What's with 4 ohm speakers?

I'm just now reading through all this and have to apologize for my 1st post. Its really a half ass response, but I did it for a reason. As far as 4 ohms not being an average, thats my error. I always thought nominal meant average (in context of speaker impedance.) I also should have put an exception in for most tube amps and a few SS ones, as well.

When I read the OP, I couldn't make up my mind if it was an attempt by someone who doesn't like high end audio for some reason and just wants to start an argument, or possibly a beginner who just doesn't know. Its just a vague statement with no equipment or examples listed. Usually, when someone really wants to find out something, they do a little better with the specifics. Thats why I made the if you have a good amp comment. I just pictured a beginner with something like a Sony receiver possibly looking to move up. In that context, a typical entry level SS amp shouldn't have too much problem driving a 4 ohm load.

Unfortunately, it looks like I may be right. Everyone here is giving some really high quality answers and the OP is no where to be found. If it makes any difference, I read through all the posts and thought they were truly excellent.

Tell you what I'm going to do. Got another couple projects coming up this summer. I'll make up a 'quick and dirty' mono cabinet with 4 small, induvidually sealed midwoofers. Each will have it's own terminals that I'll hook up individual, parallel pair, series pair and series/parallel, measuring amperage, voltage and frequency response. Don't have state-of-the-art testing gear but should be consistent. No crossovers. Bottom woofer will be at least 1.5 feet above floor. Planned drivers are Dayton DS135-8's, which are fairly conventional except for small size and required cabinet volume.

Since the question was never about percieved sound quality or matching amps, (tube or SS) I'll just use what I have.

Never actually seen this done before, just math and theory.

For modern amps 4 ohms is a doodle. Its not an issue.

Thanks
Bill

Ngjockey, Pipedreams has done something like that. I've seen Pipedreams that were 4 ohms, and the exact same model in 16 ohms.

Seems to me the ZU Definition, normally a 6 ohm speaker, is also available as a 30 ohm speaker.