Where to cross in a supertweeter with 2 WR125ST's?

[Brisso57]

I have a pair of Foster E100T10 ribbon tweeters, and I'm considering using them as supertweeters with a pair of CSS WR125ST's (placed one above & against the other).

I have two cabinets, each of approx 48 litres volume (which I can decrease by simply adding bags of sand). They can be sealed or vented, as I can modify the baffle.

The Fosters run from approx 6kHz to 40kHz. Approx 92dB.
Here is the data: http://www.allenorgan.com/forsale/fo...tFacePlate.pdf

Here is the data for the WR125ST's:
http://homepage.mac.com/tlinespeaker...-datasheet.pdf
86dB, but I believe running 2 in parallel with give a 6dB lift, making them net 92dB at 7 ohms?

OK.
Now I want to run the WR's full-range, and to blend in the ribbons just as the WR's fall away.

What freq should I cross over? (9500? 12000?)
What slope? Would 18dB be enough?

Thanks

Doug

[Cal Weldon]

If you have some caps laying around try a 1.5 or 1.0 mfd. May not need anything else unless you're concerned about the beaming of the WR's that seems to start about 5K. Oh and you'll only get 3 more dB for the same amount of power fed to the WR's so you might also have to add a little padding to the tweeter.

[audiobomber]

You're going to have a lot of comb filtering with a pair of WR's running that high, due to long center-to-center distances between drivers.

You should consider a 2.5-way TMM instead, which will give you baffle step compensation, allowing you to move the speakers out from the walls for best soundstaging.

[Brisso57]

Originally posted by audiobomber
You're going to have a lot of comb filtering with a pair of WR's running that high, due to long center-to-center distances between drivers.

You should consider a 2.5-way TMM instead, which will give you baffle step compensation, allowing you to move the speakers out from the walls for best soundstaging.

2.5?
Do you mean running the upper WR full range, with the lower one cutting out at, say, 4000Hz?

Doug

[audiobomber]

Originally posted by Brisso57
2.5?
Do you mean running the upper WR full range, with the lower one cutting out at, say, 4000Hz?

Doug

No, the lower woofer would cut out at the baffle step frequency (more like 400 Hz) and the upper woofer would run up to the tweeter crossover. The upper woofer-to-tweeter cross would be conventional, as in a two-way.

[Cal Weldon]

I tried this but too much combing and beaming. even when I hung a big 'ol coil on the bottom unit, I was not happy.

[Cal Weldon]

So I ended up doing this. Much better. No combing, no need for BSC. Both WR's running full and a small cap on the tweet.

[Brisso57]

Originally posted by Cal Weldon
So I ended up doing this. Much better. No combing, no need for BSC. Both WR's running full and a small cap on the tweet.

Thanks Cal. I recognize the cabinets. :-)

Doug

[planet10]

Originally posted by Brisso57
I recognize the cabinets.

The mutation of the Spawns that started the entire Chang dynasty.

dave

[audiobomber]

Originally posted by Cal Weldon
So I ended up doing this. Much better. No combing, no need for BSC. Both WR's running full and a small cap on the tweet.

Interesting idea. Maybe easier to place than bipoles?