Introducing Triumph’s SRC by Goodhertz
A New Standard and Why Sample Rate Conversion Matters

In this post we’ll cover the importance of sample rate conversion, then we’ll get the low-down directly from Devin Kerr of Goodhertz, about what makes their SRC special and what you should consider when using it.

First to answer some questions:

What is sample rate conversion?
Sample rate conversion is the process of increasing or decreasing the sampling frequency of digital audio. The sample rate is defined as the number of sample points per second.
(A 44.1kHz file has 44,100 sample points for every second of audio)

When do I use it and why is it important?
In audio, music, and film work, sample rate conversions play a crucial role in the production and mastering process. A good SRC makes it possible to change an audio file’s native sample rate with little or no perceivable loss, and they’re needed to produce the myriad deliverables that accompany most commercial releases: 44.1K for CD, 48K for HDTV; 48K, 96K, or 192K for film; and the highest possible for vinyl, high resolution, and “Mastered For iTunes” releases. A thorough understanding of sample rate conversion — when, how, and why it’s used — means better audio and delivering the right format for the job.

What traits and features are important in an SRC?

Frequency Response:
    Does it have good high frequency resolution to at least 20kHz?
    Is it flat in the audible band?
    Is it smooth?

    Are there aliasing artifacts? How much?
    Is there aliasing in the audible band?

Transient Response:
    Is there pre-echo?
    Is there excessive ringing?
    Is the filter sharper than it needs to be?

Phase Response:
    Is the phase response linear / smooth?
    Where (if at all) does it deviate from linear?

Noise / Distortion:
    Is there added noise or harmonic distortion?

    How long does it take to convert sample rates?


Our interview with Devin Kerr of Goodhertz (DK):
Goodhertz logo
What is Goodhertz’s background?
DK – Goodhertz began in 2012 as a collaboration between myself and Rob Stenson. At the time, I was working as a mastering engineer, and Rob was an interface engineer at Twitter, but we both wanted to make audio software. Three mutual friends (independently) suggested we combine forces, which we did in late 2012. Goodhertz has been pairing clean interfaces with great-sounding DSP ever since.

What was your goal when developing your own SRC algorithm?
At first, the purpose was completely selfish: we wanted a great SRC for upsampling in some of our plugins. But then we realized that it’d be great as a standalone converter too, and we set about making a standalone sample rate converter that was, put simply, the best available — both sonically and in terms of processing speed and latency performance. Secondly, we also wanted to take some of the guesswork out of sample rate conversion, and we worked with Audiofile Engineering to make it easier for users to get the best performance without needing to adjust a bunch of (potentially) confusing SRC filter parameters.

What makes the Goodhertz SRC special?
The Goodhertz SRC has, arguably, the ideal balance between frequency response and transient response — two of the most important characteristics of any sample rate converter. This means that it does its job with the least possible sonic impact, preserving crystal-clear high end while also maintaining sharp transients. The Ghz SRC has virtually zero aliasing (sampling artifacts), with performance better than -192 dB.

Check out Infinite Wave Mastering’s results for the Goodhertz SRC on their comparison page.

What is the difference between linear-phase and minimum phase, and what are the trade-offs between them?

Linear Phase
Goodhertz Linear Phase image

    Perfect, linear phase response
    High latency
    Both pre- & post-ring

Minimum Phase
Goodhertz Minimum Phase image

    Some phase deviation
    Low latency
    Post-ring only

The main tradeoff between minimum and linear phase SRC’s is between phase response and transient response. Minimum phase designs have the advantage of no pre-ring, which many feel gives a psychoacoustically advantageous transient response, but they also have the disadvantage of a less-than-perfect phase response. Linear phase designs, on the other hand, have a perfect phase response but contain pre-ringing, which can have a smearing effect on sharp transients.

Which option — linear or minimum — depends on your particular application and tastes. Our advice: try a couple conversions, perhaps even a couple in a row: 96kHz → 44.1kHz → 96kHz → 44.1kHz for both minimum and linear phase, and see what differences you can identify. If you can’t hear the difference, it’s probably safe to stick with linear.

Do you have anything you can share about the future of the Ghz SRC?
One feature of the Ghz SRC is that it’s super fast — so fast that it can be used in realtime, at full quality, in a lot of cases. We already use it in the HQ Modes of some Goodhertz plugins, and we expect to use it a some other cool realtime applications soon!

So… What’s Next?

