Hardness vs. Density

[clintfaas]

First off I wanted to thank you all for the outstanding info! I've been lurking for a while and have found more good stuff here than I could have imagined!  This is my first post to the site and to say I'm a beginner at call making (or wood turning) would be an understatement. 

Ive searched for this but haven't really found what I'm looking for.  From what I've gathered there are several key woods that people use that are tried and true for call. So really no need to reinvent the wheel.  However, in comparing wood to things like Bocote, Cocobola, Osage Orange and ABW, there is A LOT of great looking wood that shares similar physical properties.  Originally I was under the impression that hardness was the most important thing but the more I read it seems like density has a greater affect on sound.  Can someone clarify this for me?  If I want to look at trying other woods what would be the better comparison?

[Chris @ STW Outdoors]

Wood density is what you are wanting. I have attached a list of woods and their densities. I have been meaning to post this for everyone and I guess this is a good as a place as any. I got this from a website that someone else directed us to and just put it in an excel format for easier viewing, but I can not upload that. So, I put it into word. I placed the wood in order of density. It is rated at pounds per cubic foot. This should help you as you determine what woods to use.

To answer your question, you should look at a post on the history of reelfoot calls. It was a recent post about the guys who first came up with modern duck calls. It was their trial and error that determined a more dense call was louder and thus attracted more ducks, because it could be heard from farther away. I would guess that the more dense a material is the better is resonates the sound. As in, it does not absorb as much of the audio energy as a softer wood might. Like when we use cork board for sound dampening in auditoriums for acoustics. Which is also why acrylic is so heavily used in the call industry. Hope this helps.

[Chris @ STW Outdoors]

Seems I cannot insert a word document either. I will just post some of the top woods in this thread.


Snakewood   81   Maria-preta, Arvore-da-chuva   59   Jarrah   54
Verawood   78   Marishballi   59   Osage orange   54
Lignumvitae   77   Okan   59   Pradoo, Burma padauk   54
Blackwood, African   75   Quebracho Colorado   59   Sucupira   54
Grenadilla, Mpingo, ABW   75   Sandalwood   59   Tualang   54
Ebony, Brazilian   74   Bocote, Cabreuva, Santos Mahogany   58   Wenge   54
Pau-santo, Angelica   73   Pearwood, African; Aboga   58   Anchico   53
Ebony   68   Piquia   58   Angico, Vermelho   53
Cumaru, Brazilian Teak   66   Turpentine   58   Cherry, tropical/Mayan; Machiche, Cerezo   53
Ironbark, red   66   Pau ferro, Brazilian ebony   57   Patens   53
Kurupaya   66   Purpleheart, Amaranth, Pau roxo   57   Rosewood   53
Curupay, Curupau   65   Timborana   57   Rosewood, Indian   53
Marblewood   64   Azobe   56   Tiete rosewood   53
Satinwood   64   Karri   56   Ziricote   53
Chechen, Black poisonwood   63   Mahogany, Santos' Cabreuva   56   Balau   52
Cocobolo   63   Mangrove, red   56   Beech, Australian; Blackbutt   52
Curupixa   63   Olive, Brazilian; Taxi   56   Etauba, Itauba   52
Macawood   63   Roxinho   56   Garapa, Goldenwood   52
Faveira   62   Tamarind   56   Shedua, Amazakoue   52
Mora   62   Wallaba   56   Shorea   52
Oak, live   62   Boxwood, Buis   55   Bloodwood   51
Patagonian Rosewood   62   Bubinga, African rosewood   55   Hickory   51
Tiete chestnut, Almendrillo   62   Grapia   55   Moabi, Guajara   51
Brushbox   61   Gum, spotted; Australian hickory   55   Persimmon   51
Massaranduba   61   Kempas, Thongbueng   55   Amendoim, Ybyraro   50
Bulletwood, Balata, Macaranduba   60   Morado   55   Cherry, Bolivian   50
Mahogany, Brazilian Tiger   60   Pyinkado   55   Degame   50
Paraju, Brazilian redwood, Jutahy   60   Rosewood, Brazilian; Jacaranda   55   Dogwood, flowering   50
Goncalo Alves, Tigerwood   59   Tallowwood   55   Greenheart   50
Ipe, Lapacho   59   Tigerwood, Muiracatiara   55   Ironwood   50
Manbarklak, Black kakaralli   59   Afromosia   54   Ivorywood, Pau marfim   50

[dogcatcher]

Ask one of the moderators to post it for you.

