On Magic Beans "True Target": Dirac Live 2-Pass Procedure.

Sunset on summer 2026...

Ahhh, fall is coming and can be felt in the air here in Vancouver. At this time of the year, I get the compulsion to make sure I finish discussing topics I had examined in the summer and wrap up loose ends.

A couple of weeks back I discussed the Magic Beans Audio "True Target" app, an interesting program that I think can help improve sound quality for many audiophiles who use DSP in their rooms as a technique for "speaker correction" - that is, a system that flattens the direct sound coming from one's speakers above the modal and transition frequencies while respecting sensitive zones in the speaker response.

I mentioned near the end of the article about a "DLBC (2-pass calibration)" procedure. For completeness, I figure I'd give this a try and discuss in this post.

Magic Beans Audio: True Target. DSP correction fine tuning, concepts, and effects.

In my previous post, I discussed target curves and gave examples of curves you might want to consider when implementing DSP correction in your sound room.

While the use of full-range target curves is not uncommon, as discussed, there are those who advocate against doing so and would insist that only partial corrections in the bass frequencies up to the Modal+Transition Zones should be applied. There are of course some good reasons for this line of thinking which will be addressed.

As you can see in the comments last time, I had a long discussion with Joe Mariano (aka Joe N Tell) of Magic Beans Audio about his product called True Target. I continued my discussions with Joe via E-mail and he provided access for me to the Pro version which allows export of the curves to Room EQ Wizard in order to have a deeper look under the hood at how the system works.

The picture above was taken right before one of my measurement sessions with Magic Beans highlighting some "tools of the trade" used to perform the tuning.

Let's talk about the Magic Beans* True Target app. 

[Standard version regularly priced at US$249 should suffice for the vast majority of users, Pro version US$399 allows up to 128 channels and unlimited daily calibrations.]

Room Target Curves - then, now, and options to try...

Be it resolved that there is no such thing as achieving sonic perfection - technically at least based on objective ideals, but "perfect" can also be a subjective state of mind.

In domestic homes, we're simply not going to be able to achieve near-perfect rooms. Likewise, no sound system will be absolutely transparent although the digital electronics side will get much closer to "perfect" than analogue playback and loudspeakers. Furthermore, beyond what we can say about our domestic playback systems, despite all the care and detail-orientedness put into a recording studio, they're not identical even if they followed published standards (like ITU-R BS.1116, or EBU Tech 3276), and besides, is there ever such a thing as a perfectly engineered recording? Or a perfect performance from our favorite artists for that matter?

While perfection might be out of reach, let's not turn away from the pursuit of what is reasonably accurate which is something we can all do to some extent whether it's choosing better-engineered gear, working on small room acoustics, or using DSP to improve frequency response and/or time-domain performance at our listening position. Regarding the specifics of DSP room correction, let me refer you to previous articles covering various methods here, here, here, here, and here.

The intent of this post is to focus on the topic of Room Target Curves which we define and apply when doing EQ and DSP correction. Let's explore a little history, what they are, what they look like and considerations for what to try at home.

miniDSP UMIK-2 USB measurement microphone (also ambient noise floor, measurements of my system using Dirac Live with Paradigm + SVS subs)

Well, as mentioned previously, it was a great holiday season and here's another gift from Audio-Santa 🙂 - the miniDSP UMIK-2 measurement microphone. I bought this through Solen.ca here in Canada and they did a great job with the order and quick shipment. Amazon Canada often has limited stock of miniDSP products.

I'm sure the miniDSP company is well known to many audiophiles at this point. I bet many of you, like myself, already have one of their UMIK-1 microphones which I've used in a number of the acoustic measurements on this blog since 2019.

As you can imagine, the UMIK-2, initially released in late 2020, is an evolution of the UMIK-1 with upgrades which we'll talk about. First, let's have a peek at the physical device itself.

Linn's SPACE Optimisation DSP feature for their DS/DSM digital audio streamers. Does it even work?

Linn Klimax DS/2 streamer getting tested.

A couple months back while evaluating the Linn Klimax DS/DSM streamers, I mentioned that the products have the capability to implement what Linn calls "SPACE Optimisation" (Speaker Placement And Custom Environment, we'll call it SO for short); available since 2015. Because the products are network-connected, they're always online and through the Linn Account webpage, you can check the settings for your streamer and activate the SO function.

