Frequently Asked Questions

  Q: Minimum OS requirements? 
  A: macOS 10.11 (El Capitan) or later
Windows 10 (build 17763) or later,but except Enterprise
>2.4GHz CPU with at least two cores
Must have stereo input and stereo output
Less busy multi-tasking workload is recommended.
  Q: How to install?  

The software is being distributed via App Store or Microsoft Store.
The best way to download and install the app is to use the OS built-in "Store" app (such as "App Store" on macOS or "Microsoft Store" on Windows 10+). A registered user account with Apple or Microsoft will be required to start with.

Although a transaction can be finished outside of the "Store" app, e.g.: via a Web browser, the actuall download/install has to be completed by using the OS built-in "Store" app. So, it is recommanded to do all the procedures by using the "Store" app. Do not try to download the app via a Web browser.

Related questions: Why App Store? Side-Load Possible?  Repurchase or renew?

  Q: Why App Store?  

Yes, App Store is frustrating.
For buyers, the registration procedure is overly cumbersome. For sellers,considerable amount of sales will be cut off, not to mention the restrictive rules for getting app approved there. Fortunately, there are also non-negligible benefits. App Store resolves many common problems of software distribution for both sellers and buyers, as enumerated below:
- Centralized and regulated marketplace
- Trusted/secured payment
- License management/transfer/sharing/revoking
- User account, invoice/receipt and tax
- Auto update of purchased apps
- Anti-virus
- Anti-piracy
- App search
- Download hosting & bandwidth, 24x7 availability world-wide

It's all about software distribution model. In the past, the Creditcard/PayPal and activation-key is used to be the traditional way which requires each software developer to pay administrative effort/overhead behind the scenes. The new MS/Apple Store eliminated the overhead, which allows small developers to focus more on development work without being often distracted by the retail hassles. Otherwise, if each software developer has to set up its own solution for providing the aforementioned services, the developer will be much distracted from developing/improving apps, until being saturated as a full-time sales. And the app's final price will be considerably higher due to the additional distribution overhead which has no contribution to the app's functionality & quality. Thus, the buyers may end up paying more for less, and the transaction may not necessarily be easier as it might seem -- imaging the concern of giving credit card to a stranger, filling in forms with personal information, manually typing in the received license key and dealing with activation errors email/phone...etc.

The decision may sound fancy/ridiculous at first, but the motivation behind it is a realistic compromise rather than a hipster idea.

Related questions: Side-Load Possible?    Repurchase or renew?

  Q: Side-loading possible?  
  A: Unfortunately, installing the app on a computer without going through the App/MS Store (aka: side-loading) is not supported because apps designed for App/MS Store are "sandboxed" by its technical root, which is not suitable for being distributed via the traditional way. Either Apple or Microsoft are enforcing sandbox technologies on their latest operating systems (macOS or Windows), which requires App/MS Store as the centralized software distributer. Developers are encouraged to adopt the new sandbox technologies for being more "future proof" into the new ecosystem, at a cost of losing backward compatibility with the traditional package based installation.

Related questions: Why App Store?

  Q: Too expensive?  
  A: Yes, this is surely not a life-changing app that everybody needs everyday. But it still requires comparable amount of time, efforts and knowledge to develop because niche needs are not negligible needs. It makes total sense for those who have been needing such a specialized tool for a long time, or completly the opposite for others. Nevertheless, if someone is willing to commit, would it worth being recognized?

Related questions: Too Cheap?    Repurchase or renew?

  Q: Too cheap?  
  A: Well, inexpensive ≠ inferior quality. The app is not an impromptu product, an academic demo or an experimental prototype. It is nothing lack of deep thoughts, scientific research, software engineering and originality. However, it is certainly not flawless and may contain bugs — like with any other software products including those high-profile apps. Perhaps, it is a poor product in terms of profitability. But the birth of the app would not happen if it was solely driven by commercial motivation.

Related question: Too Expensive?    Repurchase or renew?

  Q: For Win8/7/Vista/XP?  
  A: Unfortunately, this app is based on the new sandbox technology which is not backward compatible with Win8/7/Vista/XP.

Related questions: Why App Store?   Side-Load Possible?

