da175 and hivi b1s dipole speaker

[MisterTwister]

here is another weird project from mistertwister.
da175's cones are slit and covered with cascade damping spray.
so they've become dayton revelators
hivi tweeter will be horn/waveguide loaded.
this is a leftovers project, I'm not buying any more parts for it.
just using whatever junk I can find in my house.

[sdclc126]

How did you "slit" aluminum cones? Or did you slice the damping spray after application?

Have you measured the woofers to see what affect the spray has?

What sort of XO are you planning?

[badman]

Yeah, same re: slicing.

did you do before/after measurements?

[DcibeL]

As with the above comments, if you have no means of measuring the T/S parameters and frequency response (distortion plots would also be a big plus) I would have to say that you've effectively rendered your drivers useless. I have to assume you have some means of measuring frequency response since you plan to put the HiVi 1" drivers in a waveguide.

Visually, the copper center plug looks nice, but the cone coating looks lumpy and gross. Hope it's not sticky, or it might be a furry driver in a year or so.

[MisterTwister]

aluminum cones are slit with utility knife.
I'll do some measurements after I mount drivers on baffle.
and I already did freeair distortion measurements, just to
check that there is no serious problems with drivers.
cones coating is not sticky, it's damping material for cars.
i've done one pair of speakers with hivi tweeters already,
Hi-vi B1s
those speakers were pretty much lucky accident
I hope these will be too

[MisterTwister]

da175 distortion.
both drivers mounted on baffle, measured at 14in on tweeter axis.
I think it's good enough, there is no offensive peaks.
unfortunately my winmls pro demo expired. I think it gives more accurate harmonic distortion results than arta.

[MisterTwister]

b1s without rear chamber, same 14in distance.

[MisterTwister]

I made series crossover -> 0.2mh inductor and 30mfd cap
there are two ugly dips in frequency responce.
my only hope is that longer phaseplugs will fix those dips.
I didn't listen to these speakers in stereo yet, so can't comment on how they sound.

[MisterTwister]

measured at 18in on top woofer axis (it's more like listening axis if one sits on a couch) 2k area distortion is always there on both speakers.

[Caferacer]

Did you just mask them and spray? That's awesome. Bozak used to perforate their aluminum midrange cones and rubber coat both sides. Always seemed like a great idea to me.