For you recording guitarists....I've got news

  • Thread starter Thread starter RICK FITZPATRICK
  • Start date Start date
RICK FITZPATRICK

RICK FITZPATRICK

New member
Hello all you recording geetar pickers:D I've got some news for you. Maybe you already know, but I've been pickin guitar over a quarter of a century, and JUST came across some info that flat out knocked me off my guitar pickin stool:eek: :rolleyes: :eek:
Let me explain. For a long long time, I ASSUMED that guitar was a mid and high frequency instrument, and to a certain extent, it is if you play on the high frets. A few weeks ago, I finally decided, since this acoustics thing requires knowledge of the frequency range of instruments in order to do some calculations, I decided to find out the actual frequency range of guitar, since I play one. I got on the web, and found a website, that gave the frequencys for every musical note from the low C(0) to a high B(9) on what ever instrument will go that high. The C(0) is about 16.4 hz, and the B(9) about 15.8 khz. Man, thats a hell of a range.
The point of this excercise, is to find out what ultimately is the 1/4 wavelength of each note on the guitar, as OC703 type absorbers work by 1/4 wavelength reflection off a boundary. At least from my understanding of the theory.
So I start figuring out the wavelengths of these musical frequencys to come to a conclusion about absorption in my studio design. I'm working my way up from C(0) right up to E(2), and just as I am punching the numbers into the calculator, I became focused on the frequency of E(2), which is the low E on a guitar. Thats when it hit me. WTF!!!! 82. hz?????? NAW!! Can't be. Must be a mistake. HOW IN THE F....could this be.

How many of you use a 440 tuning fork to tune up these days? And when you do, how many use it to tune an open A string, or the A note on a E string, and then tune everything from there. Probably not many of you. Most of you are probably using digital or analog electronic tuners right? How many of you have one that lables the "A"note as 440 HZ, and when you tune your A string, the Tuner says your in tune, when a little light above the "A" lights up, or a needle on the meter goes to the "TUNED" point, right. Theoretically, yes. HOWEVER....this is NOT 440 hz folks.

When stunned by the fact that the open E was 82.5 hz, it was because of this fact. A(2) which is ONLY 5 halftones up the chromatic scale, could NOT POSSIBLY have increased in frequency in that few steps, to 440 hz!!:confused: Ok, what the hell is going on. LOW AND BEHOLD......OMG!!! A(2), the open A on a guitar is ONLY 110HZ!
Its the A note on the high E string that is 440 hz. What have I been thinkin? DOH!

HOLY SHIT. All this time, and I'm talkin 35 yrs, I am thinking this A note is 440 hz. What a MORONS MORON. ....DUH! How the hell could I have not been aware of this. Damn. Well, I know what most of you are sayin.....BIG DEAL. Get a grip dude. Ok,
No big deal. UNTILL, you figure out that this is NOT mids, nor mid lows, this is LOW FREQUENCY. PERIOD. Guys, this is a RECORDING BBS, and people are talkin absorption, diffusion, etc etc, but WHAT THE FUCK does it mean, unless you understand the ACTUAL musical frequencys that are in question.
I mean, published absorption tested specs for bass absorbers barely go this low. ON GUITAR? Wow. Ok, so what does this mean. It means just this. For
A 1/4 wavelength for an open E string is a WHOPPING 41.5 inchs. That means there ain't a snowballs chance in hell that most of your open chord work is being absorbed!! CAUSE ITS LOW FREQUENCY!! On a fucking guitar no less. That also means all you people playing acoustic guitar with mostly open strings, are NOT getting your moneys worth outta yo 703 supposed bass traps!! Ha! Maybe harmonics....but that AIN"T BASS BABY!! Look at it this way. When your playing all open chords on guitar, the highest note your hittin is maybe a G on the third fret of the high E string. That note is
391.9 hz. It has a wavelenth of 2.9 ft....so a 1/4 wavelength is STILL 8.2 inchs....so you tell me...thats TWICE as thick as 4" 703....and its supposedly absorbing acoustic guitar.....NOT!!! This tells me, that so called BASS absorbers arn't even absorbing normal ole guitar ranges up to the doggone 4th fret, even at 4" thick. LET ALONE A REAL BASS. A FEMALES voice begins approx at E(3) which is around 164 hz. ONE HUNDRED SIXTY FOUR HZ baby!!
Thats a 1/4 wavelength of 1.72 ft! .......so lets get real. IF the theory that states that resistant absorption materials only absorb THOSE frequencys with a 1/4 wavelength equal to, or less than the distance from the face of the absorber, to the boundary behind it is TRUE.....man. I"VE BEEN IN HAZE......AND.....

