"stacking" binaurals

[busboy]

This comes out of comments MrNiceGuy left in my "Theta or Delta" thread . . .

Niceguy had mentioned running two binaural beats simultaneously . . . a soft Theta and a louder Delta. I've never used more than one beat perfile, so I was excited at the possibilities, but before I start mucking about I wanted to get some binaural beat users feedback on the effectiveness of running two seperate tones simultaneously.
My question comes from the procedure that makes them effective. By running two tones at slightly different hertz, the brain splits the difference and then drifts into the brainwave state associated with that "difference". If two different tones are run simultaneously, then (a) the brain has to split the difference between two sets on tones and (b) the brain is encouraged to enter two different states at the same time.
I would assume that setting the different beats with different tones would allow the brain to distinguish them, but does feeding the brain two different beats cause the brain to split the difference again? For example, if I run a 2 hz tone (Theta) and a 6 hz tone (Delta), does the brain simply split them and drift into a state equivilant to a 4hz tone (low Delta)? If so, what's the benefit of running two different beats rather than running one and targeting that at the bridge between Delta and Theta . . . say, an oscilating beat that slowly drifts between 5 and 1 hz? What would be the practical difference between that and runing a 5 and 1 hz tone simultaneously?
If I achieve the same effect, I'd stick with the single tone to keep files as simple as possible. If the dual tones provide an additional benefit that a single tone does not, then that's something to explore.
Any experience or advice on this?

[CG091581]

Two binaurals will create atleast two additional binaural frequencies, if the carrier frequencies are too close. I like to keep the carrier frequencies for multiple binaurals atleast 100 Hz or more apart to avoid additional crossovers.

Example:

left/right

100/110(10 Hz) + 120/135(15 Hz)


120-110 = 10 Hz
135-100 = 35 Hz



The brain can use multiple types of brainwaves simultaneously.

Too many binaurals at once might cause confusion, but around 4-5 at a time should be OK as long as the carrier tones are far enough apart.

[busboy]

"The brain can use multiple types of brainwaves simultaneously.

Too many binaurals at once might cause confusion, but around 4-5 at a time should be OK"

I would not have thought that this was possible -- thank you for providing some extremely useful knowledge.
Hell with 4-5 beats. I'll be happy running a soft 1.5 Theta and a louder 5 Delta. I'm not yet at the level where I can see the practical benefit of running anymore than that (at least for trancing -- those are the two states I'm trying to deal with, so 2 beats should be more than enough)

thank you again

[MN_FriendlyGuy]

So far, the discussion has been about beat-frequency. But we've ignored an important factor - pitch. (Unless that's what CG091581 meant when using the term 'Carrier Tones')

When listening to music, we often hear chords... multiple notes played simultaneously. When this happens, we rarely hear the individual notes. Instead, our minds perceive harmony/dissonance.

Busboy, the beat 'voices' you're going to be stacking - try giving each one a distinct pitch. For example: a basic chord of 'C' & 'G'

'Deep C' is 2 octives below 'Middle C' and has hz rate of 65.40
'G2' has a hz rate of 97.99

Source of information: Wikipedia
http://en.wikipedia.org/wiki/Piano_key_frequencies

Since the fundamental nature of binaural beats is imperceptible dissonance between left ear and right ear pitch, I hope you're using a tool like BrainWave Generator. BWG gives you control over the pitch (end result) that's perceived without needing to calculate differences (left/right) to create the desired 'beat' effect.

[busboy]

I had been concerned that if the pitches were harminically compatable that there might be some form of "blending", so I had for the first experiment seperated the pitches by quite a bit . . . the Delta I ran at just under 400 and the Theta I believe was set at around 100. Since the Delta is running in the final file at a much lower volume, I made that one the high tone . . . I don't mind a louder low tone (usually comes through like a hum), but a louder high tone really gets annoying.
The Wiki link was something I hadn't considered. I was just setting tones based on what sounded compatable with the vocal track and any other effects I'm mixing in, using the highly scientific method of recording and mixing it in, listening, deciding it sucked, then moving the pitch setting up/down 50 until it seemed to fit in. Obviously, if I'm setting them to actual musical note frequencies, getting them to sound nice would be alot easier.
If using actual notes, I take from your post that setting an actual chord would effectively cancel out the effect? That makes sense to me, and was one of the reasons I tried to shy away from notes. Also, setting the tones at actual musical note settings may raise another complication that just occured to me . . .
I had been layering in subliminal tracks and barely audible tracks to create a background distraction so the pauses in the vocal track didn't cause me to start thinking too much -- my concious needs something to play with or it gets agitated and therefore not relaxed. Recently, I've come to question the effectiveness of subliminals alltogether, based on various studes I recently read (although I plan to do a series of experiments next week to verify for myself whether they are effective). If I'm stripping out the subvocals, that leaves only Mino's "subliminal" file to serve as a distractor (I run it at barely audible levels, so my mind can try and figure out what the voices are saying -- a nice distraction).
If I'm using the voices exclusively as a distractor, I had planned on editing them out and mixing in actual music instead, again at a nice soft volume so they dont interfere with the beats or vocal tracks. Some early experiments with this have been promising . . . especially with 12-15 minute files. I take a 3 minute music clip (something mellow and smooth, Like Ray Lynch), then repeat the clip for the length of the file dropping the pitch of the music a little each time (also overlap the music and fade in/out from each so there's no perceptible shift). It seems the "dropping music" might be oddly effective as a sort of audio suggestion to go deeper . . . . some more experimenting will hopefully reveal more.
Anyways, back to the concern. If I set the beat tones to actual notes, I'm wondering what risk there would be to the beat tone forming accidental chords with the musical file, and would that interrupt the formation of the beat. It probably won't be too much of an issue either way . . . At most, an accidental chord would occur for a moment or two, and an extremely temporary interruption in the binaural beat isn't going to destroy the overall effect.
Assuming I set the binaural carrier tone to a musical note, do you think it would be more beneficial to mix it in with the musical background or seperate them (via volume settings)? Mixed in allows it to become essentially hidden, but will the tone be "lost" in the croud of musical notes? Running it at a more pronounced volume seems like the better/effective approach, but I'm thinking about listeners who don't like binaurals. I actually like the hum, but many people I know find it annoying, so blending it into/under more pleasant musical notes would make the file more enjoyable for them . . . but would it be less effective?

