CES 2018 Show Highlight: Sonarworks Headphone Correction Equalizing Software

I got the call a couple weeks before CES. A familiar Public Relations firm wanted me to meet up with a new client. I resisted initially...too many scheduled meeting can get in the way of an efficient route traveling the acres of CES show floor. "But," the rep said, "it's Sonarworks, the folks that do headphone compensation, and they want to meet you." Ahhhh, I know of them and am curious. Compensating headphones is tricky business; I would like to hear their story. I arranged a fairly early morning meeting so as not to impede my daily routine...and boy am I glad I did.

Helmut Blems, CEO, and Janis Spogis, VP Products, were engaging and competent spokesmen for the Sonarworks products, able to clearly understand and directly address my technical questions...until they wouldn't. There's quite a lot of proprietary technology they've invented to perform the difficult task of compensating headphones and as I tried to drill into the details there was only so far I could go before company secrets closed the door. None the less, it was quite obvious they knew what they were talking about, and what they knew was some pretty delicious secret sauce.

Sonarworks has a suite of tools for professional recording studios to equalize their studio monitors. Helmut went into detail about some of their measurement techniques and the data produced. They're able to produce acoustic maps of control rooms and provide users with a powerful set of room tunings that permit the engineer to create a very tight sweet spot while working, and then switch to another room tuning to produce a sweet spot at the couch behind the engineer for producers and artists to hear the mix. Very cool stuff, you can check it out here.

No surprise, with numerous successful studio tweaks under their belt, recording professionals started asking if they could do similar things for studio headphones. They started looking into it...no surprise, they found out it was a lot harder than they expected. When I told them I felt EQing headphones was at least four times harder than EQing speakers they both nodded their heads in agreement. None the less, they persisted.

Though they wouldn't go into detail, they've found a way to transfer their understanding of neutral on speakers to headphones. They do have at least four measurement systems to acquire data for over-ear, on-ear, in-ear, and intra-conchal (ear-bud) headphones. They've taken may thousands of headphone measurements, and currently have compensation curves for 117 headphones.

Their True-Fi headphone compensation software ($79) is available as a plug-in for a variety of digital audio workstations and full-featured music playback software, but they also have versions that get installed on MAC or PC computers that inserts itself deeply into the audio playback system to allow compensated playback from any audio source. They will also soon be shipping apps for both iOS and Android playback, which will be included with your $79 purchase when available. My understanding is that he $79 price also includes all current and future headphone compensation curves developed.

The proof is in the pudding though, so they gave me a little demo. They played the same track on a cellphone driving a Marshall Monitor headphone (an abysmal sounding headphone) and from a laptop driving a Sennheiser HD 650 through an outboard DAC. Both were compensated. I switched back and forth listening for tonal differences. It was a very weird experience. Both headphones sounded very similar tonally...but there were differences in imaging, dynamics, and resolve. Then the compensation was turned off. OMG, the Marshalls sounded bad, and while the HD 650 returned to a familiar sound signature, it was indeed less neutral to my ears.

Needless to say I didn't leave without a request to sample the software...and have already received a promo code to download the full product. This should be fun!

Helmuts and Janis give you the full rundown in the video.

View on YouTube here.

Anders's picture

I uninstalled Boom 2 from my Mac. I found after several adjustments that I preferred my Focal Elears as they are. The necessary boost in the higher frequencies ended up being tiring, so I reduced it, basically getting back to the sound signature that I have. Alas, nothing gained.

Downloaded Sonarworks' program, and it appears from a quick try to be much better. These are my observations (having my Elears directly attached to my iMac):

( ) Without the True-Fi enabled the Elears appear muffled.
( ) The soundstage is wider and the sound is more forward leaning.
( ) The balance is better.
( ) The "Adjustment for Age" works well giving a good boost in the higher frequencies.
( ) The user interface is easier to work with than Boom.

I would suggest that you try it out - there is a 10-day free trial period.


steaxauce's picture

It's about time you discovered these guys! I've been using Sonarworks for years and consider it to be an essential part of my listening configuration. I'm hooked.

The results are excellent with the HD800. I'd spend the money to upgrade to a new flagship in a second if a headphone ever came along that I was confident would give me better sound post-calibration than the HD800, but it's hard to tell, since reviewers (rightly) tend to focus on the tonal balance of headphones. But tonal balance doesn't matter much when using calibration.

