Thanks for help adding CT125s to single driver rear horns.

[DizRotus]

I have a pair of DIY single driver rear horns see:

Single Driver Rear Horn Experiments

http://forums.klipsch.com/forums/thread/548426.aspx

I also have a pair of bass reflex enclosures (similar to Tekton) using the same drivers. Both enclosures sound very good with fantastic imaging, which is the strength of the single driver format. Nonetheless, they sacrifice the extreme highs and lows.

I also have a pair of CT125s and a pair of T2A autoformers that I would like to re-purpose to add high frequency output to the single drivers.

In fooling around crudely, it's apparent that the CT125s add the shimmer of cymbals to single drivers. The CT125s alone are too hot for the single drivers. I'm hoping to tame them slightly using the T2As.

I'd like suggestions from those more knowledgeable that yours truly (which excludes essentially no one) about which taps to use on the T2As and/or about adding inductors and/or capacitors to the mix.

I know there are better ways to skin this cat if starting with a blank sheet of paper, those suggestions I don't need. The whole purpose is to get the most out of what is already available with minimal additional expense. It's a hobby, not a business model.

[Axz Hout]

D

[DizRotus]

Chris-

The very term crossover suggests a greater degree of sophistication than I'm envisioning. PWK called Heritage "crossovers" balancing networks for a reason. I'm envisioning more of a controlled overlap than a crossover. The single drivers start seriously rolling off above ~8K. I want to protect the CT125s from signal below that. The power levels involved are not high.

While the T2A may not be needed for attenuation of the tweeter, it could be used for that. A simple capacitor would block low frequency energy from reaching the CT125. I doubt that an inductor is needed to block high frequencies from the single driver; the natural roll-off should suffice. The single drivers are efficient, but not as efficient as the CT125s, therefore, some attenuation would be needed. The T2A can substitute for an L-pad. It's not ideal, but it's here.

In reading through the old post about the single drivers, I see where I once said that I wouldn't add tweeters or sub-woofers. Again, I'm not trying to approach audio perfection. I am curious about using parts at hand to add some high end sizzle. At most, I'll experiment with adding capacitors, resistors, inductors and trying various taps on the autoformer to see if the benefit can exceed the drawbacks while spending a minimal amount of time and/or money.

[Axz Hout]

Y

[Axz Hout]

y

[Axz Hout]

t

[coolhandjjl]

I'm envisioning more of a controlled overlap than a cross over.

Overlap = Bad

Most audio gear crosses over with a slope on each end from 12dB/octave ~ 24dB/octave. Having two different drivers producing the same frequencies creates weird sounds and the dispersion patterns are uneven. Some needs dictate extreme slopes of 120dB/octave.

[Marvel]

Neil,

I would think that an L-pad to adjust the gain and a single cap should work ok for what you are trying to accomplish. A single order crossover should still sound ok. I would assume the voice coils of the two will be close so they are fairly time aligned.

Should sound nice.

Bruce

[DizRotus]

Chris-

These are the kind of suggestions I'm seeking.

Thanks,

Bruce-

I want to avoid purchasing L-pads. The speakers sound very good within their limitations, but I want to see if I can use the CT125s to make them sound better, even if only only temporarily at an experimental level . Yes, the voice coils would be essentially in the same plane.

Thanks

[BEC]

Neil,

You can connect the T2A like the crude drawing below. Shown is the connection for 3db of attenuation. Moving the 2uF cap to tap 3 would give you 6db of attenuation. Tap 2 is 9db and tap 1 is 12db.

The cap at the input of the T2A is just a large value to allow all frequencies to pass but block any DC that might come from the amp. Just a safety feature in other words. For experimentation, not left unattended, you could leave out that cap.

Bob Crites

[DizRotus]

Bob-

Thanks and Merry Christmas!

I'll report back with the results.

[djk]

It should be mentioned that the T2A without the 20µF cap is an 8Ω impedance at 30hz, decreasing to less than 1Ω at DC.

Bob is correct, no cap is fine for experimenting.

[DizRotus]

It should be mentioned that the T2A without the 20µF cap is an 8Ω impedance at 30hz, decreasing to less than 1Ω at DC.

Bob is correct, no cap is fine for experimenting.

I'll use the 33µF caps from now dissected Heresy networks to experiment.

[DizRotus]

Using the schematic and advice supplied by Bob, as well as Dennis' s helpful confirmation, I constructed this crude network to mate the CT125s to my experimental single driver speakers.

[DizRotus]

Rather the using the 33µF caps from old Heresy networks, I used a pair of 30µF caps and a pair of 2µFcaps that were available. The numbers "4", "3", "2" & "1" on the board correspond to the T2A taps. By moving the alligator clip I can adjust the attenuation as per Bob's notes.

My initial impression is that it sounds very good at tap 4 with the least amount of attenuation. That's probably due to my 64-year-old ears and the high frequency hearing loss caused by a DJ biz when I was young and foolish.