Speakers ABC

[panoramamonk]

Hi,

Lately I spread my focus from turntables/cartridges to speakers. Here I have a few questions. Please comment.

1. size of drivers
learnt from wiki that it's measured from centre of screw to that of the oposite, or more commonly the dia. of "basket". Would it be more accurate for the industry to claim a driver size according its effective area, which I think is the dia. of cone, or that of edge(foam) and tweeter diaphram?

2. most of the speakers, 2-way, 3-way or more ways are supposedly to cover a lot of the effective frequency. using the examples of 12"+4.5"+1" or 8"+1" or 6"+1", each is complete by itself. however, when i added a 8+1 to a 12+4.5+1 as speaker B, i found "something” there that was missing w/o it. why? (i know this is a stupid question, but i would be much more stupid if i don't ask).

3. can anyone suggest an effective way to add a 8" (or both 8" & 6") to the said 3 way?

[TheSeekerr]

Originally Posted by panoramamonk

Hi,
1. size of drivers
learnt from wiki that it's measured from centre of screw to that of the oposite, or more commonly the dia. of "basket". Would it be more accurate for the industry to claim a driver size according its effective area, which I think is the dia. of cone, or that of edge(foam) and tweeter diaphram?

Yes, although it's largely consistent - I remember seeing one driver somewhere that was a 5" driver in an 8" frame, but such things are the exception. At the end of the day it's largely irrelevant, because it's nonsense to say that one driver is better than another based purely on its size.

Originally Posted by panoramamonk

2. most of the speakers, 2-way, 3-way or more ways are supposedly to cover a lot of the effective frequency. using the examples of 12"+4.5"+1" or 8"+1" or 6"+1", each is complete by itself. however, when i added a 8+1 to a 12+4.5+1 as speaker B, i found "something” there that was missing w/o it. why?

Well, yes, multiple driver systems are designed so that each driver exploits its strengths and other drivers conceal the weaknesses. ie. if you need bass response to 20hz, you'll likely need at least a 12" driver, but they tend to have poor performance past, say, 150-200hz, so you need another driver to take over from there.

Point is, it's all about the crossover. If two drivers are well matched and the crossover is well designed, there are no "gaps" or weak areas, except debatably in the crossover region itself. Since more drivers means more crossover regions, designs beyond a 3-way tend to bring more problems than they solve. (the only use I'm aware of for 4+ way systems is those requiring very high power handling for extreme volume).

So maybe your three way is poorly designed, and just doesn't sound that good as a result. Maybe your 2 way is well designed but lacks bass extension, so you found the combination with the 3 way design pleasing.

My suggestion is that you try your 2 way speakers with a stereo pair of subwoofers, rather than adding extra drivers to your 3 ways.