I did buy an LCD4 at one point, but the HD800 with SW (SW800?) smoked it. It wasn't close at all. Until some trustworthy people (like Tyll) start reviewing headphones with Sonarworks and tell me otherwise, I'm inclined to think that switching to one of the other flagships from Audeze, Focal, etc. would lose me the HD800's great imaging without giving me much else in return.

Tyll, you should really give Sonarworks a serious look. The WoF might end up looking pretty different. :D

mtmercer's picture

I've used Sonarworks Reference 4 Systemwide for calibration with several headphones I have. Like steaxauce, I am hooked. HD800, unlistenable to me stock. HD800 with Sonarworks... Whammy! Focal Elears... Ditto!

My Sonarworks Sleeper is the Sony MDR-7506. That headphone is mindbogglingly good with the Sonarworks calibration.

It doesn't work for everything. The Phillips SHP9500 sounds pretty bad once calibrated due to the bass distortion.

Tyll - If you are taking requests, I wonder how the Elear with the Sonarworks Reference 4 profile (I vote linear phase filter) compares with the stock Focal Clear.

gzost's picture

Are you using the default or a custom calibration for the MDR 7506? With the Fostex TH-x00 I was surprised how much the custom calibration differed from the default curve. I'm curious how Sony are doing regarding consistency in production.

mtmercer's picture

Regarding Sony's consistency in production, I only have one pair so I can't comment one way or the other.

Regarding which calibration I use, I basically do the same thing for all the headphones I have that have average Sonarworks calibrations which is: Start out with the average flat calibration in Reference 4 systemwide. Then, I use the tilt feature to tilt the frequency response to whatever I prefer for whatever I am listening to for whichever headphone I am wearing. I'm pretty sure the tilt feature is only available in the Reference 4 plug in and Reference 4 Systemwide, not True-fi. Note I listen to music and use Sonarworks for personal enjoyment. I do not do any mixing or mastering.

metal571's picture

Including measurements of headphones that are currently running Sonarworks profiles in future reviews would be really interesting. Could have 3 measurements per headphone - one with EQ "to taste" or "by ear", one with Sonarworks, and one uncorrected. EQ is a very useful review tool - I tend to use it as part of identifying differences in grain/detail/THD and soundstage between headphones as that is most of the difference left after calibration via EQ. I was starting to wonder if anybody would ever come up with a system like this, so it's very interesting to see it come to life. Bravo to these guys, really cool stuff. I'm sure the upcoming InnerFidelity graph tool will have an EQ generator based on user preferred FR as well, right? Right? :P

jpelg's picture

Seems like an effective product that works as designed, with good support, at a very reasonable price. I look forward to trying the mobile version.

detlev24's picture

...can be found in the comment section of Bob Katz's last blog entry:

https://www.innerfidelity.com/comment/515270#comment-515270 and following.

Enjoy! :)

GumbyDammit223's picture

I am using their plugin and Foobar 2k with my HD700's and couldn't be happier. The sound just seems "fuller" now when the plugin is enabled. I initially had a bear of a time getting it to run on my computer but Mattis with their customer service group spent MUCH time with me and MANY emails getting it working. I haven't purchased v4 yet but will probably do so this weekend.

hanshopf's picture

I sent three headphones to Sonarworks for calibration. I was quite pleased with the profile for HD800, but not pleased with their profile for my LCD-X. But it's normal, I guess, that the quality even for customized profiles varies a bit. The engineer can have a bad day or whatever (there must be some final tuning by ear).
After having been initially very convinced by Sonarworks, I later felt that their EQ-machine degrades quality too much. At least one year ago it was not on a par with EQ-machines like for example DMG Audio's "EQuality", which I used.
Furthermore with headphones like HD600 Sonarworks does not work in my opinion. It's technically not possible to give them a flat bass. It just blurts with Sonarworks' profile.

killarunaxx's picture

Hi Tyll just wanted to bring to your attention that for the past few months the updated .pdf bundle of measurement pages seems to be corrupted or something.

I've been having having difficulties opening it and when it does open there are a lot of blank pages. Not sure if that has anything to do with my pdf reader (I tried different programes).

Though individual downloadable .pdf works just fine, but it's more convenient to check from the bundle.

