Would this be possible?

You could ask these guys:

Knuckle Bass Website

 

Who needs a 15(!) Hz E when you can't really hear it and probably need several kilowatts to amplify properly?

 

u could hit that brown note

 

If you have the right combination of scale length and string gauge you can indeed hear it.

20 Hz is attainable in a studio and with ELFs or El Wappos. I have driven both with half of my Crest LT1500

 

What's the purpose of going so low?!?!?!? In which musical setting could these notes be useful?

I don't think the human ear can hear such low frequencies. What you hear is probably only the harmonics. As Warwickben said, "u could hit that brown note".

 

The purpose it has served to this point is as sub-support for intricate upper range bass parts - halves, quarters and eighths. It sounds much better and stronger than the sub bass effects currently being offered on the likes of the SWR 750x.

It can be heard but it is quite subtle - certainly not for everyone.

And the brown note supposedly lives somewhere between 16 and 17 Hz.....

 

Your soundguy will want to kill you...but then he'll switch on the subsonic filter...

 

I tune one 4 string to ADGC using Heavy gage strings designed for a 5 string (BEAD - tuned down whole step). I use .145 for the low A and .110 for the D. I buy the individual strings to get the sizes that work for tuning this low. www.juststrings.com sells individual strings including a .145 Ken Smith B. I had to cut a special nut to accomodate the thickness of the strings (a .145 is a massive string).
The advantage to using ADGC is that if you learn a song on a normally tuned 4 string (EADG) using the 3 higher strings, you can easliy convert that to the ADG strings but an octave lower in this new tuning.
I found that the low A is about as low as one can go and still be able to recognize the pitch. I rarely use this bass live but when I do I use 2 18s for the bottom. If I need those deep low notes normally, I use a dbx 120xp subharmonic synthesizer (which in reality only goes down to low A also).
There are several 7 string players on the forum that use a low F# (string lower than the B). Frequencies that low would require something like a 21" speaker or a Bag End ELF system.

 

Good on ya for your tuning choice! When I built my four string the A is what I was after. I use .140s for my A but my scale length is longer.

I just wasn't happy with the tension or the tone using a .145 on a 34/35/36" scale length.

 

Scale length is key for accurate intonation. Most 5 string basses with a 34" scale are not very accurate. If the 12th Fret is tuned to the open B string, the first few frets are usually sharp. This partially is true also on some 34" 4 string basses with the E string dropped to D.
A 35" scale helps the B string but usually the 1st and 2nd fret are still sharp when the 12th fret is in tune.
The longer the scale, the less tension is needed to get the proper pitch - so smaller strings could be used for the same pitch. I have seen custom basses that have very tight accurate lows with Detuned tunings. One local guy built a 6 string with a 38" scale - He tunes F# B E A D G. The tension on his strings are very tight - I think he uses a .140 for his F# because it was the thickest string he could get in that length.

 

Getting the gauges was the tough part for me. As for the scale length, I arrived at mine based on contemporary wisdom and available supplies.

I like the B I get out of the majority of 35" basses. As it was an A I was after specifically I did the math and arrived at 39.5" as that is how much longer 2 frets would make the scale length.

I had originally intended to stop at the A but I got to talking with John Turner on another forum (I guess they let him out now and again ) and he had me wondering how low my bass would go.

As I had the benefit of two extra frets I figured I could hit the E. But it cost me plenty to find the appropriate string gauge to pull it off.

I'd love to see/hear your local guy's 38" - better still to actually talk with the person

 

I just saw this tread & have to say that my friend knuckle_head makes some incredible basses!

The longer scale length & tuning made me a little skeptical at first; however playing one changed all that. The low A string had more tension & snappiness than most E strings. It's an amazing experience & one I can’t wait to repeat.

Mark
AccuGroove.com