Folded Horn Acoustic Guitar Patent # 10,777,172

Member
Joined 2021
Paid Member
Just passed 27,000 hits thank you all!

First the known:

When I tried the Roland AC60 I blew out a driver. Hey Art, any info on what happens with a blown driver? I can't see any damage, but one of my drivers is as dead as a doorknob, replaced them both to be safe.

I played with only one driver, actually sounded pretty good, but not as much power of course.

After both new drivers installed, using the AC33 as before, sounds great again! This is option A, I love it, and this baby is complete. Can have all installed in guitar, OR can still do with external amp, just love this sound.

Now for the unknown:

I have four drivers wired in series with the AC60, so my 4 ohms drivers will work correctly this time, and will play with my second folded horn guitar, but playing my Guild through the horns as I did before.

Man I am embarrassed that I ****** up the impedance matching on this, hell it says 8 ohms right on the back mags of the driver as always, I just did not look, assumed they were the same, big mistake.

The good news is I got a real world lesson of how incorrect impedance matching will **** up everything! Live and learn.

I just finished a great jam session, so the AC60 will be next weekend, but can't wait to test this, now that I have it right. This is the unknown, and will be option B with an external amp. JJ as you note, I can add pedals for all kinds of interesting options. Let's rock!
 
You can make a driver saver using a 12V light bulb from an auto parts store. These come in various size and shapes and the trick is to find the goldilocks one for your application. The lightbulb takes the heat, instead of your speaker voice coil when things get crazy. It's an old trick that saves tearing apart a cabinet to replace a driver. Chosen right, it adds non-linear compression; sounds the same most of the time, puts a ceiling on the loudest, speaker blowing dynamic (or sustained) signal levels.

A possible way to choose would be to drive the maximum continuous Wattage rated for the speaker into a dummy 8, 4 Ohm load with the lightbulb in series. The filament should begin to glow as you approach that Watt value.
 
  • Like
Reactions: 1 user
Member
Joined 2021
Paid Member
OK who sent me this? I have the link, but the DIY thread is dead. Horn Chair, I love it! Talk about feeling the music in your body!


1689480227224.png
1689480174609.png
 
Member
Joined 2021
Paid Member
I put my soundboard back on, and the guitar sounded like ****, I was like WTF? Something happened, and I could not figure it out.
The piezo and magnetic pickups were both feeding back at about 6 or 7 on volume, my tone was gone, WTF???

I was like what happened to my horns? They are great, they do not change, went to bed totally frustrated.

I put a flashlight inside the guitar, oh ****, I forgot to seal them! The chamber divider has serious gaps, I mean an 1/8" or more.

They MUST be sealed, as Art and JJ have told me before, and I agree.

The sound was pouring into the top chamber, my guess is looping back to pickups to create feedback, killing my horns and killing the sound.

I don't like to make mistakes generally, but sometimes they help. Reading something in a book is one thing. but ******* it up yourself is quit another, it really gets your attention! I only use tape to seal, but it does the trick. This time put it on heavy, and guess what? The offending feedback at a certain frequency before is gone! Can't believe it, it works!

I really love horns when they work, meaning when I get them right, they make this guitar sing!

Hey Art, can you please give me some info on dB levels. What is stage monitor dB? What is Keystone Sub dB at drivers? What is the dB at tenth row? What is dB at the back of the concert hall, you get the idea. I am reaching 120 dB at the guitar, but further out is another story. Thanks!
 
Member
Joined 2021
Paid Member
Thanks Art, appreciate the info very much, some light reading to help fall asleep! I printed out all (14) pages, looks like the go to for understanding SPL, dB levels and so much more.

I attached my technical and marketing info again, for anybody interested, that has not seen it before. This is what I sent to Gibson, along with the full patent, detailed 2D working drawings and a cover letter. The 3D CAD model will be included if I ever get a serious offer.

I found a third person at Gibson, sent that out, and also sent to Yamaha Guitars.

I just printed many color copies, so need to FedEx hard copy packages, about 50 pages total, everything included.

When my guitar has problems, it has serious problems, God forbid this should happen when I am doing a demo. When it is bad, I would get laughed out the door, feedback, bad tone, not as much power...ah the struggle of the underdog! I think I have it all worked out now (yeah, right).

But when it is good, watch out, it is seriously good. It sounds like no other acoustic guitar I have ever played. I apologize for the arrogance, but I am trying to get myself to be more of a salesman, I am not very good at that. I love the music, the technical details, the design, the build, the testing, the problem solving and the jamming.

