InnerFidelity April Update

Headphone Measurements
Lots and lots of new headphones measured since the last update. I'd like to thank Joker for shipping me a bunch of in-ear monitors for measurement, a very interesting collection. There were so many headphones to be measured in fact, that I didn't get a chance to listen to them all, so my comments will be brief, and some I won't comment about at all---though I will add a list of those not mentioned at the end.

As usual I've updated the AllGraphs.pdf of course, and added the cans to the measurement datasheets page. New additions include:

  • AKG K267 Tiesto - Boy, I think I like this headphone. It has three settings on the earpiece that control acoustic changes in the capsule. I found the sound tasty, if a bit uneven and closed in---like all sealed cans. I'm looking forward to some serious listening sessions. These cans are getting a review. Also measured were the Tiesto K167 and K67, which I found unsatisfying.
  • Sennheiser IE 800 - Argh, what a troublesome little pair of headphones. They simply refuse to seat properly in my measurement head. And their tips are quite unique, so I can't use alternate ones to try to get a better fit. Bottom line: You can't trust the measured data for this headphone. I've now measured an early pair and a current production pair, and it does seem like bass response improved and the ringing has been reduced a bit. I also suspect that some of the ringing seen may be due to acoustic interactions between the cans and the poor fit in the artificial canal that might not actually exist in use with a real human ear. They fit nicely into my ears, and I felt the sound pretty darn good, though I did hear some funny sparkle that might have been this resonance. At any rate, don't take these measurements as representative of these cans, pretty sure Joker will be reviewing them. Sorry, I wish I could have gotten a better measurement.
  • Mr. Speakers Mad Dog - Dan Clark has been working diligently on his Mad Dog modified Fostex T50RP headphone and good headway has been made. Response from 10Hz to 1kHz is pretty darn good, but roll-off after that point is a bit to steep and deep for me, making a somewhat unresponsive sound to my ears. Most measures are quite good otherwise, but THD is up quite a bit from last time I measure a version of this can. Gotta hand it to him though, squeezing performance out of this decades old design is quite an accomplishment.
  • Yamaha Pro300, Pro400, and Pro500 - Finally got my hands on the new Yamaha Pro line of headphones. I found the Pro300 pretty poor, but the Pro400 and Pro500 were okay, and sounded better to my ears than the measurements would indicate. Five years ago they may have ranked right up with contenders, but recent stellar entries into the field of full-size, sealed cans push these well into the pack of also-rans. Measurements show pretty uneven response, in particular the humpity-bumpity impedance plots indicate a lot of uncontrolled resonances around the driver. Also, 20 Ohms seems just way too low to me. I really wish manufacturers would stick to 50 Ohms and above to take advantage of better damping factors. I won't be reviewing these.
  • Philips Fidelio S1 and S2 - A couple of months ago I measured the pre-release versions of these dynamic in-ear cans and thought them pretty good. Philips sent the final production versions and measurements show only modest changes...a bit for the better as I see it. I enjoyed them on brief listen, and sent them off to Joker for further evaluation and possible review.
  • Torque t103z - Another tunable in-ear, the Torque t103z is a handsome and nicely designed in-ear with screw on filters quite similar to the AKG K3003. This is a great concept, but all too often fails to impress. Sadly, this is the case again. Best I've heard of this type of IEM is the now discontinued Audeo PFE 1XX series, and the Sleek SA7.
  • Thermaltake Isurus - Wow! For $29 bucks this little gem measures spectacularly. This is on of Joker's IEMs that didn't make it into my ears, but after perusing the measurements I wish it had. Pretty stunning.
  • V-Sonic GR07 and GR07 Bass Edition - I regularly get folks asking me if I've heard these, and boy am I glad Joker's pile-o-cans came with examples of this fine little headphone. What a treat! This $180 dynamic IEM just goes to show you that dynamic drivers hold as much promise for high-end IEMs as balanced armature based products---in some ways more, as you don't run into the wild impedance swings of BA IEM crossovers.
  • Unmentioned but Measured - Astrotec AM90; Audio Technica ATH-CKM50, ATH-CKM500, ATH-W5000 2013; HiSound Audio Crystal, Hiphone HP4, Wooduo; Monoprice 8320; Panasonic HJE120; Philips Construct, SHL3000, SME3580; RHA MA150; RockIt Sounds R30, R50; Sony MH1C; Soundmagic E10; TDK MT300; V-Sonic VCO2; Westone UM1, W2, UM3X, and 4R.