We are very excited to announce that RØDE Microphones has acquired FiRe – Field Recorder! This really is bittersweet for us here at Audiofile Engineering. We are very proud of FiRe and very sad to see it go. That said, it’s going to a great home. We know that the folks at RØDE are going to take great care of it!


As you all probably know, the iPhone was unleashed upon the world in June of 2007. Ev and I, as you might suspect, stood in line so we could each have one of the first batch. Of course, just having an iPhone changed our lives. We could never have predicted how it would impact us shortly thereafter.

The Developer Program

In March of 2008, Apple officially launched the i(Phone)OS Developer Program. Shortly before that, we were approached by another company who very much wanted to ship an app in time for the launch of the App Store. Luckily, we had the unique expertise to be able to do the job. After 8 hair-raising weeks, we had developed one of the first 800 apps to debut on the App Store. At the core of this app was the first high-quality, low-latency, bi-directional audio system for iOS. Since then, we have been extremely lucky to have been involved in numerous other audio-related firsts on iOS including the first MIDI interface accessory, the first app to integrate with SoundCloud, the first 96kHz-capable audio input accessory and many more!

We Did Start The FiRe

It took us over a year to develop FiRe. We knew that there would quickly be many voice recorders, but we wanted to do more. We wanted to make it so someone could fully replace their handheld field recorder with their iPhone or iPod touch while fully taking advantage of the unique features of these amazing devices. Who could have ever imagined a handheld recorder with a big, beautiful, color touch-screen and internet connectivity?

In 2009 we launched FiRe and it was an instant success. We were lucky enough to have crossed paths with the talented and creative folks at SoundCloud, and FiRe became the first app to ever integrate directly with this now wildly successful social network! It drew a large, high-quality waveform on the screen. You could navigate your recordings via touch. You could upload your recordings instantly to SoundCloud or via FTP. We had accomplished our goal: your iPhone could replace your field recorder and do things they couldn’t do. But there was one thing missing…

Pass The Mic

A great microphone. If you are an audio nerd, there really is nothing more satisfying than a great microphone. Sure, the iPhone had a microphone. It’s a passable mic, but we desired something better. So, we started searching for a partner with the hope that we could leverage our experience in the MFi (Made for iPhone/iPad/iPod) program to create a total solution. Eventually, we were extremely fortunate to cross paths with the Peter Freedman and the many extremely talented people at RØDE Microphones. They created the beautiful and powerful iXY: the first 96kHz-capable audio input accessory for iOS. Finally, your iPhone was professional field recorder… and so much else!

So… What’s Next?

We are very excited for the future of FiRe and more amazing RØDE accessories. And, we’re not letting go of it completely. We’re currently putting the wraps on the next version which will sport some very cool new features. Also, we will be working with RØDE to transition the app to their new development team. Of course, we will support our current users during this transition.

Beyond that, we are very excited to dig into major updates to all of our Mac OS X applications. Triumph 2.1 is coming this fall. We are very excited to announce Spectre 2 as well. If that wasn’t enough, iOS companion apps for both Triumph and Spectre are in the works! And, we won’t stop there: updates of Sample Manager and Rax are also on the roadmap.

I will close simply by saying “Thanks!” Thank you to everyone who bought FiRe. Thank you to our beta testers and those who helped localize version 1. Thank you to everyone who sent us feature suggestions or amazing recordings you have made with the app. We couldn’t do any of this without you!

Win a RØDE iXY Microphone

Contest closed!

Congratulations to our winners: Josef Israel and Chaz Mortimer.

Our friends at RØDE recently released iXY, the world’s highest quality stereo microphone for iOS, capable of up to 24-bit/96k recording when paired with RØDE Rec or the upcoming version of FiRe. We’re excited to have worked with RØDE in the development of the accessory and software.

To celebrate the release, we’re giving two lucky winners the chance to win an iXY microphone!

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How to Win

For the chance to win, you need to do 3 things:

  1. Leave a comment at the bottom of this page so we can contact you if you win.
  2. Post this tweet or share either this contest page or this photo on Facebook.
  3. Follow @audiofileeng on Twitter or Like Audiofile Engineering on Facebook.

Rules & Conditions

  • You may only enter once.
  • Make sure you use a valid email address when you comment so you can be contacted. Email addresses will not be made public.
  • Entries will be accepted until February 22nd at 11:59pm EST and winners will be announced and contacted on February 23rd.

Triumph Launch Week Giveaway

Contest Closed! Thanks to everyone who entered, and congratulations to our winners: Martien Bélanger, Sebastian, Travis Keir, and F Harvell.


