I used sim software in the early nineties (Netcalc and Boxcalc). I wrote my own code too. I wouldn’t do without it (been there done that when I started this DIY thing).
USB mics? I don’t bother. The normal mic and USB interface give me more. And reliable timing, I have yet to see the USB mic with synchronous AD/DA-converter.
Software: ARTA suite, Boxsim or VCAD, Basta!, Hornresp and occasionally other tools.
USB mics? I don’t bother. The normal mic and USB interface give me more. And reliable timing, I have yet to see the USB mic with synchronous AD/DA-converter.
Software: ARTA suite, Boxsim or VCAD, Basta!, Hornresp and occasionally other tools.
Measurement and simulation are rather different things. An engineer (an applier of scientific laws using maths) performs measurements to check simulations or when unable to perform simulations. The pros of simulation are that they enable questions to be answered and a loudspeaker designed in a reliable methodical quantitative manner guided by the relative sizes of the physical processes involved. Being effectively the definition of an engineer it is by far the preferred approach for engineers. The cons of simulation are that it requires the science and maths to be understood sufficiently for all assumptions involved to be understood if the simulations are to be reliably interpreted and used. Engineers study for years to acquire this sort of thing in their fields which most people obviously don't possess. Without it simulations become more magical sometimes viewed as better than they are, sometimes viewed as worse but whichever they are less reliable for making decisions. Without engineering knowledge measurements start to become more attractive even though they provide only a small amount of information and lack information on the physics involved to guide reasoning.
Cheap USB mics are fine if you understand what they can and cannot provide and make your decisions accordingly.
What problems are those?
Electrical simulation at audio frequencies is sufficiently accurate, as is small signal analysis of their effect on acoustic signals.
@andy19191 I have to concur. Even with engineering grade and some acoustics and perception courses it still takes me quite some thinking to interpret measurements and simulations. Luckily smart people here and on other communities help one out. It is a lot easier to do things reasonably right, if you want to learn each time. Access to cheap and good equipment these days come as a big bonus. So it seems to me for the inexperienced rather the plethora of possible measurements and sims can be confusing than that the relevance of them would be arguable. I don’t see any attraction in that though.
Hello
I use LEAP and CLIO/CLIO Pocket for measurement and simulation. I know these are not low cost and unfortunately LEAP is no longer available. The bottom line is the accuracy of the simulators is dependent on your measurements. It's critical to be able to take reliable and repeatable measurements. Of course getting know the simulation software is also important but it's very true garbage in equals garbage out. There is no way around that.
You should be able to do take a verification measurement with your designed crossover and be within a dB oxer most of the range. If your are new to this I would take the time to work on your measurement technique. That will go a long way to getting the most out of your simulation software.
Rob
I use LEAP and CLIO/CLIO Pocket for measurement and simulation. I know these are not low cost and unfortunately LEAP is no longer available. The bottom line is the accuracy of the simulators is dependent on your measurements. It's critical to be able to take reliable and repeatable measurements. Of course getting know the simulation software is also important but it's very true garbage in equals garbage out. There is no way around that.
You should be able to do take a verification measurement with your designed crossover and be within a dB oxer most of the range. If your are new to this I would take the time to work on your measurement technique. That will go a long way to getting the most out of your simulation software.
Rob
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https://www.parts-express.com/Audio...coustic-Measurement-System-390-900?quantity=1
If my understanding is correct, this 'kit' can also measure Cumulative Spectral Decay.
If my understanding is correct, this 'kit' can also measure Cumulative Spectral Decay.
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I have never used the Clio Pocket system... my understanding is that it is a high quality "turn key" measurement system. It is not the cheapest option, but the turn-key aspect may justify its price for some people...
Simulation software is not a magic wand. It will not enable someone to magically design good speakers if they do not understand acoustics, signal processing (filter) theory, and basic analog circuits. With that said, simulation software used properly is a huge aid in designing speakers.
