Cross-over schematics for the 4660

[Lancer]

Looks like about 30W into the driver would concurrently exceed the 20W rating of the two parallel resistors. How hot they gotta get to set the glue ablaze?

All those resistors in front of the tapped autotransformers take a beating. I've seen 4333's with their 7.5 ohm 40 W resistors burned to a crisp.

Here's the impedance curve of a 2344A/2425H with the 1.55 mH inductor (-6 dB tap) from an L300/4333 without the 7.5 ohm resistor and with the 7.5 ohm resistor. One can see it keeps the preceeding series capacitor from going haywire.

[Zilch]

I have some new resistors on the way, and I'll try that when I install them. Good trick to tame the impedance there and, I assume, get requisite additional attenuation (about 3 dB?), as well.

These parallel pairs read 18.2 and 18.4 Ohms, respectively. Can't read the actual values on them, if it was ever there. Should read 19.5 Ohms if they were actually 39 Ohms per the schematic; being fried like this would likely change their values, tho.

I'm using single 18-Ohm aluminum N/I ones as replacements, which I'll mount on heat sinks. Paired 40-Ohms might be a better choice, now that I think more about it.

Not gonna beat myself up over it, tho, as I have no clue at this point what I'm gonna ultimately DO with these things. The horns themselves are sounding good with better crossovers, and if they go back in these boxes, they'll likely get 2235H's mated in them instead of 2225/26.

Maybe I use them for backyard theater....

[WTPRO]

Hi everyone,

I noticed that some of you are using the WT2 and thought I would post an FYI that an FAQ and an alpha version of the next WT2 software release has been posted to www.woofertester.com. Just keep in mind that the alpha code is a testbed for new features. Help for now is in the FAQ. Neve the less, I think a few of you will like it.

- FAQ: A number of examples have been posted showing things like how to test multiple driver, dual voice coil drivers, effect of series/parallel resistors and more.

-WT2: Box simulation with data overlay. This is a new child window where th idea is to overlay the measured phase and impedance to that of the simulator. If they match, you are going in the right direction. Works for free air, sealed and vented boxes

- WT2: Frequency dependent Rem/Xem. Ever noticed how the older T/S models did not produce acurate phase and impedance at the higher F's? The addition of freqeuncy dependent Rem/Xem in series with the electrical tank fixes this. The WT2 will measure -and- now model this.

-WT2: Improved USB support where Windows was making a mess of things. In 1.01 getting the WT2 to be recognized sometimes involved mucking around with the multimedia device manager. This should be solved now.

- WT2: The left mouse button will now set an arbitrary frequency and the right mouse button will log that data point into the present data buffer. These data points are not part of the T/S test, but they can be used to smooth (beutify) the curves or zero in on something of interest.

- WT2: The addition of an external parallel resistor (to keep the current driver happy) and some math now allows the WT to measure capacitors.

Note: The alpha code will be getting updated from time to time. The about dialog (also pops up on start) includes build time information.

Best regards,
Keith Larson

[email protected]
DSP and Analog Consultant
Lincoln, Ma 01773

(a C&S Audio Partner)

[Zilch]

Here are CLIO response results for 4660 crossover using pairs of 2426H and 2426J drivers on 2346 "Everest" horns. Measurements taken perpendicular to horn face:

[Zilch]

Thanks again to Mr. Widget for sharing his equipment and expertise.

[Not to mention his patience with the Zilchster.... ]