I remember being intrigued by this function and the claims of significant room-correction capability. For this post, let's take some time to explore what Linn SO features. To start, here is what their literature says about the intent of the system:

Space Optimisation is a toolset available to all Linn DS/DSM system owners which uses highly sophisticated acoustic modelling to build up a complete picture of how your speakers, their placement, and the unique characteristics of your room interact to affect the sound you hear. Space Optimisation takes account of the characteristics of your speakers, such as the position of each drive unit and the response of bass reflex ports, and of the characteristics of your room, such as room dimensions, construction materials, and features like doors and windows, to accurately model these interactions. It then precisely identifies frequencies that are artificially distorted by your environment, and reduces their energy and decay time, to reveal the music that would otherwise be hidden. It also applies a delay to each speaker to ensure the content from each speaker reaches your ears at the same time.

Dirac Live 3 with Bass Control (DLBC): A look and listen with the Integra DRX-8.4.

I talked about the use of Dirac Live 3 in late 2024 after upgrading my receiver to the Integra DRX-8.4 which integrates the full-bandwidth DSP room correction as part of its feature set. Many modern multichannel receivers these days have Dirac as a feature included like the Onkyo TX-RZ70 or Pioneer Elite VSX-LX805 (both offering 11-channels amplification like the Integra). I have to say that I love this Integra unit with all its multichannel bells and whistles - not to mention great sound as well, of course.

I mentioned in the previous article that Dirac Live Bass Control (DLBC) is available as an upgrade for US$299 which activates the license on your account when you run the Dirac Live Room Correction Suite, unlocking the "Bass Control" module.

So, let's activate that and get into this with a look and listen to what DLBC brings to my set-up and of course some results in my room. (For reference, here is the official DLBC manual, and Dirac's Frans Rosencrantz's 2020 article "Bass Control, Where Did My Bass Go?".)

Dirac Live 3: A look & listen with the Integra DRX-8.4 - the process, microphone placement suggestion, tweaking, and multichannel/Atmos results.

As discussed years ago with my sound room set-up, I believe room correction DSP is very important and has become part of my routine whenever I make significant changes in room layout or when I incorporate new equipment. I would argue that an audiophile who has not seriously spent time trying this likely has not heard the best sound in their room from their system. Simply put, you'll notice a level of control and audible difference way more than just swapping hi-fi DACs, amps, etc. hardware.

With the arrival of the Integra DRX-8.4 receiver recently, I started using the included Dirac Live Full Bandwidth license embedded in the hardware. As I had done in the recent past with Acourate and Audiolense XO, let's dive into the steps I used to get Dirac running and the results I achieved. Hopefully this discussion could be useful for those of you thinking of trying out Dirac.

I'll document the steps I followed, issues I ran into, and tips to overcome problems.

The Dolby Atmos Music Target Curve. And on being an audiophile "tonmeister".

[For the post this week, let's take a pause from the Pacific Audio Fest 2024 discussions (last 2 weeks). Next week we'll have a Part III discussion about audio shows.]

Standardization is generally good.

I've discussed in previous posts that Dolby Atmos defines loudness characteristics for recordings and this has helped preserve dynamic range in multichannel/Atmos albums following their guidelines. Likewise, we can benefit from standardization of the frequency response as this will allow us to better "translate" the sound from the studio into our sound rooms. This idea is not new for audiophiles. The ill-fated (with good reason) MQA promised that we could experience the "sound of the studio", but they never could deliver in a large part because there was never any standardization for essential parameters like the frequency response, among other failings. In the same way, back in the day (~2014), this was the promise of hi-res audio by Neil Young and Pono that you would somehow get the "finest digital copy" and this would represent the sound the artists intended from the studio; clearly they overpromised and under-delivered by 2015.

It's one thing to standardize between the studio and home ("inter-system") playback, but it's also important to standardize "intra-system" - that is, between all the speakers in your set-up when you're doing multichannel such that each speaker is calibrated to the same timbre. This is important in a multichannel layout since we do not want "objects" moving through space changing tonality because of mismatch between speakers around the listener. The Dolby Atmos Music Target Curve is Dolby's recommendation for the music studio frequency response. This curve evolved from the X-Curve, an 'X'perimental frequency response based on some early empirical work exploring the performance of actual theater sound systems starting in the 1970's, and evolved over the years. See this paper for more details, note some similarity of the Dolby Atmos Music Target Curve to the SMPTE 202M - 1998 X-Curve.

As with all things in audio, nothing wrong with asking whether this curve is the "best". 🤔

AudioVero Acourate v3.1 - room correction with bass pre-filtering and Inter-Channel Phase Alignment (ICPA).

After writing the post on Audiolense recently, I thought it would be good to have another peek after a few years now at AudioVero's Acourate (€416 non-EU countries); the latest version 3.1 released in June 2024.

