It shouldnt be that hard to put the, or a mag pickup atop a wood block so it pokes up through the soundhole and attaches and / or touches only to the dividing board. Even fancier if you can rig a height adjustment for it, while you're at that. See if the 370 resonance dissappears or changes.
Yeah that just might work JJ, plus I am starting to think about small speakers rated at 40 watts, more power always, IF the feedback goes away at the upper volume range. Which of course would require a larger amp, which of course pushes me to admit I must have an internal AND external amp option, no going back now, too much to lose by not trying this. I can add to my second patent as I have the opportunity to make corrections, which always happens.
Art - I did note your speaker dimensions on my PPT, just wanted to make sure you were OK with that. In no way do I think my horns are similar to yours, but conceptually I like to make comparisons. You driver is much larger of course, and I can not keep up with your horn volume (as a ratio), but I do have the horn length based on 1/4 wavelength. My lowest frequency is approx. 80 Hz, which is about a 14 foot long wavelength, which needs 3.50 feet horn length to capture 1/4 wavelength, I have 5 feet. Your horn lowest frequency is approx. 40 Hz, which is about a 28 foot long wavelength, which needs 7 feet horn length, and you have 10 feet, easily covered, same with Klipsch K-horns, approx.
Since my horns are covered, they are very easy to test at different lengths. I know my drivers in my guitar without horns sound like ****, and I have measured it for proof. I also know they sound great through the horns, and I have measured that also with success. I am going to measure 1/4, 3/16, 1/8, 5/32, 1/16 horn lengths, and plot them together for comparison, let's see how critical this is, and how it changes at different lengths.
Yeah the room acoustics I doubted made a difference, I am sure I adjusted pots to get a difference, and thank you for the notch out comment, will need that for sure, unless I make a change in some other way. One note, just one, goes crazy, plus you can see the big spike on my Frequency Output curve, exactly at the offending frequency.
Since my horns are covered, they are very easy to test at different lengths. I know my drivers in my guitar without horns sound like ****, and I have measured it for proof. I also know they sound great through the horns, and I have measured that also with success. I am going to measure 1/4, 3/16, 1/8, 5/32, 1/16 horn lengths, and plot them together for comparison, let's see how critical this is, and how it changes at different lengths.
Yeah the room acoustics I doubted made a difference, I am sure I adjusted pots to get a difference, and thank you for the notch out comment, will need that for sure, unless I make a change in some other way. One note, just one, goes crazy, plus you can see the big spike on my Frequency Output curve, exactly at the offending frequency.
I wonder what would happen if I did this. I have a new amp that is 80 watts with 4 speakers that I could rip apart and test???
I love these Tectonic 3" BMR drivers, they sound great, and I don't see much else that would be an upgrade for a small full dynamic range speaker. I have seen these rated at 100 Hz to 20,000 Hz ( I have also seen 150 Hz...) Obviously the external option is getting more appealing to me. I mean externally it would just be circuit boards, pots, and wires, no cabinet or speakers, you might be able to put that in a small backpack of some type. JJ has hinted at this before...I think maybe Art did also, and Ian at Chicago School of Guitar Making suggested the external amp also.
I love these Tectonic 3" BMR drivers, they sound great, and I don't see much else that would be an upgrade for a small full dynamic range speaker. I have seen these rated at 100 Hz to 20,000 Hz ( I have also seen 150 Hz...) Obviously the external option is getting more appealing to me. I mean externally it would just be circuit boards, pots, and wires, no cabinet or speakers, you might be able to put that in a small backpack of some type. JJ has hinted at this before...I think maybe Art did also, and Ian at Chicago School of Guitar Making suggested the external amp also.
As a kid, I was always fascinated by exhaust manifold construction on a car engine. Sometimes it seemed like they just didnt care - at all - about right angles and flow paths, sometimes it looked like they tried to make paths as straight and smooth as possible in a casting, then there's the full header pipe where everything is uniform, smooth and balanced.
My intuition says you want to rotate the new speaker 90 deg to the right and arrange it to fire directly into the end of the horn routing, versus that right-angle setup of your original speaker position. Then you dont need the old position at all anymore. Or keep all 4 for the additional power handling you're looking for.
