Plenty of talk of this little $30 wonder here...
http://www.head-fi.org/t/569239/monoprice-hi-fi-dj-style-headphone-review
Generally considered a great value, particularly if you're looking for something bass heavy.
Here's my little mod experiment. This is a fairly standard treatment (with variations) that I give most headphones when I'm in the mood to crack them open...
1. Sprayed the cups with a rubber sealant. Sprayed the rear of the driver baffle as well (after masking all the important bits). This is to provide a seal and slightly mitigate those hard plastic reflective surfaces. Do note that this step is very messy. If you were to skip any step, this would be it.
2&3. Place acoustic foam into the cups. The type I used had a heavy rubber backing.
4. Double layer of micropore tape over the cup vents. Scrap piece of acoustic foam wedged into the hinge knob, since the hinge actually has a hole that vents directly out and is arguably larger than the cup vent itself.
5. Vibration dampener (dynamat or fatmat or other) on rear of driver. I just used scrap pieces of whatever I had left. I modded a previous pair that simply had a square rotated 45° on the back. Micropore tape over half the driver vents.
6. A piece of velour and cotton layered into the cups. I teased out the cotton first, and tried to arrange them such that the wire did not lay directly against the driver but had the cotton sandwiched in between.
7. (no pic) Cut a large piece of soft thin felt the same size as the baffle plate and stuck it under the pad
Most noticeable sound changes
- better isolation
- bass maybe ever so slightly decreased, but clarity improved
- treble extension greatly improved
- midrance clarity much better (probably due to the treble)
- overall frequency response is bass sloped, with the typical treble wobbles though more subdued than other closed cans