If you’ve been keeping up with us on Twitter and Facebook, you know we’ve been working tirelessly to perfect Triumph, our brand new audio designer for Mac OS X.

We’re excited to announce that Triumph is now shipping and available on from our online store!


Download Triumph today to begin a 15-day trial.

Take advantage of 25% off Triumph now through November 11th (Midnight Minneapolis time).


To celebrate the release, we’re giving four winners the chance to win a great software bundle, including:

  • Quiztones, a frequency ear training app for Mac OS X or iOS.
  • Spectre, a real-time audio analyzer for Mac OS X.
  • Sample Manager, the quintessential batch audio file processor for Mac.
  • Gobbler (free 25GB account for 6 months). Gobbler provides fast and secure backup, collaboration, and asset management for pro audio creators.
  • Ozone 5 from iZotope. Ozone is a complete mastering system in a single integrated plug-in, featuring eight essential mastering tools.
  • SoundCloud Pro (free 6 month Pro account). Create, record and share the sounds you create anywhere to friends, family and the world with SoundCloud, the world’s largest community of sound creators.

For the chance to win, you need to do 3 things:

  1. Leave a comment at the bottom of this page so we can contact you if you win.
  2. Post this tweet or click the Like button on the Triumph product page or at the top of this blog post.
  3. Follow @audiofileeng on Twitter or Like Audiofile Engineering on Facebook.

Rules & Conditions

  • You may only enter once.
  • Make sure you use a valid email address when you comment so you can be contacted. Email addresses will not be made public.
  • Entries will be accepted until November 6th at 11:59pm EST and the winners will be announced and contacted by November 8th.

FiRe Microphone survey

Do you use an iOS external microphone?  We want to gather some general opinions on external microphone usage with iOS devices and which features are most important to you.  Even if you don’t use an external microphone, you can still share ideas on what your dream iOS external mic looks like.

FiRe Microphone Survey

The Future of FiRe

As we prepare for the launch of FiRe – Field Recorder 2.0, we’d like to know a little more about you, your previous experience with FiRe and your hopes and dreams for the future of FiRe! Please take a moment to fill out this survey:

The Future of FiRe

Burying Treasure

I’m a pretty cool-headed person, but a recent TED talk (and corresponding CNN article) by author and audio branding specialist Julian Treasure has me incensed. I’ve respected the TED talks for quite some time, but Treasure’s presentation on “10 things you didn’t know about sound” contains some awfully fuzzy “facts” and lots of misconceptions about sound. Being very sensitive to the subject of audio and sound, I’m compelled to debunk some of his more dubious assertions.

1. “You are a chord.”

It may be a nice way to imagine yourself, but this definition of a “chord” makes no sense in a classical or even musical context. Treasure’s only supporting evidence here is this quote: “the fundamental characteristic of nature is periodic functioning in frequency, or musical pitch.” The quote comes from a co-author in a paper presented at a South African music educators’ conference, and it deserves scrutiny. It’s basically saying that nature is a musical pitch. But listen to running water, listen to wind through trees, listen to animals bark or roar. There is no singular identifiable “musical” pitch, it’s simply noise. These are the sounds of nature. There is not one single plant or animal or natural phenomenon (outside of a natural whistle effect or an advanced animal language) that is capable of producing identifiable musical pitches. The “fundamental characteristic of nature” cannot be a pitch, nor can it be periodic. There are far more examples of natural NOISE than there are of natural PITCH.

The assumption of “matter being vibrating energy” to support his argument is equally ridiculous, supported by no actual evidence. It’s a fever dream of New Agers who want to understand string theory but don’t. I don’t truly pretend to fully understand it either, but I know it’s certainly not established enough to support an argument that people are musical chords.

2. “We see one octave; we hear ten.”

A cheap attempt to boost the importance of audio over visual stimuli. I would be surprised to find anyone who, if forced to sacrifice one one of their senses, would vote to lose their sight over their hearing. We may not sense as much logarithmically, but Treasure forgets dimensionality. We can sense more *dimensions* of the visible spectrum that we can of the audible spectrum, in addition to having a higher sensitivity to wavelengths in that range. We can gather much more information and sensitivity in the visible frequencies than in the audible frequencies, even though the range is smaller.

3. “Schizophonia is unhealthy.”

