I think a Sitka Spruce soundboard can provide some improvements for sure. Measuring taps on the soundboard looks promising (see attached REW), but not anything groundbreaking. Given that taps are pretty lame compared to actual playing, this could be significant, we shall see. I am attaching my video again in case anybody missed it. Let's Make The Acoustic Guitar Rock!
https://drive.google.com/file/d/151VdED1pT8BZCCgMVRBT0IgrH90lAWq1/view?usp=sharing
https://drive.google.com/file/d/151VdED1pT8BZCCgMVRBT0IgrH90lAWq1/view?usp=sharing
Folks - Please correct me if I'm wrong about this.
So, as I understand, you can - with the right stuff - get an "Impulse Response" of your guitar speaker cabinet, load it into this device, then it "convolves" that with the input signal from your guitar, to sound like it's being played through the speaker as an audio signal. In other words, you could play it through your hifi speaker / headphones, but it would sound like your guitar speaker / cabinet.
Conversely, you could get the "Impulse Response" of your guitar speaker, invert it in some kind of software, then this device outputs the opposite of what the guitar speaker does. Such that if you put the output signal back through the guitar speaker, all its character disappears and it sounds like a flat response full ranger.
Therefore, if an impulse snapshot were taken of the FHAG speaker system, inverted, loaded into this device - then any FR character of the horn system would be homogenized into a flat FR, sounding more like a HiFi / PA / Monitor speaker. Real Time convolution for only ~$150! If you can believe the just statistically significant 4.5 star reviews...
(For my own purposes, I like to sing through my acoustic guitar body via an exciter driven by an mic / amplifier. It's attached to the back of the guitar body on the inside. Exciting a braced, shaped piece of wood that forms the rear wall of a cabinet is a reaaally wonky way to make a speaker. The FR you get isnt exactly what you'd call "flat". So, IR the exciter setup, invert that, load it into this thing, put it in the signal chain before the amp and resulting FR should be better, right? Right?)
So, as I understand, you can - with the right stuff - get an "Impulse Response" of your guitar speaker cabinet, load it into this device, then it "convolves" that with the input signal from your guitar, to sound like it's being played through the speaker as an audio signal. In other words, you could play it through your hifi speaker / headphones, but it would sound like your guitar speaker / cabinet.
Conversely, you could get the "Impulse Response" of your guitar speaker, invert it in some kind of software, then this device outputs the opposite of what the guitar speaker does. Such that if you put the output signal back through the guitar speaker, all its character disappears and it sounds like a flat response full ranger.
Therefore, if an impulse snapshot were taken of the FHAG speaker system, inverted, loaded into this device - then any FR character of the horn system would be homogenized into a flat FR, sounding more like a HiFi / PA / Monitor speaker. Real Time convolution for only ~$150! If you can believe the just statistically significant 4.5 star reviews...
(For my own purposes, I like to sing through my acoustic guitar body via an exciter driven by an mic / amplifier. It's attached to the back of the guitar body on the inside. Exciting a braced, shaped piece of wood that forms the rear wall of a cabinet is a reaaally wonky way to make a speaker. The FR you get isnt exactly what you'd call "flat". So, IR the exciter setup, invert that, load it into this thing, put it in the signal chain before the amp and resulting FR should be better, right? Right?)
Deconvolution of an impulse response (IR) would require long processing time, the latency would make it difficult to play.
In addition, the FHAG's recorded IR would be different at any different mic location.
Deconvolution of that response would only remove the FR character of the horn system from the particular place it was recorded, and could make the sound far different (worse..) at others.
Deconvolution of an impulse response is over my head. I will stay out of this one, but please keep the conversation going if required!
I have a new set of headphones that are very nice, not cheap, man the guitar video sounds even better!
I don't want to get into dimensions of my horn/body tuning at the throat, but I started low (about 125 Hz), then adjusted up to about 150-200 Hz. I know the natural resonant frequency of the guitar body is about 164 Hz, because my second fret fourth string on an E chord (164 Hz) will sustain pretty much forever, if the amp is cranked up, talk about sympathetic vibration. This of course is the octave up of the low E string of 82 Hz, which is the second harmonic of the low E string fundamental we have talked about recently.
Art - my question is, does this natural resonant frequency actually favor the second harmonic of the low E string? Meaning if the body was not tuned to this frequency, we would hear more of the low E string fundamental?
I see that standard acoustic guitar bodies have a resonant frequency of between about 100 Hz and about 300 Hz, depending on their size, thickness, bracing, material...I really like 164 Hz, down in the lows that I love!
I have a new set of headphones that are very nice, not cheap, man the guitar video sounds even better!
