A “build once, cry once” bass rig for Low F# tuning

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Alexander Eddy
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A “build once, cry once” bass rig for Low F# tuning

#1 Post by Alexander Eddy » Sun Oct 24, 2021 2:56 am

I have just bought the full compliment of of BFM plans.
I have increasingly been using basses tuned with a low F# string. I don’t play metal, but have been using the lower tuning either when playing with a keyboardist playing in my territory, when playing in an 18 piece stage band or just for something fun. The low F# obviously places increased demands on my rig and most of my shows are indoors, with the bulk of the bass in the mix coming from my rig.

I am seeking suggestions for a biamp bass rig using two BFM cabinets. I was considering a dual 3015lf loaded fearful style cab, so comparable performance is a prerequisite.

Most stages I play on aren’t particularly deep, so that is a consideration. It’s not unusual for me to play somewhere other than directly in front of my rig (if I’m up front singing), so the idea of a biamped rig that will allow me to point the highs/mids towards me has appeal.

I need something that can get fairly loud and low in a format that is not overly deep.

At the moment I am considering an SLA Pro with 4 x Alpha 6 speakers (which I already have) with a 20” wide T39 below it.

Is there any sense going to the complexity of a DR200 if it is just going to be a top box for bass?

I am just about to start a 2x12 O15 as a general purpose bass cab. It may well meet my expectations, but then building stuff is fun.

Bruce Weldy
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Location: New Braunfels, TX

Re: A “build once, cry once” bass rig for Low F# tuning

#2 Post by Bruce Weldy » Sun Oct 24, 2021 8:24 am

For a rig that's not too deep, the T39 and OT12 combo would be ideal. Build the T39 the same width as the OT12 and you have a nice looking rig. And keep it up against the wall - you won't get any cancellations and it will get some boundary loading.

BTW......how big is an F# string? Size of a telephone pole?

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

himhimself
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Location: Bloomington IN

Re: A “build once, cry once” bass rig for Low F# tuning

#3 Post by himhimself » Sun Oct 24, 2021 8:59 am

Bruce Weldy wrote:
Sun Oct 24, 2021 8:24 am
BTW......how big is an F# string? Size of a telephone pole?
Ever look "under the hood" of an Imperial Bosendorfer? Love those extra low notes, all the way down to 20hz. Although I'm sure the rainbow of harmonics coming off those massively thick and long strings has more to do with the sound than the fundamental.
2xT30 (20", 3012LF)
2xT30 (21", 3012LF)
4xOtop J-array (Beta12, melded/straight piezos)
Truck Tuba (MCM)
Next up: 2xJack12 or family of table tubas

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Bill Fitzmaurice
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Re: A “build once, cry once” bass rig for Low F# tuning

#4 Post by Bill Fitzmaurice » Sun Oct 24, 2021 10:27 am

The amount of 20Hz fundamental is going to be practically nothing. With just about every instrument made, including pipe organs, the second and third harmonics dominate until the fundamental is at least 50Hz.

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Seth
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Re: A “build once, cry once” bass rig for Low F# tuning

#5 Post by Seth » Sun Oct 24, 2021 12:10 pm

I use a single 16" 3012LF T39 with a single 2x6 SLA (have two, but just use one most of the time) for practice space, small gatherings, and occasionally medium size outdoor shows (augmented with more tops for coverage), mainly for PA. However, I've DI'd bass into it a number of times and, to my ear and tastes, it sounds phenomenal through the T39/SLA combo.

With DSP, a two way system like you're talking about can be tuned to sound pretty much however you want it to sound. Add in a modeler and you've got a pretty versatile and potent combo.

I highpass at 45Hz per the plans on a 24dB slope and currently have the system tuned close to this example. I like it a lot.
Image


For an idea of the T39 output potential, it's pretty much maxed out in the video below. It was completely sufficient, just at/near it's limit. Video was taken roughly 100' away from the "stage"
(wear headphones)



Amp wise, the SLA and T39 work very well off the same power, so one amp will do fine.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Alexander Eddy
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Joined: Fri Feb 09, 2007 7:52 pm
Location: Australia

Re: A “build once, cry once” bass rig for Low F# tuning

#6 Post by Alexander Eddy » Sun Oct 24, 2021 9:13 pm

Bruce Weldy wrote:
Sun Oct 24, 2021 8:24 am
For a rig that's not too deep, the T39 and OT12 combo would be ideal. Build the T39 the same width as the OT12 and you have a nice looking rig. And keep it up against the wall - you won't get any cancellations and it will get some boundary loading.

