Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
I have used these headphones for years, for listening to music on numerous systems, hooked up to a desktop stereo as well as a laptop computer. I own more than one pair, use them constantly, and did not think much about them. They were cheaper than dirt and did the job.
But in hindsight, and now that I have devoted a bit more time evaluating many other headphones, I took these outstanding Panasonics for granted. THESE ARE EXCELLENT HEADPHONES.

Their sound is exceptional. They should not be disrespected or dismissed. They blow away inexpensive headphones that look similar to it. And shockingly, they blow away many full-sized headphones,including some that cost 20 times more, $100 and up, particularly  in terms of treble clarity.

This may seem like a bold claim, but I stick by it: these are better than many headphones on the market. Yes, it makes sense to maintain reasonable expectations (these are, after all, under $10 headphones) but the RP-HT21s far---far---exceed these expectations. In addition to being among my go-to headphones for daily use, they are so good, I use them to test audio gear, and as a reference versus other headphones.

The RP-HT21s offer clear, crisp, well-defined mids and sparkling highs. Wonderfully bright and airy, no muddiness or veil. In fact, the treble is so good that I include these among my treble reference headphones when testing and comparing other headphones. It leans towards cool rather than warmer, in tone. The sharp clarity is this set's strength. The bass is tight, clean and solid. It is not boomy, loose nor overwhelming in quantity but enough for any music. The imaging is extremely clear. These little headphones even offer a bit of soundstage with good imaging and separation.

Again, keep in mind that the drivers are small. Don't expect a big picture or full sound like that offered by full-sized cans, but if you appreciate the sound of clean, brighter headphones (Grado, AKG, Beyerdynamic), you will like what the RP-HT21s offer within its capabilities.

The drivers are 30mm. They are fairly easy to drive: low impedance (24 ohm) but sensitivity is medium (100 db). I find that I have had to turn them up a minor notch or two for volume.

They are ideal for use through smaller sources, but I find that they sound just as fine over larger stereo systems. I tested them through various sources, and they sound great through all of them, small as well as bigger. They are good without EQ. With EQ, they can be fine tuned to even more impressive levels. Bumping up the bass a few notches, and the treble just a bit (I love detail) can really transforms the RP-HT21s into the surprise performers. They also respond well to amping. Just be careful not to blow them out.

These super light portables are ideal for indoor listening. For outdoor use, they are certainly portable, but they are open air. These are on-ear headphones---as in small drivers right on the opening of your ear. There is no real seal. Which means that you will also hear everything in the room around you, no isolation. If you are type that listens outdoors at high volume, a set of full sized closed headphones would of course be better. These are best at low to medium volume, they struggle a bit when cranked up. For quieter listening, the Panasonics make me very happy.

The build quality of these is actually better than similar cheap plastic headphones, just a bit more sturdy. The fit can start out a bit tight, very snug on the head, but they break in, no problem. They are comfortable on the ear, and I often prefer them to full-size headphones that can get hot. The foam covers are replaceable, but the headphones are so cheap, it makes more sense to just buy a whole new set if the covers wear out.

I am finding that good versions of these types of headphones have become more difficult to get, and these Panasonics really are far better than the Maxell HP-200, Coby CV-H32 and other terrible cheapie throwaways; the ones that look similar, and are sold with computer equipment and given away on airplanes. They are vastly superior to cheap ear buds and IEMs. They beat or compete admirably against portables such as the Koss Porta Pro, Koss KSC75 (which costs more than twice as much), and the Sennheiser PX100 and PX100 II, which are ten times more expensive.

The L-shaped plug and cord are of better quality than the flimsy wires you might find on other phones in the same bottom end price range.

The RP-HT21s get my vote as the best sounding dirt cheap headphones out there. And they may also be the cheapest good headphones out there, too. These are under $10 headphones, capable of real surprise. So cheap, you can try them without guilt. And if you love them like I do, own many pairs.

Even if you have other good headphones, it is worth having these.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: A: very positive