Crossover crazy

[Dryseals]

OK, I'm not new to speakers, been at it since the 70's. But I skipped out the later 80's and 90's.

I'm building my kid some speakers for his surround sound in his room, some close outs from PE, small three ways, Hi Vi woofers, Vifa mid range and Dayton tweeters.

When it came to the crossovers and the increase in copper prices, I started looking for a cheaper way to finish the goal. So I have been going crazy buying 3 ways off of Ebay. I bought some MB quartz D55 crossovers (6 of them) for a fraction of what it would cost to buy the components for one speaker. But I find that they are for 2.5 speaker.

Since I'm an old timer, I wondering, what is a 2.5 speaker? Is this for tweeter, midrange and woofer with the cut off on the woofer being high enough to allow a sub woofer?

Help please for the modern speaker terminology challenged.

[ocool_15]

2.5 is referring to using a single tweeter and I would think 2 identical woofers. One woofer will play like it would in a regular 2 way but the 2nd is added to extend the low frequency. Also you can displace more air.

I can not recall any 2.5 system that used different drivers.

Parts Express Project with 2 6.5"

Center channel with a similar idea

[Variac]

Sio you have two woofers in parallel and then you roll one of them off with a low pass crossover. the other keeps going until you roll IT off to transition to a midrange or tweet. This exagerates the low bass (duh!) which is often just what you need to counteract Baffle Step and move a lot of air in the low frequencies.

What's baffle step? That is best to search the forums to learn about

Variac

[Dryseals]

Thanks guys, I got the concept now. I originally drew out the crossovers and was a tad confused as to the values used once I had the obtained the coil values (had to desolder a leg on each and measure the values with SoundEasy. Then using SoundEasy, a few jumpers and a few resistors, I was able to get a good view of the actual crossover points, which confused me.
For some reason I had it in my mind that "2.5" should be, tweeter, mid and half the woofer, thus the point five. Something used to in a small surround system where the 125 and belows were crossed out in the surrounds. And I couldn't find any info on the web as to what the 2.5 actually stood for.

The PE article on the UBTs cleared it up and got me thinking. I have several sets of drivers laying around, could be fun.

Thanks again.