I mean the tapped horn driver arrangement above is just as valid as anything I'd say. FAIK it'd work great. However, if the current speaker chamber were a solid hunk of wood, could you mount a mag pickup there, just in front of the bridge? Who know what top bracing that hole would disturb, just thinking about a rock solid mount point for the pickup. I assume that's what you need to crank it without feedback.
My intuition says you want to rotate the new speaker 90 deg to the right and arrange it to fire directly into the end of the horn routing, versus that right-angle setup of your original speaker position. Then you dont need the old position at all anymore. Or keep all 4 for the additional power handling you're looking for.
I mean the tapped horn driver arrangement above is just as valid as anything I'd say. FAIK it'd work great. However, if the current speaker chamber were a solid hunk of wood, could you mount a mag pickup there, just in front of the bridge? Who know what top bracing that hole would disturb, just thinking about a rock solid mount point for the pickup. I assume that's what you need to crank it without feedback.
JJ - I have some manifold parts that are plastic filled with fiberglass, you would not think plastic could handle the high temps, but it can. We built the tooling for a German company, the injection mold alone was $500,000 plus.
Back to music, yes I will try the speakers rotated, and really need to try in many different positions. I feel like I have reached a goal, that now allows me to try many different ideas with simple but effective tests. I like trying four speakers, how much power increase measured in dB at different areas? cancellation? Tone and FR changes? All interesting to think about, and how it might improve this guitar!
I rewrote my letter to Gibson Guitars first, more letters to do, will mail these out with design, patent, REW data, tech specs, marketing info, detailed drawings...but this time it will not be "how can you help me build this" (sent two years ago), but "I have built this, it sounds great, 4X the power of a standard acoustic guitar (Holy Grail), do you want to play it yourself?"
I have 11" x 17" detailed guitar drawings, but for some I will send the full scale plot, literally 3 feet tall by 12 feet long (many views), off the E size roll plotter, looks nice if you like big prints hanging on your wall.
I know magnetic pickups sense the steel string vibration in a magnetic field, but don't understand it much more. How will taking them off the soundboard help?
I know piezo pickups sense vibration using crystalline materials, and having them on the bridge and away from the horns where the speakers are mounted works, zero feedback. I also know if I mount them within 3" of the speakers on the same surface, they will feedback badly, so I think the piezo pickups are not a problem, and they sound good, mixed with the magnetic pickup, really good. All 'feedback" from DIY friends always welcome!
Back to music, yes I will try the speakers rotated, and really need to try in many different positions. I feel like I have reached a goal, that now allows me to try many different ideas with simple but effective tests. I like trying four speakers, how much power increase measured in dB at different areas? cancellation? Tone and FR changes? All interesting to think about, and how it might improve this guitar!
I rewrote my letter to Gibson Guitars first, more letters to do, will mail these out with design, patent, REW data, tech specs, marketing info, detailed drawings...but this time it will not be "how can you help me build this" (sent two years ago), but "I have built this, it sounds great, 4X the power of a standard acoustic guitar (Holy Grail), do you want to play it yourself?"
I have 11" x 17" detailed guitar drawings, but for some I will send the full scale plot, literally 3 feet tall by 12 feet long (many views), off the E size roll plotter, looks nice if you like big prints hanging on your wall.
I know magnetic pickups sense the steel string vibration in a magnetic field, but don't understand it much more. How will taking them off the soundboard help?
I know piezo pickups sense vibration using crystalline materials, and having them on the bridge and away from the horns where the speakers are mounted works, zero feedback. I also know if I mount them within 3" of the speakers on the same surface, they will feedback badly, so I think the piezo pickups are not a problem, and they sound good, mixed with the magnetic pickup, really good. All 'feedback" from DIY friends always welcome!
Because if the soundboard is somehow moving relative to the strings, it'll pick up that as well as the strings moving relative to the soundboard - given the pickup is mounted to the soundboard. (As I understand it, everything's moving relative to one another on an acoustic guitar). On an electric, the pickups are mounted much more solidly, which is why they can handle higher gain on the amp w/o feedback.
I was thinking more like here and here;
The amplified speaker output makes the body resonate, the strings vibrate at the resonant frequency, the pickups pick up the string vibration, an acoustic/mechanical feedback loop.
