I may be all wrong, but it sounds like you are describing the Ohn F that was from mid 1970's. I'm sure if you google it you will find pictures of it somewhere. I think there was also an Ohm A bigger model that came out 1st. We sold the original Ohm F where I worked back then, and I can still remember the Ohm rep coming in to modify our demo's. He took a straight blade razor and made randon slits in the cone material and then filled the area with silcone grout.

Quadlover is right on the money.

Ohm is still alive, too.

http://www.ohmspeaker.com/

Cheers!

Infinity also made a couple of models in the mid-70's that used the "ice-cream cone" Walsh tweeter: the Monitor and Monitor IIA.

The link is www.ohmspeakers.com.

I attended what was billed as the "world premier" of the Ohm A back in the early '70s. A friend of mine bought a pair of the early serial number units. At a party in his house, I was engrossed in a conversation while the speakers played a vocal music. I suddenly stopped and turned my head to look for the singer. No other speaker has caused that reaction from me before that time. Unfortunately, those were very inefficient speakers requiring lots of power, but couldn't handle a lot of power. Their later version the Ohm F was more efficient and sold much better on the market. Latest are the Walsh series 3.

Because those speakers were virtually omni-directional, you can hear both even if the speakers are lined-upalong your direction of sight. Again, no other speaker at that time could do this. It's not these interesting tricks that make them interesting. It was the unbelievable clarity of the sound that was most impressive.

Ohm Acoustics offers a generous in-home try-out of their products (120 days I think). They also take trade-ins and offer value upgrades to owners of older Ohm speakers, also with a generous try-out period, but not as long as for the new product.

Today, speaker technology has advanced for many products, such that you can find really good ones available from a variety of companies.

piramid was another company with a similar design

I've seen an extension of the Walsh design made by German Physiks speaker. They take the concept really far with respect to detail, but it's expensive. Maybe Stereophile can do a review of the Ohm Walsh 5 S3's and the German Physiks units too. They are "essentially" single-driver omnipolar speakers (Ohm uses a supertweeter).