Art - I thought maybe you had crossed paths with the Japanese at some point. I may need to add a Process Map to my Kaizen. Really layout every detail of the recording process, right down to outside possible noise sources.
Yes my noise floor varies by 45 dB on the low end, but my Frequency Output also varies by 30-35 dB in the highs and midrange. I know noise is more prevalent on the lows, and I am trying to eliminate as much noise as possible of course. Record late at night, not much traffic, turn off all appliances, AC...I actually tried to use some wireless speakers much earlier, the noise was noticeable, in the garbage they went.
I do not understand how the REW data includes noise, so any thoughts you have on this, and my Frequency Output in general would be greatly appreciated!
JJ- yeah I just found the 20 Hz-20 kHz fit button in REW, was staring right at me all this time, below 20 is a waste. To your point I probably should not plot below 40 Hz, but I am interested in undertones, another topic I don't fully understand. Even above 16 kHz may also be wasted plot space.
My acoustic guitars (Taylor and my FHAG) both drop of considerably after the low E string frequency of about 80 Hz, as all do, BUT my FHAG also drops of at 80 Hz, but not near as much. Why? I can hear the added lows. Remember, when I played music through my horns only, uncovered, not great, then covered, the bass went through the roof, same thing with the FHAG of course. So the 45 dB noise floor difference is a result of this, me thinks, just a great increase in the lows, and I can hear it!
Yes my noise floor varies by 45 dB on the low end, but my Frequency Output also varies by 30-35 dB in the highs and midrange. I know noise is more prevalent on the lows, and I am trying to eliminate as much noise as possible of course. Record late at night, not much traffic, turn off all appliances, AC...I actually tried to use some wireless speakers much earlier, the noise was noticeable, in the garbage they went.
I do not understand how the REW data includes noise, so any thoughts you have on this, and my Frequency Output in general would be greatly appreciated!
JJ- yeah I just found the 20 Hz-20 kHz fit button in REW, was staring right at me all this time, below 20 is a waste. To your point I probably should not plot below 40 Hz, but I am interested in undertones, another topic I don't fully understand. Even above 16 kHz may also be wasted plot space.
My acoustic guitars (Taylor and my FHAG) both drop of considerably after the low E string frequency of about 80 Hz, as all do, BUT my FHAG also drops of at 80 Hz, but not near as much. Why? I can hear the added lows. Remember, when I played music through my horns only, uncovered, not great, then covered, the bass went through the roof, same thing with the FHAG of course. So the 45 dB noise floor difference is a result of this, me thinks, just a great increase in the lows, and I can hear it!
Typically, as was recently mentioned elsewhere in here, the brain is well capable of perceiving low frequency presence as ear-re-assembled from higher harmonics. I think it was said that for a bass guitar, there's really not much 40 Hz there in the open E, it just sounds that way from all the harmonics present in the string vibration. Maybe that's how they get away with those little bass amps with 10" speakers...
I know low frequency is a problem regarding noise floor. We had an acoustic test chamber that was located next to the shock and vibration lab. They moved it farther away, toward the other end of the building. I looked into floor isolation methodologies and found these elastomer pucks / rail system that we incorporated. Still, the noise floor of that test chamber varied with time of day, at one point being the best @ Intel - but only at night, when everyone was gone and all other nearby activity ceased.
I'd like to see you have your best shot with Yamaha, who I presume know more about instrument building and making measurements of than ordinary folks like you and I. If you told them something like "my guitar makes sub 40 hz sound - I can hear it!" well, I'd guess that wouldnt be so respected by them. A better mistake would be to chop everything off below 80, assuming nothing's happening below the low E, with a concert tuning. Also I'd think measuring all the way out to 20kHz would appear a little sophomoric to them being this is a guitar instrument, versus say, a hi-fi speaker.
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OK Coach, I never said "my guitar makes sub 40 Hz sound - I can hear it!" I agree that would be ridiculous. I have said, in different forms, I can hear the rich lows being boosted, and that is true. The difference from horns covered to hours uncovered is almost absurd. I will have a spare guitar body apart at any serious demo I do, and say listen to this. No horns, eh...then horns, wow were did those lows come from. I will include this in my video also, another reason a video is a must. I just found out the iPhone 15 has a USB-C connector, no way I am buying anything but that, I can't stand the piece of **** Apple Lightning connector.