Upcoming Projects
Ultimate Headphone Guide - My parent company, Source Interlink Media (SIM), is the largest men's enthusiast periodical publisher in the United States, producing titles like: Motor Trend, Powder, Surfer, Motorcyclist, Stereophile, and over a hundred other magazine and website special interest journals. For the last few years, the Automotive Group have been publishing a special interest publication (SIP) called, "The Ultimate Wheel and Tire Guide". While not associated with any one particular brand in the group, editors in the group rally to produce the most comprehensive guide to wheels and tires available, and it has become a very popular and profitable publication for Source Interlink. As such, SIM management has been looking for another topic that may duplicate that success, and believe they have found one in headphones.

A project called "The Ultimate Headphone Guide" has been initiated, and I've been asked to help as copy editor for the publication. The guide will be about 250 pages and is projected to be on sale at newsstands this fall for $9.99. You can think of it as a yearbook for headphones, which will contain hundreds of pictures with short descriptions of the headphones displayed, intended to give readers a sweeping overview of this year's products. It will be break headphones down into three broad categories: around-ear; on-ear; and in-ear headphones, and I'm happy to say, will also include a category for headphone amplifiers.

The beginning of each section the guide will include some editorial content providing readers with a overviews of each category helping potential customers orient themselves and their needs within the vast array of products available. But there will also be articles in the back of the book on such topics as: "How Headphones Work"; "Hearing Safety", "What is a Headphone Amplifier"; "How to Properly Insert and Use In-Ear Monitors", and a number of other headphone related articles.

While this will take away some of my time from InnerFidelity writings, I think it is a great opportunity to reach out to the broader consuming public and provide them straight talk on the values of headphones and how to approach a headphone purchase---something that they're not getting much of right now. As time goes on I will likely be posting some of my initial thoughts on the various articles in the guide eliciting comment from InnerFidelity readers. I've got a pretty good grip on the information that should appear in the guide, but I'm constantly impressed by the breadth of knowledge of IF readers and feel like I'd be missing out on an opportunity to produce a truly complete book if I didn't include a chance for IF readers to make suggestions. You can expect posts on these subjects a couple of times per month. I hope you'll participate in the process.

Headphone Measurement Tool - Part of the Ultimate Headphone Guide will be an on-line buyer's guide tool for folks wishing to search through headphones on their iPads and smartphones. This effort has put the headphone measurement display tool at a lower priority. However, it is still very much alive because as time goes on headphone measurements will become part of that guide. So while you shouldn't hold your breath for InnerFidelity measurements in an on-line tool, you can rest assured that the future does promise a really terrific way to browse through and evaluate huge numbers of currently available headphones. Patience will pay off in spades, the headphone measurement tool is still on the "must have" list.

The High-End Show, Munich - May 9-13 I will be traveling to Munich for The High-End Show. John Atkinson and Stephen Majias are unable to attend the show for Stereophile, so they've asked Michael Lavorgna of AudioStream, Michael Fremer of Analog Planet, and myself to attend the show and to report for Stereophile's website. I've heard this is a terrific event and am very much looking forward to it. I will no doubt produce a few posts for InnerFidelity, but the bulk of my effort will appear on Stereophile's website. I'll be sure to remind IF readers when the time comes; I'd love to hear your comments on Stereophile's website as my reports appear.

