You should better save your Money an not waste it. Even 40$ is to much.   The Headband Design is a totally disaster. Only Koss Designers have an idea how torturing the Costumers with an air filled headband in professional Recording. Come on, On-Air Torturing by Design.   The Vinyl Cushions...

Koss HV/pro capsule (new Koss micro lightweight element design back in the 80s with better resolution compared to the older pro4AA and HV capsules) 100 Ohm ~94dB/1mw anisotropic ferrite magnet 16 or 35 microns thick low mass diaphragm with a 4 layer self supporting voice coil. 55-57mm...

  Look at a standard Koss UR/29 capsule.   Hopefully the manufacturer made a driver redesign on his HAMT1 for better resolution capabilities. The Koss capsule performs slightly better over the K240 driver.

The voice coil wire isn't glued to the diaphragm. One possible option is to buy the pro4aa and transplant the HV diaphragm with voice coil onto the pro4aa capsule. Koss redesigned the newer pro4aa capsule with a wire canal to eliminate direct wire contact to the diaphragm. At all its try and...

KOSS HV/Pro with about 60000 hours of real playtime from 1998 as a lifetime replacement for the HV/1LC. The best warranty and quality gift, KOSS could made. The second oldest headphone A/250 worn out within one year under studio conditions. Pads Replacement after few months of use. About 5000...

Koss TD/80 vented in old revision. RH3C= UR/29. RH2C=UR/18.

Koss pro4 series depending on Revision. H40dB modH~50dB M30dB modM~35dB L15dB modL~25dB The two chamber design on the pro4 Koss stereophones block out very well the noise in both ways. The vacuum oriented seal provide the needed Isolation, but the older oil filled ear cushions should...

There are two versions of the pads. The old pleather ones and the new Version from variable density molded foam. Koss listed the newest pads on the older webpage. Pad replacement for about ~25 Years. You can use the HV1 pads, but the frequency response is not nearly as flat with these pads.  ...

Take a Shure SRH 840, be happy.

I have the DT880@600 and the T40RPMK2 for comparison.   The Auditor driver is in terms of transient response, natural timing response and texture superior without the typical self compression and dynamic limitations on a lot of dynamic and planar drivers. Koss made the low budget frame for...

Why don't you search your question on the forum? The answer is years old.   Ety 4 graph from innerfidelity. The DT1350 has a different sound signature. The K701 is near for that you searching for, but it lacks last percent of resolution and refinement. The ESP/950 should fit with it...

Quote:   They do.   Up to date koss exchanged product quality for lifetime warranty marketing and the DJ100 is an untypical Koss product in their headphone line up.    The pro4 line is low budget developed and manufactured for the warranty marketing.  I've got the pro4AAAT and AAT...

Shure SRH840. The closed HD650.

How can you? The pro4aaat shell is so badly designed with a lot of resonance and work properly only with the 250Ohm closed back driver. Koss made better 60 Ohm drivers for the the ESP Enclosure. 

This hole has nothing to do with your problem. It is only in the acoustic dampening paper. The driver is under the felt. You can fix your rattling problem with duct tape. Put a piece of it on the felt and pull the tape off.