One of my favorite songs to play on this guitar is a simple jazz progression in G, start with a G7, which I like, because to me, 7th chords sound just a little dissonant, interesting sound, then use 9th chords up and down the neck for everything else. I admit this can also sound very very good on a big fat Gibson electric hollow body (watch the feedback), or my Heritage HS335 semi-hollow body through a nice fender amp, but I like it on acoustic guitar.
God knows I will never come close to playing like the great Wes Montgomery, but he has influenced me in this regard, I am absolutely stunned by his beautiful playing, see attached if you are interested.

My second favorite song to play on this guitar is in E, I call it backwards Melissa, because it is the Allman Brothers "Melissa" played backwards, but jamming far harder. Hey the Brothers jam hard, but this is one of their mellow songs, always loved it. I remember my guitar teacher turning me on to them when I was 14 years old. BTW his name is Mike Flynn (Chicago) and I saw him jam with Heartsfield once, he is a friend of the band, Art maybe you know him? What a great guy, and great guitar player! I think I may have mentioned this before.

But my favorite song to play on this guitar - just played it hard, wife out of town! is what I call open D. I drop the sixth string to D, and play a chord progression up and down the neck, where all six strings are always used, some are fretted and some are open, for the entire song. It progresses up to the 15th fret, which is an open D chord one octave higher. I used to play this on a regular acoustic guitar, but you had to beat the hell out of it to get the song right, not good. On this guitar, I barely touch the strings and the song is rocking, great tone, great power, go from chord to chord effortlessly.

I crank the volume to a point where it "almost wants to feedback, but does not" :ROFLMAO: It just gives phenomenal sustain, through the entire song, the guitar becomes a sonic machine, never ever experienced an acoustic guitar sound like this. I love it!

For this song I have the back of the drivers uncovered. I generally keep them close to my body, but when needed I move the guitar slightly away from my body, and the back of the drivers start to sing also, fantastic! At the end of the song, I hit the final D chord hard and let it sustain, I swear with this guitar it will go for 60 seconds easily, then when it is about to stop, I pull the guitar away from my body, and get another 30 seconds of D chord sustain. Then when it is almost done again, I smack the top of the neck (head) with my hand, and get another 30 seconds of sustain and the body comes alive again.

OK I know most people don't want to hear that, but I love seeing (hearing) what this guitar can do, it is a sonic machine (for an acoustic).

If I am lucky enough to get a call for a demo, man I am ready, will play the open D song to start, let's rock! Comments always welcome, please jump in!
 

Attachments

  • Folded Horn Acoustic Guitar 7-12-23 U.S. Patent #10,777,172.pdf
    3.6 MB · Views: 61
  • Wes Montgomery Full House.pdf
    19.9 KB · Views: 52
I keep seeing - in the latest attachment - a cutout in the dividing panel that allows the back of the drivers acoustic access into the chamber between the dividing and soundboard (top) of the guitar. My intuition tells me that would put the guitar's acoustic system well into the "No Hope" arena. Instead, I would think that as much acoustic isolation as possible between the speakers and guitar's soundboard would be the "Preferred" way to go.

Of course, I could be completely wrong about that. Never the less, I figured it was worth mentioning.

One could fool with the idea of leaking sound from the back of the drivers out of the guitar body in the back, and/or into the front chamber using various means to do so - but I would think that would be something considered well after the whole thing is established and sound; solid, well behaved and predictable build to build. I can say one thing for sure; generally, for power handling, a horn driver needs a air-tight, sealed chamber to push against. I think you'd be sorry if you just blow past such an idea, starting with these "open back" designs on either side of your instrument, right at the outset.

This advice and two cents maybe gets you a cup of coffee... All, FWIW.
 
Member
Joined 2021
Paid Member
JJ - you are completing right, my latest jams had the horns 100% sealed, and the double thru chambers you see on the PPT, are just not covered in the back for this photo only. I assure you they have been completely sealed from the back lately, and give me the deep chamber that is connected to the top chamber, but sealed from the horns. No way I would get the great sound I have now without this, and the horns being sealed. Actually extra sealing to be safe, the sound was the best I have heard yet, the air column as you mention is critical, I always picture it in my head. I need to make a clear polycarbonate chamber divider and load the horns up with smoke so I can actually see this work, pretty fascinating really!

For now the only area unsealed is the back of the drivers, and I have tested with those sealed also. They are usually partially sealed by my body when I play. I know this is unusual, but for this guitar it is working, to feel it in my body, and then easily move the guitar away and open the sound from the driver backs, very interesting phenom. Will I test again with these drivers also sealed 100% from the back, sure will, but man the sound now is really great.