Anything under the 20 Hz limit of human hearing should be removed, sure, but why would I want to remove under 80 Hz? I am showing a 15-30 dB increase in everything under 80 Hz (per above). No way that is going away, it is real.
So out to 20 kHz is sophomoric eh? I disagree, it is more like grad school, if you want to use that type of lingo. Ok I can't hear all the way up to 20 kHz at my age, but others can. I can likely get to about 17 kHz. Seeing that my FHAG is still at 87 DB at about 19 kHz, I think it is a pretty big deal, compared to about 55 kHz for my Taylor, that is 32 dB difference. I don't care if it is a hi-fi speaker or a guitar, that is big. I mean the lowest harmonic is almost higher than the entire FR of a standard acoustic guitar, and yes I can hear that also. Sparkling! Not dink...dink tinny ****.
This time I got 1,000 hits in 12 days, new record, it usually takes about a month or a little more. That's all I got for now, let me have it again and thanks!
Anything under the 20 Hz limit of human hearing should be removed, sure, but why would I want to remove under 80 Hz? I am showing a 15-30 dB increase in everything under 80 Hz (per above). No way that is going away, it is real.
So out to 20 kHz is sophomoric eh? I disagree, it is more like grad school, if you want to use that type of lingo. Ok I can't hear all the way up to 20 kHz at my age, but others can. I can likely get to about 17 kHz. Seeing that my FHAG is still at 87 DB at about 19 kHz, I think it is a pretty big deal, compared to about 55 kHz for my Taylor, that is 32 dB difference. I don't care if it is a hi-fi speaker or a guitar, that is big. I mean the lowest harmonic is almost higher than the entire FR of a standard acoustic guitar, and yes I can hear that also. Sparkling! Not dink...dink tinny ****.
This time I got 1,000 hits in 12 days, new record, it usually takes about a month or a little more. That's all I got for now, let me have it again and thanks!
Sometimes I just need to look at the horns uncovered, and consider why this is working so well. Look at these horns (waveguides), and in a guitar! .250" thick walls. It might not be a hi-fi, but man it sure does steal many ideas from folded horn speakers. Cut from a 6" thick x 18" wide x 24" long piece of Rock Maple.
Covered, that is just the lower chamber (except the outer walls), then a standard guitar chamber on top of this. I wonder how the two really do interact with each other. Likely pretty difficult to measure that in some meaningful way. Oh yeah, and 1/2" thick chamber divider to prevent feedback.
Let's Make The Acoustic Guitar Rock! Why should electric guitars have all the fun?
Well, if you're using concert tuning, the lowest frequency input through the bridge is ~80. Percussive thumping the strings and soundboard aside. That stuff comes through BTW and I've noticed on my Kala guitar (which I believe the Shadow pickup system has a design defect) It revealed one of my KEF "egg" speakers recently purchased at a thrift store is blown. How? By moving the cone like a bass drum would with every strum - one is silent, the other scritch-scritch. There's really no need for it, though it does add a percussive element, so if I played like, say, John Mayer and had an amplifier that reproduced the thumps, it might be a useful musical element.
IMHO, it's not something you'd want to subject your small diameter drivers to. The last thing they need is for the voice coil to be un-centered in the gap because of a sub-80Hz transient, while trying to speak the rest of the cord's notes. If I was designing your amplifier for this guitar, I'd allow for a drop D tuning at the low end - and the rest of the seismic stuff would be gone.
I personally have a hard time believing 19 kHz makes it from the driver surface, off the wall directly in front of it, around and around all those turns, but, stranger things have happened. If you sent me one of your horn bases, I'd be glad to test it outside, relative to a generic commercial HiFi speaker. I have a set of Tectonic tebm65c20f on hand (if that's what you're using, but doesnt look like it) which would save shipping weight!
Well, what you can do is drive the horns with a tone from REW, Pink Noise, Music (etc) and then listen to what comes through your pickup system with it connected to another amplifier. You can mute the strings with cloth or foam if you need to keep tension on the bridge for the pickup to work. Simply listen to what comes through, originating from the horn drivers. Maybe even have the second amplifier far off in another room, and use its headphone output.
