass could be a little more strong, but we pay that for extremely high resolution: each and every note is presented precisely and lively. I have no reason to use my Sennheiser HD-580 again.
As always, I pulled out some polyester fiber from a pillow and insert them into the back chambers:
Once you have wireless cans, you never go back to wired. For example, it is now so relaxing to listen to my favorite tunes while washing dishes - no more fear of wire hooked up to the door knobs!
The transmitter is portable, powered by either 5V DC or two AA batteries. Note the AA batteries can be rechargeable but the transmitter won't charge them. They last for 150 hours. The headphones use two AAA batteries and can be charged in them. They last for 24 hours.
The ear pads are around-the-ear type, so they won't sit on my ears to add pressure to my ears. The cups are large enough to cover and not touch my ears; so they are extremely comfortable to wear 16 hours a day and 7 days a week.
RS160 is closed type, can provide quite good noise isolation. When you wear them in a library, your music won't bother others nearby (no audio leak like open type cans) and their talks cannot annoy you. They are great to use on a bus, train or airplane.
RS170 is also closed type, but the transmitter (base) is not portable. You can simply hang the headphones on the base and the base will charge them. The base also offers bass boost.
RS180 is open type, I might get a pair of its headphones (HDR-180) to use with my RS160's portable transmitter. Open style cans always sound better than closed type, but only the RS160 comes with a portable transmitter that Sennheiser does not sell separately. So, I have no choice but to buy the RS160 first.
RS120 is the analog version with lower dynamic range, 65dB vs. 85. The sound is even more musical and lovable than RS160, because the cans are open type and the transmitting is FM not digital. However, its ear pads are on-the-ear type. These pads are still very comfortable, but I can only wear them for 1 hour or 2, then my ears hurt. The old model, RS130, has around-the-ear pads like the RS160, 170 and 180, but they are discontinued and very hard to find these days.
MM 500-X is for Bluetooth. Unfortunately, it does not use AA or AAA batteries like above models. It is closed type.
As you see in above photo, I connect the transmitter to my portable HD radio, making it a portable wireless music system. This is the 3rd version from Insignia, the perfect version. The 1st version was almost perfect except that the firmware had a serious bug that freezes the radio frequently. Yes, all firmware versions had the crash problem, see my other article for details. The 2nd version was a total failure - crappy touch screen, short battery life and poor reception. It is nice that Insignia listened to us and made the 3rd version back to the 1st version and fixed the crash problem.
From left to right is the 1st (NS-HD01), 2nd (NS-HD02) and 3rd (NS-HD01A) versions. The left two are going to ebay soon.
This new version comes with a matte and more durable case, and a hostler too. Now, Insignia: if you're still listening, add a microSD slot for MP3, then you have a killer portable audio device! Even better, if you can work with Sennheiser to build in a KLEER chip, then we no longer need the transmitter. How nice that would be?