Found an old pair of HD-400. Refoamed it with grey earpads and now they sound very smooth in the midrange and treble is sparkly. They sound better than Koss Portas.   How do they compare with the legendary HD-414?   What would be comparable today?   Thanks

Do you like them more than the Sennheiser HD600?   How do they compare out of the box to T20 V2?

You have pretty much described the Koss PRO/4AA or 4AAT series. Great sound, clamps tight and built like a tank. And the famous Koss lifetime warranty is the best in the industry. Oh and closed cans as well as very affordable.

Well its winter time and I'm working on my neck muscles. No pain no gain. But if the HD280 sound anything like the Shure headphones I think I'll keep using my Koss  PRO/4AA.

Anyone every compare the old workhorse Koss PRO/4AA to a modern day closed headphone from Sennheiser such as the HD280 or HD25? The Koss was found in virtually every major studio in their heyday.Still remarkable sounding and under $80 typically.    

Interesting how has burn in improved on the sound compared to new?

Got the Koss PRO/4AA rebuilt. Sounds completely different.Great lows, smooth highs, could be more transparent.Maybe more burn in will help.    

Just got them back and wow, what great service. The Koss Pro/4AA are bad sounding either. Bass is deep and tight. Warm sounding,good detail but not exaggerated. Does not sound like the flimsy Sennheiser 5XX models.   Never tried the Sennheiser HD280 Pro, maybe someone can compare them...

SE102 VS SE115 Are they work buying for under $50? I haven't heard the SE102 but the SE115 has a lot of bass. I'm not sure if they are that durable either, for an introduction to IEM should I buy one or something totally different? Need sound isolation.

What is the complete upgrade for the T20RP V.2? Should the felt on the back cover the vents completely? I found some felt from pads that you stick on the bottom to prevent scratching surfaces at the dollar store but the fabric places didn't have any and suggested thick cotton. Does that...

Are they any instructions or pictures for a newbie to take the K240 apart?

How do they compare to HD600 or HD650's? Or Audio Technica ATH-M50's for similar price range?

Has anyone found frequency response graphs for these or other Fostex RP headphones? I've got the T20RP v.2 which seems to be considered the most desirable after the original T50.

Are they any frequency response graphs for the TP50RP or other models? I would prefer them to the 598's which have the typical loose bloated bass.

I thought the only difference is one is closed and one is semi open. Probably Wikipedia but could be wrong.