The 1/2" wood seperator may be massive and stiff enough; there also may be other materials (plexi, sheet aluminum, Corian, sheet steel) that work even better and at thinner guage. There's relatively high current flowing through whatever wiring to those speaker drivers, that makes a magnetic field which can get into your acoustic / magnetic pickup system. The wood wont stop it, but certain metals will. Also proper wire dress will help that a lot.
Keep on rockin' with this, until Yamaha gets their hands on it. It'd be so interesting to see what they'd do with it. I'd bet they wouldnt even let you know, until a product was on the market!
The noise floor you recorded is real, but a rising response below 80Hz clearly shows it's noise rather than speakers.
You shouldn't remove the response under 80Hz, but you want to present believable information, which applies to the upper end as well.
The "folded horn acoustic guitar only" shows a 20 dB peak at 55Hz, that could be a thump, or noise- the problem is you still don't know what is causing the obvious discrepancies, so can't begin correcting them.
By the way, 20 Hz is not the limit of human hearing, and it appears Yamaha has a -55dB room drone going on around 15Hz in their resonance enhancement plots ;^)
Let's say Yamaha chopped everything below the "Low E" point, perhaps leaving a smidge border so the red/yellow ridge doesnt run right on top of the "Time" axis. Wouldnt change a thing in what they're trying to show; would have prevented you from detecting the "-55dB room drone going on around 15Hz" in their data.
There's no way Joe K is going to get as clean a noise floor as Yamaha did, probably within an acoustic test chamber the likes of which places like Yamaha, Intel can afford.
I'd say chop away, as long as:
1. Only serves to remove useless / nonsense information.
2. Doesnt disrupt what's trying to be conveyed, i.e. the "goes loud / sounds good" aspect of Joe's invention. Where the "goes loud" aspect is only an amplification of what the strings are putting into the soundboard. The "sounds good" aspect is only a tonal balance on top of what sound the strings are making.
On the high end, I'd say chop away too. (Not seeing a lot of red ridges in Yamaha's graphs on either side of 10k...) Consider a guitar has ~4 octaves. I get 1280 Hz at the top for concert A tuning. Really need to display out to the 10th harmonic of the highest possible note? I know it's easily possible with modern analysis tools, but unsure if including near or above 10k is useful, regarding conveying "goes loud / sounds good" for an amplified guitar.
All of the above is IMHO, of course!
Art I checked my silent dB level in the room I use for REW recordings, about 30-35 dB. I also waited for my wife to walk around and get some of that noise, up to 40-45 dB easy, even a good 20 feet away, amazing. I am trying to get a better feel for the noise floor, and yes, I am concerned about that, BUT I can see it affecting the Taylor, which I don't care about, because that is just for comparison. The FHAG should be safe, as it is higher, so no noise floor data. In fact, if the Taylor noise floor is higher than the Taylor frequencies I am trying to measure, then by comparison, the FHAG no horns compares more favorably, and of course the FHAG volume 7 looks great either way, no noise floor problem there.
Yes the 55 Hz thump concerns me, what the hell is that? The crazy thing is the Yamaha "drone noise" looks like it is higher than 15 Hz to me, but their data is difficult to read. It might not be at 55Hz, but getting close. Why do both dip below 100 Hz, then rise? I saw this on another REW I did earlier. Maybe all three are just bad data, or MAYBE there is some crazy undertone showing up? Like the first undertone below the fundamental? Plus this is drop D tuning, so my low string is not approx. 80 Hz, it is approx. 70 Hz. Ok maybe a crazy theory, but I had to ask! Oh yeah, and I did Google 20 Hz low for human hearing, looks like some people can hear lower than that, go figure. If you ask JJ I might be one of them, since I can hear low frequencies really well.
JJ - I see Yamaha goes down to 0 Hz with their data, I like that, keeping mine, or maybe 20 Hz bottom. Is see they only go up to about 12 kHz on the high end, not sure why. I would consider cutting it off there, but from 12 to 20 on REW is obviously not weighted the same, likely for good reason, so I don't think it would look that different, I kind of like seeing all the harmonics.
Would I like you to have the guitar body in yours hands, yes, and I am sure you would give me great info, no doubt. Am I shipping this, no ******* way. I have shipped many components at work, I do not trust shipping in any way, too risky!
I visited a new plant yesterday for a work project, and they guy who runs the plant had a Gibson plaque engraved on his SUV, so of course I bit. We talked for about 30 minutes, he has 10 guitars, loves the idea, and wants to make one out of plastic (because he is a plastic molder, making parts from our steel mold). He has a 1000 ton press, so he could do it (if somebody paid a fortune to build the mold). I told him no way, I can't stand plastic guitars.
