First Development version of Boxsim in english language

[Willy_65]

Port BR25.50 in Boxsim

Hello Uwe
I want to build the Couplet but first simulate it in Boxsim.
I encountered a problem there, namely the port BR25.50 which is an angle reflex tube. Is it correct that I enter the distance to the top wall for entering the distance between the end of the tube and the opposite wall?

See topic on forum.zelfbouwaudio.nl

Thanks,
Willy

[UweG]

Obviously the optimizer could do something positive at the beginning and then could not optimize significantly for a long time.
The impedance response seems to be quite good according to the requirement. Frequency response is also very good, phase situation also very good. Efficiency could be better, maybe you do not need a box with PA like efficiecy and maximum power.

[Willy_65]

Hello Uwe,
Can you explain a bit how the results should be interpreted at the output of the Optimizer?

[mcl2k6]

Hello mcl2k6,

I do not have personal experience with the AL170.
In general it is known that new drivers have stiffer suspensions compared to used ones and additionally Thiele/Small parameters depend on the voltage level where they are measured. If you measured with only some mV (e.g. without a power amp) you may get higher fs than at 1 Volt or even 2.83V.
Nevertheless 56 Hz free air sounds much for me. Maybe you can ask the technical support: technik@visaton.com

Thank you for the answer. Obviously here I was measuring the speaker using the headphone out from my soundcard - therefore using low power. I'll try to repeat with a power amp!

[UweG]

Hello mcl2k6,

I do not have personal experience with the AL170.
In general it is known that new drivers have stiffer suspensions compared to used ones and additionally Thiele/Small parameters depend on the voltage level where they are measured. If you measured with only some mV (e.g. without a power amp) you may get higher fs than at 1 Volt or even 2.83V.
Nevertheless 56 Hz free air sounds much for me. Maybe you can ask the technical support: technik@visaton.com

[mcl2k6]

AL170 resonance frequency

Hello UweG,

I am currently building a new project with some brand new AL170. Somehow, the bass reflex box measurement didn't quite add up with what had been simulated, in a sense that the resonance frequencies were off by around 10-15 Hz or so.
Therefore I've thought on doing some measurements of the drivers.
I did some basic measurements using ARTA LIMP, to see the driver impedance in free air. The rule of thumb states that the impedance of the speaker is the highest at it's natural resonance. What I got is that this is highest at 56Hz. The datasheet states a value of just 38Hz.
What might the difference come from?
As stated, the drivers are brand new. Do I need to "break-in" them for some time, so the mechanics settles, and the suspension softens?
Please see the attached screenshot, red line is from one speaker, green is from the other.

[V12]

OK, clear. Thank you UweG!

[UweG]

Oh, I think I did not recognize some posts.

@Willy_65: Boxsim should open with the same window size and position as it was, when you closed it, if the complete window fits on the screen.

@V12: The easiest way to handle the SEO for own measurements is to set it to zero. That means that the phase response you measured has to refers to the plane of the baffle.

@mcl2k6: They are mesured with the WG148R, but nlcarbon already mentioned it. There is no acoustic difference between the two waveguides.

[nlcarbon]

Both type of WG have the same acoustic properties.

[mcl2k6]

Hello Uwe,

There is a new tweeter model in the 2.0 DB, G 25 FFL_WG.
I presume this had been measured with one of the Visaton waveguides compatible with it. Which one was used?
Currently I know of two of these:
- the square one, WG 220x150
- the round one, WG 148 R

Thank you!

[V12]

Sorry if it is repeated question and the wrong place.
I have to add my own driver.
But how to measure the "position of point of sound origin (SEO)?
Is it a distance from baffle to the center of voice coil?

[Willy_65]

Hello Uwe,
I was annoyed that Boxsim was always opening at the size of 1960 x 720p. If you then open the crossover editor (in smallest format) that window partly overlaps the Boxsim graph window. You then have to reduce that window to see the graph completely because if you click on the graph window during the overlap, that window will not get the focus.
That would not be a problem if Boxsim always remembered the last size, but after a restart it will do that again in the large standard dimensions.
I had already tried to change the size in the INI-file, but it was always reset in the INI to the default values.
I have now put those 2 values in comment and now the program remembers the last used window size. See:
#Window
w1 = 1
wt = 4
ww = 1029
wh = 769
# ww = 1069
# wh = 720
update 13/01: clarification
If the "ww" value becomes smaller than 1004, the standard dimensions of the window are reset to ww = 1096, when closing Boxsim.

update 12/01:
Is it, in a subsequent version, also possible to keep the popup window "Edit part" with the proposed value of the elements always visible? Now the window "Crossover network parts" always comes across the popup and you always have to put it next to the popup to make the right choices of eg inductance and resistance.

[Willy_65]

Thanks Uwe,
In my INI-file the line had to be added on the last line, not before "#Window".
See INI in attachment.

[UweG]

@Willy_65:
You supposed right. The bug in Boxsim refers to the writing of the graph thickness. The program tries to read it. It look for a line that looks like that, if the thickness is set to the middle value:

GThickness=	2

Possible values are 1, 2 and 3. This line has to be in the section #Option, e.g. after the line

Impmax=xxx

, before the line

#Window

. That's where the program should have written it.

Referring to the other issue: Boxsim definitely starts another instance if you start it twice. But if it open a popup window, it is placed more or less arbitrarily. It can happen that it is placed over another instance of Boxsim and it looks as if the other instance has popped up that window.
I will try to find another solution, maybe by letting it pop up over the optimizer window.

[Willy_65]

@Willy_65:
I'm a bit confused because Boxsim cannot load two files at the same time. I will try to reproduce this issue this evening.

for your information:
I have linked the .BPJ extension to Boxsim 2.0.
Then I double-click a project file that opens it in a first instance of Boxsim. Then double click another file and it opens in a new instance of Boxsim.
And so I can continue for a while.
I work with two 24 "screens and in this way I can easily open 2 projects: 1 on the first screen and 1 on the other, including the crossover editors.