A different approach to a bass rig. Is this possible?

[WB]

Will do.

[Tom Smit]

WB-you'll have to post in the "come Hear Them" when it is time.
Fingal, Dutton, Iona Station, Talbotville? My folks live in St. Thomas.

TomS

[T_Gowan]

Hi

I'm in KW and would be interested in hearing any BFM systems in use in our area too.

Thanks

Tom Gowan

[WB]

My folks live in St. Thomas.

TomS

Every summer I do a few Sunday outdoor band shell concerts at Pinafore Park. The only thing is the one band I'm playing a non-BFD horn, and the other band I'm using a commercial 12" direct radiator, which I'm hoping to solve when I finally get around to finishing the O10 I started.

The O15Sub/OT12 combo I use in a couple of country bands, mostly around the Tillsonburg area. While I'm very happy with it, this summers project is to redo it all by building a modular 2 piece lightweight O15Sub and DR250.

[Tom Smit]

LOL! I played one of those horns way back in '73. My My favourite fourth son can play one of those plus a valve one. Currently, (because of his abilities, and a lack in the Grade 8 band) he plays a trumpet.
It would be interesting to hear the O15Sub/DR250 combo sometime.

TomS

[dug dog]

this summers project is to redo it all by building a modular 2 piece lightweight O15Sub and DR250.

Hey WB:

This sounds like an interesting project. I remember you mentioning somewhere in the forum that you were using an O15 sub and and OT12. I'd love to know what you're thinking as I'm still banging around the merits of different configurations and may try to incorporate some lightweight composite sandwich panels using rigid pink insulation and 1/8 inch ply. I threw together a simple project to see what kind of results I could get and documented it here.
http://www.talkbass.com/forum/showthread.php?t=537802

At the moment I'm trying to decide whether I need to get some more power, build multiple cabs, or what. If money were no object, I'd probably get me a whole whack of wattage and build some smaller, direct radiator cabs using the Kappalite LFs, but I'd like to get by with my existing amp, so keep coming back to the O15, though, as I mentioned earlier, it's really more cab than I'd like to carry around. If you have a scheme to make it lighter or more modular, I'd love to hear it. It was suggested earlier, that the O12 should be everything I need, but with 300 watts @ 8 ohms, I'm concerned about running out of headroom. I suppose I could always build one and find out, but shop time is in limited supply and I've no idea how easy it would be to sell a second hand driver around these parts. The used scene here is nothing like in the U.S..

Anywho, I've ordered the full set of plans, so will keep dreamin' until they arrive.
Cheers.

[WB]

I'd love to know what you're thinking as I'm still banging around the merits of different configurations and may try to incorporate some lightweight composite sandwich panels using rigid pink insulation and 1/8 inch ply. I threw together a simple project to see what kind of results I could get and documented it here.
http://www.talkbass.com/forum/showthread.php?t=537802

Very interesting. Enjoyed reading that thread.

I'd probably get me a whole whack of wattage and build some smaller, direct radiator cabs using the Kappalite LFs

I know it's tempting to go that way, but I now find the lower the efficiency, the more the higher distortion from direct radiators really annoy me.

If you have a scheme to make it lighter or more modular, I'd love to hear it.

No real scheme, except to make the O15Sub two boxes instead of one. This time, I'm going to try 3/8" BB, with 1/4" bracing, no access panels, and move the horn into the center of the cabinet where the horn itself will a be big brace. I figure each should be about 35 lbs, which is good enough for me. Since the box will support a DR250, I'm going to make the sub boxes about 22" wide, 14.5" high (each), and 21.5" deep. Being modular, there may be times when I'll only use one box for sub, it all depends on how it works out.

So many choices to make.

[dug dog]

No real scheme, except to make the O15Sub two boxes instead of one. This time, I'm going to try 3/8" BB, with 1/4" bracing, no access panels, and move the horn into the center of the cabinet where the horn itself will a be big brace. I figure each should be about 35 lbs, which is good enough for me. Since the box will support a DR250, I'm going to make the sub boxes about 22" wide, 14.5" high (each), and 21.5" deep. Being modular, there may be times when I'll only use one box for sub, it all depends on how it works out.

Very interesting. I'm all ears. You're thinking a 3012LF in each box? Since I have very limited knowledge re: horn loaded drivers, I have no idea of what's possible, but this sounds like a fantastic solution. Any interest in starting a thread to discuss it?

I think it's time for me to do some more reading on the subject of horn loaded drivers.

[bgavin]

This time, I'm going to try 3/8" BB, with 1/4" bracing...

More and more, I'm finding the 3/8" genuine BB is entirely sufficient.
These designs are self bracing for the most part.

Bill recommends bracing for any panel span exceeding 8".
This would probably be reduced somewhat for 3/8", as his recommendation was referencing 1/2" material.

My OT212 boxes are entirely 3/8" BB and solid as a rock.
They come in at 55 pounds with 2512 drivers and bare wood finish.

[WB]

You're thinking a 3012LF in each box?

Yes. I've been waiting a long time for the 3012LF's so I can try this. I asked Bill If two 3012LF's can be considered a drop in replacement for the 3015LF and he said yes.

Since I have very limited knowledge re: horn loaded drivers, I have no idea of what's possible, but this sounds like a fantastic solution.

I think so.

I think it's time for me to do some more reading on the subject of horn loaded drivers.

The short horn only loads the driver starting in the midrange. The horn for the O15 when being used as a sub is really a flared port. The slot loading of the driver, into the flared port really increases the efficiency in the low end. My O15TB Sub measured 100 dB's at 1 watt, 1 meter at 50 Hz, which is quite remarkable.

I just got home and see a brown truck has dropped off a few boxes from parts express. That combined with the fact that I've taken the next couple of weeks off work means I'll be able to make some saw dust.

Here's some O15TB Sub build pics from last year if you're interested.

[dug dog]

I just got home and see a brown truck has dropped off a few boxes from parts express. That combined with the fact that I've taken the next couple of weeks off work means I'll be able to make some saw dust.

Excellent timing. Can't wait to see how it turns out!