He said he liked his RainSong, but admitted it sounds a bit on the high end with plastic/carbon fiber, but also said they are now starting to fill them with more glass fiber, to give it more mass (like wood). And they are also making some sort of a soundboard that looks like wood, or has a wood skin, so it is prettier, not ugly like carbon fiber (again like wood). No dice for me, why not just use wood! Oh yeah somebody could run over your carbon fiber guitar and it would not break. Really, how often does that happen? Taking care of a fine instrument is a hassle? Then why do people have 100 year old Martin's that are highly sought after, and from what I am told sound better?
To each their own of course. Love the responses, keep them coming. If you are watching this thread and have not chimed in yet, please do. No comment is too small or large, love to hear everything. If you like it, great. If you don't like it, also OK. Just tell me why, or give new opinions, or give me **** for something I said that you don't agree with. Tonight I do one thing only, play this guitar for three hours, what a joy! I used to play guitar for an hour then stop, not anymore, I need to learn more songs!
Yes the 55 Hz thump concerns me, what the hell is that? The crazy thing is the Yamaha "drone noise" looks like it is higher than 15 Hz to me, but their data is difficult to read. It might not be at 55Hz, but getting close. Why do both dip below 100 Hz, then rise? I saw this on another REW I did earlier. Maybe all three are just bad data, or MAYBE there is some crazy undertone showing up? Like the first undertone below the fundamental? Plus this is drop D tuning, so my low string is not approx. 80 Hz, it is approx. 70 Hz. Ok maybe a crazy theory, but I had to ask! Oh yeah, and I did Google 20 Hz low for human hearing, looks like some people can hear lower than that, go figure. If you ask JJ I might be one of them, since I can hear low frequencies really well.
JJ - I see Yamaha goes down to 0 Hz with their data, I like that, keeping mine, or maybe 20 Hz bottom. Is see they only go up to about 12 kHz on the high end, not sure why. I would consider cutting it off there, but from 12 to 20 on REW is obviously not weighted the same, likely for good reason, so I don't think it would look that different, I kind of like seeing all the harmonics.
Would I like you to have the guitar body in yours hands, yes, and I am sure you would give me great info, no doubt. Am I shipping this, no ******* way. I have shipped many components at work, I do not trust shipping in any way, too risky!
I visited a new plant yesterday for a work project, and they guy who runs the plant had a Gibson plaque engraved on his SUV, so of course I bit. We talked for about 30 minutes, he has 10 guitars, loves the idea, and wants to make one out of plastic (because he is a plastic molder, making parts from our steel mold). He has a 1000 ton press, so he could do it (if somebody paid a fortune to build the mold). I told him no way, I can't stand plastic guitars.
He said he liked his RainSong, but admitted it sounds a bit on the high end with plastic/carbon fiber, but also said they are now starting to fill them with more glass fiber, to give it more mass (like wood). And they are also making some sort of a soundboard that looks like wood, or has a wood skin, so it is prettier, not ugly like carbon fiber (again like wood). No dice for me, why not just use wood! Oh yeah somebody could run over your carbon fiber guitar and it would not break. Really, how often does that happen? Taking care of a fine instrument is a hassle? Then why do people have 100 year old Martin's that are highly sought after, and from what I am told sound better?
To each their own of course. Love the responses, keep them coming. If you are watching this thread and have not chimed in yet, please do. No comment is too small or large, love to hear everything. If you like it, great. If you don't like it, also OK. Just tell me why, or give new opinions, or give me **** for something I said that you don't agree with. Tonight I do one thing only, play this guitar for three hours, what a joy! I used to play guitar for an hour then stop, not anymore, I need to learn more songs!
I have no idea why they went so low in those charts. Perhaps to frame the "Low E" response in the middle of the graphic. I'm sure they all sat in a meeting about it and the marketing people's opinion of how it should look prevailed; after all, they're trying to catch the attention of musicians with engineering data. I can understand what the two graphs say and what their point is, but I'm a degreed engineer with at least some background in acoustics.