WHERE HAVE WE BEEN?........NO ONES WATCHIN THE HENHOUSE WHILE THE FOXES ARE STEALIN THE CHICKENS DUDES!

Maybe thats a little rash, but the fact remains, even the acoustics "bible" states that for porous absorbers to be effective they must "approach" the thickness of ONE FULL WAVELENGTH.....hmmmmm...sounds like another contridiction. But that is even worse. A 100 hz sound has a wavelength of 11.3 ft!! And a Low E on guitar is 82.5 hz!! Soooooo...you guys tell me. ALL the tones within the first 4 frets are BELOW the ability of 4" 703 to absorb them, let alone 2 or 3". At least from my understanding. That is why slat absorbers, and corner bass traps are recommended over flat type porous absorption. Mainly, because of the depth of corner traps. Slat absorbers are a resonant absorber. They work by other principles. Therefore, they do not have to be as thick as a 1/4 wavelength. Thats why most studios utilize them in one form or another. But thats a study for another rainy day.:p

My only purpose with this thread, is to illustrate something to those of you who have been guilty as I have of NOT KNOWING THE TRUTH about instrument frequency range.
I'm no doggone acoustics expert by any stretch of the imaginations, but this ain't rocket science. The facts speak for themselves. What may be lacking on my behalf is a TOTAL understanding of absorption principles, but IF what I've been told, and read at least 100 times is true, then so are my statements. At least as true as the contradictions on numerous acoustics websites. That is my disclaimer.

Don't let lack of a few little facts confuse and distort your understanding of whats going on sonicly in your studio. Remember, these are MUSICAL frequencys, and therefore are a constant in ALL studios.
Ok, I'm ready for the flame job dudes.
Cheers

fitZ
 
I was under the same impressions you were when I started looking into sound treatments. I honestly had no idea that a low-E was 82.5Hz.

A handy little graphic for this is one I found in a Google search that has a piano keyboard at the bottom, and above is the range of various instruments in relation to a keyboard. I thought the graph was wrong when I saw the range of a guitar!!!

On your previous thread about your diffusor/absorber.............

Have you used Sayer's spread sheet to figure out slat width and thicknesses? I don't have Excel, so I had to do the calcs by hand on paper. I found that the only way I could get down to 250Hz was with 5" WIDE slats an inch thick.............

Check out John's site for the graphic of a drum room he did where they used 2x6's and 2x8's turned EDGEWISE to get all the way down to kick-drum cycles. That room must have cost a ton of $ to do.
 
I found that the only way I could get down to 250Hz was with 5" WIDE slats an inch thick.............
Click to expand...

Hey C7, about the thickness or depth of the slot. That is the VERY reason I posted my idea for the slat BOX thing. Did you see that? Why use a solid board, when you can build boxes of ply or mdf, ANY depth and width you want. Use them like boards. It was
a short jump to realizing that you could then CURVE the fronts with BENDER BOARD!!
AND then another short jump to thinking....wow, not only do I have DEEP SLATS(hollow), then I could put a SLOT in those too!! AND THEN, realizing as long as you kept the slots BETWEEN boxes within the formula, like John uses varied slot widths,
and varied slat widths, I'm also using varied SLOT AND SLAT DEPTHS!! Add this too. Another short jump, and I realized, why not put a false back in the big box, and make it a PANEL absorber, within the hemholtz absorber:eek:

