Seas DXT tweeter test page posted

[dlr]

I've done a bit of testing with the new DXT tweeter. They looked too interesting to pass up, so I bought a pair. I'm going to do some additional testing for off-axis response to the tweaking I just finished. This is one very interesting driver.

I still will likely do some more tweaking, but from what I've seen, other than the mods that make some minor improvement, I doubt that there'll be much else that can be done, unless I find some better damping for the vent. The variations reported in the impedance curve are probably due simply to differing ways in which the supplied vent damping is positioned. I've tested, but not posted the impedance change with my lamb's wool tweak, though the FR change is shown. I probably need a higher density than my first try as the impedance peaked a bit on the low end of the bump.

The other thing I noted was that the mesh screen covering the dome was not all the way in on one of my pair. That was actually fortunate for me as I did remove it for a time. I still have one more mod to test related to this.

dlr

[mbutzkies]

I read your article with great interest. Two things were not clear to me.

First, you mentioned you thought the groove that held the screen is responsible for the 13k dip, why not fill that in with blu-tack as well?

Second, you mentioned the felt ring trick on the pole piece had a negative response. Can you put a graph of the response up? I can think on how you could have no effect, but a negative effect is suprising. Was the felt ring interfering?

Thanks a lot.

[dlr]

I read your article with great interest. Two things were not clear to me.

First, you mentioned you thought the groove that held the screen is responsible for the 13k dip, why not fill that in with blu-tack as well?

Second, you mentioned the felt ring trick on the pole piece had a negative response. Can you put a graph of the response up? I can think on how you could have no effect, but a negative effect is suprising. Was the felt ring interfering?

Thanks a lot.

The it might be possible to fill it in some, then position the screen, it's an idea worth trying, but may be counter-productive given the fact that the screen still has to go back in. My next test plan is to leave the screen out and fill that in. If that's what you mean, that's in line with my thoughts as well. It does leave the dome exposed, though.

I think that the felt ring inside may have interferred. The profile of the DXT is lower and flatter than many others are. Either I made it too high and there was contact or the height creates a resonant are between felt and dome, I don't know. It didn't seem to be worth pursuing, but I may still try a thinner piece. Just looking at the response, though, makes me think that it's not going to be of much use, the driver is very good up high as it is.

Dave

[mbutzkies]

I was thinking of removing the screen. I think I would rather use EQ than the little diffuser thingy to bring up high frequency response. When the diffuser is used, there seems to be an off-axis cancellation created. I don't know if this off axis cancellation is audible or not, but the graphs look better.