  Q: For Linux?  
  A: Unfortunately, there is no plan to make a native app for Linux. However, the PC version of the app may work in VirtualBox on Linux. But Wine is not supported.  
  Q: Trial/demo version?  
  A: No,but with apologies. This requirement itself is natural, logical and fair, but can not be realized right away because staged license management costs too much overhead. It is not as simple as it looks like. Once the app opts in the new ecosystem, it follows the Citizenship Code there and wishes the system becomes more sophisticated and flexible in serving customers in future.

Related questions: Why App Store?   Side-Load Possible?

  Q: Is this app for me?  
  A: It's hard to say but here are a few self-test statements for assistance. If any one of the following statements is true, please consider it as a warring sign.

 - I'm looking for pro tools for my science research project.
 - I'm measuring data for convincing others more than just myself.
 - I'd like to configure a tool in every detail and do not mind managing complex settings.
 - I'm rather conservative in giving my trust to new software tools.
 - I can't tolerate more than 10 second time mismatch between two clocks at my home.
 - I prefer numeric readings over analogue gauge.
 - I prefer modern or futuristic GUI rather than retro control panel.

  Q: In which degree it simulates the real hardware?  
  A: It comes with both limitations and extensions.

- The performance varies depending on the actual sound card used.
- It may not be immediately ready for measuring absolute voltage unless a rather rigid calibration work has been performed (as described in the embedded user's guide).
- An average sound card can not measure higher voltage above 1.0V unless a physical attenuator has been added.
- The software measures everything with digital algorithms instead of analogue circuits, which may not necessarily give the exact identical readings as given by an analogue hardware instrument.

- THD at 1kHz in addition to only 400Hz
- Speed at 3150Hz in addition to only 3000Hz
- W&F in (W)RMS in addition to only Peak
- Spectrum analyzer
- Frequency Response plotting (White, Pink and Sweep)
- Lite Oscilloscope
- Lissajous display with slow-motion ellipse
- Advanced wow and flutter analyzer

  Q: Repurchase or renew?  

No, no periodical repurchase or renewal will be required after the initial purchase. The software is distributed with perpetual license (no time limit). According to the current Store policy (both MS and Apple), it can be re-installed on the same computer, or, installed on limited number of different computers — under the same account used for making the initial purchase, there will be no repeated charge. After installation, the app works offline — no network connection is required to keep it working.

However, the app is exclusively licensed by either MS Store or Apple Store, where app authors are not given a method to share or transfer licenses between the two separate ecosystems — although the the author wished so. As a result, a license acquired on Windows will not be transferable/extendable to macOS, or vice versa. Really sorry about that.

  Q: Is it a Pro tool? Why it is not for laboratory?  

No, it is not a tool for professional audio measurements, nor suitable for scientific research projects. This is by design. The app is intended to perform a set of pre-defined conventional audio tests in one go, but can't be configured in every detail to meet tight standards.

Like in many other technical fields, tools are typically classified into consumer-grade tools and pro-grade tools since it is unrealistic to satisfy all by one. Although each individual user's requirements varies more or less, it is important to understand that a software product is not an exception from the mass production model, which can only meet the "common" needs of the targeted user group.

This app is largely optimized/priced for consumer use. Most of the functions will work right away with the default settings for conventional purposes without requiring/allowing rich parametric configurations. Actually, a challenge in planning this software product was not what to include, but what to exclude. The original feature list was much longer than what has been actually implemented today. It deliberately excluded those "double-edged sword" power features that comes with heavy side-effects, hidden implications or requires steep learning curve to be used correctly. Although a hundred features means 100 opportunities for professionals, it also means 100 chances of potential mistakes for consumers. A consumer oriented software product with a busy UI (like a spaceship cockpit) would be stressful to use. While this app may be limited in flexibility, it may also be safer to use. Please be advised before going for acquiring it.

  Q: Can it compensate the sound card FR characteristics?  

No, not by default. A sound card may work in different modes (combinations of various sample-rate, bit-depth, channel layout, I/O ports ... etc.) at both input and output ends. Although FR compensation for a given mode is technically possible, managing multiple compensation profiles for different modes of the sound card will be an extra workload for non-pro consumer users and increase the chance of error by mismatch.