AND THEN, I just realized too, why couldn't you make the back, like a quadratic diffuser in the opposite direction of the slots, which actually gives you a varied depth hemholtz box too!! Whether or not any of this brainfart material WORKS, is why I posted it in the first place. From the formulas, I don't see why not. But then again, I'm no physics or acoustics expert. Thats why I ask here.
But at least it gives you a way of getting DEEP slats. Even if you had to fill them with CONCRETE:D hahahahahaha!! Or something dense. Thats why I came up with putting a slot in the curved front of the boxes. I thought, well I better put 703 or batts in there, but WAIT, in that case, its the same thing as a hemholtz absorber too! IF YOU HAD holes or a slot in the front. COOL. The formula only address ONE slot. Sooooo, you tell me? What I DON'T understand yet, is what tells you how much absorption is attained by ONE SQUARE FOOT OF SLOT!! OR what tells you the LENGTH and WIDTH of the box itself. How much absorption does a 3/16" slot, 48" long give you in Sabines?
Nobody has answered this question for me yet. All I understand is the FREQUENCY at which the slot absorbs with a certain width slat, and certain depth slot, certain width slot, and certain depth box. Nothing tells me HOW MUCH absorption you get with ANYTHING, let alone the TOTAL square footage of a slot. Barefoot did acknowledge the fact that the percentage of slot vs. the area of the front of the whole absorber is the percentage of EFFEClENCY.....hmmmm...theres another one. But nothing about actual absorption coeffiecient(spelling sucks!). Man, this stuff REAKS of ambiguity!
However, I DID dig out my Alton Everest book yesterday, and intend on STUDYING the hemholtz chapter thouroughly. Not that it does me any good!! I'm a dunce when it comes to the calculation things. Man, its been what...45 years since algebra class...:eek: :confused: :eek: hahahahahaha...fuck...am I old or what. Well, enough of my acoustics confusion class for the moment....time to ACTULLY get something done today in the studio. Been here 6 months and barely got my console assembled. Thats all. Today I intend on mounting the belly racks so I can at least hook up my speakers.

AND DON'T GET ME STARTED ON SPEAKER PLACEMENT!!!!!!!!!!!!!!! I did a search just last night. HOLY SHIT.....talk about a MILLION different opinions. CRAP. I'm just going to move them around till the damn things sound good! And since I have NO acoustics except BAD acoustics, what the fuck. My room is MOSTLY for listening anyway. Got no one to record with here yet. Soooooo, the only one I have to impress is ME anyway!:p
And he doesn't get anal about it. Hahahahahaha! As long as I can hear the music, thats all I give a damn about, I mean, I turn on a little ole portable radio in the shop and it sucks, but I love to hear public radio and music on those stations.


fitZ :)
 
Don't forget... the low E (E2) on a guitar has a FUNDAMENTAL frequency of 82.xx, when you pluck it, the actual sound is comprised of the fundamental PLUS harmonic overtones.... which is why a low E on guitar does not sound like a bass... and middle C on guitar doesn't sound like middle C on a piano.

The harmonic overtones are what really give the distinctive sound of one instrument over another.
 
I'm not sure you want to think of slats in terms of absorbtion.

From my understanding, the SLOT width combined with SLAT width & thickness determines which FREQUENCY the slat will RESONATE.

The slat resonates at the desired frequency, and then you have cloth right behind the slat, and RFSB behind that to convert the vibration energy in the slat into heat, which the insulation absorbs and kills.

The idea behind varying the slots and slat width is to create diffusion as well as tune the absorber for a broadband result.

This is pure conjecture on my part, but here goes anyway.....

Not all waves are gonna hit square on a slat. Some are bound to break right into a slot. The fiberglass is gonna take care of those, and if there are any reflections BACK from inside the box, they're gonna run right back into your already-vibrating slats, where they're gonna get killed all over again.

The varying depth of the box is achieved in John's corner traps by use of a triangular design. I don't think building individual boxes for depth is worth the effort, myself.

John's designs on wall units use 12-degrees as the default angle.

If you built the back of a full-size wall unit with 12-degrees of deflection alternating, combined with 4" or more of RSFB and slot resonators across a straight front, you should have one helluva broadband absorber.