BTW......how big is an F# string? Size of a telephone pole?
Depending on the bass it’s on, anywhere from a 0.160 to a 0.192”

Alexander Eddy
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Location: Australia

Re: A “build once, cry once” bass rig for Low F# tuning

#7 Post by Alexander Eddy » Sun Oct 24, 2021 9:16 pm

Bill Fitzmaurice wrote:
Sun Oct 24, 2021 10:27 am
The amount of 20Hz fundamental is going to be practically nothing. With just about every instrument made, including pipe organs, the second and third harmonics dominate until the fundamental is at least 50Hz.
And that’s part of my conundrum. I’ve no desire to reproduce an F# fundamental, and I haven’t played a rig that will reproduce the second harmonic with a great degree of authority. What I don’t know is whether I need that second harmonic and whether being able to reproduce it at stage volumes will add to the thickness of the low end

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Bill Fitzmaurice
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Re: A “build once, cry once” bass rig for Low F# tuning

#8 Post by Bill Fitzmaurice » Sun Oct 24, 2021 10:30 pm

With F# at 23Hz the second harmonic is 46Hz, which is well within the T39's capability.

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Seth
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Re: A “build once, cry once” bass rig for Low F# tuning

#9 Post by Seth » Sun Oct 24, 2021 11:21 pm

"Need" is highly subjective. Typical bass rigs don't really produce a powerful bottom end and the majority of what we hear from them is above 80Hz or so.

That said, with the T39/SLA system tuned as I mentioned above, open E on a standard 4 string (41Hz) is addictingly visceral... even with the highpass set at 45Hz.

So, while it's not entirely needed to get the job done, you may find a whole new world of pleasure and energy in the room when the bottom end is represented with authority. Even an 8x10 SVT doesn't do what the T39 does down low. Some of which is due to the limited tunability of a standard bass amplifier without a decent DSP suite. But still... I think you may enjoy hearing/feeling it.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Alexander Eddy
Posts: 13
Joined: Fri Feb 09, 2007 7:52 pm
Location: Australia

Re: A “build once, cry once” bass rig for Low F# tuning

#10 Post by Alexander Eddy » Fri Oct 29, 2021 3:16 am

Thanks for the advice, folks.

Seth, I very much like the clarity of your setup. I'll be using onboard amps with DSP for my setup. I'll be doing a t39 for the bottom end. I have enough drivers lying around to build an SLA Pro, an Otop 15, and finish the Omni 15 I have started. The Jack 15 is calling my name as a stand-alone cab for normal tuning.

So many good choices - I guess I'll just have to build a whole bunch of cabs and have some options!

Bruce Weldy
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Location: New Braunfels, TX

Re: A “build once, cry once” bass rig for Low F# tuning

#11 Post by Bruce Weldy » Fri Oct 29, 2021 5:35 am

Before just grabbing any speaker and trying to use it, check the plans for the T/S parameters. You can't just slap any speaker in any cab and expect good results.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Alexander Eddy
Posts: 13
Joined: Fri Feb 09, 2007 7:52 pm
Location: Australia

Re: A “build once, cry once” bass rig for Low F# tuning

#12 Post by Alexander Eddy » Fri Oct 29, 2021 6:02 am

Bruce Weldy wrote:
Fri Oct 29, 2021 5:35 am
Before just grabbing any speaker and trying to use it, check the plans for the T/S parameters. You can't just slap any speaker in any cab and expect good results.
Well aware, thanks Bruce. I have speakers within spec for all the cabs I mentioned.

Bruce Weldy
Posts: 7694
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: A “build once, cry once” bass rig for Low F# tuning

#13 Post by Bruce Weldy » Fri Oct 29, 2021 9:40 am

Alexander Eddy wrote:
Fri Oct 29, 2021 6:02 am
Bruce Weldy wrote:
Fri Oct 29, 2021 5:35 am
Before just grabbing any speaker and trying to use it, check the plans for the T/S parameters. You can't just slap any speaker in any cab and expect good results.
Well aware, thanks Bruce. I have speakers within spec for all the cabs I mentioned.
Then start making sawdust!

And take pictures......there are lots of purveyors of gear porn that frequent this site.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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