This is a made-up term for hearing one thing and seeing another. Almost everybody who listens to music, whether it be through headphones or piped-in through speakers in the elevator you’re riding, experiences this every single day. If it had any measurable detrimental effect, our society would certainly have noticed by now. His subsequent note about talking in a subway train (not to each other but into a phone, etc.) being an unnatural state and about silence being a more natural state has more to do with social sciences than with audio and sound. It may seem strange to see someone talking into “thin air,” but it’s something that we are going to have to get used to as a modern society.

4. “Compressed music makes you tired.”

This is one of the common complaints about modern music, but Treasure gets the definition of “compressed” twisted. The type of compression that does indeed tire your sense of hearing is a DYNAMIC AUDIO compression, where the “soft” sounds are nearly as loud as the “loud” sounds. Almost all modern popular music is created in this way so that a song potentially sounds “louder” than other songs. But the compression that Julian goes on to describe is the DATA compression inherent in MP3 and AAC audio file formats. Although they use psychoacoustic algorithms, these formatting-based compression techniques do nothing in terms of the dynamic changes that can tire your sense of hearing. True enough, modern music in general can tire your ears, but it has less to do with the digital makeup of your MP3 or AAC files than it does with the larger advent of digital audio.

5. “Natural sound and silence are good for you.”

This sounds all well and good, but the big question is: HOW? What does the absence of audible sound do to your brain, and is it only a healthy state to be in? I would argue that silence could have just as many detrimental effects as benign ones. Imagine someone who is without audible sound for months — someone in solitary confinement, for example. I would hypothesize that the lack of sensory input could send one’s brain off-balance, perhaps to a point of madness in extreme cases. Maybe that could be considered “overdosing” on the “healthy” aspects of silence. In any case, the assertion that silence is simply “good for you” is deeply oversimplified.

As for “natural sound,” well … what IS natural sound? As opposed to, say, *supernatural* sound? ALL sounds are natural to the extent that they are created and/or propagated by nature. If he’s talking about sounds such as wind blowing through trees or a rushing river as being “natural,” isn’t he countering his point about natural sounds being musical pitches, and that they are the most healthy?

6. “Sound healing”

Here, Treasure goes on to theorize that sound by itself can heal. We need a much more robust definition than that, simply because it can be severely misconstrued and misused, opening the door for all kinds of musicological quackery. For starters, we need to punctuate the difference between *sound* and *music*. Music is a cultural construct that the modern brain is trained to comprehend. Music can and does affect moods and thoughts. Using music to change moods and thoughts in the context of *therapy* is valid, but therapy and “healing” are not necessarily the same thing. Sound, meanwhile, can be defined simply as waves of air. These waves do nothing more to the body (at normal levels) than radio waves. Very high levels of sound can move the body physically, just like a strong wind. This is not inherently therapeutic, nor is it healing It’s simply physics at work. Using long tones as “shamanic and community chants” do is little more than meditation, and is not a cure for ailments.

Treasure has some interesting ideas, I’ll give him that much. But they need to be fully investigated and vetted before they spread around the general consciousness as some sort of sound-and-health doctrine.

A survey to serve you

In our ongoing mission to maintain attentive contact with our customers, we’ve created a short survey to learn a bit more about their/your communication habits. Please spend a couple of brief minutes answering these questions and help us determine how best to serve you. No personal login is required, and as always, every shred of information about our customers is kept 100% confidential. Thanks in advance for participating.

Audiofile Engineering Survey

Modern Guitar Festival Recap

Back in October, the second annual Modern Guitar Festival was held at the Cedar Cultural Center in Minneapolis, curated by musician Mike Michel. As described by Mike, it’s sort of a “mini-NAMM show” where guitarists, listeners, gearheads and fans of music or audio gadgetry can come together and check out some really cool stuff. Audiofile Engineering was proud to be a sponsor of this year’s MGF. In addition to giving attendees a hands-on introduction to stuff like ProTune, FiRe – Field Recorder and the MIDI Mobilizer, we got to mingle with some really incredible craftspeople from around the Upper Midwest and get a close look at their handmade guitars, tube amps, effects pedals and more. Our friends at Northern Outpost Media put together this video recap of the event. Check it out (especially if you’ve been dying to know what Matthew and I look like) and keep your eyes/ears open for news about next year’s MGF.


Mainstream Press!

photo by Emily Utne

The last time Ev or I (or any of us, for that matter) were written up in Minneapolis’ venerable City Pages, it was to talk about our various musical projects. However, last week we had our nerd coming-out party via a very flattering article on Audiofile Engineering.  We must admit that it’s nice to get some ink in a publication that our wives/parents would actually read and recognize for a change.

You can read the article here: