My honest review of Acourate

[Keith_W]

I have been using Acourate for slightly more than two years now, and I think I know enough about this software to write an honest review. If you can't be bothered to read the entire review, this is it in a nutshell: it offers unprecedented power, allows you to do nearly anything you can think of, but is severely limited by pointless interface issues that slows you down and makes learning it difficult. There is almost zero automation, and doing simple tasks requires multiple repetitive actions that you have to perform over and over again.

 

I will not go over what Acourate can do because it has been covered by Mitchco here and by Archimago here. Suffice to say it offers everything that I can certainly think of - crossover generation, individual driver correction, driver time alignment, IACC measurement, pre-ringing compensation, and overall room correction. There are even some people who have used Acourate to create a virtual double bass array (also see Red Spade Audio description here). What you can do with this package is only limited by your skill and the computing power you have available. If you use a third party convolution engine like HQPlayer, it is possible to "max out" the settings by using a 192kHz .WAV file, convolve in DSD512, use very long FIR filters, and do it in 8 channels. My PC (which was no slouch at the time it was built) isn't powerful enough to run all the settings maxed out unfortunately. 

 

All the reviews I have read so far are typical of audio reviews - they are universally glowing, and very rarely point out the shortcomings of the product. Some of these shortcomings can be real dealbreakers (e.g. did you know that Dirac ONLY generates filters in its own proprietary format which can not be exported, so the ONLY convolution engine you can use with Dirac is its own!). Fortunately Acourate allows you to generate filters in .WAV format or its own proprietary .CPV format in a number of sampling frequencies from 44.1kHz all the way up to 192kHz so it doesn't suffer this particular limitation of Dirac. 

 

The major problem with Acourate is the interface. 

 

One example: creation of a full set of filters requires four steps - 1. Create the basic crossover, 2. Convolve the crossover with your previously measured driver response (if you haven't done this, add another step), 3. Measure pulses and adjust the time delay (you have to do this manually by looking for the peaks yourself), 4. Perform overall room correction. Each of these steps requires creation of a separate folder, copying of the previously generated filters into the new folder, and then you have to change the working directory to point at that folder. Add all this up for an 8 way system and there is a tonne of unnecessary mouse clicks and work. For me to generate a set of new filters takes me a couple of hours easily. 

 

I would suggest the author do this: the author of Acourate should realize that most people do not change the configuration of their systems very much once it is in place. For example, if you have a 2 way crossover, you will not be changing this configuration every week (e.g. 2 way this week, 3 way next week and then back to 2 way). When you open your new copy of Acourate, it should invite you to perform a series of individual driver measurements which it can save somewhere safe. This is what most of us do anyway. It can then use all these measurements to generate whatever crossover you want, all you need to do is to specify the details of the crossover. This alone would merge steps (1) and (2) above and save about 30 minutes of opening and closing files, copying into new directories, and so on. 

 

Another example: loading pre-saved measurements or crossover curves. You select the radio button that you want to load it into. Then "File - Open", and it opens into the active curve. If you accidentally fail to choose a new radio button, then the newly loaded file will over-write your current curve. It would be much easier if every curve you load automatically opens in a new chart. And if you want to close a chart, you have to select the radio button to activate the chart, then go "Edit - Close". Why not do what other Windows programs do and have an "X" which will close it down immediately? Why is there a limit of 6 charts that can be open at any one time? This limit means that you have to open and close charts multiple times just to create a filter for a single channel. I would suggest that an interface like REW's (where the curves are presented in miniature form in a pane on the left) would be the easiest way to do it. 

 

The other problem with Acourate is the lack of automation. If you want to perform time alignment, this is how you do it: 

- Generate a four way crossover (XO1, XO2, XO3, XO4)

- rotate XO1 by 0 samples

- rotate XO2 by 1000 samples

- rotate XO3 by 2000 samples

- rotate XO4 by 3000 samples

- perform a measurement sweep 

- create a dummy XO and rotate XO1 by 0 samples, XO2 by 1000, XO3 by 2000, etc. 

- Zoom in to sample 0 and note where the measured peak is compared to where it should be. You do this by selecting the sample that you want, then typing in the magnification that you want in the little boxes on the y-scale (it would be far easier if you there was a shortcut, e.g. in photoshop you hold down the ALT key and drag the mouse). Write this down. 

- Repeat for XO2, XO3, and XO4, but each time with different magnification 

- Go back and adjust XO1, XO2, XO3, and XO4 by the number of samples that you wrote down earlier. 

- Repeat all the above steps for the other channel. 

 

This procedure takes an hour, easily. We could save an hour by getting the software to perform the rotation and look for the peaks itself rather than requiring human eyes and lots of repetitive effort to do it. 

 

My other criticism of Acourate is that it is rather opaque. The menu system does not make sense to me, and some of the menu options are written in engineer's German English (e.g. why use "Project Workspace Definition" when it is easier and clearer to use "Active folder"; or "Rotation" which actually means "Adjust time delay"). This unnecessarily steepens the learning curve. 

 

And the last but most important problem: there is no manual. There are other resources (see below) but there is no manual. 

 

For all these reasons, Acourate is nearly impossible to use if you are a beginner. When I started using Acourate, I already had some experience creating digital crossovers and using DSP but even with that background I found it impenetrable and was not able to do anything. Even now, having used Acourate for a couple of years, I suspect there is even more functionality that Acourate can provide which I have no idea of because the interface is so obtuse and the labeling is so difficult to understand.

 

Purchase of Mitchco's eBook is mandatory, but I have some criticisms of that book too. The main one is that it does not explain all the options available in Acourate. I suspect there is a lot more that Mitch knows but did not put in the book in order to keep it shorter and more readable. For this reason I have been crossing my fingers and harassing him in PM's for a second edition of the book which alas I feel is not going to happen now because he seems to be more interested in Audiolense these days. 

 

Your other option for help with Acourate is to look at the Acourate Wiki, but as far as Wikis go this one is quite incomplete and is nearly as opaquely written as Acourate itself. But if you know what you are looking at, it will fill in some things that Mitch's book does not tell you. 

 

Your last resort is to ask Uli himself in his own forum, which is a Yahoo group frequented by a number of other knowledgeable and helpful Acourate users. I have asked many questions on that forum, and I find it genuinely useful and a fantastic resource. Unfortunately, it is a closed forum and you require approval to join. Yahoo groups isn't a great way to communicate and it would be much better if Uli used conventional forum software like VBulletin like everybody else. I think that Uli could spend less time answering questions in that group if the interface were redesigned and he wrote a better manual in the first place. 

 

In short: Acourate is an extremely powerful toolbox which is limited by its interface and its insistence on boring, unnecessary, and repetitive tasks that really should be automated or simplified. It takes me hours to generate a new set of filters when I am convinced it could be done in less than half that time if the interface was redesigned. I know that asking for an interface redesign is not a small task, but Uli needs to realize that the interface is creating problems for users by needlessly increasing workload and making navigation difficult. I doubt if he would redesign the interface, so I haven't bothered asking. For this reason I am going to move away from Acourate and try something else. 

[Kal Rubinson]

2 minutes ago, Keith_W said:

(e.g. did you know that Dirac ONLY generates filters in its own proprietary format which can not be exported, so the ONLY convolution engine you can use with Dirac is its own!)

Thanks for all the interesting commentary on Acourate but I have to ask about this minor point.  Dirac can/does generate VST-compatible filters which I run with JRiver.

[dziemian]

I am also using Dirac's vst plugin with Jriver. I wish Dirac had a crossover capability. I am staying away from Acourate because the reasons you wrote about.

[Gadgety]

Thank you, Keith_W for your succinct summary and review of Acourate. Great suggesting improvements which could broaden the appeal of a technically superior product. Because of its complexity, and the user being dependent on the creator to have the full benefit, the product is extremely vulnerable. For example should the creator fall ill, where does that leave the user?

[mitchco]

Even with the book I wrote, which covers several acoustical topics other than Acourate, just scratches the surface of what Acourate can do. It is a professional's digital audio toolbox for Digital Signal Processing (DSP). It makes the assumption that one understands DSP. Meaning one has had College/University level training in DSP or is a DSP professional in the industry. Uli's toolbox contains virtually every filter function one can use for DSP audio.

 

The quality of Acourate and especially the quality of the filters are top notch. The book I wrote is complete in the sense that it covers virtually all aspects of using Acourate for DSP'ing ones loudspeakers and room. It provides a repeatable process for digital XO's time aligning and linearizing drivers, smoothing the frequency response at the listening position plus excess phase correction. This covers 99% of the usage scenarios for anyone wanting to use DSP for loudspeaker and room correction. There is even added sections on advanced acoustical measurment techniques like beamforming .

 

So Acourate coupled with online tutorials, articles here on CA and elsewhere, Acourates Wiki and support forum, plus my book should have everyone covered. Of course there are edge cases, but that is why Uli provides excellent support, along with the forum with very knowledgeable members.

 

With that said, I highly recommend Acourate if you have a technical background and even if you don't, there are many helpful resources that would guide you through designing and generating  top notch FIR filters. There is some level of automation in the tool for basic loudspeaker and room correction and after a few tries, should take one 30 minutes from setting up the measurement mic to listening to music.

 

If you are looking for a more automated approach, with the capability of digital XO's and other features that don't exist in other DSP toolsets, then I recommend giving Audiolense a go, in which I wrote a CA article on. I can say that the filters generated by Audiolense are as good as Acourates, but comes with more automation. I have another upcoming article using Audiolense to integrate subwoofers with mains.

 

Finally, there will absolutely be a 2nd edition of my book expanding on what currently is there, plus the addition of other DSP software that I feel is on par with Acourate from a SQ perspective. 

 

Folks, designing your own custom FIR filter for your specific loudspeakers in your own listening environment is something that one could not even do 10 years ago, let alone making available to consumers. The power of today's DSP software is extremely sophisticated and does take some time and effort to understand what is going on, how to apply in order to deign and generate good sounding filters. However, software like Audiolense can have one designing a complicated multi-channel digital XO filter and be listening in to the excellent results in 30 minutes. It doesn't get any better than that.

 

Feel free to reach out to me via PM is you have any specific questions.  Enjoy the music!

 

Kind regards, Mitch 

 

 

[Gadgety]

6 minutes ago, mitchco said:

Finally, there will absolutely be a 2nd edition of my book expanding on what currently is there, plus the addition of other DSP software that I feel is on par with Acourate from a SQ perspective. 

 

 

 

Great Mitch! Any timeline on that?

[mitchco]

Hey Gadgetry, not yet. I am still evaluating which DSP tools will make the next Edition. Also, I have been collecting feedback from the community to see which DSP features provide the most interest for the majority of folks. I have a list from Keith, but also looking for common goals. For example, subwoofer integration is high on the list for many folks...

 

Is there something specific you are looking for?

 

Kind regards, Mitch

[Keith_W]

Hi Mitch, thanks for posting in this thread. Do you know of any good resources to learn more about DSP besides the book that you wrote? 

[mitchco]

Hi Keith,

 

A good one is The Scientists and Engineers Guide to DSP: http://www.dspguide.com/ which you can read online and download the chapters.

 

Another is: https://ccrma.stanford.edu/~jos/ Especially the Introduction to Digital Filters.

 

A list can be found at: https://dspguru.com/dsp/books/favorites/ and DSPGuru is good in its own right.

 

Hope that helps.

 

Mitch

 

 

 

 

[pompon]

I don't understand how you get confused at this point.

 

Align microphone with acourate tool require seconds only.

Generate filters (4 way) is less than 1 min.

Mesurement is 60 sec

Run the 4 macro is less than 60 sec

 

 

[aps]

On ‎2‎/‎04‎/‎2018 at 8:19 PM, Keith_W said:

For this reason I am going to move away from Acourate and try something else. 

 

How are the investigations of other options proceeding?

[Keith_W]

Come to a halt for now. I am doing some extra work to buy new toys

[LewinskiH01]

I find Acourate great: works very well, very flexible, and not very expensive. Sure it requires you spend time to learn and ask questions to figure things out...but isn't that discovery process part of the fun? It is to me. Just like learning about building speakers.

 

Per Mitch's article I looked into Audiolense, but it's a lot more expensive.

 

I have found Uli and the Acourate forum members very helpful. And I certainly have no DSP school training.

[LX521]

I wish Acourate had a batch mode like Matlab, where you could replay the Acourate history file, for example, after re-editing it. In fact I am starting to use Matlab instead to create filters for xovers. Its been 30 years since I used Matlab, so I am a bit rusty.

[hvbias]

Thank you for the balanced review Keith. Do you have any plans to try Audiolense? I have tried finding pros and cons between the two software but have not been able to find much.

[StreamFidelity]

Many things written here are correct. In a simple stereo setup, however, Acourate is no higher science.

 

I measure once or twice a month and adjust my room correction. Because I enjoy it and it works fast. In contrast to many other applications, one measurement is sufficient. The process is always the same for me:

 

1. Use microphone alignment for centering the microphone.
2. LogSweep Recorder is the measurement program. Be sure to include the microphone calibration file.
3. Check the reverberation time. If the reverberation is too big, experiment with dampening materials. For example, carpets have helped me. Further acoustic optimizations (eg hanging blankets) are not possible. It is and remains a living room.
4. Check IACC Interaural Coherence (will be displayed at step 2). For me, changing set-ups of the speakers and the chair, as well as clearing away obstacles (footstools, fountains, etc.) helped.
5. Room Macro 1: Use Amplitude Preparation to smooth the frequency response. I use the default Psychoacoustic. Some find sliding better, because less smoothing is done.
6. Room Macro 2: Use Target Curve Design for your favorite sound. According to my previous experience, the success of the room correction stands and falls. Who just thinks to use the default setting (linear frequency response) has actually lost already. I have recreated the sounding of my speakers.
7. Room Macro 3: Use inversion for the frequency response correction.
8. Room macro 4: Filter generation for the phase correction and the creation of filter files (WAV) run. Do not forget Subsonicfilter, so that the bass drivers are relieved in the frequency responses, where anyway only "hot air" comes out. I create filters in very high resolution (384 kHz) and deposit them in HQPlayer.
9. Room Macro 5: Use Test Convolution to control the room correction. For example, if there are precursors in it, repeat the 8th step with other Excess Phase Window settings. The test is very close to reality, as I found out by measuring myself.

 

In any case, some start-up assistance is required by experienced Acourate users. The reward of the effort is an enormous increase in space and precision.

[asdf1000]

3 minutes ago, StreamFidelity said:

According to my previous experience, the success of the room correction stands and falls. Who just thinks to use the default setting (linear frequency response) has actually lost already. I have recreated the sounding of my speakers.

 

Hi, do you limit room EQ to schroeder frequency (200/300/whatever Hz) or apply room EQ to the full audio bandwidth, 20-20kHz?

 

[StreamFidelity]

Time optimization by phase correction is always performed over the entire frequency response 20 Hz - 24 kHz. Currently I'm trying an amplitude correction only up to 1.2 kHz. It sounds great.

