Turning PA 2-way into 3 way?

[pat1929]

Hi! (not sure if I should post this here, or in tech talk? did both, but I'll remove the redundant one).
Anyway, I got a nice pair of older Bag End Ta12-jr's, that sound great, are pretty loud, but just don't do anything below 100hz. (the manual 75 hz, but I had them tested, and the graph falls off a cliff @ 100hz)
here are all the specs I have from the manual:
-2 way vented enclosure, 1.1ft
-99db 1w/1m
-passive time align x-over @ 2.5khz
-150w continuous, 600w peak
Rather than dealing with a separate sub system, I was thinking about just building a bass bin with a built in x-over of some sort to extend the range and power of the system, effectively making them a 3 way speaker. I'm guessing if the tops are 8 ohms, then if I get a subwoofer @ 8ohms, I could effectively have a 4 ohm speaker (?) which mean I could just use 1 power amp very efficiently (currently have a qsc rmx1450 or a crown Powerbase 2).

Any Ideas suggestions on what kind of driver for the sub? enclosure size? (I'd like to keep the whole thing slim and tall though)
- x-over? I'd prefer something off the shelf, since the idea of designing a crossover makes my eyes blurry... but open to suggestions... thanx P

[wg_ski]

A separate subwoofer. Passive crossovers at subwoofer frequencies are a bad idea in general, and to match sensitivity with your tops the resulting bass bin would be quite large. Probably too large -- 8 to 10 cubic feet.

[pat1929]

hmmm...so maybe, if I went the external x-crossover route... what kind of setting would I need, and what kind of enclosure/driver? (though I still want to see if there's a passive solution)
thanx p

[Sydney]

In response to your similar post:
The cost of the crossover components rises as the frequency drops:
Sub crossovers use more expensive parts.
Nowadays the cost of active crossovers and amps is not excessive.
IMO: Go active with a high sensitivity design, but expect a large cab for that efficiency.

[pat1929]

thanx for all the input guys... looks like active is the way to go then (and I do have enough amps...)... so maybe I'll just focus on building a good bass box...
any ideas on that front? how to choose the right driver/ and box design?

[Music is life]

thanx for all the input guys... looks like active is the way to go then (and I do have enough amps...)... so maybe I'll just focus on building a good bass box...
any ideas on that front? how to choose the right driver/ and box design?

What wg_ski said.
Also:
You could build 2 t39s from Bill's plans using the 3012lf.
You could build (2) simple reflex cabs from this driver:
http://www.eminence.com/speakers/spe...ppalite_3015LF

Advice is build 2 smaller cabs single driver (for easy transport) and always group them together for better bass.

Here are some cab designs from Eminence. http://www.eminence.com/pdf/Kappalite_3015LF_cab.pdf

If a little more than you want to pay this is not bad at all:
http://www.eminence.com/speakers/spe...el=Kappa_15LFA
You loose a few db in total output and it's heavier to move around.

Use 1/2 baltic birch and brace them very well inside.

[Taterworks]

Whatever you do, don't modify the Bag Ends in any way. Those are some pretty good-sounding speakers all by themselves (and classics), and they have resale value, but they will lose that resale value if modified.

The deep-pocket solution would be to add one of the new powered Bag End INFRA subwoofers with the built in INFRA integrator (something they really should have done all along) but any competent PA subs (and you could go powered for simplicity) should be easy to mate with the Bag Ends.

[madmallard]

worth enough to sell and buy something more suited to his needs?