For years, Acourate has been the room-correction filter toolbox I've used (at least since 2016, updated 2019, plus discussion on partial correction in 2021). Now that it has been half a decade plus a pandemic (!) since the step-by-step 2019 update, let's look at the latest version which has brought with it changes in the user interface as well as the Inter-Channel Phase Alignment (ICPA) feature released in version 2 which I had not discussed previously.

Before getting started, a big thanks to Mitch Barnett of Accurate Sound for his YouTube video a couple years back using Acourate 2 showing the technique around pre-filtering and ICPA. I've taken inspiration from his video, applying it to my home set-up, and converting those steps into a written blog format for the current Acourate version. If what I'm doing here is not clear, make sure to also check out the video since Mitch might have already covered your questions/issues there.

Let's get started!

Seating variations, multi-seat correction & multichannel DRC. The audio "sweet spot".

A look at the rear of my room and the sofa seating - surround speakers, LP rack for a little bit of diffusion room treatment. For best practice, it's important to not sit too close to the back wall. I have 3' between the couch and the LP rack, and the rack is about 17" deep before that back wall. 

Before putting the UMIK-1 microphone away after using Audiolense XO as discussed last time, I thought it would be interesting to explore in greater detail what happens with frequency response and time-domain performance as we sit off the "sweet spot" where the measurements were collected and correction calculated for.

In the image above, I've put a meter stick on my listening couch to identify the seating positions 1 and 2-feet to the right and left of that sweet spot so I can take detailed measurements of what happens to the sound coming from the 5 main speakers at those positions with and without DSP turned on.

Multichannel Digital Room Correction with Audiolense XO. And "What's your budget?".

As you might recall from over the years, I strongly believe that one of the most important things one should try as an audiophile seeking high-fidelity - after having a decent sound room, and getting good equipment - is to consider the use of room correction. It could be as simple as frequency-domain EQ correction for larger bumps and dips (as discussed with the Behringer DEQ2496 hardware back in 2013-2014, device measurements here), or the much more sophisticated frequency and time-alignment of filters created by software like AudioVero's Acourate (and 2019 update) capable of much higher resolutions.

The power that one has to optimize and customize the sound runs well beyond most hardware upgrades other than wholesale speaker replacements and changing sound room! The change one can expect with room correction dialed in is astronomical compared to all the snake oil tweaks, cables, hi-res DAC/streamers, even amplifiers you might want to throw at your system.

These days, I've increasingly been converting multichannel content over to my Roon server, typically 5.1 SACDs and DVD-As but also Bluray rips, ideally lossless TrueHD with 7.1 channels. Unfortunately, Roon is currently unable to decode codecs like EAC3-JOC (lossy multichannel/Atmos) or TrueHD (lossless, based on the MLP codec) so the content typically gets transcoded to multichannel FLAC-compressed PCM which can handle up to 7.1.  

Although Acourate can be used for multichannel filter creation, the manual procedure here is unfortunately quite involved and more than most audiophiles would like to get their hands dirty with! Which is why today's post is going to be about multichannel digital room correction using Juice HiFi's Audiolense XO (€390, currently version 6.21). I see that there is the less expensive Audiolense Surround which I suspect could be enough for many users, and if all you need is 2-channel stereo, there's Audiolense 2.0.

Accurate Sound's Hang Loose Convolver Multichannel on low power Mini PC. The disgraceful AQVOX ethernet switch. And some E1DA upcoming evaluations.

Over the last few weeks, I've been using the inexpensive Beelink Mini S Intel Celeron N5095A PC in my music system. Recently, I posted on using it in Linux as a streamer with HQPlayer upsampling and for multichannel Roon capabilities. As you can see in that post, for audio purposes, even this level of CPU performance on a modern entry-level machine is enough for what would be advanced PCM upsampling (ie. 1M-taps realtime PCM) and even IMO very good PCM-to-DSD256 performance. More evidence to remind us that there's generally no need to get excited about some of the more expensive "audiophile" computers and streaming machines which are often embedded low-power computers at heart.

Recently, my friend Mitch Barnett of AccurateSound.ca wondered if I could look into the performance of his latest version of Hang Loose Convolver (HLC) with this low-power computer using my power limited and quiet fan BIOS settings. HLC is an advanced standalone, VST3 plug-in, or AU (Mac) plug-in that provides the ability for audio lovers to load in various convolution filters, allows for easy level matching, and provides basically immediate switching (0.1ms) between these filters for accurate A/B listening comparisons. Let's take a look at this on the Beelink.

