• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Tools for building better DIY speakers

Winkleswizard

Active Member
Forum Donor
Joined
Jan 14, 2020
Messages
107
Likes
104
Location
Stow, Ohio USA
#1
From a discussion that started in a speaker review,thought it would be helpful to have somewhere to share what tools you might be using to design and test speakers. Currently, I use Bassbox Pro, REW and XSim. Bassbox is only one I paid for and is getting a little old. My designs are mainly subwoofers and has done well for that. Would like to replace Bassbox eventually. Anyone else care to share?
 
Joined
Jan 30, 2020
Messages
14
Likes
16
#2
I have used winisd for sub modeling.

Arta for measurements (and you can even make a jig for driver specs)

Pcd for crossover design.

I have heard a lot of amazing diy designs, only build 2 from scratch so far.
 

jhaider

Addicted to Fun and Learning
Joined
Jun 5, 2016
Messages
540
Likes
447
#3
VituixCAD is an outstanding software for processing measurements and simulating crossovers.

When I simulate subwoofer boxes, I use the Unibox sheet for Excel. I have always gotten good agreement between simulated and measured enclosure Q and resonance.

Other key tools:
1) measurement space.
2) turntable for polar measurements
 

ctrl

Member
Joined
Jan 24, 2020
Messages
75
Likes
176
Location
DE
#4
One of the best (and free) tools for passive and active loudspeaker crossover development is VituixCAD. It also comes with some very helpful tools.
Even with this tool it is possible to do simple simulations for loudspeaker baffle.

A tool for crossover development with simple simulation of complete loudspeaker cabinets supported by the loudspeaker manufacturer Visaton is Boxsim 2.0. Most Visaton loudspeaker measurements in infinite baffle are already included in the program. With it you can easily simulate your own (Visaton) loudspeakers. Unfortunately the current version is only available in German.

For high quality simulations of complete loudspeakers ABEC is suitable (complete docs are in English). In the free version projects cannot be saved, but for DIY the use of this version is sufficient.
In order to create reliable simulations with the program, however, you should expect weeks or months of self-study.

Included in the program is a software for displaying the simulation results VACS and a program for simulating rotationally symmetric drivers, wave guides and horns in an infinite baffle AxiDriver.

There are several threads in a German forum:
- Introduction in ABEC (...and of course it's in f.. german ;))
- The helpful simulation of a 2-way loudspeaker with a wave guide. I will attach the file to the post here.
- A description how to determine the directivity and the early reflections for the simulations from ABEC in the viewer VACS. Attach the two pdf-files to the post - unfortunately it is written in German, deepl.com helps.
- A short introduction to AxiDriver with an example simulation for a horn - file attached.
- Many results for simulations done in ABEC show how powerful this tool is for the DIY loudspeaker developer.

:eek: Don't let the amount of information overwhelm you :eek:
 

Attachments

Last edited:

Arnandsway

Senior Member
Joined
Sep 13, 2018
Messages
328
Likes
223
#5
I read everywhere that high Q resonances should be limited i.e. resonances caused by the cabinet. Are there any (free) tools that can simulate the behaviour of a woofer pressurising a particular cabinet?
I know Solidworks and Comsol are able to do this, but I don't really want to spend tens of thousands on this as a amateur DIY'er.

If someone can share me information or best practises, that would be great. I already started a thread on Constrained Layered Damping where helpfull information has been shared. But actual guidance or best practises based on scientifical research still is hard to find.

One (amateurish) project showed how bracing and different materials are helpfull: http://www.hsi-luidsprekers.nl/index.php/projecten/12-kast-materialen-onderzoek
 

Arnandsway

Senior Member
Joined
Sep 13, 2018
Messages
328
Likes
223
#6
Now to contribute to the topic, I use Vituixcad and REW as well. And to create FIR-filters I use RePhase. Lots of helpfull information on the diyaudio.com forum on this.

To design a active, multi-amped speaker, @pos posted a guide:
So here is how you can do it (among many other possible scenarios) :
- For each driver (with several measurement per driver, as discussed above), use minium-phase EQ to get the amplitude reasonably flat within the pass band (the more you can trust your measurement(s), the more precise you can go, hence the reasonably)
- Use the "compensate" mode in the minimum-phase filters tab to flatten the natural high-pass and low-pass of your driver by trial and error (you need a measurement with a low noise floor, as it will quickly realize when playing with that feature...).
- at that point you should have a linear amplitude and phase (in the pass band and around, depending on your noise floor). If you don't then adjust your "compensate" settings, and also play with the "time offset" option in the measurement tab. You should not have to use phase EQ.
- Do not operate your driver with this kind of correction of course: this is only a temporary state!
- Apply the desired linear-phase high-pass and low-pass filters, and make sure you do not exceed the capabilities of the driver (excursion down low, breakups up high, directivity, etc.).
- Check the correction curve with the measurement bypassed to make sure it does not get too high in amplitude (for example if the target high-pass filter is much lower or with a shallower slope than the natural one...).
- For good measure, use the main volume attenuator in the "general" tab and make sure your correction does not exceed 0dB (amplitude offsets will have to be dealt with at some other place, for example in the crossover engine or in the amplifier...).
- Always use complementary slopes for your crossed-over drivers (ie LR of identical slopes on both sides, "reject high" on both sides, "reject low" on both sides, etc.). Try to avoid brickwall filters as these will add additional constraints for complementarity (same number of taps, etc.). If you need steep slopes you will be better off with high order LR "shapes".

When generating the impulse, if you do not have constraints on the number of taps (which should be the case if you are using jriver on a descent computer) you should use the "middle" centering option, and a large number of taps (64k should be more than enough for any realistic situation). With that many taps you can use a gentle windowing algorithm such as Hann, Blackman or Nuttall, without loosing much precision or steepness. You can also handle the delays inside rephase, directly specified as distances, eg "middle+3cm" to compensate for your driver's geometrical offsets (you can check that afterward with the "inverse polarity" method, seeking for the deepest null at the crossover point)

Once each driver is EQed and filtered that way you can add them together in your convolution engine.
I think Jriver will require a different set of impulses for each sampling frequency it might have to handle...
 
Top Bottom