This came about from a sincere hatred for the Caliper (original) MRTW unit as it employs a finicky, difficult and variable MRTW ribbon return system that not only degrades over time, but is variable in humidity, and affects long term crossover response stability. I have been doing these Caliper ribbon units for nearly 12 years and have to say I really dislike the original design, as a quarter turn on a clamp screw can kill the actual ribbons mercilessly!!
I developed a new interface for these about 5 years ago to solve this problem in the Calipers, and it actually;-
1) brings their sound quality up to beyond a Caliper Signature
2) Allows for assisted shaping of their upper frequency
3) Allows a lesser priced (shorter) Caliper Signature actual ribbon unit to be used
4) makes their measured parameters accurate to <0.03 of an ohm typically
5) Increases their life and stability
6) Allows for easier future MRTW ribbon replacements, without the stress of the original circuit system -
VERY user friendly for subsequent replacements.
7) decreases electrical degradation, and seems humidity independent
8) Decreases the chance of ribbon fractures at the clamps
like all "magic bullets" it's not a cheap system. It uses the finest quality components to not only lift the original design but take it to previously inconceivable levels of quality, letting the KLM5 ribbon do it's work unhampered by multiple and variable pressure contacts.
Installers are aware of this modification for the Caliper, and a couple have probed over time to see if I would supply this kit in a form that would suit the Duetta's (all), Caliper Signature and Diva mid-range.
Well - to be honest I just never got around to doing it! So now I am going to fix that. Benefits 4-8 apply for the other speakers when fitted with their own adaptation of the return circuit.
Available to be fitted by myself or Installers this mod is now offered, using Audiophile very high grade wiring, and quality connections, the PARTS kits cost;-
Caliper (includes full interface) $350 - only suitable for the original Caliper
Caliper (all types) (no interface) $240
Duetta (all types) (no interface) $280
Diva MR (no interface) $300
All plus postage costs at cost.
Actual ribbon prices on top of the return kits of course - though the Caliper kit actually allows for the lesser priced Caliper Sig ribbon to be used.
Fitting the kits initially is a task for an Installer and best done as part of a full restoration. Once the kit is fitted - MRTW's become easier for user replacement for future replacements.
Retrofitting of speakers already restored by Installers is possible though better to do this when the MRTW is replaced for safety - contact your Installer-Agent for details!
Take care - Graz