Instead, it is recommended to see and know the FR limitations/imperfections of the sound card before doing FR measurement. To do so, just loop back the sound output directly to the input and do a FR sweep with this app.

[Update] However, as of version 2.4.0 and later, the app comes with an option to scan the sound card for compensating its frequency response characteristics towards a flat line. It is not engaged by default and needs to be activated manually by the user with the awareness of all the implications.

As a side note, due to the Nyqvist law applied in practice, 44.1kHz sample-rate is not really ideal for measuring FR up to 20kHz. Using 48kHz or higher will be recommended.

Related questions: Is it a Pro tool?

  Q: Can it work with my gaming or pro sound device?  

It depends. The app works only with standard stereo input/output audio configuration. This is the typical and intuitive audio configuration for consumers. Advanced sound devices that come with different channel layouts other than the standard stereo will not automatically work. Channel re-mapping (to the standard stereo) will be required outside of this app, by using software tools provided by either the Operating System or the device manufacture.

Some gaming sound devices may come with built-in sound effects, some other entertainment sound devices may come with hearing enhancement filters, which will defeat the audio measurement purpose and impact the results. Those filters should be disabled before using any audio analysis tools including this app.

Related questions: Is it a Pro tool?

  Q: No sound or crash?  

The most likely cause is incompatibility of some (older) sound driver(s). An easy way to tell the case is to check if the sound card/device needs a factory provided software driver to work properly, especially if the factory provided software driver was made for older OS versions than current OS (even if it appears to work on the current OS). If so, a good way to further test the case is to temporarily replace the sound card/device with a another newer one that can automatically work on the current OS without needing a proprietary software drivers, or with a software driver designed for the current OS. For example, if it is an external USB sound device, try again with the built-in sound card if available, or vice-versa.

Technically, App/MS Stores are not only a new business model but also a new technical platform. Apps designed for the App/MS Stores are fundamentally different from the traditional apps. They are required to adopt the new generation of sandbox technology on each platform (macOS or Windows respectively) for being more "future proof" into the new ecosystem, at a cost of sacrificing backward compatibility with the traditional technologies. For some older sound cards/devices which have to rely on proprietary (factory provided) software drivers to work properly, if the software drivers already existed before the birth of the new sandbox technology, it may not be fully compatible with the new technology. In this case, apps based on the traditional technologies may continue to work without problem, whereas, apps based on the new sandbox technology may demonstrate problem, although all the apps are installed and tested on the same system.

So, one solution is to check if the sound card/device manufacture has published an updated software driver for the newer OS. If not, another solution is try to temporarily uninstall the old proprietary software driver and see if the new OS can recognize the sound card/device as a plug-and-play device and automatically install a built-in native driver for it. If so, using the OS built-in driver instead of the (older) factory-provided driver may have better chance to resolve the problem. However, please note that even the sound card/device can work with a built-in driver this way, it may lose some control or special features. It's a matter of trade-off after all.

Finally, the app assumes that the sound card should at least support the standard stereo mode by default. If the sound card is a PRO advanced card, or a theatre/game enhanced card with multi-channel setup, the user may be required to manually configure the channel layout in order to map multiple channels to the standard L/R stereo channels.

Related questions: Why App Store?   Side-Load Possible?

  Q: Resizable UI, or full screen?  

No, unlike a DAW app, this app is a panel-based app without document editing area. The amount of displayable information will not change according to the size of the window. The app is also based on several existing in-house utilities which had been well fitted for low profile computers. The benefit of a resizable UI may not be significant enough to justify the software re-engineering efforts and price increase.

However, the use can adjust the scale of the entire display as a temporary workaround.

Related questions: Is it a Pro tool?

  Q: Unexpected W&F spikes on some PCs?  

This is a known issue occasionally observed on some Windows PCs (not on Mac). The cause is that the new C# based audio programming interface keeps creating too many small blocks of memory for transferring audio data without reusing them, which significantly increases the workload of the "Garbage Collector" at the system level to recycle them. Normally, this is not a big deal, but the W&F algorithm in this app is rather computation intensive and easily interrupted by a busy CPU, which manifests as intermittent spikes (every few seconds) caused by the audio dropouts.

