Some time ago a good friend of ours, who is a high-end enthusiast and avid music listener, obtained the Usher TD-10 high-end speakers. At the beginning he was satisfied with their sound, but after a few changes and upgrades in his system, notably the better source (DAC, CD player and streamer/server) he started to feel that Usher TD-10 should sound better.
After sorting out all of the aspects of his system, source components, amplification, cables, electricity (power conditioners and main cables), stands and racks and the room acoustics, his sound expectations were still not fulfilled.
The only thing still left untouched were Usher's crossovers and internal wiring and damping.
After sorting out all of the aspects of his system, source components, amplification, cables, electricity (power conditioners and main cables), stands and racks and the room acoustics, his sound expectations were still not fulfilled.
The only thing still left untouched were Usher's crossovers and internal wiring and damping.
Thus he asked if we feel confident enough to try to sort this out; having some experience in speaker building/upgrades along with our extensive expertise in turntables design/manufacture, and knowing that some of the most admired local speaker builders will more than happy to help and provide some good advices, we decided to accept the challenge.
Removing the bass drivers in order to inspect the design of the crossovers, we became assured that crossovers along with internal wiring are the definitive bottle neck of our friend's audio system. Used components, capacitors, coils and resistors, internal wiring, crossover's PCB's (common to other Usher speakers models as well) and internal cabinet damping looked questionable.
After obtaining the Usher's TD-10 crossovers schematics, we measured all the original crossovers components, and the coils were measuring very bad, their internal resistance in particular; further, all the coils were made of the same diameter copper wire which is not very good; furthermore, overall price of the crossovers components with internal wiring didn't look right, considering the retail price of the Usher TD-10 speakers.
After obtaining the Usher's TD-10 crossovers schematics, we measured all the original crossovers components, and the coils were measuring very bad, their internal resistance in particular; further, all the coils were made of the same diameter copper wire which is not very good; furthermore, overall price of the crossovers components with internal wiring didn't look right, considering the retail price of the Usher TD-10 speakers.
Thus we decided to rebuild the crossovers with the high quality components of the same values, avoid any PCB's, using point to point soldering instead, upgrade internal wiring and speaker terminals and try to improve box's internal damping, using 100% natural long hair wool and good quality damping panels, made of natural cotton and wool.
After some research and recommendations we decided to use:
- Jantzen Audio Wax Coil (paraffin-wax impregnated pure copper foil-based inductor) for the coils
- Jantzen Audio 10W The Superes resistors
- Jantzen Audio Amber Z-Caps and Silver-Z Cap capacitors for the mid/tweeter part of the crossover
- Clarity Cap CSA capacitors for bass part of the crossover
- generic pole terminals were changed with the WBT-0705Cu nextgen™ pole terminals
- all the internal wiring was done with the Van den Hul CS12
After some research and recommendations we decided to use:
- Jantzen Audio Wax Coil (paraffin-wax impregnated pure copper foil-based inductor) for the coils
- Jantzen Audio 10W The Superes resistors
- Jantzen Audio Amber Z-Caps and Silver-Z Cap capacitors for the mid/tweeter part of the crossover
- Clarity Cap CSA capacitors for bass part of the crossover
- generic pole terminals were changed with the WBT-0705Cu nextgen™ pole terminals
- all the internal wiring was done with the Van den Hul CS12
Due to the physical size of the chosen crossovers components and restricted space inside the boxes, we finished with the somewhat odd crossovers plan, but that was the only way to assemble them in such a restricted space, using point to point soldering only, and maintaining the appropriate distance and orientation between the coils. Crossovers were separated to the bass part and the mid/tweeter part and built onto two 10mm Baltic Birch plywood plates of different size, accordingly.<
We decided not to glue the crossovers components, but to use the self-locking plastic loops/ties for fixing. In order to achieve good isolation of the components against vibrations and resonance we were inserting the rubber-cork pads/tracks between the self-locking plastic loops/ties and the components, between the components and Baltic Birch plywood plate and also between the components itself.
We decided not to glue the crossovers components, but to use the self-locking plastic loops/ties for fixing. In order to achieve good isolation of the components against vibrations and resonance we were inserting the rubber-cork pads/tracks between the self-locking plastic loops/ties and the components, between the components and Baltic Birch plywood plate and also between the components itself.
New crossovers were mounted inside the boxes, fitting perfectly on the bottom of the box, thus we soldered all the wires and pole terminals and left them working a couple of weeks in order to burn-in. After the burn-in period and some initial listening tests, we did new internal damping.
First, we fully stuffed the separate mid/tweeter chamber with the 100% natural long hair wool (produced and bought locally), damping the mid driver resonances. For the bass chamber, we've tailor cut damping material sheets in a way to fit inside the boxes, using internal box bracing and curve shaped boxes sides to support them in place, thus avoiding gluing. Further, we added 100% natural long haired wool and some natural wool pressed sheets on the top of the crossovers and behind the bass driver in order to fully tame the resonances in the bass chamber.
First, we fully stuffed the separate mid/tweeter chamber with the 100% natural long hair wool (produced and bought locally), damping the mid driver resonances. For the bass chamber, we've tailor cut damping material sheets in a way to fit inside the boxes, using internal box bracing and curve shaped boxes sides to support them in place, thus avoiding gluing. Further, we added 100% natural long haired wool and some natural wool pressed sheets on the top of the crossovers and behind the bass driver in order to fully tame the resonances in the bass chamber.
After the critical listening test, we were surprised how good the final results were; most notably the soundstage became bigger in all directions, voices and lyrics became more intelligible, beginning and end of the individual notes/sounds became very clear, and lot of the new details started appearing, making listening more enjoyable and emotionally intensive, than it was before crossovers rebuilding and upgrade.
Having invested lot of energy, time and money in his system, the owner was finally grinning from ear to ear, playing some of his fav CDs/tracks.
Usher TD-10 have two reflex ports, the smaller one for the mid/tweeter chamber and the bigger one for the bass chamber/driver, so if required some additional fine tuning, it's easily doable by closing/semi-closing the ports.
Having invested lot of energy, time and money in his system, the owner was finally grinning from ear to ear, playing some of his fav CDs/tracks.
Usher TD-10 have two reflex ports, the smaller one for the mid/tweeter chamber and the bigger one for the bass chamber/driver, so if required some additional fine tuning, it's easily doable by closing/semi-closing the ports.