Oh, OK. There's still plenty of experimental room to play; you could lightly / heavily stuff the little chamber with "poly-fil", line it with thick felt padding, even put something solid in there to reduce the squeezable air volume. Who knows which way it needs to go to sound best? Could be it wants a bigger volume, could be smaller. Generally it's "standard practice" to have some sort of absorptive material behind a driver like that, otherwise the sound bouncing around in there can come back out through the speaker cone, which is fairly transparent acoustically. It helps some...
Am I recalling correctly that you had a version where the horn mouths were on either side of the neck heel? Is there a way to route the labyrinths so that one horn exits stage left, the other stage right? I think they could even end up slightly different lengths, which would "cover" more spectrum than with them each at the exact same length. I would think that would do it to get the projection "about" the instrument, versus blasting out to one side or the other. (you might want to hit the drawing board with that, before someone else thinks of it and "improves" on your invention with such an idea...)
If it were a solid body electric, I'd suggest a couple of teardrop cutouts in the top above each horn exit area, with the present horn openings closed or louvered. But, seeing as it's a braced acoustic top having to handle the string tension, I'm unsure if you could make those cutouts in both the divider-top and spruce-top, with some sidewalls added around the shape to keep the sound from entering the space between. Unsure what the new cutouts / walls would do to the top's membrane-o-phone behavior. I see it as only getting stiffer.
https://www.dropbox.com/s/o6p72b0fdn34m31/FHAG1.wav?dl=0
Hello all - link attached so you can hear the difference from standard acoustic guitar and Folded Horn Acoustic Guitar. I am posting this so you can hear the difference in dB level. This is my first try with a USB mic and the tone is not great, so do this is for power level ONLY, tone to improve later.
I also attached a PPT showing FHAG and standard acoustic guitar general recording levels, not the same song posted, but you get the idea.
Started to drum sand the soundboard in assembly, to match the body, need to be careful, don't hit the screws!
Shop music for tonight was Pink Floyd, Muddy Waters, and anybody interested in a good download, check out "Another Man Down" by Heartsfield on the Foolish Pleasures album. Starts acoustic guitar, goes electric, a little jazzy, then same sax, four part harmonies, rocks it to the bone and ends up a with some blues, amazing. I bet Art remembers this one! Thanks! Joe
Hello all - link attached so you can hear the difference from standard acoustic guitar and Folded Horn Acoustic Guitar. I am posting this so you can hear the difference in dB level. This is my first try with a USB mic and the tone is not great, so do this is for power level ONLY, tone to improve later.
I also attached a PPT showing FHAG and standard acoustic guitar general recording levels, not the same song posted, but you get the idea.
Started to drum sand the soundboard in assembly, to match the body, need to be careful, don't hit the screws!
Shop music for tonight was Pink Floyd, Muddy Waters, and anybody interested in a good download, check out "Another Man Down" by Heartsfield on the Foolish Pleasures album. Starts acoustic guitar, goes electric, a little jazzy, then same sax, four part harmonies, rocks it to the bone and ends up a with some blues, amazing. I bet Art remembers this one! Thanks! Joe
I downloaded the file, extracted the "with horns" part in the middle to a separate file, the acoustic alone at the end to a separate file. Had REW do the frequency analysis of each, put on the same plot. Surprised to find some frequencies (ex, around 175, 2kHz) the SPLs are the same.
Using the math functions in REW, I then did A(horns)/B(no horns) to create the third trace, which I believe represents the SPL gain of the horns over frequency - relative to the guitar alone; playing that shuffle, in that room. (So when the blue line is riding right over the top of the red, the net sound added is zero) I also used 12th octave smoothing, otherwise the plots just looked like space dust...
Unsure if this is a correct, fair or whatever analysis. It seems to show the difference in SPL between the two recording sections over frequency. Or at what frequencies the perceived loudnesss increase is coming from - between those sessions, in that room. I'm assuming REW is plotting the peak SPL level it finds at each frequency in the analysis across the whole recorded file imported into it.
If the electrical signal from the amplifier was recorded along with the acoustic output of the horns, then using such an analysis, one could show the frequency response of the horns (in that room). FWIW, I can show you how I did it in Audmonkey (Audacity) and REW.
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Thanks JJ! Very interesting, I see some frequencies have about 30 dB difference, also 20 dB, I see much of this. I have also seen the 100 and 175 Hz very high spikes from the acoustic guitar only, have posted this before. They are very peaky here, and the Folded Horn Acoustic Guitar is much smoother in this area, a good improvement. If those two spikes were removed from the acoustic guitar, it would look (and sound) smoother, then move it up 20 dB, all good.