The technical solution is to replace the audio programming interface from C# based to C++ based at the deep lower level. This requires non-trivial work with unpredictable schedule. Before that, users are recommended to use this app on a relatively faster PC, and keep the workload of the PC as low as possible, for example, close other programs that are temporarily not needed when using this app.

[Update] Since version 2.4.8, the app is able to use WASAPI audio interface as the second option, which significantly reduced memory garbages. However, it is currently in experimental stage.

  Q: Why use systemwide input/output volume controls for calibration?  

Systemwide input/output volume controls are the native sound volume controls on the control panels provided by the Operating System. They are the master sound volume controls of the entire computer system.

In addition, each individual app may decide to provide in-app audio volume controls for the sake of convenience. This is a desirable feature for entertainment apps, but with considerable drawbacks for an audio measurement apps. as detailed below:

1) Input/output volume control can be implemented by hardware or software. A hardware volume control does not mean having a physical knob/slider on the sound card, but means a hardware-based volume control adjustable by program. Having a programmable hardware volume control is a desirable feature of a sound card because it can keep the ADC/DAC working in an optimal range for ideal resolution. Whereas, software volume control only works after the ADC and before the DAC which has no help to the ADC/DAC. The pros and cons of hardware versus software volume controls are pretty similar to the optical-zoom versus digital-zoom on a digital camera. While the former preserves resolution by scaling, the later does not. If a sound card supports programmable hardware volume control, it will be taken by the systemwide volume control UI at the first place. Whereas, an in-app volume control is typically pure software. So, using the systemwide volume control is always the first-class choice.

2) An in-app volume control works typically as a second & local volume control in addition to the global systemwide volume control. The combined dynamic range of such a two-staged volume control will be narrower than each individual one, which compromises the measurement range and accuracy, especially when one has positive gain and another has negative gain, or vice-versa.

3) While the systemwide volume control always plays important role, it is typically off the screen, hence, its value is invisible most of the time. If a measurement app does not provide an in-app volume control by design, the user will be encouraged to bring up the systemwide volume control for level calibration, effectively avoiding any unexpected implications.

4) Although some system technically allows adjusting the systemwide volume control inside an app. The side-effect of such a UX design is rather counterintuitive which may result in unexpected surprise in other apps running on the same system. Such a UX design is not adopted by this app.

To conclude, it is highly recommended to use the systemwide volume controls for doing calibration when using this app.

However, not all soundcards & drivers are equal. It is found that software drivers of some minority sound cards do not support volume control on the system control panel at all. For this exceptional case, the app comes with in-app input sensitivity and output gain adjustment. But please note, use this feature only when absolutely necessary for the exceptional cases.

  Q: Please recommend a sound card?  

Thank you for asking, but it's hard to suggest a specific sound card because there is no best one for everyone.

However, here are a few general criterias for selecting a sound card for this app:
(1) Choose a sound card that supports the version of your Operating System, especially with an external USB sound card.
(2) Avoid a sound card with only microphone input but no line-in input.
(3) Avoid gaming sound cards since they often come with unwanted sound effects.
(4) Choose a sound card that supports plain standard 2-channel stereo input/output by default. Avoid multi-channel PRO sound cards unless you are confident to manage channel remapping.
(5) If extended FR measurement is preferred (>= 22kHz ~ 26kHz), choose a sound card that supports 96kHz sample-rate.

Related question: No sound or crash?

  Q: How to keep updated?  

After installing the app, updates will be managed by the MS/App Store. With the auto-update feature enabled, the app will be kept up-to-date automatically whenever a new update is released. If auto-updates are disabled, a red marker will appear on the app's icon, prompting the user to update the app manually using the MS/App Store app.

Related questions: Why App Store?  Side-Load Possible?

  Q: Please check my order  

Always glad to assist, but please note that the MS/App Store operates differently from other online stores (e.g.: eBay). In this case, app authors do not have control over customer orders, their information and transactions are not visible to the app authors. To check orders, it's recommended that customers use the MS/App Store, or reach out to Microsoft or Apple customer service for assistance.

Related questions: Why App Store?  Side-Load Possible?  Repurchase or renew?