One of my fav parts of the Sound City movie was when Dave asked the designer of the famous mixing console what made it sound the way it does. The designer is going on about leakage inductance of the transformers he used in each channel and Dave's like "C'mon man, I barely graduated High School". The sound shaping effect of leakage inductance in audio coupling transformers is something I'd have trouble grasping upon a casual explanation. I'd probably need to sit with it for a while...
Likewise with those waterfall decay graphs Yamaha marketing presented to an audience of musicians. Nice try and I bet somebody gets it enough to buy a guitar. In marketing to Yamaha however, I have to believe the audience would lean a lot toward engineers (does the idea show technical merit) and luthiers (can this be built in a practical way). No way are they going to machine it out of a solid wood piece. They can probably afford the mold to make it out of plastic, put the wood soundboard on it. I think they have plastic "bowled" guitars already and you can bet they sound good and are real performers acoustically for the money. That's Yamaha.
Yeah I hear you JJ, who I am trying to connect with? Well, many different types of people: engineers like us, audio professionals (I am not in that group, but trying, you and Art are saving my ***), guitar players, guitar technicians, luthiers, marketing people, business people that are carefully watching sales projections and net profit margins...so I try to put a little bit of something for everybody into my presentations. To Art's point, I did not add the details concerning mic placement, distance...many technical details that audio experts want, will add that for sure, but to your point, many guitar players don't care about that, they just want it to sound good. Plus I have not done any cost analysis, that needs to be added also, I have done enough of that at work, so I have all the templates to use.
My PPT that I sent Yamaha must have been good enough, because it got the attention of Yamaha U.S. and Japan, so I will take that, was really a relief for me, I thought I would be ignored, **** happens! BUT when I go a step further with my Kaizen for Yamaha, I will certainly add more technical detail, so I really appreciate your comments above, something to chew on for sure.
I am thinking about my recent data, below is just a quick snag for comparison. I will go into REW and try to present the data in different ways, see how it looks, and post for comments.
Also to your point JJ, would Yamaha cut this from a solid piece of wood? You may be right, they may take another approach, but hell, they have their own forest for tonewood, so who knows? The wood I used can be considered a standard component, I bought it on Amazon. Maple is everywhere, hell it is in my backyard. Have you ever seen a plastics facility that makes actual plastic pellets by the trainload? A pox on the landscape, and absolutely horrible for the environment. The design and CNC programming was time consuming for sure, but once you have it, not so bad. Make sure the wood is square, make sure it is indicated on the machine correctly, make sure your huge end mill is sharp, hit the start button and let her rip. Not difficult in a production environment, Yamaha would kill it.
That said, maybe they would bend wood and glue, maybe (God forbid) they would use plastic. Give me any plastic part, I will crack it in 5 seconds if I try. I am not talking about a bowl, that by the nature of its shape has strength, I am talking about a bowl with horns added, a much different animal. If you notice on my folded horn body, there are only two straight pieces of wood, and they have huge radii on the ends. The rest of the guitar is curves and radii everywhere, a monster for strength. I bet I could throw it off my roof onto the side walk and it would just bounce, but I am not going to try, just a thought.
Now carbon fiber, that I admit is a game changer, but just not sure about tone, I need to buy a RainSong guitar! Remember though, carbon fiber delaminates from within, so true product testing is not complete, they have not been around long enough. Mine will be here in 100 years, if taken care of, wood is proven. I love to try my hand at innovation, but the direction needs to be correct, not just innovation for the sake of it, and I believe I have done that, OK hope!
I had so much fun jamming last night, man did the guitar sound great, I am keeping the volume on 7, the sweet spot, 112 dB. OK a little on 7-1/2, probably about 115-117 dB.
When I build my next soundboard, I am considering using two smaller sound holes, one directly over each 4-1/2" chamber, will be interesting to hear and test that, was a real game changer when added, but kind of kills my space for the amp and battery back, tradeoffs. What do you think coach?
I am going to jam again tonight, two nights in a row helps me get through the traveling work week with zero jam time, man I am playing my guitar again like I did in my twenties. Oh yeah and I am looking at iPhone 15 high quality mics with USB-C connection, the iPhone 15 comes out 9-22, but likely in stores a little later.
I bought some small set screws, I will grind a small sharp tip on the end, then but one in each threaded location on the body outer wall, but the soundboard on top of that, give it a few careful whoops all around the perimeter, and I will have my soundboard hole locations, dead nuts perfect. Last time I measured and it worked, but was not perfect, a few areas look a little shabby. Plus I am sanding my varnish and adding more coats, just for practice, talk about marketing, needs to look pretty for many people. Hey I appreciate a beautiful looking instrument for sure, but quality sound is King!!