[scintilla]

I tend to agree with some of the interface frustration but I have had success with 3 of my systems now for basic room corrections.  I took analog filter design and DSP in college more than 20 years ago, but I don't really think any of it helped.  All I can remember from DSP (even though I still have my book, homework sets and notes) is suffering through all of the algebraic substitutions for time series and trying to grok convolution. None of that is particularly helpful for using acourate.  Like most things, I think it is simply an iterative learning  process that builds competence. I bought Mitch's e-book but haven't started it yet.  I am sure I will learn a few more things that way too. In the end, my system now sounds better than any system I have had in my life. Using Pure Vinyl with a plugin convolver Roon and HQPlayer, I can RC every source including vinyl, casette tapes, an FM tuner, CD's and digital files. Let me tell you, a casette made in the early 80's on an early 70's pre-Dolby BIC deck by my father of a 1950's record sounds a whole lot better than I thought it did once I could hear it properly reproduced.

[jamesg11]

On 5/10/2019 at 7:01 PM, StreamFidelity said:

Time optimization by phase correction is always performed over the entire frequency response 20 Hz - 24 kHz. Currently I'm trying an amplitude correction only up to 1.2 kHz. It sounds great.

Above methods  - for 2 channel ... does this cover 2.2 , stereo + stereo subs (in my room, subs are confined to corners, ie in line of L, R front to listening position)?

[StreamFidelity]

10 hours ago, jamesg11 said:

Above methods  - for 2 channel ... does this cover 2.2 , stereo + stereo subs (in my room, subs are confined to corners, ie in line of L, R front to listening position)?

I know from other users that subwoofers can be integrated with Acourate. Some even create the crossovers for speakers. Unfortunately, I have no experience with it.

[sledwards]

On 5/10/2019 at 4:46 AM, StreamFidelity said:

Many things written here are correct. In a simple stereo setup, however, Acourate is no higher science.

@StreamFidelityBeen reading about Acourate and I think I may give it a go. I have a question about mics. Currently I use a UMIK-1 USB mic with REW. It looks like the author recommends a separate mic/preamp combo to run Acourate, but UMIK-1 works but maybe with some errors? Any advice here? 

[dennis88]

that is also my setup (UMIK-1 and Acourate). I've read about the potential clock drift and Ulrich Brüggemann explained on how to omit it (have not had the time to try it out myself though):

 

(https://groups.yahoo.com/neo/groups/acourate/conversations/messages/9557😞

The Dirac option introduces Dirac pulses before, between and behind the logsweeps. Thus it is possible to measure the number of samples between the Diracs in the recording. If the number differs to the number of samples in the original logsweep then it is possible to calculate a correction factor. A multiplication with the samplerate gives a new samplerate. So you can apply a samplerate conversion (TD-Functions - SRC - special) to the logsweep recording and finally run a logsweep convolution on the resampled recording. This procedure allows to compensate a clock drift or time stretching/compression effect caused by a USB microphone.

 

Here's a workflow some user has posted:

1.    A mono logsweep is generated, including Dirac pulse option, at 48 khz samplerate

2.    The distance between the Dirac pulses is 1080000-24000=1056000 samples in the original sweep

3.    In the rec logsweep the distance between pulses has been found as 1056021 samples (21 more)

4.    The logsweep_rec has been resampled at 47999.045 hz samplerate 

5.    Now the distance between the Dirac pulses is again 1056000 

6.    A logsweep convolution (menu Logsweep/Logsweep convolution) has been done

7.    The result, Pulse48L, has been saved

 

[StreamFidelity]

5 hours ago, sledwards said:

Currently I use a UMIK-1 USB mic with REW.

 

Unfortunately, I have no experience with UMIK-1 USB Mic. I'm using the Microphone calibrated by AudioVero. The calibration file compensates the irregularities in frequency response of the mic. This is essential, otherwise the measurements are wrong.

[sledwards]

28 minutes ago, StreamFidelity said:

 

Unfortunately, I have no experience with UMIK-1 USB Mic. I'm using the Microphone calibrated by AudioVero. The calibration file compensates the irregularities in frequency response of the mic. This is essential, otherwise the measurements are wrong.

The UMIK-1 has calibration files (0 and 90 deg position). What I am not sure is if they are compatible with Acourate.