New testing data

I've added a page on the DXT to my site as well

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.

Dave
 
ucla88 said:
Hi all,

I've posted new test data on the Seas DXT small waveguide tweeter.

Enjoy!

www.audioheuristics.org


Why don't you do a more compreshensive set of off axis measurements? Every 10° is a minimum IMO, out to 80-90°, but 7.5° or 5° would be better yet. 15° is just too course. Once your setup to do it, its just a few more minutes of time. Send me the data and I'll do a polar map for you. That would really show the information that is needed to judge somethings quality.
 
Hi Dave, Earl,

I can do 5 degree or at least 10 degree increments. Still, it will take a while so it may be a month or so. I'm trying to get some work done on the dipole in my limited speaker time.

I was hoping Seas would come out with a bigger waveguide/horn. Still, it's a very nice dome tweeter for the money.

I'm looking forward to Dave finishing his measurements.
 
ucla88 said:
Hi Dave, Earl,

I can do 5 degree or at least 10 degree increments. Still, it will take a while so it may be a month or so. I'm trying to get some work done on the dipole in my limited speaker time.

I was hoping Seas would come out with a bigger waveguide/horn. Still, it's a very nice dome tweeter for the money.

I'm looking forward to Dave finishing his measurements.

I'd request 7.5 ° because thats what I use and I could just load in your data and plot out equivalent data plots. 7.5° is easy because you just bisect the 15° marks on the turntable. And its easy to lay out every 15°. 10° is a lot more difficult.
 
gedlee said:


I'd request 7.5 ° because thats what I use and I could just load in your data and plot out equivalent data plots. 7.5° is easy because you just bisect the 15° marks on the turntable. And its easy to lay out every 15°. 10° is a lot more difficult.

I don't use a turntable, most of my measurements are on a 2mx2m board. I can to the off-axis in 7.5 deg increments, it's just time-consuming. I'll try to do that before I leave for vacation on Sunday.

Dave
 
dlr said:


I don't use a turntable, most of my measurements are on a 2mx2m board. I can to the off-axis in 7.5 deg increments, it's just time-consuming. I'll try to do that before I leave for vacation on Sunday.

Dave


Just make a turntable - two pieces of mellamine, a pin in the center, a little grease on the boards and you have a turn table. Just rotate the whole board.