the following examples of the golf club head according to one or more aspects of the present invention will be described using one or more definitions , provided below . referring again to fig1 and 1a , “ reference position ,” as used herein , denotes a position of the club head 100 where the hosel centerline 108 is in an imaginary vertical plane 122 and is oriented at a lie angle α of 60 ° with respect to a ground plane 124 . the plane 122 is oriented substantially parallel to the striking surface 114 . unless otherwise indicated , all parameters below are specified with the club head in the reference position . referring again to fig1 and 1a , “ reference position ,” as used herein , denotes a position of the club head 100 where the hosel centerline 108 is in an imaginary vertical plane 122 and is oriented at a lie angle α of substantially 60 ° with respect to a ground plane 124 . the plane 122 is oriented substantially parallel to the striking surface 114 . unless otherwise indicated , all parameters below are specified with the club head in the reference position . referring to fig1 a and 1b , “ face center ”, e . g ., a face center 120 , as used herein , may be located using a template 126 , having a coordinate system with a heel - toe axis 126 a that is orthogonal to a sole - crown axis 126 b . an aperture 128 may be located at the origin of the coordinate system and each axis may be divided into evenly spaced increments . the template 126 may be made of a flexible material , e . g ., a transparent polymer . the template is used as follows : 1 ) the template 126 is placed on the striking surface 114 with the heel - toe axis 126 a substantially parallel to the plane 124 . the template is then moved back and forth in the heel - toe direction along the striking surface 114 until the heel and toe measurements at the opposite edges of the striking surface 114 are equal . 2 ) the template 126 is moved back and forth in the sole - crown direction along the striking surface 114 until the sole and crown measurements at the opposite edges of the striking surface 114 are equal . 3 ) the template 126 is moved with respect to the striking surface 114 as described in steps 1 and 2 , above , until the heel and the toe as well as the sole and the crown measurements along the corresponding axes are equal . a point is then marked on the striking surface via the aperture 128 to indicate the face center 120 . referring to fig1 c , “ center apex ”, e . g ., a center apex 130 , as used herein , refers to a point of intersection between an imaginary longitudinal vertical plane 132 and the top edge 116 of the striking surface 114 , with the club head 100 in the reference position . the plane 132 is oriented substantially perpendicular to the striking surface 114 and passes through the face center 120 . referring to fig1 d , “ overall length ”, e . g ., an overall length 134 , as used herein , denotes the shortest horizontal distance between an imaginary front vertical plane 136 , substantially parallel to the top edge 116 and passing through the center apex 130 , and an imaginary rear vertical plane 138 that is parallel to the front vertical plane 136 and passes through the furthest rearwardly projecting point 139 of the club head 100 , opposite the striking surface 114 . referring to fig1 e , “ overall width ”, e . g ., an overall width 140 , as used herein , denotes the shortest horizontal distance between an imaginary toe - side vertical plane 142 , substantially perpendicular to the striking surface 114 and passing through a furthest laterally projecting toe point 144 , and an imaginary heel - side vertical plane 146 that is substantially parallel to the imaginary toe - side vertical plane 142 and passes through a furthest laterally projecting heel point 148 , located at a vertical height of 1 . 905 cm ( 0 . 75 in ) relative the ground plane 124 , with the club head 100 in the reference position . referring to fig1 f , “ heel region ”, e . g ., a heel region 150 , as used herein , denotes the portion of the club head between the imaginary heel - side vertical plane 146 , substantially perpendicular to striking surface 114 and passing through the furthest laterally projecting heel point 148 , located at a vertical height of 1 . 905 cm ( 0 . 