My PPT that I sent Yamaha must have been good enough, because it got the attention of Yamaha U.S. and Japan, so I will take that, was really a relief for me, I thought I would be ignored, **** happens! BUT when I go a step further with my Kaizen for Yamaha, I will certainly add more technical detail, so I really appreciate your comments above, something to chew on for sure.
I am thinking about my recent data, below is just a quick snag for comparison. I will go into REW and try to present the data in different ways, see how it looks, and post for comments.
Also to your point JJ, would Yamaha cut this from a solid piece of wood? You may be right, they may take another approach, but hell, they have their own forest for tonewood, so who knows? The wood I used can be considered a standard component, I bought it on Amazon. Maple is everywhere, hell it is in my backyard. Have you ever seen a plastics facility that makes actual plastic pellets by the trainload? A pox on the landscape, and absolutely horrible for the environment. The design and CNC programming was time consuming for sure, but once you have it, not so bad. Make sure the wood is square, make sure it is indicated on the machine correctly, make sure your huge end mill is sharp, hit the start button and let her rip. Not difficult in a production environment, Yamaha would kill it.
That said, maybe they would bend wood and glue, maybe (God forbid) they would use plastic. Give me any plastic part, I will crack it in 5 seconds if I try. I am not talking about a bowl, that by the nature of its shape has strength, I am talking about a bowl with horns added, a much different animal. If you notice on my folded horn body, there are only two straight pieces of wood, and they have huge radii on the ends. The rest of the guitar is curves and radii everywhere, a monster for strength. I bet I could throw it off my roof onto the side walk and it would just bounce, but I am not going to try, just a thought.
Now carbon fiber, that I admit is a game changer, but just not sure about tone, I need to buy a RainSong guitar! Remember though, carbon fiber delaminates from within, so true product testing is not complete, they have not been around long enough. Mine will be here in 100 years, if taken care of, wood is proven. I love to try my hand at innovation, but the direction needs to be correct, not just innovation for the sake of it, and I believe I have done that, OK hope!
I had so much fun jamming last night, man did the guitar sound great, I am keeping the volume on 7, the sweet spot, 112 dB. OK a little on 7-1/2, probably about 115-117 dB.
When I build my next soundboard, I am considering using two smaller sound holes, one directly over each 4-1/2" chamber, will be interesting to hear and test that, was a real game changer when added, but kind of kills my space for the amp and battery back, tradeoffs. What do you think coach?
I am going to jam again tonight, two nights in a row helps me get through the traveling work week with zero jam time, man I am playing my guitar again like I did in my twenties. Oh yeah and I am looking at iPhone 15 high quality mics with USB-C connection, the iPhone 15 comes out 9-22, but likely in stores a little later.
I bought some small set screws, I will grind a small sharp tip on the end, then but one in each threaded location on the body outer wall, but the soundboard on top of that, give it a few careful whoops all around the perimeter, and I will have my soundboard hole locations, dead nuts perfect. Last time I measured and it worked, but was not perfect, a few areas look a little shabby. Plus I am sanding my varnish and adding more coats, just for practice, talk about marketing, needs to look pretty for many people. Hey I appreciate a beautiful looking instrument for sure, but quality sound is King!!
Turn on your AC or heater and check again.
There is loads of LF noise in the FHAG volume 7 not present in the other two recordings.
Don't know, not my circus, not my monkeys ;^)
Log scales are just different, not difficult. The ridge is between 10 and 20Hz, typical of LF duct noise from air handling.
Most people need around 90dB SPL to be audible at 15 Hz, their LF noise floor is at least 35 dB below that, while the HF decays off scale.
The guitars have little output below the low E (81Hz), but something in the room does, whether from airborne or mechanical coupling.
Even the best anechoic rooms are not anechoic at VLF.
Really good rooms have absorbtion wedges that are 3 or 4 feet long (cutoff frequencies of about 70 and 90 Hz), at lower frequencies there may be standing waves present.