Simulation software must be paired with high quality measurements. The designer must provide accurate impedance data for each driver, and a measured acoustical response for each driver. The acoustical measurements have to be scanned and collected in a certain manner in order to be valid and usable in simulation. In my opinion, making high quality measurements is one of the most challenging aspects of DIY speaker design. It is always crucial to verify simulation results with measurements. It is all too easy to make a mistake in analysis / simulation, and performing frequent measurements is a critical quality control check on the analysis/simulation.
Quoting myself from another thread:
I can tell you what i use, but that is not necessarily what I would recommend to a new designer just getting started on the learning curve.
Acoustical measurements require a test microphone, which usually means a small capsule omnidirectional microphone with a calibration file. Entry level measurement microphones are about ~ $80. You can use a USB microphone which plugs directly into a laptop, or you can use an XLR-connection microphone. The USB option has the advantage of being simple, plug and play, and fewer opportunities to mess up the measurements. The XLR-connection mic will require a USB audio interface. The USB option can serve you well for a time, but eventually your skill and knowledge will progress to the point where you will want more data than it can supply. At that point you will have to switch to an XLR-mic and a 2 channel audio interface. Only you can assess your technical skill and knowledge and judge which type of mic you should start with.
I started with a Dayton Omnimic, which has its own measurement software. When I decided I wanted to do full polar measurements to support a more robust simulation, I bought a Berringer UMC202HD USB audio interface, and an Audix TM1 microphone.
I use ARTA for acoustical measurements. It is not free, but the liscensing fee is modest. Other people use REW, which as far as I know is free.
I am not an expert on impedance measurements. I know there are inexpensive ways to measure impedance that T/S parameters, but I use the Dayton DATS v3 for this.
For simulation, I use VituixCad. It is free. It is very powerful. I love this software. BUT...The program is designed for people who already know what they are doing. It is not a learning tool, and the users' guide is a reference, not a tutorial. If you have not done speaker design before, starting with VituixCad would be like trying to study calculus without have learned algebra, geometry, and trigonometry first. However, some novice designers have successfully worked through the Vcad complexity, so once again only you can assess your technical skill and knowledge and judge how you should proceed. I would expect that an electrical engineer (with no speaker design experience) would move faster up the Vcad learning curve than a car salesman (with no speaker design experience).
I am not the right person to recommend alternatives to VituixCad (such as WinSD, boxsim, soundeasy, others). This thread https://www.diyaudio.com/community/...-design-your-own-speaker-from-scratch.332688/ discusses a lot of software options. I can recommend Xsim as a good learning tool. Xsim is a free crossover circuit simulator. It simulates the response of the speaker on one axis, but for a beginner, focusing on one axis is not a bad way to learn.
I hope this helps...
j.
Simulation software is not a magic wand. It will not enable someone to magically design good speakers if they do not understand acoustics, signal processing (filter) theory, and basic analog circuits. With that said, simulation software used properly is a huge aid in designing speakers.
Simulation software must be paired with high quality measurements. The designer must provide accurate impedance data for each driver, and a measured acoustical response for each driver. The acoustical measurements have to be scanned and collected in a certain manner in order to be valid and usable in simulation. In my opinion, making high quality measurements is one of the most challenging aspects of DIY speaker design. It is always crucial to verify simulation results with measurements. It is all too easy to make a mistake in analysis / simulation, and performing frequent measurements is a critical quality control check on the analysis/simulation.
Quoting myself from another thread:
I can tell you what i use, but that is not necessarily what I would recommend to a new designer just getting started on the learning curve.
Acoustical measurements require a test microphone, which usually means a small capsule omnidirectional microphone with a calibration file. Entry level measurement microphones are about ~ $80. You can use a USB microphone which plugs directly into a laptop, or you can use an XLR-connection microphone. The USB option has the advantage of being simple, plug and play, and fewer opportunities to mess up the measurements. The XLR-connection mic will require a USB audio interface. The USB option can serve you well for a time, but eventually your skill and knowledge will progress to the point where you will want more data than it can supply. At that point you will have to switch to an XLR-mic and a 2 channel audio interface. Only you can assess your technical skill and knowledge and judge which type of mic you should start with.