75 in ) relative the ground plane 124 , and an imaginary offset heel - side vertical plane 152 . the plane 152 is parallel to the plane 146 and is spaced a distance x therefrom in the direction of toe 102 . preferably , the distance x may be less than 20 % of the overall length of the club head , more preferably less than 15 % of the overall length of the club head , and most preferably less than 10 % of the overall length of the club head . referring again to fig1 f , “ toe region ”, e . g ., a toe region 154 , as used herein , denotes the portion of the club head between the imaginary toe - side vertical plane 142 , substantially perpendicular to striking surface 114 and passing through the furthest laterally projecting toe point 144 , and an imaginary offset toe - side vertical plane 156 . the plane 156 is parallel to the imaginary toe - side vertical plane 142 and is spaced a distance y therefrom in the direction of the heel 104 . preferably , the distance y may be less than 20 % of the overall length of the club head , more preferably less than 15 % of the overall length of the club head , and most preferably less than 10 % of the overall length of the club head . referring to fig2 , “ survey length ”, e . g ., a survey length 240 , as used herein , denotes the maximum horizontal length of a stiffening element 260 in a top plan view with the golf club head 200 in the reference position . as illustrated in fig2 , the club head 200 , oriented in the reference position , is divided into four quadrants by an imaginary longitudinal vertical plane 232 , substantially perpendicular to a striking surface 214 and passing through a face center 220 , and an imaginary transverse vertical plane 258 , orthogonal to the imaginary longitudinal vertical plane 232 and bisecting the club head 200 at one - half the overall length . a first quadrant , quadrant 1 , is proximate the striking surface 214 and a heel 204 of the club head . a second quadrant , quadrant 2 , is proximate the striking surface 214 and a toe 202 of the club head . a third quadrant , quadrant 3 , is proximate the toe and is located rearward of quadrant 2 . a fourth quadrant , quadrant 4 , is proximate the heel and is located rearward of quadrant 1 . referring again to fig2 , the club head 200 may have an interior cavity characterized by a crown portion 212 , a sole portion ( not shown ), the toe 202 , the heel 204 , and a face portion 207 . the linear stiffening element 260 may be disposed within the interior cavity and may extend from the heel region to the toe region , as defined with respect to fig1 f . to orient the stiffening element 260 within the interior cavity of the club head , at least two regions of high deflection may be identified , e . g ., using computational analysis and / or empirical techniques . once the high - deflection regions have been identified , the stiffening element 260 is disposed in at least three of the four quadrants , described above , at an angle θ to the imaginary longitudinal vertical plane 232 , such that the stiffening element 260 passes through at least two of the identified regions of high deflection to improve the dynamic excitation response of the club head . for example , the linear stiffening element 260 may be oriented at an angle between 50 ° and 85 ° relative to the plane 232 , preferably between 60 ° and 85 ° relative to the plane 232 , and more preferably between 70 ° and 85 ° relative to the plane 232 , depending on the location of the high - deflection regions of the club head . by using a single stiffening element to reinforce more than one high - deflection region , an increase in discretionary mass may be achieved . the discretionary mass may be distributed in the club head to improve mass properties and / or inertial characteristics . the stiffening element , according to one or more aspects of the present invention , may be disposed within the interior cavity in any orientation . for example , as shown in fig2 , the stiffening element 260 may be disposed in the first , second , and third quadrants at an angle θ to the imaginary longitudinal vertical plane 232 . in other examples , the stiffening element , e . g ., stiffening element 260 a ( fig2 a ), may be disposed in the first , third , and fourth quadrants . preferably , the stiffening element , e . g ., stiffening element 260 b ( fig2 b ), may be disposed in the second , third , and fourth quadrants . more preferably , stiffening element , e . g ., stiffening element 260 c ( fig2 c ), may be disposed in the first , second , and fourth quadrants . referring to fig2 - 2c , the use of an advantageously oriented stiffening element , according to one or more aspects of the invention , e . g ., stiffening elements 260 - 260 c , produces a club head having a favorable dominant resonant frequency of vibration . the dominant resonant frequency of vibration is the frequency that produces the greatest sound energy . to measure the sound energy of a given resonant frequency , a time - amplitude plot , with the amplitude along the y - axis and the time along