The reason a solid body electric does not feed back as much as a hollow body electric is because it has very small resonant chambers above the frequency range excited by fundamental note frequencies.
Pouring wax into unfilled pickups reduces the small microphonic resonant chamber size within.
I think the soundboard is shaking the pickup, relative to the strings. That shaking is probably coming from the speakers (what else?). The soundboard moves under the influence of the speakers, because it's light and flimsy. Your divider board - with all the routed structure underneath it's fastened to - is heavy, stiff and wont be shaken by the speakers as readily.
You could poke the pickup up through the soundhole to try, so as to not have to cut up anything. I saw one yesterday on ebay with long mounting bars running down each side side, easily screwed to a wood block. Then just afix the block to the soundboard with rubber cement, so you could yank it off when done experimenting. Literally cement half A to half B.
I cant find that particular pickup anymore on ebay. After searching through several hundred...
You could poke the pickup up through the soundhole to try, so as to not have to cut up anything. I saw one yesterday on ebay with long mounting bars running down each side side, easily screwed to a wood block. Then just afix the block to the soundboard with rubber cement, so you could yank it off when done experimenting. Literally cement half A to half B.
I cant find that particular pickup anymore on ebay. After searching through several hundred...
Yes, thank you very much Art and JJ. I mean I play a single string and the other strings vibrate as a result, from the soundboard. Of course this means the soundboard affects the other strings and magnetic field. I say this like I knew it, but no, did not really think about that until your help.
I think this can be a real advantage, if applied correctly, or could also be detrimental.
I am going with good, because I played tonight, and had this guitar rocking so well with a drop D, I let it ring. I had the piezo on 10, and the mag on 9 - if you put the mag on 10, toast! I know, I need more head room. I had an open D chord with drop D sustain for two minutes, not kidding! This thing is a beast!
I am thinking about four speakers as mentioned before, not that I need it, but am curious about how much more power I might get. What say you? Let me have it!
I think this can be a real advantage, if applied correctly, or could also be detrimental.
I am going with good, because I played tonight, and had this guitar rocking so well with a drop D, I let it ring. I had the piezo on 10, and the mag on 9 - if you put the mag on 10, toast! I know, I need more head room. I had an open D chord with drop D sustain for two minutes, not kidding! This thing is a beast!
I am thinking about four speakers as mentioned before, not that I need it, but am curious about how much more power I might get. What say you? Let me have it!
Thanks much Art, if I use a new amp with more power and four speaker connections, then use the new positions shown in this attachment, I understand it "could fill in dips in the response at some frequencies while canceling at others". Do you think the canceling could work to my advantage, as in cancelling the 370 Hz frequency that is casing feedback problems?
Do you think I could get the +6dB output with this arrangement? I would love to get another 6dB. I like what I have very much, but of course I am getting power hungry. I mean my horns are not even close to full size horns, so more power is something I will always be chasing, as long as it does not cause feedback problems.
As I said earlier, I had a drop D chord sustain for two minutes. This time I had the back of the speaker chamber uncovered. When I played against myself, this chord had great sustain, when I moved the guitar about 3 or 4 inches away from my body, that is when I got the two minute sustain. If if really moved it away from me it could feedback of course, but move it closer and feedback gone, can control it just through moving the guitar. I can also control by how much I touch the soundboard that is vibrating like a bitch.
I don't want this when I am playing a finger picking song, but I love it when I am trying to rock, the ability to control this is fantastic, with more power would be even better.
Plus I like the pickup relocation and wax ideas.
I have 26,000 hits now, came much faster this month, hope people are enjoying this thread, let me know your thoughts please! Criticism is always welcome, great way to learn.
I attached a draft letter I am editing for Gibson. It might end up in the garbage, or might do well, know knows, worth a try! Any thoughts on additions, corrections...?
Tonight is the Eagles tribute band Heartache Tonight, playing right across the street at Strawberry Fest, my buddy is doing the sound. Marketing says best Eagles cover band in the country, we shall see (hear) if that is true.
We are going to see Bonnie Raitt in Indy early July, I know that will be great. Love her beautiful voice and killer slide guitar. Let's Rock!
Do you think I could get the +6dB output with this arrangement? I would love to get another 6dB. I like what I have very much, but of course I am getting power hungry. I mean my horns are not even close to full size horns, so more power is something I will always be chasing, as long as it does not cause feedback problems.