I have never seen the 1,500 Hz to 3,000 Hz the same, ever, so not sure what is happening there, may not be accurate? Now the harmonics do meet at about 15,000 Hz on some songs, and others they never meet, but of course get close.
I have an acoustic guitar in my hotel room, lending it to a friend at work. I just played it, and I really am not used to an acoustic guitar being so weak anymore. Once you get used to more power, it is just not the same, not kidding.
I am on vaca for the next two weekends, so out of commission, a joy, but I wish I could take my shop with me!
I have never seen the 1,500 Hz to 3,000 Hz the same, ever, so not sure what is happening there, may not be accurate? Now the harmonics do meet at about 15,000 Hz on some songs, and others they never meet, but of course get close.
I have an acoustic guitar in my hotel room, lending it to a friend at work. I just played it, and I really am not used to an acoustic guitar being so weak anymore. Once you get used to more power, it is just not the same, not kidding.
I am on vaca for the next two weekends, so out of commission, a joy, but I wish I could take my shop with me!
I am taking my neck and some diamond files on vacation, need to smooth out the frets at every position, at least taking some of the shop with me!
Tonight I decided to try an "acoustic guitar amp" again. I have posted data on this before, the bass is weak, and the dB is not as strong before it distorts, but close. When I turned it on tonight it squealed like a pig! OK I had it pointing straight at the guitar, and when I turned it away, of course, it slowly got better, no surprise, but it reminded me how my guitar NEVER does this, the 1/2" Baltic Birch chamber divider seems to do the trick, encouraging, we shall see.
This is a Fender amp, and I love old Fender tube amps, but this one is solid state, just not the same, at least with an acoustic guitar. This amp and the Roland amp I am using the guts on, are the best amps I have heard from all my testing for acoustic guitar, they are good amps, but you can not beat the horns!
I then played my horn guitar again, and the warmth and bass were back, love it!
Tonight I decided to try an "acoustic guitar amp" again. I have posted data on this before, the bass is weak, and the dB is not as strong before it distorts, but close. When I turned it on tonight it squealed like a pig! OK I had it pointing straight at the guitar, and when I turned it away, of course, it slowly got better, no surprise, but it reminded me how my guitar NEVER does this, the 1/2" Baltic Birch chamber divider seems to do the trick, encouraging, we shall see.
This is a Fender amp, and I love old Fender tube amps, but this one is solid state, just not the same, at least with an acoustic guitar. This amp and the Roland amp I am using the guts on, are the best amps I have heard from all my testing for acoustic guitar, they are good amps, but you can not beat the horns!
I then played my horn guitar again, and the warmth and bass were back, love it!
Maybe someone makes a horn-amp, routed out of layered / glued up MDF sheets - instead of the normal U frame way with a speaker on a baffle and side panels. Worth a shot with the USPTO, just for the sound signature of it? I'm sure you have your laptop with you on vaca!
JJ - for better or for worse, I always have my laptop with me.
I like the horn amp idea, really would be a small PA system for an amp. Art, what do you think?
Not sure if it is worth the work, but you never know, def an interesting idea!
It is your idea JJ, go for it, write a patent!
Seriously, if anybody on diyAudio needs patent help: technical, legal and drawing, I would be happy to help. It is a pretty fair amount of work, but after you figure it out, not so bad!
I like the horn amp idea, really would be a small PA system for an amp. Art, what do you think?
Not sure if it is worth the work, but you never know, def an interesting idea!
It is your idea JJ, go for it, write a patent!
Seriously, if anybody on diyAudio needs patent help: technical, legal and drawing, I would be happy to help. It is a pretty fair amount of work, but after you figure it out, not so bad!
https://www.youtube.com/results?search_query=tedeschi+trucks+mini+desk+concert
Check out the above link for some excellent music!
Check out the above link for some excellent music!
But the idea is entirely based on your perception of how the horns sound, relative to an ordinary dime-a-dozen guitar amp. So it's really yours; who knows, if you like the sound maybe others will too. I'm sure the horn mouths could be arranged to project out the front of the cabinet, like you're considering with the guitar body.It is your idea JJ, go for it, write a patent!
Small high frequency horns are used in most small PA systems, bass reflex works better in terms of output and smoothness than small low frequency horns for the low end if considering around 1 cubic foot (28 liters) of cabinet size.
Yes, so a guitar amp with small frequency horn and a bass reflex, or ported in some way?
We see many speakers of course with horns, why not an amp? I have never seen one my self. Interesting idea. Do I have time to do this, no! Would I help write a patent for somebody that has a good idea for this, yes!
I finally got back in the shop and have the soundboard drum sanded/hand sanded to match the body, not bad!
Then my wife asked me what was the loud F bomb? I was cutting out the sound hole, after small drilled holes, with a jigsaw.