I don't want to get into dimensions of my horn/body tuning at the throat, but I started low (about 125 Hz), then adjusted up to about 150-200 Hz. I know the natural resonant frequency of the guitar body is about 164 Hz, because my second fret fourth string on an E chord (164 Hz) will sustain pretty much forever, if the amp is cranked up, talk about sympathetic vibration. This of course is the octave up of the low E string of 82 Hz, which is the second harmonic of the low E string fundamental we have talked about recently.
Art - my question is, does this natural resonant frequency actually favor the second harmonic of the low E string? Meaning if the body was not tuned to this frequency, we would hear more of the low E string fundamental?
I see that standard acoustic guitar bodies have a resonant frequency of between about 100 Hz and about 300 Hz, depending on their size, thickness, bracing, material...I really like 164 Hz, down in the lows that I love!
The acoustic feedback loop you create with amplification is not necessarily the the natural resonant frequency of the guitar body. A peak in the response of the loudspeaker or transducers could accentuate response at any note frequency.
With amplification, you can sustain any chord indefinitely just by increasing volume selectively ("parametric equalization") around it's main note frequencies.
Yes, though when amplified the "natural resonant frequency" is changed to the "aggregate resonant frequencies".
If you were to cut (reduce) the louder (more resonant) frequency ranges, the lower fundamentals would be relatively louder, so you would hear more of them.
The horn's response drops off below ~125Hz (and above ~2kHz IIRC), and the relatively small body volume resonance does not reinforce the low E fundamental much by comparison to the octave higher.
Play the guitar acoustically like in post #1012, you'll see a different resonant response than when you amplify it.
A "good" acoustic body will resonate the strings over a fairly wide range, though certain frequencies will predominate, and "ring" louder and longer.
Since your FHAG body is not large enough to provide much resonance at the 82Hz fundamental, its second harmonic is louder-no surprise, even a dreadnought or jumbo size won't be, though the relative difference in level may be less.
Changing the guitar body's acoustic resonances requires woodwork- bracing, materials, thickness, volume, shape and openings all interact with each other synergistically.
Much easier to change the response electronically
I forgot how to change the (over ten year old..) battery in my Ovation Elite, when reading the manual saw this:
24dB difference between Larry Coryell's "extroverted sound" and his "introverted feel" envelope shape.
Art
It's not that hard conceptually. Plenty of YT videos on the topic, probably worth a watch sometime.
Basically, you do a frequency sweep (which you've done already using REW - nothin' new there) of whatever speaker / cabinet, who's sound character you want to put over any audio signal - usually from a guitar pickup. Within that frequency sweep, some "tones" will be louder, some softer in a relative sense.
Now imagine a graphic EQ with many, many bands. The levels are set in a corresponding way to the tonal character contained in the frequency sweep measurement, such that any signal going through it gets louder / softer in the same way - this is simplistically speaking.
Why would you want to know? Just to grasp that anything you can "do" a frequency sweep of, can be captured and rendered as a tonal effect (for ~$150 these days...). You could "measure" one of your acoustics, play an electric though that as a tonal effect and - supposedly - it would sound "like" the acoustic.
You could capture a sweep of Art's SynTripP speaker systems setup out in a big field just before several hundred people show up for a show - play your guitar through that and - supposedly - it'd sound like it was going through that system. At least, from whatever vantage point out in that field the sweep was recorded from.
Just an interesting way to transcend time, space, mechanical structures. If Larry were alive today, he might have a few dozen such sounds corresponding to speaker cabinets, guitar bodies, maybe even pickups that he could have compartmentalized into "great for jazz chords - lots of low end" as just another selection on that pedal.
When I was first listening to him in high school / college, such signal processing tricks were unthinkable. They were just building hardware that could to the 1st step. That TC Electronic box pedal being like the difference between a AT&T touch-tone desk phone and an iPhone. Take advantage of it, ya know?
Last edited:
Thanks Art and JJ! - I saw Larry Coryell at The Jazz Kitchen in Indy back in the day, man can he plaaaay! I am trying to remember, I think maybe he was playing a big blonde Gibson hollow body electric, maybe an L-5 like Wes. Saw Kenny Burrell about the same time, both small "jazz halls", what a great way to listen.
Art I printed out Larry's settings, I need to do more of that. I have been going for clean, literally all tone in the off position to see what the guitar and horns can do. My video responses have been very very positive. A music head friend that I respect said "man so clean, so clear, so full, love it!" another said put this damn thing on Shark Tank, sounds great! I will not do that, just not part of my strategy.
Anyway, time to explore more sound options for sure. JJ I also printed your Impulse IR Loader Pedal, something to try for sure, I have no idea what it will do to my sound, but from your description, worth a try!