As I said earlier, I had a drop D chord sustain for two minutes. This time I had the back of the speaker chamber uncovered. When I played against myself, this chord had great sustain, when I moved the guitar about 3 or 4 inches away from my body, that is when I got the two minute sustain. If if really moved it away from me it could feedback of course, but move it closer and feedback gone, can control it just through moving the guitar. I can also control by how much I touch the soundboard that is vibrating like a bitch.
I don't want this when I am playing a finger picking song, but I love it when I am trying to rock, the ability to control this is fantastic, with more power would be even better.
Plus I like the pickup relocation and wax ideas.
I have 26,000 hits now, came much faster this month, hope people are enjoying this thread, let me know your thoughts please! Criticism is always welcome, great way to learn.
I attached a draft letter I am editing for Gibson. It might end up in the garbage, or might do well, know knows, worth a try! Any thoughts on additions, corrections...?
Tonight is the Eagles tribute band Heartache Tonight, playing right across the street at Strawberry Fest, my buddy is doing the sound. Marketing says best Eagles cover band in the country, we shall see (hear) if that is true.
We are going to see Bonnie Raitt in Indy early July, I know that will be great. Love her beautiful voice and killer slide guitar. Let's Rock!
I can't recall, did you model this in Hornresp?
I find modelling simpler horns easy enough, but multi drivers etc would initially be a challenge for me. Steep learning curve.
Others on DIYaudio are a dab hand though.
Hornresp could tell you where your cancellation and reinforcements are going to be.
You can then move the drivers about in the model, try drivers of different sizes, different T&S parameters (perhaps a range of sizes might work best), etc.
I've found Hornresp invaluable for tapped horns and mid bass horns with driver parameters.
Also used to get the profile for tractrix and Le Cléac'h horn profiles for compression driver use at desired cutoff frequency, that I've then gone on to make.
Measuring them, confirms the maths in Hornresp really works!
The measuring are very close to the Hornresp predictions!
Ignore, if already done.
Ah yeah post #44!
Not sure how you'd model the acoustic element + the horn / driver power though?
Perhaps that too can be done.
I find modelling simpler horns easy enough, but multi drivers etc would initially be a challenge for me. Steep learning curve.
Others on DIYaudio are a dab hand though.
Hornresp could tell you where your cancellation and reinforcements are going to be.
You can then move the drivers about in the model, try drivers of different sizes, different T&S parameters (perhaps a range of sizes might work best), etc.
I've found Hornresp invaluable for tapped horns and mid bass horns with driver parameters.
Also used to get the profile for tractrix and Le Cléac'h horn profiles for compression driver use at desired cutoff frequency, that I've then gone on to make.
Measuring them, confirms the maths in Hornresp really works!
The measuring are very close to the Hornresp predictions!
Ignore, if already done.
Ah yeah post #44!
Not sure how you'd model the acoustic element + the horn / driver power though?
Perhaps that too can be done.
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Thank you for staying with us Steve! I have much data from REW, just learned it in the last year, love it.
Art and JJ have done great work for me in Hornresp. I have not learned this software yet, on my long list!
The Holy Grail of Acoustics and Audio Engineering for me are Art Welter (Weltersys), Tom Danley (Danley Sound Labs), Paul Klipsch of course, and Earl Geddes.
You might know them all, but if not, spread it around Europe!
Art is on my thread, man does he know his ****, and is very helpful.
Tom is a guy that I follow at times, high respect from the community, not on my thread, would like to see him join, need to reach out.
Paul Klipsch was of course a legend.
I would like to reach out to Earl Geddes, he is a Waveguide man, PhD, very knowledgeable. I saw one of his threads earlier, he got sideways on a guy big time on diyAudio, the moderator had to jump in. That does not bother me, passion is OK, but I try to keep my thread friendly, and loaded with experience, knowledge and great testing, to see what really works!
BTW - saw the Eagles tribute band tonight. First song was lame, I was like oh no. Then they played Witchy Woman, and rocked it hard. They kept going and I had a blast listening to them, very talented guys! The youngest guy in the band was playing a Tele (not my favorite guitar), but he killed it! The drummer was actually the best singer. They closed with Joe Walsh Rocky Mountain Way, one of my old favs. The other guitar played broke out an SG and was killing it, I think maybe a glass slide. Let's Rock!