As always, thank you for the knowledge and advice Friendly.

p.s. -- yes, I'm using Brainwave Generator. Audacity has a binaural beat generator (via a plug-in), and it actually seems to have a few advantages over BG -- you can set smooth transitions from the different levels, whereas in BG the shifting up/down seems more abrupt. Regardless, BG tones just sound nicer to me, so I've been using that eclusively for the binaurals.

[MN_FriendlyGuy]

If using actual notes, I take from your post that setting an actual chord would effectively cancel out the effect?

Nope - It's fine to use chords. In fact, I prefer it.

I especially enjoy taking a harmonic with higher pitch and faster beats and gradually lowering both until they become an exact match with the second 'voice'.

Anyways, back to the concern. If I set the beat tones to actual notes, I'm wondering what risk there would be to the beat tone forming accidental chords with the musical file, and would that interrupt the formation of the beat.

The situation you're describing is one of artistry rather than science. I do something similar for spoken files. (Disclosing secrets here)

- Import a non-binaural mp3 into audacity

- If the mp3 is stereo, split it. If it's monaural, duplicate it

- Select the left channel. Use the 'Change Pitch' effect to raise the pitch of the left channel by 0.04

- Select the right channel. Use the 'Change Pitch' effect to lower the pitch of the right channel. (-0.04)

- Make the two tracks stereo

- Listen to your work. If necessary, make corrections by redoing the work.

- Import your original (non-binaural) mp3 again

- Reduce the volume of the non-binaural track slightly

- Listen to your work, adjusting the volume control. Your goal is to distinctly 'hear' the sound in the center of your head as well as 'hearing' it in your left and right ears.

Happy experimenting! And now you know what I do with my spare time.

[CG091581]

Solfeggio frequencies
Add digits together until your left w/ a single digit # (3,6,or 9)
Each set of three is always in harmony.

174Hz = 3
417Hz = 3
741Hz = 3

285Hz = 6
528Hz = 6
852Hz = 6

396Hz = 9
639Hz = 9
963Hz = 9

For info check this link
[url]http://educate-yourself.org/pnl/solfeggio01dec06.shtml[/url]

It doesn't have to be just 3,6, or 9.
For example:
127= 1+0 = 1, 271=1, and 712=1


From my experience with binaurals, harmony(for the carrier frequencies/pitch) works better when all the binaurals are the same frequency as each other.

[busboy]

*sigh*

Have you ever been to Disneyworld? You wait in line for a ride, and it slowly snakes back and forth. Finally, you get to the door. You go inside . . . just to see that there's another line.
I'm having some bad Disneyworld flashbacks. Every time I feel like I'm getting a handle on this stuff . . . I round a corner and realize I'm back in rookieland.
Unfortunately, I'm not going to have too much time to play with this new data, as I need solid working files by 3PM Thurs PST so I'll have to go with my current sloppy stuff, but it looks like I'm going to be very, very busy this weekend. Both of you . . . some serious knowledge here, and although you can see it I'm genuflecting in respectful awe. Thank you.

@Friendly . . . so you split the vocal and turn that into the binaural "tone"? You sneaky dog you! That's so brilliant and "Zen-minimalist" I had to actually pause and let it soak in when I read it. Don't have the audio chops to hack something like that, but by completely eliminating the tone you clear the file for any secondary sounds while still keeping the core element -- damn! That's good.
the Wiki link is extremely helpful. Still just running tones at this point, but at least they sound better. I was starting to worry . . . I like the hum and all, but 2 hours of it might have been over-the-top. At least now it's a more pleasant sound.

@CGO -- not going to have time to put these together by tomorrow, but an awesome resource for this weekend. Much thankls.