T.H.E. Show Newport - Richard Beers and crew have invited me to attend the THE Show in Newport (So Cal) May 31-June 2. The are making a big effort to highlight headphones at the event and have reserved a large area of the show for headphones and related products. There will also be some panel discussions on headphones that I will sit in on. I heartily encourage Souther California readers to come for a visit and enjoy this effort. And if you see me (I'll be the guy wearing an Hawaiian shirt), please tap me on the shoulder and say "Hi!" I'll post a reminder again about a week before the show.

I'll be on Home Theater Geek this Monday! - My dear colleague Scott Wilkinson over on's "Home Theater Geeks" has asked me to guest on the show this Monday, April 8th, at 5PM EST, 2 PM PST. We're going to chat about audio virtualization, head related transfer functions, and all manner of spacy in-your-head-audio stuffs. I hope you'll join in to view. If you log into the chat session you can ask questions and watch people comment on the dialog as it happens. Quite fun, I really enjoy doing it.

That's it for the April update. My condolences to all the allergy sufferers out there, but I'm sure glad spring has arrived---time for oil changes on the motorbikes!

Theo's picture

Hi Tyll,

I really would appreciate a review of the MrSpeakers Mad Dog with the Alpha ear pads.




Impulse's picture

I was hoping for that too, maybe even a Paradox comparison, but it doesn't seem like he's enthusiastic enough about them for a full review... Are the measurements for the latest version gonna be posted later?

Edit: Found the newer measurements on the All Graphs pdf. Huh, seems the roll off past 1K increased significantly with the latest iteration...

Tyll Hertsens's picture

He's getting me another pair shortly as there seemed to be something amiss with the pair I received.

mikemercer's picture


Life is wild.  You sent me my first USB DAC/portable headphone amp (Headroom Total Bithead) that I use to this day!  I believe that was back in 2004.  Sometime around there.

Now we get to have you out to our little event: The Headphonium at T.H.E Show Newport!!

Plus: I get to jive it up on the headphone panel with you, George Cardas, Alex Rosson from Audeze, and Michael Goodman from CEntrance! Yeah hooh.

Psyched to see ya!


robotskill's picture

I'm really interested in how this turned out, were you able to measure them again? I would as well be interested in measurements for the balanced version if or when it could ever be accommodated =)

Alondite's picture


Glad you finally got a chance to hear them! I love mine. Even after hearing much higher-end stuff I still love my GR07. Treble's a bit hard/metallic with some sibilence, but they're just good at everything. At under $200, I can't think of any other headphone I'd rather have. 

HK-47's picture

It would be nice if you could make an online database, where one could easily pick out headphones based on category (open, closed, over-ear, on-ear etc.), pricing, impedance, sensitivity, 2/3-button remote, pricing, and so on.

And then each headphone's page can have a link to reviews from Innerfidelity or other reputable sources, and of course links to retailers for purchasing them.

Tyll Hertsens's picture

...but it will no doubt take a while to get there. It's coming though.

tony's picture

Hello  Tyll ,

I'd like to thank you for helping me understand this world of headphones ,

On the larger scale I'd suggest that you are one of the finest Journalists of any field . 

Congradulations on your success .  I first encountered you in a RMAF Seminar , I then found you to be enlightening , you continue to outpace everyone . That Steve Guy with the Hippy Hairs is also a Gift to the World ( you can tell him I said so ) .    

I purchased the Schiit M&Ms based on your comments about Jason and the Company , you were quite right , they are a great company with great products .  I'll purchase more Schiit stuff as I up-grade .  

I will be at the next RMAF to evaluate third tier products like the SD800 and SET amps .  I hope to sit in on one of the Seminars .  

So far , the money you saved me with useful advice prompts me to offer you a nice dinner or something else useful .   

I wish you well ,

My best regards,



alexandrov's picture

Hi Tyll, 

I think the next logical step of this site is to make some graph-comparison tool. It's unuseful (at least to me) to look at a headphone graph alone.


bugmenot's picture

Ditto. If you folks don't have resources/time/whatever to do it I'd love to help.

