Arm/Cartridge Matching Graph

By means of this nomograph, you can quickly and easily determine the compatibility of any cartridge and arm we have tested. Ideally, the arm/cartridge resonance frequency (indicated by the diagonal lines) should fall at 10 Hz, but anywhere between 8 and 12 Hz will assure good warp tracking and accurate bass response. (It is usually okay to let the resonance rise as high as 15 Hz, although we don't normally recommend this.)

Begin by looking up the weight and dynamic compliance shown in the cartridge report and the effective mass listed in the turntable or arm report. Add the weight of the cartridge to the effective mass of the arm to get the total effective mass. Then find the point on the graph where the vertical line for the total effective mass intersects the horizontal line for the cartridge's dynamic compliance. For a good match, this point should fall in the white region, between the 8- and 12-Hz diagonal lines.

When necessary, you can back-figure compliances and effective masses for cartridges and arms tested before we began reporting these figures directly (in January 1983). For cartridges, took up the vertical resonance frequency (measured in the SME 3009 Series II Improved arm) and the cartridge's weight. Add 15 grams (the SME's effective mass) to the cartridge weight to get the total effective mass. Then find the intersection of the vertical line representing that mass with the diagonal line representing the measured resonance frequency.

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Now you can read off the compliance from the horizontal line passing through the point of intersection.

For pickup arms, look up the vertical resonance frequency as measured with the Shure V-15 Type III cartridge Find the intersection of the diagonal line for that frequency with the horizontal line representing the Shure's dynamic compliance of 22.5 × 10 -6 cm/dyne. Reading down the vertical line on which the point of intersection lies will give you the total effective mass of the arm with the Shure V-15 Type III mounted in it. Then subtract 6.3 grams (the weight of the V-15 Type III) to get the arm's effective mass.

Because of differences in measurement techniques, manufacturers' specifications for compliance and effective mass often differ from our findings and may therefore yield inconsistent results if used with this graph.

Copyright © 1988, ABC Consumer Magazines, Inc. Italics are EL's.