the x - axis , may be generated . the resonant frequency having the greatest area underneath the curve is the dominant resonant frequency of vibration . generally , the first resonant frequency of vibration is the dominant resonant frequency . preferably , the first resonant frequency of vibration may be between about 1800 hz and about 7500 hz , more preferably between about 2500 hz and about 6000 hz , and most preferably between about 3000 hz and about 5000 hz . in some instances , the dominant resonant frequency may be the second , the third , the fourth , or the fifth resonant frequency of vibration . further tuning of the dynamic - excitation response of the club head may be achieved by modifying the width and / or height of at least a portion of the stiffening element , according to one or more aspects of the present invention , in the regions of high deflection . for example , the stiffening element may comprise one or more heights corresponding to one or more regions of high deflection . moreover , the stiffening element may comprise one or more widths corresponding to one or more regions of high deflection . increasing the height and / or the width of the stiffening element advantageously reduces the deflection in the corresponding region or regions of the club head . the width of the stiffening element may vary between about 0 . 2 mm and about 5 mm , preferably between about 0 . 75 mm and about 2 mm , and more preferably between about 1 mm and 1 . 5 mm . the height of the stiffening element may vary between about 1 mm and about 25 mm , preferably between about 3 mm and about 20 mm , more preferably between about 5 mm and about 15 mm , and most preferably between about 8 mm and about 12 mm . the survey length , e . g ., the survey length 240 ( fig2 ), of the stiffening element 260 may be greater than the overall width of the club head . for example , the ratio of the overall width to the survey length may be less than 0 . 97 , preferably less than 0 . 95 , more preferably less than 0 . 90 , and most preferably between 0 . 85 and 0 . 97 , depending on the angle between the stiffening element 260 and the plane 232 . a longer stiffening element may be required to reinforce multiple regions of high deflection . the overall width of the club head may be greater than about 110 mm , preferably greater than about 115 mm , and more preferably greater than about 130 mm . the survey length , e . g ., the survey length 240 , may be at least about 50 mm , preferably at least about 100 mm , and more preferably at least about 125 mm . the stiffening element , in one or more aspects thereof , may be coupled to at least one of the sole portion and the crown portion , e . g ., by welding , adhesive bonding , or integrally casting the stiffening element with the club head . suitable adhesives include thermosetting adhesives in a liquid or a film medium , e . g ., two - part liquid epoxy , modified acrylic liquid adhesive , foam tape , or the like . referring to fig3 a , orientation of the stiffening element relative the crown and / or the sole may be determined by the location of the high - deflection regions of the club head . for example , regions of high deflection may be located on both the sole portion 310 a and the crown portion 312 a . as shown in fig3 a , the stiffening element 360 a may be coupled to both the sole portion 310 a and the crown portion 312 a to reinforce such high - deflection regions , thus improving the dynamic - excitation response of the club head . additionally , the stiffening element may be coupled to portions of the club head other than the sole portion and the crown portion . fig3 b illustrates a club head where the regions of high deflection may be located primarily in a sole portion 310 b of club head 300 b . hence , a single linear stiffening element 360 b may be disposed on the sole portion . in another example , shown in fig3 c , the regions of high deflection may be located primarily on a crown portion 312 c of the club head 300 c . thus , a single linear stiffening element 360 c may be disposed on the crown portion . the stiffening elements described above may be formed from metallic and / or non - metallic materials . examples of metallic materials suitable for fabricating the stiffening elements may include stainless steel , 6 - 4 titanium alloy , 10 - 2 - 3 beta - c titanium alloy , 6 - 22 - 22 titanium alloy , or the like . suitable non - metallic materials may include composite materials , e . g ., cfrp , and thermoplastic materials , e . g ., polyurethanes , polyesters , polyamides , and ionomers . the stiffening elements may be manufactured , e . g ., via a casting , forging , powdered