Some introductory thoughts on Koss.
I have to admit significant mixed feelings about Koss. On the one hand, they've produced some truly excellent headphones in terms of value/dollar. The Porta-Pro (reviewed here), KSC-75 (and earlier variants), and ESP 950 headphones have had a strong following and fan base in the headphone hobby since day one. There's even a meme of sorts among enthusiasts giving advice to novices entering the fray, "Buy a set of Porta-Pros, then, if you can find something better, get it." Many experienced…

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Measurements
Raw frequency response measurements show an ear pad that varies some with bass placement. In listening tests it became apparent that the actual ability to seal and deliver bass response was much worse in real listening situations. (I guess I try to be careful when taking the measurements. I think it would be very difficult to have the goal to recreate real-world listening performance when positioning the headphones, as opposed to trying for best seal in each position.) If these headphones don't seal…
Master & Dynamic MH40 ($399)
"My goodness, what a striking headphone," was my first thought laying eyes on the sealed, around-ear, Master & Dynamic MH40. My impressions remained quite similar during my first listening tests. Now, with many months experience, I can say with surety, "striking" is an excellent descriptor.
Let's start with the look of these cans...which is for me a strike right down the middle of my modern-day geek sensibilities. Real leather, real metal, stitching and texture, utilitarian yet…
Sound Quality
Now that I've spent a little time complaining about the problems of a strongly sealed headphone, I'll do an about face and mention what seems to be their characteristic strengths: dynamics. Maybe it's the tight pressure coupling of the driver into the ear that does it, but holy mackerel, what ever it is, the MH40 hits hard. Unfortunately I can't find it again, but a quote from one of the Head-Fi threads on the MH40 keeps repeating itself inside my…
Click on graphs image to download .pdf for closer inspection.
Raw frequency response plots show a headphone with significant changes in response due to positional changes on the ear. These cans were quite challenging to move on the ears and get good measurements; I spent quite a bit of time in each position to ensure a good seal. Because it was so cumbersome, I did allow one set of measurements with poor bass response into the set as it probably is indicative of how they will get heard on the head at times. You can see that changes in seal effects response all the way…
Audio Technica ATH-MSR7 ($249)
Saw these at CES with their official "Hi-Res Audio" sticker. My mind's first thought: Yeah right, like "Digital Ready" meant anything either. Turns out the label is pretty darned accurate.
The ATH-MSR7 is a circumaural, sealed headphone with a 45mm angled driver. The styling is handsome and conservative with a pretty nice mixture of materials for a headphone at this price. It does bare a striking resemblance to the Sony MDR-1R. With both in hand I'd say the Sony looks better with excellent…
Sound Quality
It's been a tough week around the InnerFidelity lab. I've got the Pono in and have been blind testing it against all sorts of stuff. Blind testing is a pain in the butt, and definitely not the way I like to listen...but it's got to be done. The trick with the Pono is I've got to use a roughly 30-50 Ohm relatively efficient headphone for volume matching with all the other things I'm testing it against—I'll go into why in the Pono review—and it's got to have killer resolution as blind testing Amp/DACs requires the ability to hear into the very finest details. I had…
Click on graphs image to download .pdf for closer inspection.
Looking at the raw frequency response plots we can see that the MSR7 is relatively insensitive to positional changes on the head. A fairly broad hump in the bass and mids does good job of approximating flat, but clearly has an overall tilt that diminishes the bass and cools the overall response in that area.
The rise to the treble peak starts at 500Hz, goes up 10dB by 2kHz then remains flat to 5kHz. The problem is it rises too fast relative to the target response and causes a rise in the upper-mids…
Editor's Note: Famed recordist Bob Katz is a headphone enthusiast...who knew?
Bob recently offered to write a series of articles for InnerFidelity readers on his recent adventures with headphones. I just couldn't turn down an opportunity for a peek at our favorite head-worn audio device through his venerable ears.
Please help me welcome Bob during his stay here at InnerFidelity in the comments below!
(For more info on Bob check out his website.)
Bob Katz's Corner: Episode One
Single or…
The Headphone Slutz group meeting was fast approaching, and the demo cans would soon arrive from the Cable Company. I was excited! In a few weeks I would be able to hear and compare four of the world's best headphones, in my own room with the finest associated gear and music sources, and share that experience with seven friends.
I knew I would need a real good dynamic headphone amplifier, with a quality that could hold its own against my KGSS Stax amp. So after discussing headphone amps that I could afford with my good…