So Art "much easier to change the response electronically" I know this is true. I wonder what a great guitar company could do with this concept. I mean horns in a guitar just work! I may not have it perfected, but man it is a great start! If I can do this at work and in my basement shop, imagine what a serious guitar company can do with this concept, and apply the suggestions from you guys, would be beyond what I have done. Plus the horns could be any design they can fit in a guitar. I have proven that (2) five feet long horns can fit in a guitar. Way way more horn than Bose put in their radio, or other guitar companies have used in their guitar, it is a proven concept, and it will NOT feedback uncontrollably.
What I would really like to do is cut the back off a big old Gibson L-5 (JJ has made comments on this type of design before), and build a crazy horn system on a new back with larger sides, put that beast back into the guitar, with a huge upper chamber and lower horn chamber. The only problem is you would need arms the size of a gorilla to play it! Keep the comments coming everybody. If you are watching and have not commented yet, please join the conversation!
Art I printed out Larry's settings, I need to do more of that. I have been going for clean, literally all tone in the off position to see what the guitar and horns can do. My video responses have been very very positive. A music head friend that I respect said "man so clean, so clear, so full, love it!" another said put this damn thing on Shark Tank, sounds great! I will not do that, just not part of my strategy.
Anyway, time to explore more sound options for sure. JJ I also printed your Impulse IR Loader Pedal, something to try for sure, I have no idea what it will do to my sound, but from your description, worth a try!
So Art "much easier to change the response electronically" I know this is true. I wonder what a great guitar company could do with this concept. I mean horns in a guitar just work! I may not have it perfected, but man it is a great start! If I can do this at work and in my basement shop, imagine what a serious guitar company can do with this concept, and apply the suggestions from you guys, would be beyond what I have done. Plus the horns could be any design they can fit in a guitar. I have proven that (2) five feet long horns can fit in a guitar. Way way more horn than Bose put in their radio, or other guitar companies have used in their guitar, it is a proven concept, and it will NOT feedback uncontrollably.
What I would really like to do is cut the back off a big old Gibson L-5 (JJ has made comments on this type of design before), and build a crazy horn system on a new back with larger sides, put that beast back into the guitar, with a huge upper chamber and lower horn chamber. The only problem is you would need arms the size of a gorilla to play it! Keep the comments coming everybody. If you are watching and have not commented yet, please join the conversation!
Mealwaysthought the easy way to change how it sounds from your base design is to play with the passage routings. So that one horn can go lower, while the other gives up its low end response to the first one's ability to drop down closer to open E. It could even be a two way, with the longer horn covering the first 3 strings, the shorter one the high 3 - with the right pickup. Sort of a "woofer / tweeter" arrangement conceptually.
Then you can get into the electronics to support the two different horn structures and their frequency ranges which would probably be some EQ differences - say, for sure the somewhat smaller horn wouldnt need to be fed any frequencies below , say the open G, The split pickup sensing the string vibrations in two sets of 3 strings would do that automatically. You could blend just the treble from the low 3 into the shorter horn, to keep them sounding sparkly. Stuff like that.
Who knows, maybe that would be an evolutionary step, maybe no one would like it as much as the original's sound.
Speaking of sound, you could take a frequency sweep of the FHAG in the format that one of these IR pedals can use, then those with electric guitars could get an idea of what their playing through your guitar sounds like. That'd just be a file someone could download off your website.
Then you can get into the electronics to support the two different horn structures and their frequency ranges which would probably be some EQ differences - say, for sure the somewhat smaller horn wouldnt need to be fed any frequencies below , say the open G, The split pickup sensing the string vibrations in two sets of 3 strings would do that automatically. You could blend just the treble from the low 3 into the shorter horn, to keep them sounding sparkly. Stuff like that.
Who knows, maybe that would be an evolutionary step, maybe no one would like it as much as the original's sound.
Speaking of sound, you could take a frequency sweep of the FHAG in the format that one of these IR pedals can use, then those with electric guitars could get an idea of what their playing through your guitar sounds like. That'd just be a file someone could download off your website.
JJ - this is exactly the type of experimentation a large guitar company could pull of pretty easily. Since I have three guitar bodies already cut with my design, I am likely out of options for this type of big change. I could go crazy and start paying for more CNC work and hire some people to make things happen quicker, but that is just not my strategy. I have been doing this debt free, and I would like to keep it that way.
I have a simple footswitch on a small extension chord to the amp that I was smacking off and on while playing last night, should do the trick for one more recording showing a more robust "with horns" and without horns" comparison on video. This time it will be with chords, not light finger picking. Good to have both, but hopefully the chords will showcase the stark differences in a better way. When I play without horns, all OK, you know the tinny high E string can be heard, then hit the switch and BAM, wow don't wake up the wife!