I struggle with how much to show on my PPT's. I don't want to give out too much info, but you really need to, if you want to get peoples attention.

A patent is similar, but of course that is in the public domain, so anybody can see it, but if they don't know about it, will they find it? If they are a ripoff artist, obviously I don't want them to see it, but if I am trying to sell, then totally necessary.

I have gone back and forth on this issue with friends. My opinion is take the risk, nothing in life is guaranteed, don't worry about it, get it out there.

Plus my second patent will give me even more protection. I have waited 14 months now without a response, the USPTO is reporting an average wait of 16 months, so hopefully close to getting their response, and playing the back and forth game with them to get it granted.
 
don't worry about it, get it out there.
Perhaps you'll need to build up a few "loss leaders"; where you virtually give the product away just to get it in the hands of certain performers. Makes you wonder what someone like Michael Hedges could have done with it. Jerry Garcia used a two-cord connection on his guitars; so that's not unheard of.

I imagine it's like anything; once you get so 'n so to use it in a video, everyone will want one. I wonder how Yamaha is doing with their Transacoustic units in that regard; sounds nice, but does anyone who's a recognized artist actually use one?
 
Member
Joined 2021
Paid Member
JJ - I would give one guitar away to a great performer, if it would spread the word, for sure. The Yamaha Transacoustic looks interesting. I think it is for effects really, a far as I can tell. Maybe similar to the Tonewood Amp, which I am looking at on my desk right now, and still have not tried, maybe tonight.

Hard copies ready for Martin, Taylor, Yamaha, Fender, Gibson and Roberto Venn School of Luthiery (they were kind enough to respond to my design back when).

I also had some email correspondence with Allied Security Trust. They contacted me, but it went nowhere, they want software and tech patents mostly. They are doing some good work to help fend off Patent Trolls, I like that.

Another PPT for fun. I see a comment about drivers needing to "loosen up", not sure about that. I do notice my guitar seems to "settle in" after about 4 or 5 songs. I know for sure strings stretch just a little bit less when you start playing, I always retune until they are stable, then they don't seem to move at all. Maybe this is also true about my crazy soundboard? It might be phycological, but it seems to happen every time. Looking forward to another great jam session tonight. Let's Rock!!
 

Attachments

  • Drivers and Horns.pdf
    503 KB · Views: 48
Member
Joined 2021
Paid Member
I posted info about the ElectroPhonic Electric Guitar before, personally I think it is a very nice design, but have never heard one, see attached.

Anybody out there ever play one? I see it is 18 watts total, 9 watts per channel, seems a little low to me. I mean my guitar is powered by a 30 watt amp, 15 watts per channel, and the drivers can handle 20 watts per channel, and it is an acoustic guitar.

Also check out the "Labyrinth" system, they do not call them horns or waveguides, not sure about this system from driver to driver, any thoughts?

I hope it is selling well, but I can't find much online about this.

You know what, last weekend I played my Folded Horn Acoustic Guitar on volume level 6-7, instead of 8-9. The damn thing rocks every bit as well at this level, was really surprised. Yes I will get REW back in the game one of these days, really need to measure that. It was so much fun, rocked great, not quite as loud, but plenty of power. The sustain was great, but of course not as great as the 8-9 level, which can feedback if not careful, but I do love controlled feedback on an acoustic guitar, if handled well, man do I love this guitar.

I am thinking about putting thin gage electric guitar strings on this beast, let's see what happens!

Package to Gibson mails Saturday, need to see if large labels are OK with post office scanning equipment, last time they said labels were too big, go figure.
One label for address, one return address, one with patent number, and one with a description of guitar, right on the front, to get their attention.

If it goes through, all the others go out, fingers crossed!
 

Attachments

  • Electrophonic Electric Guitar.pdf
    208.8 KB · Views: 52
I hope it is selling well, but I can't find much online about this.
Methinks they're a few steps ahead, particularly in the amplifier department. Are you contacting them as well to pan your invention?
Yours should outperform theirs, being an acoustic guitar to boot, which a lot of players favor stylistically. I would think you should be able to say "you can still be heard when the train comes into the station" which is something I doubt their guitar could do.

You may want to look into an earlier suggestion to arrange the horn paths such that one exits at the tail, one exits at the neck. That would give a stereo effect and make the apparent "soundstage" much wider - even in mono. Especially if you tuned each horn slightly differently; perhaps one on a natural, the other on sharps and flats harmonic series.
 
the light bulb limiter works due to the heated filament having having greater resistance than its normal room temperature so there can be significant power dropped across the bulb. Eminence uses two 211 incandescent "festoon" bulbs in parallel with the tweeter output of their crossover boards. Subjectively
that seems to work while increasing reliability of a compression driver.

