JustMLS problem

[a007udio]

Ok.

Im new to speaker measurments so i need little help.
I have JustMLS program instaled on my computer and i measuring SPL..

I measure 165mm midbass speaker but the results are strange.
The factory measurments are very diferent then my.
Why?

Im using Behringer mic and preamp.

Picture show my measurement (black) and factory made (red) wich is made by my self just for orentation. The diference is abave
3kHz.
Where i do wrong?

regards.

 

[qwad]

1st question, are you using a caliberated mic?, perhaps that is the problem also : you have to average your sweep and it is almost impossible to replicate plots done in an anechoic chbr, so you have to get as close as possible to anechoic enviroment as you can, with position of mic to speaker and room boundries, a lot of experimentation is necessary, read the manual that came with your system l'm sure it has some recommendations how to go about it, cheers and good luck TC

 

[SY]

What baffle size is that driver mounted on? Looks like classic baffle step.

 

[a007udio]

Mic is calibrated with generic file availble on net.

Measured speaker is on the floor and mic is 1cm from dust cap. No box, nothing just speaker.

 

[SY]

So, what's the path-length for the back wave?

Near-field measurement is generally NOT accurate at midrange and higher. What you need to do to duplicate the manufacturer's measurement is to use the same box and baffle that they did, If you want to get data to actually use, put the driver in the box you're planning to use, back off the mike a meter or so to acquire the impulse response. Once you get that response, truncate it before the echoes to simulate an anechoic chamber.