Thank you for your great work!

tony's picture

This seems like what Bob Katz demonstrated with his lap-top running his regular pro tools at Big Sound in Montana 2015!

I have this service from my University of Michigan Audiologists who tune my personal headphone rig to my hearing response curves.

Phonak do the same sort of thing for all their Customer base.

Audiophiles have shunned this sort of Equalization/correction although the manufacturers build-in various equalizations when they select components ( such as tube choices, etc... ).

$70 seems a cheap enough price for this set of corrections but a person can have the necessary curves by simply looking at Tyll's Book of Headphones ( that was offered to lookers at the 2011 RMAF Seminar ) or by referring to Tyll's vast data base.

Still, having a plug-in that does it all would seem to be a valuable tool, it'll save a hell-of-a-lot-of-work.

I wouldn't doubt that these lads from Latvia copied Tyll's measurements for use in their little program/application.

Tony in Michigan

ps. a little hint: you can make Sennheisers sound like any headphone ( or pretty dam close )

RudeWolf's picture

Hey Tony,

We've measured 'round 2 thousand headphones by now with circa 5 cans being measured daily. We're a team of around 30 people, so we have both the brains and the brawn to pull it off.

Rudi in the frigid wasteland that is Latvia right now.

P.S. I have some folks up in Milwaukee. Stay warm!

tony's picture

Yes, of course.

I can see the "earned Confidence" in both of you lads.

My ancestors emigrated from your part of the world to the Milwaukee area ( in the 1850s thru to the 1910s ).

I think that you will be successful in a Global sense but equalizing direct radiating transducers is still a Taboo in the United States ( for the most part ) even though it's done in Crossovers and dampening materials, wire and with many other methods.

Using careful equalization can be a wonderfully simple and useful solution.

Thank you for writing,

Tony in thawing Michigan

ps. Your English is very good.

ednaz's picture

There's a similar process to EQ in the printing business called profiling. Because every printing paper and every printer has different characteristics, if someone wants all prints to look as intended no matter which printer or paper used, profiles fix that. I have profiles for every paper I use with every printer I use. I can print an image from an old 4 color desktop printer and my 12 color monster, and they'll be indistinguishable to anyone other than someone who really knows printing. Profiles compensate for idiosyncrasies of printers and paper coatings.

Most people use commercially available profiles put out there by paper manufacturers, for as many printers as they think they need to cover the market. Printer manufacturers sometimes do the same. They're generic - someone used measuring gear to analyze prints from one or two printers, and based on what they KNOW the image SHOULD look like create a compensating profile. There's even crazy expensive software (called RIPs) that come with extremely optimized profiles for individual printers with a gazillion different papers. Still generic, just done with better equipment and more care.

Professional print shops profile each printer/paper themselves, because there's enough sample variation across same make/model printers to be visible to trained eyes. I've paid for custom profiles for my most frequently used papers, and the difference leaps off the page. To my eyes.

So... I don't know headphones as well. What they're dong for $79 is like the generic printer profiles, which are HUGE improvements but still generic. Is there significant sample variation between three Senn 650s, that there'd be justification for custom EQ? I suspect sample variation is greater at the low end? Are the differences enough that a generic profile might only be OK sometimes, superb others for the same model of headphone?

Sounds like their studio profiling - er, compensation - uses measurement devices to create the optimization for each room/speaker combination. High stakes, high value. Not sure anyone would actually pay up for a headphone profile that took account of their ears and nervous system.

Wick's picture

I am new to the whole topic of headphone equalization, so I ask your forbearance. To use software like this, would it require that I always listen to music through a computer or laptop? I tend to use a DAP for my music listening-Fiio X5 Gen III. This is an android device, so conceivably a plug-in might work with it. Can someone enlighten me as to what my music source would need to be in order to listen to my headphones with equalization. What do most people here use as a music source device?

RudeWolf's picture

Does your Android DAP support Google Play apps? Or can it set up apps from .apk files? If so, the upcoming app might do the trick.

Venture Guy's picture

I listen almost exclusively OTG. When do you think the iOS version will be available?

Wick's picture

I'm guessing from your responses that for the moment I would need to listen through a computer to use this technology.

Skycyclepilot's picture

Before I discovered Equalizer APO, which is free, I could not use headphones. The soundstage was always shifted far to the left, and trying to use a balance control to correct it destroyed the image. Nothing was in focus, aurally. It sounded awful.

