Not even the Brits held on. It's stupid. We have had dual units in Automotive engineering. We should have converted in the Reagan Era. Need Engineers in government not more lawyers from the bottom of their classes, like you know who.
Super Chorus inspired project.
The curves will tell you. make a double pole double throw switch. Measure and Listen.
You mean Mr. Magoo? Ha ha.
Are you asking about polarity or phase/time delay?
Usually, if your polarity is out of phase, when you run REW, you will see a big null around the crossover frequency.
If polarity is correct and your crossover frequencies:
1. overlap too much, you will see a hump at the crossover frequency
2. underlap, you will see a very small null at the crossover frequency
mboxler
Well-Known Member
You mentioned you will be using a Universal crossover. I believe AL's original Universal's only had the mid's polarity reversed. The tweeter filter had the same polarity as the woofer.
Just a thought here. When I was proofing the design for my two way I initially glued it all together. The second test mule was screwed together and changes were far easier and cheaper to make. There they sit to this day just screwed together and yeah the screw heads look ugly but there is no cabinet buzz from this so I just leave it alone. The second one on will be assembled with glue since I won't be keeping them.
Gigantic
A big, big love
I did. Chapter three was particularly useful, even if referring to chapter 2 for tables was a bit cumbersome in pdf format. My guesstimates weren’t far off.
My error- I’ve built 3 type E networks to one universal, so that sticks out in my memory as the orientation. I mistyped.
Gigantic
A big, big love
I’ve had similar thoughts. At the moment, I’m thinking that I’ll make a slightly smaller cabinet for the 12” woofer than I would if I’d used a larger, 15” unit, so I’m thinking that I’ll screw the motor board from the inside with pocket screws, so that if down the road, if I decide that I want to retrofit a bigger mid horn or woofer, I can reuse the front and back and simply cut new pieces for the box itself, with more volume.
The newest Universal, the “CornScalawall” (probably the stupidest name he could’ve come up with) - does not invert polarity for the midrange. I built one, and sent it to the customer, who measured the speaker after the install. I have attached the plot that he sent me. Even with a much shorter horn, the plot shows the polarity should still be inverted. Since I no longer communicate with Al, I have no idea why he chose to do this. I went back to building them with the polarity inverted, which makes sense, since the midrange is second order.
Attachments
They are wired a little bit differently too. Iterations one and two floated common for the midrange. It gave you a lot of settings for the midrange, but there were weird/inconvenient gaps. You also needed to use a chart to figure out what in the hell was going on. I had to twist his arm a bit to change it so it could do 1dB steps. Al came up with the new method of doing the autoformer labeling, which was brilliant (in dB instead of cryptic numbers).
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Gigantic
A big, big love
thought: 2 x 12 woofers vs 1x12 or 1x15? at the current moment, the plan is for a cabinet that's not more than 48" tall, between 18-1/2 to 19-1/2" wide, enough room to expand the woofer from 12" to 15," should I feel the need and if budget allows. There's still a lot of vacant real estate beneath the woofer on the motorboard, what would be the effect of running 2 Delta Pro 12A's or equivalent drivers? It should move more air, right? will it overwhelm the midrange with the ZXPC K510 & PRV D2200PH?
Invidiosulus
Well-Known Member
I think you need to get WinISD working first.
Gigantic
A big, big love
That’s a given, but I’m having issues installing it in the auxiliary drive on my backup MacBook; at any rate, I’m literally sitting on a jobsite watching poly dry, supervising the guys applying it. I’m bored and when I’m bored, I get ideas; sometimes good ideas, sometimes bad.