Splinter! Big one, about .25", I hate jigsaws, except for very crude work. From now on all by hand. Anyway I saved it with filler and glue mix. Can not see it from the top, I always stay wood safe and was lucky enough to be far away, but the back of the soundboard will be ugly!
The soundboard will sit all weekend with this drying, so another delay.
Attached is my technical/marketing PPT, def not finished, needs some more polish, but the info is sound, most of this has been posted before.
Tonight I enjoy my guitar for the first time in about three weeks, can't wait, let's rock!
We see many speakers of course with horns, why not an amp? I have never seen one my self. Interesting idea. Do I have time to do this, no! Would I help write a patent for somebody that has a good idea for this, yes!
I finally got back in the shop and have the soundboard drum sanded/hand sanded to match the body, not bad!
Then my wife asked me what was the loud F bomb? I was cutting out the sound hole, after small drilled holes, with a jigsaw.
Splinter! Big one, about .25", I hate jigsaws, except for very crude work. From now on all by hand. Anyway I saved it with filler and glue mix. Can not see it from the top, I always stay wood safe and was lucky enough to be far away, but the back of the soundboard will be ugly!
The soundboard will sit all weekend with this drying, so another delay.
Attached is my technical/marketing PPT, def not finished, needs some more polish, but the info is sound, most of this has been posted before.
Tonight I enjoy my guitar for the first time in about three weeks, can't wait, let's rock!
I always wondered how my wife did not complain about this powerful guitar as she was sleeping. Thankfully we live in a big old house built in the 1880's. Thick plaster walls, big solid doors. I play in a room that has a door, then another room and a door, then upstairs and another door. I thought, that must do the trick.
I usually wait until my wife is asleep for at least an hour or two, then jam as she is fast asleep.
This time I could not wait, only about a half hour in bed for her. I started jamming, sounds so good and powerful. She comes down and bangs on the door, are you crazy! This thing is loud though the entire house, knock it off!
It works! It works!
I usually wait until my wife is asleep for at least an hour or two, then jam as she is fast asleep.
This time I could not wait, only about a half hour in bed for her. I started jamming, sounds so good and powerful. She comes down and bangs on the door, are you crazy! This thing is loud though the entire house, knock it off!
It works! It works!
Actually, no - an amp cabinet that's a routed out chunk of wood, with two (or more) horn passages. Having the distinct feature of the drivers sharing a small sealed cabinet volume, just like inside your guitar. Since guitar amps are generally rectangular, you could have 3-4 speakers about the sealed cabinet part - with horns emminating from the front of the cones, perhaps even featuring 3-4 different lengths, by offsetting the sealed cabinet within the structure.
That idea is different from a Cornu Spiral speaker, where the speaker cone faces forward like in a normal guitar amp and the back chamber is loaded by multiple horns of all the same length. It keeps the sealed compression chamber at the rear of the speaker(s), which I'll guess is vital to have good power handling - or it shoves failure more toward the VC burning up, vs the cone tearing off its suspension, due to unchecked excursions, i.e. no constrained air mass to push against.
From my perspective, it's mostly a CAD problem to design it. Then a CNC machine to cut the wood layers, glued up in a stack to make the final structure. Maybe the CNC part isnt necessary; I read you like using Jigsaws ;')
It would also serve as a platform to experiment with the horn topology, by building something far easier than a guitar. For example, if you wanted to hear what slightly different horn lengths do to the overall reaponse, easier to build an amp speaker box than a whole new guitar for that.
Good point JJ, and maybe I can make it some sort of assembly that is modular, so it can be assembled in different ways, with different shapes, different horn lengths. OK I need to put you on the patent with me, this diyAudio conversation is proof of your input! Plus I am sure Art has some ideas also, given his Keystone...background, a three way patent!
The only problem is I don't know how I will find time to do it, I can barely finish the Folded Horn Acoustic Guitar!Speaking of, before my wife ended the jam session last night, I swear it sounded more powerful than ever, it is every bit of a before and after as shown above.
I had the back of the speakers closed, and on the wood floor. Then I had a very heavy piece of maple, about 10" x 12" x 6" thick on top of the closed chamber divider, with the horns sealed along the outside edge, I mean as close to 100% seal as possible, except the horn mouths of course. Man that guitar was rocking for an acoustic!
Time for the hardware store and some smaller hand tools, will work on it tonight, will need another coat of wood filler/glue mixture. I know, does not sound good, but this combo really hardens up well, the big trick will be getting it to match with stain. I need to put some stain in the mixture. Getting closer, would never use filler on the real guitar, just the functional prototypes, should have all the kinks worked out by then, I hope!