This photograph is here for a couple of reasons – to show you the headphones I currently use, and to compare the size and form factor of the Jabras with the others. Of these four models, the Sonys are the only "old school" headphones – I've owned this pair for twenty years. They have a ten foot long coiled cord, no ANR, no lights, no switches or knobs, and I still maintain they're the best sounding headphones I've ever heard.

The Pulsars are Bluetooth, yes, but they can also be used hard-wired with a supplied thin cable, and they're a phone headset with an extending mic tube and lots of controls. Go back and read my review for all the gory details. They're the only ones of this bunch with "supra-aural" (rest on your ears rather than surrounding them) earpieces.

TheBoom Quiets are the most expensive of this quartet and besides the Jabras, the only other pair with battery-powered Active Noise Reduction, plus the best noise-canceling mic on the planet, in my opinion.

So the Jabras are somewhere between the Sonys and the Quiets in form and function.

Let's try'em out

After examining all the goodies that came out of the package, I popped an AAA into the Jabra's little compartment, put them on, adjusted them for fit, and without connecting them to any audio source, I flipped the ANR switch. I usually keep a fan running in the living room, and for this test I turned on my air conditioner too.

Active Noise Cancellation is meant to vanquish low frequency ambient noise, and suddenly, the low hum of the fan and the a/c went away, although I could still hear them running, they sounded like someone had picked them up and moved them a hundred feet from me. As I type this I'm flipping the Jabra's ANR switch on and off and even the lower frequencies of my fingers on my laptop's keyboard vanish. I have no way to measure Jabra's claim of "92 percent" noise reduction, but that seems reasonable to me. However, with ANR on, I noticed a very faint electronic hissing noise, and to confirm it wasn't coming from the fan or the air conditioner, I went into one of my quiet bedrooms, window shut, sat on the edge of the bed and flipped the switch on and off – nope, the faint hiss was coming from the headphones' ANR circuitry. It's not loud, but theBoom Quiet's ANR circuitry doesn't produce that faint hiss.

As I walked back into the living room to continue typing, I purposely shuffled my rubber-soled shoes on the carpeting as I flipped the Jabra's switch on and off and laughed as I could actually hear the lower frequencies of my shoes against the carpet go away and come back again as the noise reduction circuitry kicked in and out with the slider. Okay, so a conditional thumbs up to Jabra for the C820s noise reduction.

The acid test – music!

I have some favorite music tracks (who doesn't?) that I use when evaluating HiFi systems, speakers, and headphones. I'm intimately familiar with these tunes since I've played them hundreds of times with all kinds of equipment, on both loudspeakers and headphones, and I choose them because they're extremely well-engineered recordings with crisp highs, solid mids, very wide dynamic range and in some cases, very VERY low bass, and by low, I don't mean "not much" I mean they have bass fundamentals that literally go down and kiss the 20hz range. These are the kinds of tracks that can make cheap, or poorly-engineered speakers bottom out and distort like crazy, or the bass simply isn't there, the highs sound shrill and screechy, the midrange, especially vocals sound artificial and "honky."

I'll list some of my test tracks – you may be familiar with these tunes, love them, hate them, that's fine, but all of them give me a lot of pleasure to listen to, especially on quality equipment. They all have one thing in common – they have very clean, wide dynamic range, crystalline highs, very low bass fundamentals, and they're melodic..

There are many more.. I could go on all day, but that's just a small sampling of tracks I use not only because I love them, never tire of them, but they are all superb performances with incredible dynamics.

All of these, and many more, are on my 700p's SD card, ripped at very high MP3 bitrates.

So I fired up the latest Pocket Tunes Deluxe which has a five-band graphic equalizer, and Kinoma Player 4 EX which has no tone controls at all, connected the Jabra C820s to my 700p with the five foot cord and spent a couple hours listening to all of those tracks and more as I fiddled around with equalization and the Jabras' ANR switch and I was mostly pleased with the quality of these headphones. Mostly.

The Treo doesn't have the best audio amplifier in the world and it's all too easy to overdrive it and induce distortion from Pocket Tunes Deluxe if you crank the volume AND the graphic equalizer too high.

Naturally, I tried similar listening tests with the same music on my laptop, which has a much better sound "card", and used WinAmp, my favorite player, which sports a ten-band EQ. Again, the Jabras delivered respectable performance, but fell short of the Sonys'.

One very odd artifact of turning the Jabras' noise reduction on when listening to music is that it totally changes the tone and timbre of that music. This puzzled me, since the ANR circuitry on theBoom Quiets doesn't. With the Jabras, flipping the switch "on" not only radically boosted overall volume, but attenuated (lessened) the lowest bass and bumped up the midrange frequencies into the realm of what I can only describe as somewhat "hollow" sounding. I can't explain it, but this was not by any means a subtle difference, and I had to race for the Treo's volume control to crank it down if I was listening loud.

To my ears, the Jabras sound much better when listening to music with ANR turned OFF.

It's a lot tougher to compare different stereo headphones' sound in an a / b test than it is loudspeakers. At any typical mid to high-end HiFi dealer, they'll have glassed-in listening rooms with comfy chairs and a switching system where a simple push of a button will change from one speaker system to another instantly. With headphones, you have to take them off and put on and adjust a different pair. If you do this at home, unplugging and re-plugging the cables also makes switching cans a process that makes direct comparisons clumsy and time-consuming.

But I did my best to compare the Jabras to my benchmark Sonys and the Sonys easily won for across-the-spectrum sound. This is not to say the Jabras sound bad or cheap. They don't. They sound respectable, they put out plenty of volume, but there was a slight but noticeable shrillness to their high end and they simply didn't reproduce the thunderous low bass notes from my test tracks that the Sonys can do without breaking a sweat.

I found the Jabras a bit fatiguing to listen to for long stretches – yes they're comfortable, they didn't make my ears sweat or my head feel like it was in a vise, but I'm talking about ear fatigue, and despite their higher cost and the fact that they were brand new out of the box, versus a pair of headphones I've used for twenty years, I can and have worn the Sonys for hours on end without wanting to take them off. I can't say the same about the Jabras, based purely on a totally subjective perception of how they SOUND to me.

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