Art and JJ have done great work for me in Hornresp. I have not learned this software yet, on my long list!
The Holy Grail of Acoustics and Audio Engineering for me are Art Welter (Weltersys), Tom Danley (Danley Sound Labs), Paul Klipsch of course, and Earl Geddes.
You might know them all, but if not, spread it around Europe!
Art is on my thread, man does he know his ****, and is very helpful.
Tom is a guy that I follow at times, high respect from the community, not on my thread, would like to see him join, need to reach out.
Paul Klipsch was of course a legend.
I would like to reach out to Earl Geddes, he is a Waveguide man, PhD, very knowledgeable. I saw one of his threads earlier, he got sideways on a guy big time on diyAudio, the moderator had to jump in. That does not bother me, passion is OK, but I try to keep my thread friendly, and loaded with experience, knowledge and great testing, to see what really works!
BTW - saw the Eagles tribute band tonight. First song was lame, I was like oh no. Then they played Witchy Woman, and rocked it hard. They kept going and I had a blast listening to them, very talented guys! The youngest guy in the band was playing a Tele (not my favorite guitar), but he killed it! The drummer was actually the best singer. They closed with Joe Walsh Rocky Mountain Way, one of my old favs. The other guitar played broke out an SG and was killing it, I think maybe a glass slide. Let's Rock!
You might want to consider weight when adding drivers for power handling. Just the battery / control effect amp and exciter add up quickly to make a perceptibly heavy acoustic guitar, in what I've been fooling around with.
I once had a Hagstrom Swede bass. It felt like it was going to collapse my spine, playing it standing up with a strap.
I once had a Hagstrom Swede bass. It felt like it was going to collapse my spine, playing it standing up with a strap.
Agree JJ, I keep adding more, which keeps pushing me to the external hardware option, but keep the internal option also, I would love to have both.
The external optional would obviously have more power, and I can keep adding to it, I can see I will. The internal optional will still be a great guitar, easier to handle and deal with, both options going on the patent. I was pissed at the USPTO for taking so long, but now that I know I must have two options, that worked in my favor. I will discuss with the patent examiner directly, to make sure he/she understands, and will approve. Talking to these patent examiners is very helpful, which I learned on my second patent. They will listen, and they will let you change if required, but only if you have a good logical, legal reason for doing so, they are good to work with.
I played my Martin Acoustic tonight, in my hotel room. It is the low end laminated Martin, not a real one, but it is a $500 guitar, and truly not bad. I tell you it is so different after playing the Folded Horn Acoustic Guitar. So much less power, must play harder which leads to distortion and string buzz. I just could not feel the strings dancing under my fingers, if that makes sense, very different. Plus the soundboard barely moves. Sustain is normal. but just does not seem normal any more. After playing a beast, a regular acoustic is not cutting it anymore, OK unless I had a very high dollar Martin, that would be great I admit. But the power from the drivers and horns is something that needs to be played to appreciate.
I can't wait to test four drivers, I bet that kills it even more, stay tuned!
The external optional would obviously have more power, and I can keep adding to it, I can see I will. The internal optional will still be a great guitar, easier to handle and deal with, both options going on the patent. I was pissed at the USPTO for taking so long, but now that I know I must have two options, that worked in my favor. I will discuss with the patent examiner directly, to make sure he/she understands, and will approve. Talking to these patent examiners is very helpful, which I learned on my second patent. They will listen, and they will let you change if required, but only if you have a good logical, legal reason for doing so, they are good to work with.
I played my Martin Acoustic tonight, in my hotel room. It is the low end laminated Martin, not a real one, but it is a $500 guitar, and truly not bad. I tell you it is so different after playing the Folded Horn Acoustic Guitar. So much less power, must play harder which leads to distortion and string buzz. I just could not feel the strings dancing under my fingers, if that makes sense, very different. Plus the soundboard barely moves. Sustain is normal. but just does not seem normal any more. After playing a beast, a regular acoustic is not cutting it anymore, OK unless I had a very high dollar Martin, that would be great I admit. But the power from the drivers and horns is something that needs to be played to appreciate.
