Confidence has been restored

[Mazeroth]

SoundEasy has been giving me crap for a long time to get running properly for measurements. Mazurek came over last night to check out my new house and I wanted to show him SoundEasy to see if he could diagnose why I couldn't get consistent measurements. Well, you know how things always go, when I showed him what the symptoms were things were working perfectly and they're still working perfectly so I think I'm in business!

For a first attempt at designing a passive crossover I took measurements of a test dipole I built last year with a cheap Vifa TC18 Infinity buyout from PE along with an RS28. I then quickly modeled a 2nd order on the woofer and a 3rd order on the tweeter with passive parts I had on hand. Within 5 minutes I had a modeled response in SE that looked very flat and had a nice, deep null when polarity was reversed showing it has good phase coherency. After wiring it up and taking a measurement I was shocked! Aside from the anomaly at ~1300 hz. things are pretty flat! The RS28 inherently has a dip in its top octave which can be seen in the measurements.

All in all I used $15 in passive parts, which includes an 18 gauge 1.5 mH on the woofer and a 0.15 mH on the tweeter. A 10 uF was used on the woofer and a 15 uf and 10 uf on the tweeter side, with a series 4 ohm resistor to pad its level. Uhh, yeah, those were electrolytics I had lying around. :roll:

I know this is a very simple design and things are going to get more complicated but I think this was needed to give me that boost of confidence to get things going. I just hope I don't forget that the most important part is listening to music and not designing speaker after speaker, forgetting why I took this hobby up in the first place. :B

[JonP]

Hmmm... I think I have 2 more of those, been using the other pair. Somewhere I should have measurments... would be interesting as well as a "confidence builder" to compare your measurements with mine...

I forget what the T/S parameters are supposed to be, these a good choice for Dipole use? What exactly makes a driver good or bad for dipole use, besides a healthy Xmax....?

[Mazeroth]

Hmmm... I think I have 2 more of those, been using the other pair. Somewhere I should have measurments... would be interesting as well as a "confidence builder" to compare your measurements with mine...

I forget what the T/S parameters are supposed to be, these a good choice for Dipole use? What exactly makes a driver good or bad for dipole use, besides a healthy Xmax....?

These were used only because I had them on hand and wanted to hear dipole mids. I wouldn't use them in a dipole design as they're an inexpensive woofer and the cost of crossover components probably wouldn't be worth it. Also, I measured its distortion and it has a rising F3 around 200-300hz that sounds real annoying, although, it could have been the woofer I was measuring as its been "thrown around" a lot.

As far as T/S parameters you want a woofer with high xmax and a high Qts, which isn't as important if you're using an active crossover but when building a passive you won't have to equalize them as much to get more bass.

Again, this was just a super quick test to see if SoundEasy was working and to see if I could model a quick and cheap passive network and to verify its response when measuring it again.