After many, many hours trying to create an equalizer curve with Equalizer APO, to correct for what I was sure was hearing loss in my right ear at some frequencies, I discovered something amazing. Delaying the sound going to my left ear by a few hundredths of a millisecond brought the stereo image to the center, much better than trying to equalize my right ear!

The only thing I can figure is that my brain processes sound coming into my right ear more slowly that it does sound coming into my left ear. I've heard others complain about lead vocals and such always being shifted to the left for them. I wonder if anyone else out there has experienced this phenomenon, or am I just as weird as everyone says I am...

jherbert's picture

Are there really people around that spend four digit amounts for headphones (not even considering "proper" amplification) that are NOT willing to spend less than 100 bucks for this great piece of software? C'mon.

echoplex's picture

I've used the Sonarworks Reference 3 and 4 plugin for headphones (marketed to pro audio users). Even with the minimum and linear phase filters in version 4, for the purposes of critical audio editing tasks, my experience has been that past 80% wet - or compensated - mix, what you hear on the flat frequency response setting is no longer believable on high end headphones like the Senheiser 800 family models, Beyer DT1990's, etc. This is especially true when using high end headphone amplifiers together with balanced connections to the headphones, where the impedance is well matched.

Given all the posts on innerfidelity about how the Harman Curve works as a technical basis for a diffuse field equalization curve in order to make headphone listening closer to listening in spekaers/monitors - THEN the big question seems to be: Why dosen't Sonarworks offer a compensation setting to implement the Harman curve (in addition to providing a flat response curve)? The answer from Sonarwokrs seems to be that there is no need for them to offer a Harman Curve setting because their FLAT frequency compensation curve achieves the same thing as the Harman curve! What? Could you please explain the technical basis for that? I've yet to read an explanation from Sonarworks about this.

Pro audio users also don't believe Sonarworks claims; no shortage of posts about this on, e.g., gearslutz.com, i.e., sans any explanation for what appears to be a bogus technical claim, then Sonarworks should not be taken seriously. As Tyl has already discovered, a flat compensated cheap headphone will probably always sound better compared to its uncompensated sound. But when using high end headphones with matched impedance amplifiers, the value of Sonarowkrs software EQ compensation seems to diminish, especially w/o an available Harman curve setting.

GimmeCans's picture

I'd try it but it supports none of my current headphones (Beyer Amiron, Etymotic hf, or Shure SE535 (strangely, it supports the SE215 entry-level basshead IEM which costs about the same as this software). I'll keep an eye on this though.

Didn't I see something similar mentioned here awhile back that purported to calibrate your headphone(s) to your individual hearing? Anybody remember what I'm thinking of?

skris88's picture

I took their challenge as on their web site. I pulled out my old AUD$30 Sennheiser HD-201s and tried them EQed against my AUD$250 HiFiMAN HE4XXs (unEQed), they sounded nearly identical.


I think this USD $80 is worthwhile. The software on a laptop with $30 headphones, and you're (nearly) in hi-fi Nirvana.

sejarzo's picture

I just acquired a pair of HE400is, and the seller included the stock HiFiMan velour pads and Brainwavz sheepskin pads. The sheepskin pads fit and seal properly against my head while the stock pads for any of the cans in that series don't. I have to assume that for some folks, the exact opposite would be true. With these phones, there is a huge difference in bass response that's entirely dependent on minute differences in how any pads seal against my head. I also found the same thing when I started using cheap pads from eBay on my HD600s. They are just a bit smaller overall, yet fit my head much better. Without doubt, they boost and extend the low frequency response versus even brand new Senn pads.

Obviously, failure to get a seal on IEMs can destroy the perceived low end response, but one can fairly easily check the seal of IEMs. My experience is that it takes a lot of twiddling around with the fit of over-ear phones to be sure that there's something close to a proper seal, and sometimes it's never achieved. I was never able to get AKG K series phones to sound right on my head, for instance--they are simply too big and the bass response was always weak, always leaking out somewhere.

That's why I don't get how measurements on a single dummy head can work well across a broad swath of users as it seems would be necessary for this application. When I tried the HE400i demo on the web site and the bass boost was ridiculously out of whack for me...as in 10 dB too much. Horrible.