5-driver speaker wiring?

[scone]

I am planning on building two 3-way towers this winter break. It's occured to me that if I use 3 drivers (for simplicity's sake, lets just say they are all 8-ohm), then after I hook them up in parallel I end up with an impedence around 2.6. It seems like this is too low, since any amp I get would have to work pretty hard to drive them... Let me know if I'm wrong.

So what if I take 5 drivers (2 woofer, 2 midrange, 1 tweeter) and I hook the two midranges in series (after the crossover circuit) and end up with 16 ohms for the pair. Same thing for the woofers. Now I would be putting 16, 16, and 8 in parallel, and would end up with 4 ohms nominal. This seems like a pretty good improvement over 2.6, since the amp will at least be rated for 4 ohms.

Obviously this would be quite a bit more expensive then using 3-drivers. Would it make sense to build the speakers this way? Is this even a good idea? And, would it improve sound quality significantly enough to warrant spending the extra money?

-tony

[BobEllis]

The crossover causes the impedance of each section to rise outside the passband to make your effective load in the neighborhood of 8 ohms with one of each driver. No need to double up on drivers unless you need the sensitivity.

If you haven't done crossover design before, I'd suggest starting with a two way or a proven design.

[scone]

Right, I figured the answer was something obvious I've actually never designed a crossover, but I'm not afraid of a little research or math or soldering. From what I had read so far it seemed like hooking them up this way might work... I couldn't find the reason why nobody did it that way so i asked.

I don't really want to build a set of 2-way speakers since I already have a set of pretty nice 2-way studio monitors. I'm actually looking to build something that can handle a bit more power... something i don't have to replace for a long time. Thanks for the suggestion though.

What if I hooked two tweeters in series and two midrange drivers in series (so the amp sees roughly 16-ohms when it's amping mid-high) and use one 10in. woofer for bass? I think this way I would end up driving the woofer with considerably more power then the other speakers (since bass requires more power/decibel anyway). I think I could use a driver with considerable less efficiency then the mid or tweeters to counteract the bass drowning out the other ranges. I haven't done the math (errm i'm not even quite sure how to at the moment), but I was wondering if anyone has seen it done this way?

If it's too complicated to build the speakers with 4/5 drivers in each I'll stick to 3. I'd like to give it a shot though.

[Bill Fitzpatrick]

You don't want more than one tweeter- trust me on that. One mid is plenty if the efficiency matches the tweeter. Pick a woofer that will provide an efficiency match.

[AndrewT]

Hi, since you have not built a xover before then can I be rude enough to suggest a few of pointers.
1 use perforated board to support your components.
2 hard wire the components on the other side of the perf board.
3 design the board for bi wire or tri wire, it really helps.
4 arrange for large gaps between the inductors and to orient the inductors at right angles.
5 try to get air cored inductors but they are more expensive.
6 go for large wire say 1.2mm for your interconnect.
7 tie down all the larger components with tie wraps through the board
some others may advise on single core or multi strand or insulated multistrand or enamelled or plastic insulated or tinned or silver plated. The options are enormous.
good luck and regards Andrew T.