Tyll Hertsens's picture

It's coming. I expect later this year.

Jazz Casual's picture

No Ultimate Headphone Guide would be complete without the Audio-Technica ATH-W3000ANV; nor a Headphone Data Sheet Downloads resource. ;) 

Tyll Hertsens's picture

You're just never satisfied, are you?

I'll work on getting a pair in.

Jazz Casual's picture

I prefer "demanding". I'd be most grateful Tyll if you could. Satisfied? ;)

WaiZack's picture

Hi Tyll, what about the HE-400 review? Weren't you going to do one with the velour pads?

Okamoto's picture

Hey Tyll, what did you think about the MH1C? It's been hyped up a lot at HF some time ago. They said it's able to compete with much more expensive IEM's.

elfary's picture

Hi Tyll,

First off i'd like to thank you for all the valuable knowledge that share with us around the globe.

As 2 year user of the um3x i'd like to know your subjective impressions about it and what's the interpretation of its 300Hz square wave plot. Does it have something to do with the very recessed low treble...

Thanks a bunch from the sunny Spain

Seth195208's picture just a couple miles from my house. See you there Tyll!

Here is a video from the 2011 show.

The 2012 show actually doubled in size over the 2011 show, but I can't find the official video. Sorry.

sue4's picture

Hello, Tyll! Could you please tell us how to physically differentiate between early Senn IE 800 and the current (2013) one? From the package details, maybe? Thank you.

tdherbert's picture


Thanks so much for providing this incredible resource.  I have a question about presentation and scaling of the impulse responses you show. First, about half or more of the range of each graph isn't used. It would be so much more useful to rescale to some reasonable maximum that would show more of the details of the decay. Second,  do you take each measurement at the same SPL from each headphone?  I'm wondering if there is a good normalization, such as does the area of the waveform always come to the same value (in other words, the integrated difference from the zero line).  I'm not sure in theory whether the area or the squared difference relative to the zero line is correct.  In any case, I think the scaling now makes it harder to compare the impulse response of different headphones than it needs to be.


Seth195208's picture


What do think about the idea of distortion testing IEM's at a 5db lower level than regular phones, since they are naturally listened to at comparatively lower levels? 

Seth195208's picture

I love to collect high value head and earphones. These have been a value leader for quite some time now, but are just too hot in the 2khz range. Now I know why I gave them away. Thanks for testing them. I'm sure this will satisfy the curiosity of many over at Head Fi.

Seth195208's picture


I apologize if this is the millionth time you've been asked these questions, but why no waterfalls? They certainly would be easy to include. Also, why THD? Is it possible for you to show the actual order of distortion components? It would be a little more informative if you could.

Jim Tavegia's picture

Now I can tell my students before they drop $200 on a set of cans they can do some homework first for only $10.00  .  Looking forward to it. Mostly now they buy them on looks.  That is sad. 

Impulse's picture

Your students don't have internet? Not trying to be facetious or obnoxious, just saying, if they're spending $200 on headphones I'd hope they have the means to do some proper research online... Cheaper than a printed mag that gets outdated in a couple of months (and I still subscribe to several printed magazines btw).

Seth195208's picture

Just purchased the thermaltake Isurus. The frequency response is somewhat similar to  Sennheiser HD800's(More similar than anything else Tyll has tested, I believe). Interesting to say the least. 

Seth195208's picture

...want to use the Isurus straight out of an iPod. The bass is way to loose and ill defined(for me), Yuck! Output impedance below 1ohm is a must, even with the Thermaltake's flat impedance characteristic. With my squeezebox touch(2 ohms), the bass is still a little loose. I've only had them for a day, so that's the only (obvious) thing I can comment on so far..Oh yeah, one more thing. Got rid of the ear tips. They suck.

shotgunshane's picture

I saw you mentioned the Soundmagic E10 was measured but I don't see it in the data downloads.  Just wondering if it was overlooked?