Speaking of my "tinny high E string" theory that I hear on all acoustic guitars, it def is not a problem on electric guitars in any way. In fact I think hanging out on the 1 and 2 string way up the fretboard on an electric guitar is wonderful, like Dicky Betts on Blue Sky, Jessica, so many great electric guitar solos that rock. When I play my guitar with the horns on, the tinny sound disappears. Not sure if it is the amplitude solving this problem, different timbre, probably a combination of issues, but it works. I might do some REW measurements with different tone settings tonight.
It seems to me the miniaturization of music listening devices has less ups than downs. It seems to be true for a jumbo guitar vs. a Ukulele, for ear buds vs. serious headphones and for small laptop speakers vs. "real" speakers. My guitar is big (about the same body size as the beloved Gibson L-5, the Granddaddy of electric hollow body archtops. It is a bit heavy, but man that heft really gives me the room to fit horns, and also get more soundboard surface area.
I have a simple footswitch on a small extension chord to the amp that I was smacking off and on while playing last night, should do the trick for one more recording showing a more robust "with horns" and without horns" comparison on video. This time it will be with chords, not light finger picking. Good to have both, but hopefully the chords will showcase the stark differences in a better way. When I play without horns, all OK, you know the tinny high E string can be heard, then hit the switch and BAM, wow don't wake up the wife!
Speaking of my "tinny high E string" theory that I hear on all acoustic guitars, it def is not a problem on electric guitars in any way. In fact I think hanging out on the 1 and 2 string way up the fretboard on an electric guitar is wonderful, like Dicky Betts on Blue Sky, Jessica, so many great electric guitar solos that rock. When I play my guitar with the horns on, the tinny sound disappears. Not sure if it is the amplitude solving this problem, different timbre, probably a combination of issues, but it works. I might do some REW measurements with different tone settings tonight.
It seems to me the miniaturization of music listening devices has less ups than downs. It seems to be true for a jumbo guitar vs. a Ukulele, for ear buds vs. serious headphones and for small laptop speakers vs. "real" speakers. My guitar is big (about the same body size as the beloved Gibson L-5, the Granddaddy of electric hollow body archtops. It is a bit heavy, but man that heft really gives me the room to fit horns, and also get more soundboard surface area.
Attachments
Awwe, you could too. People here make those "Cornu" (and other) speakers out of that cut foam board stuff from the dollar store. I'm sure you could build just the fully enclosed horn part out of that stuff too, for the sake of experimentation.
You already have the guitar; it would be a different, separate external enclosure to play it through, for the sake of hearing how different path length horns sound. Maybe inspires enough to cut one out like that! Or maybe inspires an alternate method of construction using thin bent laminated wood.
Having an L5 in the stable would be like having a Bently S in the garage. Too much guitar for my feeble hands. Hey - I got to do the feature set at the open mic and then got up a second time after everyone rotated through; played 10 songs on a lighted stage last night! As Geddy says, it "approaches the unreal". Even though nobody's there except the usual crowd of other players.
The guy that runs it is getting married and wants to have an open mic at his wedding. He's in his late 70's and always joking around, so I have to think of some tunes to subtly humor him about it. Joan Jett's version of "Crimson and Clover" comes to mind. Beatles "If I needed Someone" comes to mind. I'm already going to do Carpenters "We've Only Just Begun". It's on the 22nd, so coming up fast!
What do you mean an L5 guitar is too much JJ? No way! You would love it. I have not played one in decades, but man the sound is so powerful, I think it is easier to play, a light touch is all it takes to get that big beautiful sound.. Ok I may need to break the bank and buy one...hmm.
One of these days I may try your suggestion. I think it is a great idea, just other things going on, you know how it is.
Attached is REW measurements showing tone comparisons. This is the type of data that makes me wonder. I mean other than below 200 Hz and a little at the high end, the data does not look crazy different. My favorite red setting with all tone off has the most stable response, I think it sounds great!
Blue all treble no surprises, does not sound that great at all, much worse than the data shows in my opinion. Green which should be pretty even looks OK, but still does not sound as good as red, all tone off. I don't care who says what, man my ear guides me the best. This FHAG holds its own without any need for amp tone coloration!
One of these days I may try your suggestion. I think it is a great idea, just other things going on, you know how it is.
Attached is REW measurements showing tone comparisons. This is the type of data that makes me wonder. I mean other than below 200 Hz and a little at the high end, the data does not look crazy different. My favorite red setting with all tone off has the most stable response, I think it sounds great!
Blue all treble no surprises, does not sound that great at all, much worse than the data shows in my opinion. Green which should be pretty even looks OK, but still does not sound as good as red, all tone off. I don't care who says what, man my ear guides me the best. This FHAG holds its own without any need for amp tone coloration!