Spotmat 10

Spotmat #10

Here is the now familiar spot pattern from Spotmat #8......but the cork sheet is replaced by foam sheet, making this "Spotmat #10"

Q: Why foam...?

A: I took a hint from some other folks using foam as a mat material.

The cross-section dimension of this mat is thicker than my previous Spotmat#8, making necessary a VTA tuning session prior to any evaluation of the turntable sound quality. After putting the above mat on the TD160 pictured, and playing its first record, I was rewarded with a "more alive" sound. Attack transients are quite obviously quicker. Frequency extension appears as good as I've heard off this turntable at either end of the spectrum; highs and lows. Detail levels seem enhanced with the softer notes and sounds becoming more articulate and apparently clean. But the main difference seems to be in the increased speed of leading edge attack. The front edge of a note hits with better definition and more space and air around it. Transients, when they are quick enough, are the stuff in LP playback that can raise the hair on your arm, or the back of your neck, or make goose-bumps.

If you want to try your hand at diy'ing your own Spotmat, I'd heartily recommend using this foam material in the configuration I have shown here.

Above image is the foam sheet I found in at a "Michaels" arts and crafts store in the Everett, Washington area. The material is .09 inches thick. Cost was less than $1 per sheet.

method:

A template mat is used to draw the center hole and outer perimeter boundaries of the base mat.
A 9/32 (#9) hollow punch is used to create the center pin hole.
The outer perimeter is cut with excess material.
The blank rough mat is placed upon a turntable, and spun at 33 rpm.
a rigid fixture is devised to keep my hand steady above the spinning mat
a concentric circle is laid down in ink upon the spinning foam mat material, defining the outer perimeter
the marked mat is removed from the platter, taken to a well lit work bench where the outer perimeter is cut with a sharp pair of scissors.
Another diy template is used to lay down, in ink, the spot pattern
A commercial draftsmans inking template (Picket No. 10331) is used to mark the cut lines for the nine 3/4 inch diameter spots in more foam sheet material.
The nine foam spots are carefully scissor cut
A judicious amount of Elmer's Glue is placed on each spot location of the base mat.
The nine spots are placed to location according to the inked out pattern, working the glue in by twisting the spot over its position to spread the adhesive evenly.
The adhesive is allowed to dry for 1/2 hour