Thanks much Art, agree the guitar low is 81 Hz, but with drop D tuning on this REW data, my low is about 70 Hz. I can certainly see how the Taylor is all noise floor below 81 Hz, I can also see how the FHAG no horns is noise floor below 81 Hz, but why is it so consistently higher than the Taylor (other than the 55 Hz thump I agree is noise)? You did not address undertones. Is this a myth, is it real? Why with the exact same recording parameters and exact same song would it be consistently higher?
Also your comment about the FHAG with horns, again same exact song and recording parameters, how on earth is it possible to have noise at about 85 Hz? That is pretty damn loud, I would hear that noise before I started recording. Inquiring minds want to know!
Also your comment about the FHAG with horns, again same exact song and recording parameters, how on earth is it possible to have noise at about 85 Hz? That is pretty damn loud, I would hear that noise before I started recording. Inquiring minds want to know!
Holy **** Art, I just found my monkey! I walked around the house, all quiet. Then I went into my garage, built under the house, nothing. Then I went into my shop basement (door from garage) to make sure the AC was not pumping, had it off. As soon as I opened the door I could hear the damn pool pump. I was like WTF, I totally forgot about that, and I can not hear it upstairs. It is always on, found it!
So that is the 55 Hz bounce. I have REW data before I found this, then after I finally turned it off, about 5 dB noise floor difference (except the bounce), BUT still below the Taylor. Of course nowhere hear the FHAG on volume 7. I say the floor noise is gone on FHAG volume 7, all guitar, how could it be anything else? See attached, I think undertones are real, prove me wrong!
So that is the 55 Hz bounce. I have REW data before I found this, then after I finally turned it off, about 5 dB noise floor difference (except the bounce), BUT still below the Taylor. Of course nowhere hear the FHAG on volume 7. I say the floor noise is gone on FHAG volume 7, all guitar, how could it be anything else? See attached, I think undertones are real, prove me wrong!
Play your guitar - watch the REW analysis screen; running in real time of course.Inquiring minds want to know!
What's left when you stop playing is background noise; what's there when playing is background noise + guitar sound. There's a certain number of db - I forget - above an existing tone where a louder tone obscures it, for all intent. So if you see a tone at some frequency and then when you played it went up by 20db, it's basically all from your playing. The background 20 db below doesnt contribute much to the higher level, the way dbs add up. Of course, unsure about the number 20... Probably something easily looked up.
Congrats on finding the pool pump noise source! FWIW, I dont particularly like plastic either, given its environmental impact.
OK, you found the "always on" pool pump noise was present in one trace, but not in others
.What about the AC air handling noise you did not check on?
Do you have ceiling fans you may have forgot were running?
Wind or road noise from an open window?
Have you reproduced the LF content in real time as JJ suggests?
JJ - my main concern with plastic is the tone. Environmental concerns are also legit, but play a 3" speaker through a long PVC pipe, man the sound is bad. As you and Art suggest, I will try REW with and without the guitar, to find the noise floor. I did send REW data with silent recording, the noise floor was very low. Does not seem to be a problem. I do have REW data from December when the pool pump was permanently off, it is very similar to what I recorded recently, except of course without the 55 Hz big bump. That just basically goes away. It colors the acoustic only data, but in that region only. The FHAG is so much higher dB, it is not a problem, but I will have some do overs, just to get more reliable data, I do not like that 55 Hz spike, for sure.
I did a "noise walk" around my entire house, and outside, can't find any other culprits.
I was at a Bluegrass jam session last Sunday, a friend of mine plays banjo, and his wife plays standup bass. They had three banjos, four acoustic guitars and the standup bass, was really fun. I was handed a guitar and joined in. I am not a bluegrass player, but I followed along with the chords, nothing fancy.
The banjos were all nice older Gibson, and the Guitars were all Rosewood Martins and one Collins, all really nice. Plus of course two part vocal harmonies.
Of course I recorded dB levels on my iPhone from about six feet away, about 85 dB.
Then I walked about 20 feet away, it was all banjo (I did this before). I swear you could barely even hear a guitar. Of course the low bass thump was still strong.
I showed the guys/gals my FHAG pictures, boy did that get plenty of interest, and many questions. They said bring that damn thing next time, and I will, but it may be a while, all these old ******* are going to Florida for their hiatus.
These guys hate amps, they are an acoustic crowd. I thought I might get some push back, but they were interested because the music comes out of a guitar, not an amp!!
I did a "noise walk" around my entire house, and outside, can't find any other culprits.