SUMMER MUSINGS: Room EQ Preferences - Vintage Spendor SA1-like curve, Hang Loose Convolver (HLC), and the increasing relative importance of software.

Getting ready for an evening of digital filter evaluation!

I mentioned a few month back in my Spendor SA1 (1976) review/measurements that I really enjoyed the sound of these classic speakers!

While it would not be possible to exactly replicate their sound - these are complex devices with all kinds of unique properties including distortion idiosyncrasies and unique radiation patterns - to some extent, we can try to replicate the frequency response via DSP.

These days, we have the technology available to modify the sound we hear in the soundroom without great difficulty; the trick is to make sure the sound has improved, at least subjectively, when we add things like EQ or applied other signal processing.

Although some (typically more traditional) audiophiles will speak of maintaining "purity" of sound with minimalistic set-ups, if one is a contemporary technologically astute music lover and audiophile, especially one already using complex streamers, computer gear, networked libraries, I don't believe there should be any fear in going all the way using high-quality DSP to shape and adjust what we hear. In fact, from the frequency response perspective, we can "emulate" almost whatever we might want depending on the flexibility of the software used.

HOW-TO: Partial Frequency Correction with Acourate. Spotify HiFi coming and a look at the evolution of music sales/formats from 1980-2020.

[See Addendum update as of Acourate 2.0.]

Over the years, I've discussed the use of DSP room correction in these pages (here and here for the more recent articles). In Acourate, there's no single-step macro to tell the software to limit the correction to certain frequencies as far as I can tell. Instead, I saw this comment by Dr. Uli Brueggemann in one of Mitch Barnett's early articles (2013) hinting at a way to modify the inversion step of the filter to accomplish that task. This post is a step-by-step procedure for those interested in doing just such a thing with the software.

Note that even though I'm showing the process here, I'm certainly not suggesting that it's necessary whatsoever. In my listening, a full-spectrum room correction sounds great with the frequency-dependent-windowing (FDW) algorithm Acourate uses. Over the years with friends and family who have had the time to sit and listen, I have never had anyone complain that my usual full-spectrum filter did not sound better than the uncorrected sound in my room (and on occasion, I have measured and applied DSP to my friends'/family's sound systems as well to similar effect).

It's always great to have options though!

SUMMER MUSINGS: The Soundroom - speaker layout, vibration control & correction. (And importance for the subjective reviewer!)

I thought before summer's over, it was time to "shoot the breeze" again and talk generally about a very important topic that affects all of us audio enthusiasts with what I hope are some practical suggestions from my own "journey" here at home.

The image above of a room set-up came from an article back in 1960 entitled Room Acoustics for Stereo by Abraham B. Cohen (Electronics World, January 1960 - make sure to also check out Part 2 here from February 1960). This was a time when many homes were still transitioning from the monophonic single-channel era to the bold new world of stereophonic "3D" playback with an opportunity to virtually experience an actual soundstage in the comforts of the living room. Those must have been exciting times, perhaps comparable in my lifetime to the late '90s with the release of AC3/DTS receivers providing discrete multichannel home theater.

As you can see from the pair of articles, already back in 1960, the groundwork had been laid out for what constitutes conditions for good "stereorama" sound. Best practice tips to achieve a sense of realism, the variables related to speaker placement in a room, angles to target for from the sweet-spot, distance between speakers and orientation like toe-in. Room characteristics like absorption characteristics of materials, reverberation time, room layout were discussed as well; all this informed by decades of professional recordings and studio design that came before.

MUSINGS: "Which measurements matter?" Importance of considering the complete audio chain. And a listen to room DSP filters...

Very busy these last few days so I thought let's address an interesting discussion question I've seen over the last while about measurements and audibility. Here's a forum comment from tapatrick over on Audiophile Style the other day:

I think you have done a good job in your blog post of covering all the relevant areas involved from music production to listening. And maybe the conversation is now concluded. If only everyone would acknowledge and respect each others 'intent' as you put it then there would be a lot less misunderstanding. I am none the wiser which measurements matter but I have to say I'm now clear that measuring and analysing equipment outside of listening leaves me cold. I will leave that to others more qualified but I will keep an eye on developments...

Visiting an audiophile friend: Avantgarde UNO 2.1, KEF LS50, Tannoy 501A, and Spendor SA1. Merry Christmas & Happy 2020's...

[2020-01 - Update... The active Tannoy speaker was originally listed as the "401A". In fact it's the "501A". Text and graphics changed...]