metal forming , or injection molding process . referring to fig4 , one or more welds , e . g ., welds 462 , may be utilized to couple the stiffening element , e . g ., a stiffening element 460 , to a club head 400 . to reduce the production costs and increase production efficiency , the weld or welds may comprise less than about 70 % of the survey length of the stiffening element . in another example , the weld or welds may comprise less than about 50 % of the survey length , preferably less than about 30 % of the survey length , and more preferably less than about 20 % of the survey length . as shown in fig4 , the stiffening element , e . g ., the element 460 , according to one or more aspects of the present invention , may be coupled to the sole portion , e . g ., a sole portion 410 , via a plurality of intermittent welds and / or tack welds . preferably , each weld may be located in a region of high deflection to improve the dynamic - excitation response of the club head . spacing between the adjacent ends of neighboring welds depends on the number and location of the high - deflection regions in the club head . thus , each weld may be spaced between about 10 mm and about 100 mm from an adjacent weld , preferably between about 10 mm and about 50 mm from an adjacent weld , and more preferably between about 10 mm and about 25 mm from an adjacent weld . referring to fig4 a , the stiffening element , e . g ., a stiffening element 460 a , may comprise a first side , e . g ., a first side 464 a , and a second side , e . g ., a second side 466 a . a plurality of welds 462 a may be deposited in a paired arrangement along the first and the second sides of the stiffening element 460 a . as shown in fig4 b , the welds , e . g ., welds 462 b , may be located along only one side 466 b of the stiffening element 460 b . the welds , e . g ., welds 462 c , may also be disposed in a staggered arrangement on both sides 464 c and 466 c of the stiffening element 460 c , as shown in fig4 c . the club head may be formed from a wide variety of materials , including metals , polymers , ceramics , composites , and wood . for instance , the club heads according to one or more aspects of the present invention may be made from stainless steel , titanium , or graphite fiber - reinforced epoxy , as well as persimmon or laminated maple . in one example , the club head may be formed , at least in part , of fiber - reinforced or fiberglass - reinforced plastic ( frp ), otherwise known as reinforced thermoset plastic ( rtp ), reinforced thermoset resin ( rtr ), and glass - reinforced plastic ( grp ). the face portion of the club head may be formed of sp700 beta titanium — an alpha / beta grade alloy of 4 . 5 - 3 - 2 - 2 titanium ( ti - 4 . 5 % al - 3 % v - 2 % mo - 2 % fe ). in another example , portions of the club head may be formed of other titanium alloys including a forging of a high strength titanium alloy such as 10 - 2 - 3 ( ti - 10 % v - 2 % fe - 3 % al ) or 15 - 3 - 3 - 3 ( ti - 15 % v - 3 % cr - 3 % sn - 3 % al ), a casting of a 6 - 4 alloy ( ti - 6 % al - 4 % v ), or other titanium alloys such as 3 - 2 . 5 titanium ( ti - 3 % al - 2 . 5 % v ) or 15 - 5 - 3 titanium ( ti - 15 % mo - 5 % zr - 3 % al ). in other examples , other forging and casting alloys may be used including stainless steel and aluminum . in the foregoing specification , the invention has been described with reference to specific exemplary embodiments thereof . it will , however , be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims . the specification and drawings are , accordingly , to be regarded in an illustrative rather than a restrictive sense .
a golf club head according to one or more aspects of the present invention comprises a sole portion , a crown portion , and a stiffening element associated with at least one of the crown portion and the sole portion . the stiffening element has a survey length and at least one welded portion , comprising less than about 70 % of the survey length . the stiffening element further comprises a plurality of welded portions . the welded portions adjacent each other are separated by a distance between about 10 mm and about 100 mm . a method of producing a golf club head comprises identifying a plurality of high - deflection regions having a plurality of ranges and providing a stiffening element , at least in part coupled with the plurality of high - deflection regions . the stiffening element comprises a plurality of heights and / or widths corresponding to the plurality of deflection ranges . at least one of the plurality of heights and / or widths is different from at least another of the plurality of heights and / or widths .