[Ricci]

I've got a pair myself and I'd like to ask a favor from someone who has REW running. I'd like to see someone take a close mic frequency response of one that is hopefully in a sealed enclosure. Ported would be fine too but sealed would be best. I'd like to have something to compare against besides Illka's measurement. Somebody help a brotha out!raying:

 

[Canadian_Dude]

You want ground plane outside or is in room ok?

 

[Ricci]

Whatever you're willing to do. My measurements don't match Illka's at all. Mine were indoors about 1-2" from the cone. What set-up you got? ECM8000 mic? I'm interested to see what someone else's turn out like. Are you running a sealed set-up or ported? I can't remember. Thanks.

 

[Canadian_Dude]

I am using an analog Radioshack spl meter. I have a measurement that is about 2 feet from the cone in room. The box is 24"x24"x22" external with two 18 pr's tuned to about 18hz. The pr's are sitting about 1.5" from other objects so I am definitely losing some low end here.

 

[Ricci]

Can you humour me man? What I'm looking for is a low volume test. Put your mic really close to the cone like 1" or 25mm away and do a sweep from 0-300hz. Can you defeat your xover, or if not raise it to the highest it will go like 150hz (or whatever). Looks like maybe you did this in your measurement you posted? This will eliminate the effects of your room as much as possible and show the HF extension of the SDX. It will also show where your tune is with your pr's. you can also while you are doing this, run the same sweep at the same level with the mic 1" away from 1 of the pr's and it will show you what the pr's are doing too. Here is what my graph looks like compared to Illka's. I have a bigger hump in the response at a lower frequency, the low end rolls off faster and the high freq's have a sharper roll off as well. Mine has an xover in effect at 200hz. Illka's does not.

BTW that graph you posted don't look bad. Maybe EQ down the peak at 23hz and the one at 66hz a bit, but other than that...

 

[Canadian_Dude]

Here you go, as asked. I ran the speaker output directly into the cleanbox and bypassed the receiver, and the mic is an inch and half away(couldn't get it closer because it was falling over).

And from the PR:

 

[Ricci]

THX man:yes:. See! your upper FR to 200hz looks nice and flat also. Mine drops like 8db and I need to figure out why.

Looks like your tune is right at 18 or 19hz like it should be.

 

[Ricci]

I took my pioneer reciever out of the signal path and it made a noticeable difference on the close mic fr. This looks better.