John's designs show the FRONT of his wall unit angles at 12-degrees to provide diffusion and vary the box depth. I think the only thing you would lose in reversing and varying the BACK side would be some diffusion.

But these questions are a lot better left to guys like Barefoot and Knightfly that have the math background to back them up........
 
Another consideration is the volume of the sound source, because that is gonna determine the amount of energy present in the sine wave.

An acoustic guitar low-E is what, maybe 70dB @ 12-inches if that, struck with a pick.

A kick drum is probably more like 120dB at 12 inches. So there's a lot more energy there to vibrate a slat, and the length of the wave is gonna be a lot longer too because of the subtones Bear mentioned.

That's one measurement I have yet to see myself......... at what level dB is any given tuned slat operating at peak efficiency.

That's gotta be on helluva complex calculation!

And besides that, the energy in the wave is decaying after the hit.

I'd be curious to know if you can visably see slats resonate when a drummer is going full tilt in a tuned room.
 
Don't forget... the low E (E2) on a guitar has a FUNDAMENTAL frequency of 82.xx, when you pluck it, the actual sound is comprised o fhe fundamental PLUS harmonic overtones.... which is why a low E on guitar does not sound like a bass
Click to expand...
It also doesn't sound like a bass cause a bass low E is an octave lower at 41.2 hz., with its own harmonics as well. Thanks for pointing that out Bruce.

Hey you guys, what is your favorite mic for acoustic guitar? And how do YOU orient the player and mic in the room, if you don't mind me asking.

And C7, you say its the slats that resonate.:eek: Ill be darn. I could of sworn it was the air just like a bottle when you blow over the hole. Hmm, thanks for some insight as well. Another piece of the puzzle may get put in place yet. Ha! You know how some of the pieces in a jigsaw puzzle all look the same in the box. So far, I haven't even got the border.:D Just when I think a piece is going to fit....someone reaches over and puts their piece right where I thought mine would fit. Damn. Now, where does this diffuser piece fit. Ha!


fitZ:)
 
Last edited:
mc012's of course :)


The 12 tone western scale is far from a perfect scale.

Thats why its best to tune from the middle of the fretboard and work out the insconsistencies of the notes across the neck. E johnson tunes this way.


Id have to also ask... why would you have insulation in a acoustic guitar recording environment? wood would be the way to go
 
I record in my living room/dining room, which is an L-shape.

The dining room portion is about 10x10, and the living room about 14x 20. The ceiling is vaulted from 8' at the front/back wall lines to 11' dead center. I set up under the peak of the vault.

For micing I get the most "natural" sound (what I'm used to hearing as a player) setting a mic about shoulder to ear high, pointing at the floor.

With headphones I dial in the sweetspot usually a couple inches behind the bridge and a couple inches in front of the soundboard.

I've used this tek with an NT-2 and an NTV with pretty good results. You can pick up breathing sounds if you're not careful. Some folks into classical just accept those sounds as part of the perfromance.:)

The NTV is also good from a couple feet out. It's about 6dB hotter than the NT-2, and a bit darker.

I've got a BLUE Cactus here too but have really only had the chance to record Riley singing acapella into it. It's a MONSTER of a mic with her in front of it. When I sing into it animal control comes around to tell me I'm upsetting all the animals in the neighborhood. I don't think it's the mic's fault!

I use either a JoeMeek VC6Q or a Davisound TB-10 for pres. I have a Mackie 1402 but it sounds like ass compared to either of the outboards. Just too harsh for distance micing when you push the gain.

My "studio" setup is scattered all over the house now. Riley needs the puter for her biz so we moved it into a near cube-shaped room thats full of sex toys and soap. If I ever hit the lottery I'm gonna buy a 21st century rig and start over.
 
The 12 tone western scale is far from a perfect scale.
Thats why its best to tune from the middle of the fretboard and work out the insconsistencies of the notes across the neck. E johnson tunes this way.
Id have to also ask... why would you have insulation in a acoustic guitar recording environment? wood would be the way to go
Click to expand...

