Broke down. Got a duplex.

**Alien_Shore** · October 15th, 2012, 10:34 PM

Originally Posted by cradeldorf

Hows the project coming?

Coming along. Been doing a lot of impedance testing, math, modeling, etc.
Don P. is helping me immensely - he took it on himself to construct a filter for us to test. When that arrives, I'll be putting it through it's paces, for proper impedance and FR, and once we have that tweaked, it will be onto adjusting the time delay stuff to synch up the HF and LF.

Here's a very detailed look at an impedance sweep (400-5000 Hz) on the woofer with the zobel added. It's hard to see here because this is such a up-close view, but the zobel really flattened out the impedance of this thing!

I built this filter with 3 caps (8.2 + 8.2 + 2.0) and 1 resistor (10.0). The real-world measurement of them was 18.33uF and 10.14 ohms. I need to buy some modeling software.... doing this stuff all by hand with excel spreadsheets is tedious

**cradeldorf** · October 16th, 2012, 01:58 AM

I love that PCD from jeff bagby. so easy to do and free too!!! I used my .ZMA files from DATS.

I just redid my crossovers this morning and I'm so happy with them it's crazy. I really like the way they bring out every little nuance of the movie soundtracks. 1.5mh erse super q on the LF and a zobel consisting of a 10.3 cap and 20 ohms of resistance, The HF is a 5.1 cap hooked to a 3 ohm resistor and then a 1.1 mh coil in parallel. I also wired in my attenuators and have them set at 2.5.

**Alien_Shore** · October 16th, 2012, 09:12 AM

Originally Posted by cradeldorf

I love that PCD from jeff bagby. so easy to do and free too!!! I used my .ZMA files from DATS.

I just redid my crossovers this morning and I'm so happy with them it's crazy. I really like the way they bring out every little nuance of the movie soundtracks. 1.5mh erse super q on the LF and a zobel consisting of a 10.3 cap and 20 ohms of resistance, The HF is a 5.1 cap hooked to a 3 ohm resistor and then a 1.1 mh coil in parallel. I also wired in my attenuators and have them set at 2.5.

Thanks man. I'll download it tonight.

**donaldpatten** · October 16th, 2012, 10:35 AM

Originally Posted by Panomaniac

Ah, those are after - sorry! I'd say Mms looks low, that's a light cone. But I'm not sure. I'll see if I can dig up files on some GPA reconed 604s (ferrite) I had here.
From the plot, it looks like an ohm woofer and horn to me.

Panomaniac

What ohms ? on the woofer and horn

Thank you

Don

**cradeldorf** · October 17th, 2012, 02:50 AM

Originally Posted by Alien_Shore

Thanks man. I'll download it tonight.

If you need help let me know, I'd be glad to talk you through it.

**Alien_Shore** · October 21st, 2012, 12:07 PM

Here's an FR graph of the 604E. These FRs are "barefoot" as Don likes to say, with no XO (just a 4uf HP on the horn).
I used gated impulse, and aligned the gate time for both measurements LF and HF:

604efr

There are some crazy phase curves going on with these, but I left them out of this chart since it clutters it up so badly. That, and I have no clue what I'm looking at or how to interpret phase graphs yet.

**Alien_Shore** · October 21st, 2012, 12:29 PM

Here are the FR graphs with Don's prototype TD XO on the LF (HF has a simple HP and L-Pad). I used the same settings in HolmImpluse as with the previous measurements:

604efrwxo

**Altec Best** · October 21st, 2012, 12:46 PM

Originally Posted by Earl K

( fyi, others using WT3, which was the G1 version of DATS , had many problems with it, maybe DATS is better ??? ) .

I had issues with mine... After a couple months the software is the problem IMO. It kept crashing on my computer..So I sold it.. And worked fine for the gentleman I sold it too.. So if you have something on your computer (Other Audio Software) you could have some conflicts... I opted for the WT2 from Smith & Larson.. 10x better IMHO... And it worth the extra $60. A must for the DIY hobbyist IMO&E.

**Alien_Shore** · November 24th, 2012, 09:29 PM

The mad scientist experimentation lab has been getting a workout:
nt3003

And today, I wound my first coil... Pain in the ass, let me tell you. But really, it's amazing how accurate the Shavano DIY coil calculator is...I made my own form with pvc pipe and rolled that sucka LoL. ...
Anyway, here's the ugly thing - I affectionately call it the 2.287 mH Christmas coil!

nt3002

DIY coil winding is an interesting hobby, but I think to really get into it, you'd need something that can count turns or feet automatically for you, and some kind of oscillating line alignment gadget on there like a spinning reel does. I don't know, maybe I'll try it again and see, it is nice to be able to create precisely the inductance that your circuit needs, but it seems awfully time-consuming for what you get.