An led won't work right
 
Member
Joined 2021
Paid Member
I am pretty thrilled right now, today I received an email response from Yamaha Guitars USA. VP USA liked it enough, that he sent it to Yamaha Japan International Headquarters. They said "we find this guitar design to be very interesting" BUT we need to focus on our own internal design and build system. No surprise.

I interpret that as the Yamaha Transacoustic guitar design. I like that guitar from what I have seen online. Seems to be an acoustic guitar with technology that is close to the Tonewood Amp built into the guitar. Their prices are very reasonable, obviously due to mass production. Plus they bought Guild a few years ago, and I always loved my Guild, really great guitars. Bonnie Raitt played her Guild all night.

Some might take that as a rejection, but I, being the eternal optimist, think it is a foot in the door!

I sent a thank you to the kind gentleman, thinking I would get no response, and he said stay in touch. You never know! I find this to be highly encouraging for an outsider. The Underdog is Flying!
 
  • Like
Reactions: 1 user
I interpret that as the Yamaha Transacoustic guitar design.
All acoustic guitars have "reverb" built in, due to mechanical resonances within the body structure, which are excited by the strings. The transacoustic takes that to another level by deliberately driving the guitar's string sound back into the body, causing it to reverberate even more. Done right, it's a very pleasant addition to the guitar's tone. You can bet Yamaha does it right...

Your guitar is an acoustic amplified with speakers. You dont want the sound to be driven back into the guitar body, you want it all coming out the horn mouths. A very different animal. Done right, It should be quite superb. You can surely bet Yamaha has the facilities, engineering and production to make that happen. I'd stay in touch, definitely.

Independently, I'd research what artists Yamaha works with regularly and see if you can get some time with those players to introduce your invention. All it might take is the right Yamaha sponsored artist to tell them "I really want this" for them to give it a go as a Yamaha built and tuned prototype. Good luck with that!
 
  • Like
Reactions: 1 user
Member
Joined 2021
Paid Member
All I can say is: JJ I wish you lived down the street from me. Oh yes on all comments. I mean WTF, I like to argue with people, and I can't find a reason to do that with you!

I asked my Yamaha friend if the two systems could be built into the same guitar together. I know they are different animals, but why the hell not? We shall see.

I keep looking at the Tonewood Amp on my desk, but I just can't stop playing my guitar to try it, big problem :ROFLMAO: , I need to understand it, so I can understand the Yamaha guitar system better.

Check out Doug Henthorn, I especially like his song "Walk". I jammed with him once in a friends backyard. He was playing acoustic guitar and singing, I was jamming on the blues harp. I don't remember much about that, but I downloaded his song last week. I certainly don't remember him singing like that, his voice is seriously good on this song, and his guitar playing is great! He sang one song on a Joe Bonamassa album, very cool. Always love to spread the word about musicians, especially the ones that are underappreciated.

I told some friends and family about the hopeful Yamaha connection, and boy does the interest go up with something like that. Let's Make The Acoustic Guitar Rock! Hoping for a plane ride to Japan!
 
Member
Joined 2021
Paid Member
I finally tried my Tonewood Amp, I really like this product because it provides more sound from the guitar itself, big fan of that of course. I also think it is well designed, easy to install, and can be used on any guitar you want, great. If you are into reverb and chorus on your acoustic guitar, buy it, works great, and I also really like to support my brothers in innovation, I hope this goes well for them!

Personally I like reverb on an electric guitar (not above 3 or 4). Back in the day I thought my Fender Twin Reverb was great.

But on an acoustic guitar, I just do not see how reverb or chorus "improves" the sound, just my humble opinion, but I know others like it, rock with this!

I checked out a guy on YouTube playing the Yamaha Transacoustic Guitar, without any effects. Man that guitar sounded beautiful. I have never even played a Yamaha acoustic, sounded every bit as good as a Martin or Taylor, just beautiful. I wish I had his recording equipment and know how, I need to do that on YouTube, will check for link and send it later if any interest.

The TransAcoustic pretty much has the same sounds as the Tonewood amp built into the guitar, I think??? Again, love this in the guitar itself, but chorus is just not my cup of tea, I hope others enjoy it, and I bet they do! I can't think what I like, is what everybody else likes, that is a small minded point of view, so I hope others enjoy this very much!

My hope of course, is that Yamaha would like to further research my Folded Horn Acoustic Guitar, now that I have some interest from them, add the TransAcoustic system to this, easy to do! Let's Make The Acoustic Guitar Rock!