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

[dug dog]

Hi guys:

I've been glued to these forums for the last week or two. Fantastic info- I've learned a lot.

I'm trying to up-grade my bass rig and get the most bang for my buck. For power, I'm running a Yorkville Y400B which is supposed to deliver 300 watts @ 8ohms and 400 watts @ 4ohms, which is its minimum impedance. I play a 5er and, by times, need to keep up with a loud drummer and guitarist.

I love the look of the Omni 15 graph, but don't much care for the size and weight in terms of negotiating stairways and small car trunks. (BTW, I'm well aware of Iron Mike's law regarding Large, Loud and Lowb.)

I've banged around all kinds of different options and, although I like the thought of top/sub approach, it seems that even the largest T39 doesn't have the low end sensitivity of the O15. Also, for the size of the T39, I might as well build the O15. The O12 with the dual BP102 would be an option, but, while smaller than the 15, it looks like it will be just as heavy.

So here's my idea. I haven't seen any mention of this approach, and maybe that should tell me something. Is it possible to build one of the tops and run it in parallel with one of the smaller subs with a passive low pass filter. I'm thinking, for example, an O15 Top (which has pretty good low end on its own) supplemented by an Autotuba or T18 using as much boundary loading as possible. If I understand correctly, the AT and T18 use a 4 ohm driver but, due to the horn construction, the actual resistance is closer to 8 ohms. That would mean that my amp would still be operating within spec.

Will this work or does this fall into the "not recommended" category due to 2 different types of horns operating in the same frequency band?

Thanks a bunch for your input.

[dug dog]

A little clarification:

When I say I'm trying to get the most bang for my buck, I'm referring to building a high sensitivity cab that I can power with my existing amp, as opposed to building a smaller, less efficient radiator design utilizing the Kappalite LF drivers and buying a bigger power amp.

[Tom Smit]

Yo, welcome neighbor! I can't give you the advice you are looking for but there are others who will.
Is there PA support for the band or are you alone for bass production?

Toms

[WB]

I love the look of the Omni 15 graph, but don't much care for the size and weight in terms of negotiating stairways and small car trunks.

I love the output of my O15 sub, but like you I don't much care for the size and weight for the same reasons you cite. I plan on soon doing a modular version using two 3012LF's. I'm curious how it'll turn out. Should work.

Edit: schpeling

[dug dog]

Is there PA support for the band or are you alone for bass production?

At the moment it's just me and my lonesome on the bottom end. We aren't gigging at the moment, but there is the possibility. I realize that if we start playing out, there'll have to be some PA support.

[gdougherty]

Depends on where you're playing and what else is available.

I play bass and run PA. On several occasions we've skipped using a bass rig and just run it into the monitors. While my monitors are high passed at 100Hz, the subs take over there and at the levels I like the bass in the PA, bassists are always more than happy. Personally, I always run this way and now actually run in-ear 90% of the time I play, with the subs picking up the bottom end feel. My IEM's also don't keep the bass frequencies out as well so the volume in the low-end comes up as well with the house added. This works very well for me since my primary concern is hearing the upper freqs that actually provide the pitch. The house adds the wow.

Whenever bassists bring in a big stack on my system (even a turned up 2x10) I end up fighting them to get a good balance in the house. The bass rig is infrequently positioned well in terms of walls and the direct radiators never provide as clear a bottom end as my PA will.

If you'd be playing in a small bar band with vocal only support, you'll need a bigger stack since that's all the bar will get. If you're playing on a larger, quality PA with a competent sound person, you really shouldn't need as much. If they have good monitors, you might even be able to skip the rig and use those, especially if you get your own mix or only share with the drummer.

Just some FFT.

[Mikey]

The AT or T18 wouldn't offer you enough added benefit compared to the bottom of an O12 or O15 to make it worth doing.

An O12TB (3012LF) should be more than adequate. It will weigh 10-15 pounds less than an O15 and it's about 2 cubic feet smaller (less than 6 cubic feet). If you "need" more than that to "compete" with your guitarists, it's time to educate them.

[dug dog]

Just had an "AHA!" moment.

I didn't realize that the O12 charts are for a cab loaded with the Delta 12LF, NOT the new Kappalite 3012LF. In a post in early February, Bill stated that the new monster 12 will add 6db to the low end of the O12. That changes things significantly.

Thanks to everyone for their input.

To my Ontario brethren, I'm in Woodstock. If you're ever gigging in the London/KW area, I'd like to come out and check your sounds.

Peace.

[dug dog]

OUCH!!!

Now my poor, newbie head is spinning.

On closer inspection, in response to the question

just wondering how much of a differance there would be as far as sound with the new 3012lf in the omni12tb

Bill stated...

No change in the sound, but a 6dB increase in woofer output capacity.

I guess that means that the O12 will produce the same SPL curve using the Kappalite as it would using the Delta 12LF, but the Kappalite will be able to handle more power without distortion due to its much greater XMAX. I was all revved up thinking that the O12's response curve would now resemble that of the 15 with its beautiful flat (ish) to 40 response, but now, I think I misunderstood.

Bummed.

I was all set to fire up the saw, but, now, must reconsider......... Such is life...........

[Bill Fitzmaurice]

I was all revved up thinking that the O12's response curve would now resemble that of the 15 with its beautiful flat (ish) to 40 response, .

That's why amps come with tone controls.
If you've got the power to drive it a 3012LF loaded O12 will give all you need.

[WB]

To my Ontario brethren, I'm in Woodstock.

Woodstock? I've played there before, I'm about 45 minutes south/west of you. Grew up in Hamilton. Took this picture in Woodstock last year (the Navy Club).

[dug dog]

That's why amps come with tone controls.

I figured this might be coming my way. The EQ thing occured to me after I went to bed. I have a 10 band EQ on my head, so should be good to go. Some people think quickly on their feet. I, on the other hand, need to think a bit more before posting.

WB: You've gigged the Navy Club! I'm grinning from ear to ear. So where are you? At 45 minutes, you must be farther than London.

[Tom Smit]

So where are you? At 45 minutes, you must be farther than London.

I've been wondering that too! but he hasn't revealed it yet!

TomS

[WB]

Hiding amongst the farms and trees, near St. Thomas.



London's my daily commute.

[dug dog]

Hiding amongst the farms and trees, near St. Thomas.

That sounds nice. BTW, I'd love to get the heads up if you're giggin' the Navy Club again!