Adding mid range driver to Karlson design


2013-02-20 3:30 am
Ok...I bought a pair of huge Karlson speakers. I know they were designed for one driver, but someone put a 12" bass driver in these. No complaints with bass, so I added a pair of stand-alone bullet tweeters. Whoa....sounds far better, but no mids to be heard. Okay, I need to add some sort of midrange driver, and was thinking about mounting some sort of vintage-ish horns on top of the cabinets. What do you guys think? I'm open to any and all ideas....and, if the horn-on-top idea sounds okay, please suggest some horns that might work (cheaper the better). Thanks!


Paid Member
2005-08-16 4:21 pm
normally, a 12 inch speaker will have pretty decent midrange - if your 12s make it past 2KHz on axis, then you should be able to use a K-tube and compression driver on top.

A modest, competent 1 inch format compression driver should work well. In the US, PRV D280ti, Eminence ASD1001-B, etc. are cheap and good.

You could even start with a paper tube. A tube based on the size Transylvania Power Company's "The Tube" will work well. You could make them from plastic plumbing pipe. Make it ~5.3" long with a half-ellipse slot gapped 1/8" at the "throat" - you can make it a bit longer to mount into a thin plywood mount for the compression driver. A crossover in the 1K5-2K range should work. There's no need usually for EQ in the high pass network

the tube can be tilted ~20-30 degrees up or 20-30 degrees down

if your 12" speakers are subwoofers with high mass and high inductance then you may need some other solution.

if you have any one inch compression drivers laying around, you could give a tube a go


K-tube on a high-end electrodynamic driver
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