One of the joys of writing an audiophile blog is the opportunity to meet some interesting people in this hobby over the years! Here in Vancouver, there's no audiophile special interest group or club I'm aware of. As a result, connections are made through receiving E-mails or private messages once awhile by locals to hang out, check out gear, and listen to tunes together...

After meeting up in person a few months back, I paid one of these local audiophiles (who shall remain anonymous :-) a visit at home to check out his main system:

As you can see, he's got quite the pair of speakers and clearly his wife is highly accommodating to his audiophile "needs" ;-).

2019 Update: Basic Acourate DSP Room Correction (using Dayton Audio EMM-6 mic, and other related bits...)

As I mentioned last time, I changed the tweeter in one of my speakers resulting in a significant adjustment to the frequency response in the 2-5kHz range. This means it's time to update my AudioVero ((acourate)) (current version 1.9.12, 286€) room correction filters for late 2019. Looking back, I haven't posted on this since 2016! My, how time flies.

Given that it has been awhile, picking up Acourate again for some measurements required that I dig out my old notes and review the previous procedures again. As such I figured that it was time to write an update for a reasonably "quick and dirty" measurement which basically took me an afternoon to perform with excellent results. If you've tried Acourate, you'll know that this program is very powerful but can take a bit of time to figure out the interface and get comfortable with the process.

Okay then, let's get going with a quick but detailed summary while it's fresh in my mind and provide some pointers the next time I might have to do this again maybe in a few years :-). We'll then end this post with a few other related subtopics that came out during the measurements...

MEASUREMENTS: Digital Room Correction with AudioVero's Acourate...

A few months ago, I posted on the use of the free DRC software for audio room correction. I was already very impressed with what the technology is able to accomplish and wanted to explore this even further. In this spirit, I invested in a copy of (((Acourate))) from AudioVero. As I had mentioned previously, there are a number of other software/hardware packages to accomplish a similar task. While I'm sure other packages would do a fine job, as a JRiver user, I wanted to create WAV-based FIR filters like I did previously with DRC which I could import into the convolution DSP and Acourate allows me to do just that without needing to run any other plug-in.

Acourate isn't inexpensive and does cost 286€. However, realize that we are entering rather "specialized" territory and although I suspect many audiophiles know about FIR-based room correction, it's not exactly mainstream (for example, how often do showrooms at audiophile shows utilize room correction DSP?)... Personally, given the amount of potential improvement, we could easily spend 286€ (~$310USD currently) on stuff like fancy cables and other tweaks achieving likely no actual improvement in sound quality.

MEASUREMENTS: Sound Room Update, Digital Room Correction (DRC) and JRiver DSP Studio...

Many years ago, back in 1992 to be precise - the year Windows 3.1 was introduced, when the typical PC was running below 33MHz, and Mortal Kombat 1 was hot in the arcades - I vaguely remember reading this article from Stereophile and filed it in my memory banks as something from science fiction for another day (I heard my first MP3 compressed song soon after and thought it was amazing given the data compression!). In it, Peter W. Mitchell reportedly "heard the future" and was clearly impressed by the technical wizardry of what a "Digital Signal Processor" could accomplish. The power of the digital room correction was described as "mind-boggling". If you haven't thought much about digital room correction, I would highly recommend reading that article in its entirety and consider whether the arguments make sense to you. I don't recall reading anything further about AudioSoft or whether Snell eventually created this cartridge-based "black box" audio correction system, but as we fast forward to 2015, we are living the legacy of what was described.

These days, DSP techniques are commonplace. As digital has long supplanted analogue as the preferred method of encoding our audio and video media with high fidelity, it has all become data that we can examine and modify as we desire depending on the situation. Compress to MP3 for times we don't need highest fidelity? No problem... Resize from 1080P to 720P for the cell phone screen/storage? By all means!

Explicit uses for improving audio quality include audiophile offerings like DEQX and Lyngdorf (including McIntosh MEN-220), some products like the Devialet amps include their "Speaker Active Matching" correction filters, and the home theater crowd have been using Audyssey and the like for years.

It is interesting these days then that DSP room correction is primarily the domain of home theater and AV receivers, rather than high-end audio. In fact, reading certain "high end" audio forums suggest a stigma against DSP techniques to improve the sound of an audio system. Among audiophiles, it's not unusual to see suggestions around listening to tubes, turntables, and vinyl LPs as providing some kind of elevated audiophile experience, but I've ironically experienced the cynicism when you bring up the idea that digital room correction is important if not essential as a very desirable way of improving the high-fidelity experience.