Marvin

[Chris @ STW Outdoors]

Okay, so the above list is a little hard to look at, but you should be able to see the wood and the associated lbs. per cu foot number. The higher the number the denser the wood. These are in order of dense to least dense. I have more but this is a good starting point. I would be happy to email anyone the entire list. Just PM me your email and I will get it out. If you see woods separated by a comma that is because there are multiple names for the same wood. 

[FS Custom Calls]

Keep in mind stability and oil content as well.  A lot of woods sound great but go flat after a bit.

[Joe Short]

Hate to disagree, but density AND hardness are what makes a call sound good. The reed slaps the toneboard, it could slap really dense, but soft, wood and the sound would be quiet and dull. Conversely, a hard but low density wood, Zebrawood for example, makes a fairly loud call with nearly no depth or range. The trick is to find a wood that exhibits both qualities. Granadillo is my personal favorite for sound. Hedge, Cocobolo, Ebony, ABW, and a slew of others are highly regarded by many/most callmakers.

[ben]

Check this web site for wood hardness and make up.

ben

http://ejmas.com/tin/2009tin/tinart_goldstein_0904.html

[Chris @ STW Outdoors]

I would agree about the Sound quality and finding a good mix. I was speaking to volume and density just to get the guy pointed in the right direction with some more information.

Now as far as a reed slapping a tone board, that is a whole other discussion. Some would say that it doesn't. I am not sure that I know, but I have watched it through a clear barrel and it appeared to me that it did not slap the tone board. Of course I would really need to get a high speed camera to know for sure. 

[stumpjumper]

Reed slap HAHAHAHAHAHAHAHA NOT

STUMP

[BigB]

Ah yes, the age old debate of if the reed slaps the toneboard. I'm in the camp that says it doesn't slap the toneboard. Take a sheet of mylar, and rapidly move it to get the sheet to move like a wave form. And just by doing that, it makes a sound and it doesn't slap on anything. That same type of phenomenon occurs inside the barrel, just at a higher frequency which creates the sounds of a duck call.

Brian

[Joe Short]

If this were the case, the density and hardness of the wood would be irrelevant, only the tightness of the wedge/cork notch would make a difference and toneboard shape wouldn't be so critical. Pull one of your calls apart, suck on the exhaust and observe the reed's movement in a mirror. It DOES slap the toneboard.

[Jared at Woodruff Outdoors]

I have not decided if it slaps the toneboard or not, but even if it does not slap the toneboard, density is important.  Sound waves still have to travel the length of the tone channel.  Less dense woods are going to deaden those waves regardless if the reed slaps the toneboard. 

[Joe aka COLD @ J. A. Kolter Calls]

So Mr. Short I know you've got it together as you stated  both density and hardness play into what makes a good sounding call.  I have turned hundreds of domestic and foreign hardwoods and have found that each wood specie has different characteristics for sound quality.  Keep in mind that even some of those open grained woods work well in the sound department if they are harder in nature.  For the most part the closer grained and denser woods have a much better proven record for making great duck hunting calls.
I do however agree with Brother's Ronald and Brian regarding reed slapping the tone board.  For the most part I do think the reed itself is slapping the tone board.  The first 1/8" or less of the reed that touches the tone board top just past the cork might be considered reed slap.  But past this small portion where curvature drop exits its strictly all vibration.  It is this way with all musical reed instruments.  If we tune a call with too much air under the reed, the excessive vibration will lock up the call.  Actually the reed slaps the top of the tone board just past the cork only, after that its all vibration of the reed.  To me its a mute argument.

[Wade@WEBFoot]

...but soft, wood and the sound would be quiet and dull.

Think of the affect of soft wood as more like that of a heavily carpeted and foam lined wall type room versus one that is concrete and tin.  One reflects sound waves, the other absorbs.  And the varying volume and tonal qualities that change from wood to wood...  think of different floor, wall, and ceiling coverings.  Straight drywall and tile, painted drywall and thin carpet... and on and on and on.

So yes, hardness and density both play a role in the sound created - Im a firm believer in that.  One of the reasons I think cocobolo is so popular.

Why... on the other hand... well, that could be argued forever, and/or until we can get a very high frame rate video camera... (as the information I have seen has not come from a fast enough frame rate for me to be positive - but it does support the lack of reed/toneboard contact so far)

Some things to think about when thinking about how a call makes its sound.
How guitars make sound
How fake thunder sounds are made
Why you can hear a helicopter


Chris, if you want me to turn that doc into a PDF, just send it over and I can convert it for ya and send it back.

Wade