I started with a Dayton Omnimic, which has its own measurement software. When I decided I wanted to do full polar measurements to support a more robust simulation, I bought a Berringer UMC202HD USB audio interface, and an Audix TM1 microphone.
I use ARTA for acoustical measurements. It is not free, but the liscensing fee is modest. Other people use REW, which as far as I know is free.
I am not an expert on impedance measurements. I know there are inexpensive ways to measure impedance that T/S parameters, but I use the Dayton DATS v3 for this.
For simulation, I use VituixCad. It is free. It is very powerful. I love this software. BUT...The program is designed for people who already know what they are doing. It is not a learning tool, and the users' guide is a reference, not a tutorial. If you have not done speaker design before, starting with VituixCad would be like trying to study calculus without have learned algebra, geometry, and trigonometry first. However, some novice designers have successfully worked through the Vcad complexity, so once again only you can assess your technical skill and knowledge and judge how you should proceed. I would expect that an electrical engineer (with no speaker design experience) would move faster up the Vcad learning curve than a car salesman (with no speaker design experience).
I am not the right person to recommend alternatives to VituixCad (such as WinSD, boxsim, soundeasy, others). This thread https://www.diyaudio.com/community/...-design-your-own-speaker-from-scratch.332688/ discusses a lot of software options. I can recommend Xsim as a good learning tool. Xsim is a free crossover circuit simulator. It simulates the response of the speaker on one axis, but for a beginner, focusing on one axis is not a bad way to learn.
I hope this helps...
j.
Cheap USB microphones do not provide the phase data you need. For on-axis simulations you can get away with deriving minimum phase, but for off-axis measurements this is less reliable. So...they can be made to work with some limitations, but not sure that is "really up to task". In fact, the $22 Dayton Audio IMM-6 with the appropriate cables "can" work with limitations, but most people on this forum won't recommend a USB mic or the IMM-6.
I think HIfiim's post pretty much nails most of it. Some crossover programs (probably all listed in the last link he provides) are: Free - VituixCAD, Xsim, and WinPCD. Commercial - SoundEasy.
I'm not sure about andy19191's post - I know quite a bit of math but have never used anything other than arithmetic that my 12 year old knows to design and build a speaker. Never needed any engineering or physics either.
We used to (and some may still) do multi-axis crossover design on single axis simulators. It just has extra steps.
https://en.wikipedia.org/wiki/Voltage_divider
I guess that such 'details and requirements' are just far more simple using software.
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It’s true that you can stand on the shoulder of giants.
However, I think one has to be careful, otherwise, are we doing anymore more than copying, complete with all the faults, of what has been done previously?
I mean, in 2023, my 11 year old thinks (s)he can write an essay on any topic using <insert favourite large language module here>.
But that doesn’t mean (s)he can understand what (s)he has written, or verify the authenticity of what(s)he was generated.
And nor can the LLM.
The system measures impulse response, and the rest of the features get calculated, as CSD for instance.
I am a first generation Clio (introduced in 90's) user. I find it to be a premium tool. I don't have a problem paying more for a good tool considering the number of projects I have done so far. It has payed itself off more than a couple of times it has cost me.
The only people doubting the efficacy of measurements and simulation are the ones who have no experience with them.
the answer is: yes, it is worth the investment. To measure is to know.
Enclosure modelling software goes a long way back, as does crossover simulators (I discovered them in the mid-1990s).
I used to use SoundEasy (which has more functionality than I needed), but now - for my typical use case - it has been supplanted by a combination of REW and VituixCAD. Both of these applications have superior user interfaces than SE. I still have SE, and will revert to it for when I want to review previous work.
the answer is: yes, it is worth the investment. To measure is to know.
