Resonance Circuits and Resonance Systems

[Belfior]

There are headphones and speaker systems, that will play the opposite sound waves that cancel those sounds. I haven't heard of any house size systems yet.

I was planning a "party fence" that you put around your festival or garden party. Play all the music you want and neighbors would not know about it.

[Belfior]

Can you post a schematic of the _exact_ circuit you are using? Did you try my suggestion of reversing the connection of the Primary coil?

Using TK's version of  slayer exciter from youtube.

2n3055 as transistor and IN4007 as diodes. Pot has been from 10k to 50k without results. Changed my prim coil to 8 turns and no change. Changed prim coil polarity and no change.

I have been poking around with my oscilloscope but nothing. I should be seeing something if I measure across the resistor right?

[TinselKoala]

Well, several things come to mind. First, you probably don't have enough turns to get a reasonable electrical length for your secondary coil, which means that the resonant frequency may be so high that the transistor and other circuit elements can't keep up. This system will work best with a resonant frequency under 1.5 MHz.  Second, your primary is mounted too low. It should not be below the bottom winding of the secondary; it should be maybe 1/4 to 1/2 inch above the bottom winding.
Third, are you quite sure you have the 2n3055 connected properly, with the Base and Emitter leads properly oriented, and a good solid connection to the Case (Collector)?

The first thing I would suggest is to make another secondary coil using #24 or smaller magnet wire and at least 400 turns on a former of the diameter you are using. Second thing is to mount your 4-turn primary just barely above the bottom turns of the secondary, not below it. Third thing is to carefully verify the connections to the transistor. Don't use clipleads or other long wire lengths to connect your components!

If you can find an old big CRT television that someone is discarding, you can get magnet wire from the degaussing coil that is wrapped around the screen end of the picture tube. Also from the yoke coils, but this is more difficult to strip cleanly off the yoke.

[Belfior]

Well, several things come to mind. First, you probably don't have enough turns to get a reasonable electrical length for your secondary coil, which means that the resonant frequency may be so high that the transistor and other circuit elements can't keep up. This system will work best with a resonant frequency under 1.5 MHz.  Second, your primary is mounted too low. It should not be below the bottom winding of the secondary; it should be maybe 1/4 to 1/2 inch above the bottom winding.
Third, are you quite sure you have the 2n3055 connected properly, with the Base and Emitter leads properly oriented, and a good solid connection to the Case (Collector)?

The first thing I would suggest is to make another secondary coil using #24 or smaller magnet wire and at least 400 turns on a former of the diameter you are using. Second thing is to mount your 4-turn primary just barely above the bottom turns of the secondary, not below it. Third thing is to carefully verify the connections to the transistor. Don't use clipleads or other long wire lengths to connect your components!

If you can find an old big CRT television that someone is discarding, you can get magnet wire from the degaussing coil that is wrapped around the screen end of the picture tube. Also from the yoke coils, but this is more difficult to strip cleanly off the yoke.

I think the secondary turns might be an issue. The primary was maybe too low. The 8 turn primary that I got now is 2 inches over the bottom secondary turn. I will try these out.

2n3055 should be connected properly. I think I got one bread board lying around, so I can get rid of the clip leads. Just wanted to get this working first and then solder it to a unit.

Thx man!

[Magluvin]

@Mags
Your speakers are awesome. I've built a few bass-port and infinite baffle enclosures myself, long ago; supplied a few of my high school mates with awesome speaker cabinets for their stereos. But that was long ago, before you could get anything like the modern high-power portable amps and ultrastrong speaker magnets of today.

Now these big bass boomers in cars really annoy me as they drive by. Not because of the sound itself, but because of the massive distortion (trunk lids rattling, etc.) and the lousy music choices. I wonder if we could design some kind of interference field that I could use to put up a "bubble" around the house so those amps wouldn't work within, say, 100 feet of the property.

Hey T

Those pics of subs are examples of the large roll surrounds which reduce the working surface area of the diaphragm. I do have the pioneer shown.

Noise canceling for that would probably cause an even louder event perpendicular in both directions of the line between you and the offender. Then all your neighbors will hate you also. These days there is not as many of the boomers as there was in the 90s. The only reason they still exist is the car audio popularity has gone down hill on quality sound reproduction to hammerhead power competitions. Slamfest is the big one I believe. Car sound competitions have gone way down in popularity since the mid 2000s. Daytona Spring Break Nationals has dwindled from filling the expo center and parking lots to only a small section of maybe 100 vehicles on the speedway mixed in with the Spring Turkey car show.

Back in 1990 I moved to florida from near pittsburgh and those bass monsters that were down here then are what really got me into car audio. I needed to know how and why a paper cone moving back an forth could make things rattle in my apt from a block away.

In the beginning it took me a while to grasp the function of a tuned ported enclosure. Its become a sort of visual thing for me now.

In all that I wrote here the other day, Im a bit surprised that there isnt much comment on the resonance gains I described. In all the circuits and projects, this is actually showing very good (input vs output) gains using resonance.

I did a short search earlier for a conversion or comparison of watts to sound decebels. What Im looking for exactly is how much actual  power(W) is 1db of sound output.

The reason being is, I want to know what the sensitivity(db @1w) of say an ideal 10in speaker at 1w.  Like in the examples Ive laid out, many subwoofers out there are in the 80db range of eff and I have shown examples of some at 96db@1w and even 105db@1w.  There are some I have seen up to 112db@1w. So where is the limit? How many db@1w would a hypothetical 100% eff subwoofer be? Like is it 200db or even 300db where these real numbers I have given may be very inefficient in comparison. Didnt find that info yet. It seems to search out charts for rf signals even if i search for sound levels. Going to search more after this post.

Beyond all that, from what I have seen so far, whether it is a sub that is 83db @1w or 105db @1w, the gains assisted by implementing resonance is the same for all.

So the closer I get to a 100% eff sub, then I believe that resonance should be able to take it over the top. This possible prospect has me gleaming. And so far what I have shown is that resonance can and does give a gain. Now we just need to translate how this happens into circuit form.

Mags