I was at a Bluegrass jam session last Sunday, a friend of mine plays banjo, and his wife plays standup bass. They had three banjos, four acoustic guitars and the standup bass, was really fun. I was handed a guitar and joined in. I am not a bluegrass player, but I followed along with the chords, nothing fancy.
The banjos were all nice older Gibson, and the Guitars were all Rosewood Martins and one Collins, all really nice. Plus of course two part vocal harmonies.
Of course I recorded dB levels on my iPhone from about six feet away, about 85 dB.
Then I walked about 20 feet away, it was all banjo (I did this before). I swear you could barely even hear a guitar. Of course the low bass thump was still strong.
I showed the guys/gals my FHAG pictures, boy did that get plenty of interest, and many questions. They said bring that damn thing next time, and I will, but it may be a while, all these old ******* are going to Florida for their hiatus.
These guys hate amps, they are an acoustic crowd. I thought I might get some push back, but they were interested because the music comes out of a guitar, not an amp!!
I'd say that gives you another goal - fully integrated system, like the echo-thru-body stuff I've been playing around with. Even if the amp module / battery pack was in a box on the floor, with a cord to the guitar, it's still sound out the guitar body, versus an external speaker.
Pretty sure the Chinese sourced module I'm using only produces around or less than a watt of power, so it would not be of much help for your project. It does have the means to turn the echo effect off, FWIW. Looking at the circuit board, there's no chip on it designed to dissipate any power; like with a tab for a heat sink pad.
You could work on repackaging your Roland amp with a set of batteries - sans speaker. There's a Pignose amp I've seen that has two 12V, guessing 7Ah lead acid batteries - with a label reminding the user to keep them charged. Been done, so you can do it too and show off when those guys come back!
JJ - less than a watt of power? Been there, oh the small amps I tested, do not work for my guitar, not even close. You mentioned getting all the high frequencies through the horns is difficult, yep, that is why I have the back of the drivers open, sound into my body. BUT a guitar player never has the back of the guitar completely against the body, soooo, it rocks the highs from the back! Packaging, well yes I sure need that, don't get me started.
Noise floor attached, very low dB, not a problem.
Does anybody have problems with miniDSP mics? They are usually great, but the connector went out last time.
Now I can't get a dB level above 90, WTF.
And the lows are not up either. I thought, Oh God please don't tell me all my great old lows were from the damn pool pump, "pumping lows" into my REW? Thankfully was not the case. I did with and without pump again, to be safe, not the problem.
I will get another mic, unless somebody has an idea, can't find anything in the software that might limit dB. I mean I play, then I ROCK and dB is almost the same, something is wrong.
The good news is tonight I just get to play my guitar, LOVE IT! I am going to try some acoustic slide, lets see how that works. Slide at high volume with other strings muted can be pretty damn rocking!
Noise floor attached, very low dB, not a problem.
Does anybody have problems with miniDSP mics? They are usually great, but the connector went out last time.
Now I can't get a dB level above 90, WTF.
And the lows are not up either. I thought, Oh God please don't tell me all my great old lows were from the damn pool pump, "pumping lows" into my REW? Thankfully was not the case. I did with and without pump again, to be safe, not the problem.
I will get another mic, unless somebody has an idea, can't find anything in the software that might limit dB. I mean I play, then I ROCK and dB is almost the same, something is wrong.
The good news is tonight I just get to play my guitar, LOVE IT! I am going to try some acoustic slide, lets see how that works. Slide at high volume with other strings muted can be pretty damn rocking!
Perhaps not a true measurement then, if there's a "something is wrong" problem with the mic. One reason I have a mic SPL calibrator. These can be very expensive and the only reason I have it is cause I got it cheap off fleabay. It's like wondering if you're 6 ft tall and you have a tape measure on hand. Allows me to setup REW to a reference SPL level, so I know all subsequent measurements are better than a guess level wise.
https://www.ebay.com/itm/256229902537 is maybe cheap enough, if the Dayton is 1/4" mic diameter.
https://www.ebay.com/itm/195879414068 Maybe have a look, could be $20 well spent!
If you tell Yamaha your measurements are referenced to a calibrated level, it'll give you some more credibility with them. Details like when the calibrator was last calibrated might get skipped past. I believe mine works fine, even though it's been a few years shall we say. Better than nothin"!