Enclosure modelling software goes a long way back, as does crossover simulators (I discovered them in the mid-1990s).
I used to use SoundEasy (which has more functionality than I needed), but now - for my typical use case - it has been supplanted by a combination of REW and VituixCAD. Both of these applications have superior user interfaces than SE. I still have SE, and will revert to it for when I want to review previous work.
Indeed just like when the calculator replaced the slide rule and log tables applying the maths is getting faster with computer software but the requirement to understand what the maths is doing hasn't changed at all. By simulation I thought you were referring to DIYers beginning to use the kinds of CAE simulation software used by engineers in industry (e.g. BEM, CFD, CAA, FEA, etc...) rather than design rules expressed by the TS parameters (which are fine but not where things are growing for DIYers). I don't understand the inclusions of measurements with simulations because they are quite different things.
Anyway back to the maths and why it is relevant when computer programs are performing the heavy lifting to generate answers. If you don't understand the maths implemented in the computer software then you won't understand the assumptions made and hence what is correct and what incorrect in your simulations. For example, there are growing numbers here using BEM software to solve the linear wave equation with reasonable success for waveguides and sometimes the exterior shape of a loudspeaker. Someone proposed using it for a ported enclosure for which it is unsuitable because of the assumptions made deriving the maths. I got nowhere trying to explain why it was unsuitable and what would need to be included to make it suitable because the chap I was talking didn't believe some anonymous poster on the internet (fair enough) and wouldn't make the effort to follow the maths (not fair enough).
The main advantage of simulation is that you could save lots of time and effort while designing and implementing something. It also gives the user some kind of 'proof of concept' before he/she is into the real thing that often involves time and money. Modifications and iterations are very easy to carry out if simulators are involved.
A disadvantage is that it still requires some knowledge to 'decode' and make sense of the results. However, this is more or less the case, even when simulators are not used. Also, the validity of any simulation directly depends on the accuracy of the models it uses.
I don't understand the "problems"?
The most tricky part for most people is measuring the loudspeakers itself.
In the end that's just basically follow the same test protocol to get good and reliable results.
Which is not difficult to follow. I have had many interns and other coworkers with extremely little background and knowledge in acoustics or loudspeakers, that had little trouble getting good and reliable results.
Finding the right crossover just takes a lot of practice. But these days we are blessed with an incredible community that can easily help you moving on with it.
One very important step that is often forgotten, is that getting a good crossover filter design, starts already when thinking about the loudspeaker you're gonna make. Selecting the right drivers, shape, performance etc etc etc.
In the end it's just like cooking.
You can throw random things in a pan and hope it will taste well.
That is basically what making loudspeakers with measuring equipment and software is.
The changes that it will give a satisfying result are therefore (very) low, not as reliable and consistent.
Some people just like the unknown part of doing it the other way of trial and error.
To me it sounds just like a lot of effort while running the risk of completely failing. But whatever floats your boat.
There are also some people who just find it overwhelming and just use it as an excuse.
The most tricky part for most people is measuring the loudspeakers itself.
In the end that's just basically follow the same test protocol to get good and reliable results.
Which is not difficult to follow. I have had many interns and other coworkers with extremely little background and knowledge in acoustics or loudspeakers, that had little trouble getting good and reliable results.
Finding the right crossover just takes a lot of practice. But these days we are blessed with an incredible community that can easily help you moving on with it.
One very important step that is often forgotten, is that getting a good crossover filter design, starts already when thinking about the loudspeaker you're gonna make. Selecting the right drivers, shape, performance etc etc etc.
In the end it's just like cooking.
You can throw random things in a pan and hope it will taste well.
That is basically what making loudspeakers with measuring equipment and software is.
The changes that it will give a satisfying result are therefore (very) low, not as reliable and consistent.
Some people just like the unknown part of doing it the other way of trial and error.
To me it sounds just like a lot of effort while running the risk of completely failing. But whatever floats your boat.
There are also some people who just find it overwhelming and just use it as an excuse.