These are recreations of one of Gauss more popular models 4580/5840. A 4580 has a Kapton coil and a 5840 has an Aluminum coil. Original style cones are no longer available. The cone on this speaker (and all the other ones I've rebuilt) is from an RCF model that advertises 3,200 watts, on peaks, and 50mm of excursion before damage! So your "bass" is in very good hands! Gauss did their T/S numbers at +/- 3db! JBL and many other companies do their T/S numbers at +/- 10db! We do ours at +/- 6db. Where possible, the original spider rings were completely stripped and rebuilt with totally new moving parts including voice coils, spiders and tinsel leads. We also made spider rings out of casting resin and outfitted those with all new terminals (Brass), solder lugs and tinsel leads. What is a 4580? It's basically a Gauss "Instrument Bass" speaker! It actually has enough top end output to be an outstanding keyboard and electric piano reproducer when paired with a good quality high frequency driver. Any 4" coil Gauss can be turned into a "bass speaker"! We have the kits available. Shown is a representative voice coil of the "3" or "Extended Bass" series Gauss woofers before we install the second spider. All new voice coils installed in Gauss speakers will have similar heavy gauge, "high metal content" 12ga tinsel lead and precisely shaped loops to allow for full excursion of the coil while maintaining critical control of the leads themselves. I have 6 of them. All are Alnico. While JBL speakers will sing you a sweet lullaby at any level, Gauss speakers tended to beat you senseless over the head until you were forced to submit! You'll love 'em! These woofers are not for collectors, but for working musicians or home music enthusiasts that like their music incredibly loud for hours on end! The speakers are repainted original Gauss Almond White and a Satin Black on the magnet caps, so they look as good as they sound! Most of the labels say; "4582". One or two say "5840". A couple of them have no labels. They were really messed up, so, I just removed them. The discount shipping rate is for continental US addresses only. All others are actual cost! Thank you for checking out my listing! PEACE!