I can't wait to test four drivers, I bet that kills it even more, stay tuned!
OK, will you put both down at the end, or one up halfway? The reason I ask is because if they're a large distance apart, there will be a frequency that cancels due to the time delay from the one at the horn end to the one in the "middle", given each is driven by the same signal.
That said, when I tested a few acoustics their FR plots looked somewhat like comb filters, with peaks at whole number multiples of some fundamental frequency. Maybe that's what makes an acoustic sound like a guitar, so - done right - you may be onto something deliberately causing that effect via driver placement staggered along the horn length. (New Patent pending!)
Done right means those FR peaks land on, or nearby, concert tuning frequencies, such that the whole thing livens up when properly tuned. But not too much, else you'd get that atomic blast on just certain notes, which of course isnt how a guitar should play and sound. I'll guess just flat to concert pitches is where the comb frequency sequence should land.
Yes Yes thank you JJ, and Art also noted this. I am going back to the old play another guitar through my spare folded horn guitar, see attachment. I do want to mount the two extra speakers as you noted at option #1A, I can do this in the production design, but for testing I will do at option # 1B.
I will also test option #2, just for fun. The speakers will be mounted above the chamber divider, which will never work in production (feedback), but will be a great test with other guitar through guitar horns. If they work, they will be mounted below the chamber divider.
Art - my #2 option would cancel, I know. I see tapped horns like yours add the front and back of driver, but are they designed to be in phase? Meaning does the front of the speaker sound meet the back of the speaker sound at 180 degrees? A 40 Hz sub soundwave is 28 feet, does it meet the back of the speaker at 14 feet to be in phase, seeing how they are both in the horn path? Maybe I have this wrong? I am just learning about tapped horns, and find them to be highly interesting. Please advise my friend.
After playing tonight, I think I don't need much more power really. I play for a while and think, do I have enough? Then I turn the power off and just play acoustically, and laugh again at the difference, incredible!
I really just want more headroom!
Tonight I tested with dB meter, 129 dB at horns!!! 122 at soundboard!! Even better than guitar through guitar earlier REW testing (which was about 120 dB max).
Earlier I noted normal acoustic guitar at 85-90 dB, I think that was low through REW, not sure why. With dB meter I am getting 90-95 dB WITHOUT folded horns, great? Pretty much the same as my Taylor and Guild, but I admit not as nice sounding as either ONLY acoustically, but turn on the horns BAM, not even close, this damn thing ROCKS!
My Bose Waveguide Radio max is 109 dB, so beats that. I am splicing, and also mounted speakers tonight, hope to have ready for testing tomorrow, but I am having so much fun playing this beast, I don't really care when I get everything else completed, let's rock!
I will also test option #2, just for fun. The speakers will be mounted above the chamber divider, which will never work in production (feedback), but will be a great test with other guitar through guitar horns. If they work, they will be mounted below the chamber divider.
Art - my #2 option would cancel, I know. I see tapped horns like yours add the front and back of driver, but are they designed to be in phase? Meaning does the front of the speaker sound meet the back of the speaker sound at 180 degrees? A 40 Hz sub soundwave is 28 feet, does it meet the back of the speaker at 14 feet to be in phase, seeing how they are both in the horn path? Maybe I have this wrong? I am just learning about tapped horns, and find them to be highly interesting. Please advise my friend.
After playing tonight, I think I don't need much more power really. I play for a while and think, do I have enough? Then I turn the power off and just play acoustically, and laugh again at the difference, incredible!
I really just want more headroom!
Tonight I tested with dB meter, 129 dB at horns!!! 122 at soundboard!! Even better than guitar through guitar earlier REW testing (which was about 120 dB max).
Earlier I noted normal acoustic guitar at 85-90 dB, I think that was low through REW, not sure why. With dB meter I am getting 90-95 dB WITHOUT folded horns, great? Pretty much the same as my Taylor and Guild, but I admit not as nice sounding as either ONLY acoustically, but turn on the horns BAM, not even close, this damn thing ROCKS!
My Bose Waveguide Radio max is 109 dB, so beats that. I am splicing, and also mounted speakers tonight, hope to have ready for testing tomorrow, but I am having so much fun playing this beast, I don't really care when I get everything else completed, let's rock!