Maximum lower end of frequency range achievable from two way speakers.

[chris661]

A friend of mine sold out to that idea that a 15 inch woofer and big horn tweeter was the way to go. Now he's stuck with these huge cabinets in his living room that sound OK, but not great. They're very efficient, which would be important if they were a PA system for a rock band or if they were used outdoors, or if they were going to be driven by a 5 watt SE tube amp (which is what he's doing). The cabinets are so big that they may actually create more room acoustics problems. One might ask, if they can make speaker drivers be highly efficient (95 - 100+dB, 1watt/1 meter) then why would so many speaker driver manufacturers make drivers that are so inefficient (83dB - 90dB)? Obviously because the less efficient drivers have higher fidelity, or they wouldn't sell. For in home use, I've never thought of efficiency as being a high priority.

Simple reason: bass response. Its just the product of Hoffman's Iron Law: small, low cutoff, efficient. Pick any two.
People want useful LF response and small cabinets, so efficiency goes through the floor. I've a pair of those 6.5" TB mini-subs which need a rocket up them to do any volume - 2nd LED was lit on an NU6000, which is somewhere between 200 and 500w peaks per driver. That's a lot. They do hit mid-30s in a 14L cabinet, though, but it wasn't particularly loud by any stretch.

I also have a 15" sub that achieves the same bass response in a much larger cabinet, and can match both of those 6" drivers with very little power.

Chris

 

[Bob Richards]

If you want a small cabinet and don't need very high SPL, I find that 50watts rms (per driver biamp'd) gives me pretty decent volume, with the active EQ making the 8 inch woofers acoustically pretty flat down to 30HZ. If "room volume" is where it's just loud enough to hear every detail clearly, these speakers go at least 6dB louder than that with no noticeable distortion. In a typical apartment bedroom sized room I would never want it any louder.

 

[weltersys]

Originally Posted by weltersys
The trade offs have dictated that the best sounding wide range two way that can play at "reference level" ends up being a ported 15" and a high frequency compression driver.

I've never seen a clear statement like this before. I've seen proponents for different approaches argue the relative merits etc.

If a large ported woofer + tweeter horn is the best sounding why are there so many speakers about today which don't conform to this approach ?

Most consumers don't need theater/control room "reference level", so don't need a large ported 15" and a high frequency compression driver to get good sound.

That said, limiting a system to 2 way is just that, a limitation. Going three way relaxes the demands required of the drivers considerably, reducing their cost.

Art