Who said anything about the the 12 tone system:confused: I don't think you understand the nature of my post. I wasn't concerning myself with anything to do with the system we use. I was only trying to enlighten other guitar players to the fact that when they tune, if they start with a low a, to tune up to
"440" hz tuner, in reality, the Open A string is actually only 110 hz. and the fact that these are very low frequencys which may or may not be absorbed by certain type of room treatments that are common to home recording studios. And yes, I am well aware of the quality wood excerts on acoustic instrument sound reflections and absorption. After all, Ive only been playing guitar for 40 years, and wood working for 35. As to the use of insulation, I also don't think you are aware of slat resonators. They have both wood and slots which when built correctly, become hemholtz resonators which you will find in many professional recording studios, whether you realized it or not. Wood slats appear as wood slats to some people. Its what is behind them in a studio that is the subject of interest here. I suggest you do a search for "slat absorbers", or hemholtz resonators. It is a reacurring theme here. I wonder why. I also would have thought transcended muses would be enlightened.:rolleyes: Of course, how would us mere mortals know.
fitZ
 
yes i understand what your saying..

my post wasn't posted to you... i was generalizing towards the topic of frequencies..

but the smartass reply is what caught me off guard :confused:
 
these different BBS rooms are analogous to gangs.

you go into a town ruled by someone and they'll shoot you in the neck

well.. my necks bleeding.... next town
 
Insulation and slot resonators are used to tune a room.

Every room had modes, standing waves, and flutter echo to one degree or another.

Ethan Winer has a handy mode calculator on his site that will tell you where you have problem modes by entering the dimensions of your room. These modes can also be affected by the amount of hard reflective surfaces such as glass or brick.

In short, modes cause bass buildup and phase-cancellation if they are extreme enough, like in a cube-shaped room. Any bedroom with an 8' flat ceiling will have flutter echo that is unbearable. Treatments can fix these problems. But NOT FOAM!

I built four 42" x 90" x 6"deep gobos packed with 3-1/2 to 4" of RFSB to use as a "backstop"/vocal booth. My goal was to put mics 2-4 FEET in front of my acoustic guitars and have a lot less "room" getting into the mic from reflections and such.

The idea is to create an acoustically "neutral" space so what you get is the true tone of the instrument and not the weird artifacts your room is putting on that sound.
 
Hey JMarcomb, excuse my manners. I should have said "welcome to the board". At my age, one of the few amusements I have left are laughing at overinflated egos, as I see TONS of them here. I meant no harm, and in fact, only tried to enlighten you. I had no intention of making you " bleed". On the contrary. This bbs is VERY friendly, but unfortunately, you came on like someone who knew what the fuck you were talking about, but your words conveyed a message of unenlightenment, and I was bewildered by your lack of understanding of my post, as I was VERY clear. So, lets start over. And btw, I am nothing here. Just a wisecracking old fart with a lot of dumb questions. I
do not carry any sort of "gang" membership card. If anything, I am a loner who's only desire here is to share a common interest in studio design. So I beg your pardon. Welcome to the board.
So, tell me about your assention into the transcendental dimension. Hows Elvis?

fitZ:p
 
I don't know about you guys, but I high pass guitar generally anywhere from 125hz to 200hz, so I really don't care about too much low frequency build up. Besides, its not like I record guitar facing into a corner or something.

Also I think the fundamental of the pitch only sounds something like 20% as loud as the next partial an octave above on guitar.

An interesting experiment is to record 5 string bass and then see how far up you can highpass it and still retain a lot of lows "that you percieve as lows". I can often times go up to 75hz with something like a Waves parametric. Thats even with him playing his low B.

