wm-61a topend peak- calibration? or resolder??

[derf]

Have you seen this paper?

May be of some use:

A link you may like...

 

[sqlkev]

as jbateman said change the range on the y axis, you are getting a very distorted graph there. 3db is roughly what the peak is on the Wallin measurements for the WM61a so I think you are probably seeing pretty normal data.

with the gating you need to open up the pulse response and find the first reflection and move the upper limit of time to before this reflection.

I've attached an example pulse response graph, I reset the y axis to -200 min +200 max.... the defaults of -32K +32K with the gain of my mike at 1M is way off. I've set the gate to about 6ms but it is possible that the first reflection here is actually around 4.5ms, It will be very diffifcult to get anything higher than 6 - 8 ms before a reflection in any normal room.

Tony.

my pulse does not look like yours at all






on a note,
I did more measurements (attempt to) today and I'm getting a bit frustrated with the results,
going through many drivers, I find that the peaks and valleys aren't quite dramatic as they should be.
ie. i expect my rs125 to have the first cone breakup mode at around 4khz and 8khz, the peaks are there, but only a few dBs up

when I try to measure my horns, the upper end only rolls off a few dBs as well


I'd love to read the tutorial on speaker workshop but my laptop at the moment doesn't have any microsoftword

 

[wintermute]

you need to have the speaker as far from any reflecting surfaces (in all directions) as possible. This implies ideally it should be suspended in mid air. I put mine up on a table in the middle of the room and get so so results....

picture here --> http://www.diyaudio.com/forums/showthread.php?postid=563589#post563589 The first reflection I get it off the floor, followed closely by the ceiling, and then no doubt by walls furniture etc. Unless you have your speaker at least that high off the ground (and the ceiling and walls are no closer to the speaker than the floor) then you will get reflections showing up in your pulse much earlier.

BTW you are doing your gated measurements and pulse response at about 1M distance aren't you?? If you are too close then you won't get sensible results (could probably go as close as 1/2M???)

Tony.

 

[bowdown]

Hey Padel you mentioned that you are using the audigy 2 zs notebook soundcard for your measurements, I also would like to use that sound card with my notebook and was wandering if you could give me some information on how it works and also if you could tell me how to set it up. Any info would be appreciated anyway.

Regards

Bowdown