Beez
 
Thanks for some more insight C7..sus.
Hey beezeboy, how's the band doin? Last time I read MM's forum your band was doin pretty good. But I don't go to PSW anymore so I haven't read anything in quite a while. I got tired of that scenario as egomania runs unchecked as far as I'm concerned, and I've got no patience for it.
Last time I was there, supposedly the members of a hasbeen rock star circus known as Kiss were spatin back and forth with the most unbelievably assinine crap I've ever witnessed on a so called "professional" recording forum. Laughed my fucking ass off. I guess the pop music world hasn't changed much, as Ms Jackson is a perfect example as well. Egoinflation is still big business it seems. If these type of people had a half a clue to what they really amount to in the real world, they might actually contribute something to it besides fodder for STAR magazine . I'd love to see what they would do with a rifle in thir hands in Iraq. Instead, they demonstrate perpetual adolescence spectacurally. And what does America do but reward them with stupid industry backslap awards such as the "grammies". What a pitiful commentary on the mindset of the music industry and America at large. If America ever took its head out of its ass, there would be a TRUE awards show where they postumously passed out thier appreciation for the dead soldiers who have given their lives for the freedoms these moronic jokes of the world exploit to express their so called art. Entertainers indeed. Give me a break. I've got more respect for the grocery clerk. At least he's real.

:rolleyes:

fitZ
 
The bands doing pretty good. We had an amzing show this last Friday night here in town. We packed the house even though some well known country guy was playing in town. I can't remember his name at the moment. We are currently trying to plan a small summer tour. We need to get signed soon though because the money is getting worse and worse. I don't think any bar owners appreciate/support live music any more. Not to mention that their buisiness skills are about -25 on a scale from 1 to 10. They don't advertise or anything anymore.

You should check PSW out again. Since they got their own mixing forum the guys have all chilled out. They don't mean any harm anyway. You've just got to roll with the punches. Also realize that some of the guys on there really are hott shit and even have Grammy's to their names, so when they are busting your balls at least it is coming from the top and not some 14 year old.

Beez
 
Hey Beeze, I know what you mean about the bar scene. And I said this for at least 10 years. One of these days, there will be so few places for musicians to practice their craft and make a living, that the skill level of musicians who must "work at music" or go under, will become nonexistant. Only those who do not have to make a living will be able to aford to keep playing at a journeymans level. I mean, who the hell can afford to spend 6 to 8 hours a day practicing to get to this skill level, and work at a day job too. Just to play where? A bar 2 or 4 nights a week. OR go on the road? I don't know of many musicians who come out of the wood work after practicing for 10 years to get to the level you must be at to play a real session in a studio. I know in Sacramento, there were tons of bars that I played at for years. In 1970, my first bar band was makeing $50 a night per man. When I quit playing in bars in 1990, the pay was still $50 a night per man. By then, 4 out of 5 bars had closed. :rolleyes: Not a great incentive to keep playing professionally, and if you have a family to support, who can run off to New York, Nashville, LA or just to see if you can do what?....join another bar band? I think not. The older you get in this business, the less oportunity comes knocking.....while most people are building seniority at a job. What seniority comes from playing, other than your skill level, and if you got no place to use it. Shit. But there are the big IFS....IF you get signed...IF you get released....IF you get airplay...IF the producer don't rip you off....IF the lable don't bury you....IF you make it to the "grammies"...you might have something to keep you alive for 5 years. Mighty big ifs...Seeing how there were 27,000 CD's released last year....mighty slim odds too. Not to mention putting up with other musicians quirks...fuck. Talk about some loose brain cells. I met my share too. Some real dimwits.

But what the hell, if your young and have a hot band....lots of time to kill, no family to support, hey, go for it.:D Otherwise, its a tough road. I know. I did it. Barely made it out in time to learn some real skills. But not in time to save my marriage. Years of scraping by on musicians wages takes its toll. Thats what they don't talk about at "Musicians Friend". I'll garantee ya.

But good luck with your band. Hope I hear ya on the radio one of these days.

fitZ
 
Hey Fitz....EXACTLY right man! Can relate. I live in Wash. DC area, so there is, and has, always been "work". I still have the wife tho. 1 kid through w/ college 1 more w/ 1 year to go. lol. I'm just now going broke. Wife has worked part time for 20 yrs now.
Thank GOD I still LOOK young. If you're gonna be a musician, you either "make it" somehow (1 in a million) or..learn to read, write, and sing, all styles of music. Only then will you survive. IMHO..It is well worth it!
 
You must log in or register to reply here.
Back
Top