NS1000's respond very well to mods-IMHO
I made extensive mods to my NS1000m's. I have posted the following on PFM.
"Following a request from another poster I am posting details of the mods that I did to a pair of NS1000's. I actually sold them about 15 years ago so this was quite sometime ago!
My speakers were 1000M's, but I think my suggestions would work the same for all 1000's. They are nearly all reversible, unless you cut the original x/over board
I decided to modify the x/overs after reading about the benefits of bi/tri-wiring speakers (each drive unit draws a common voltage, but a bandwidth limited current.)
I also decided that I wanted to put the x/overs as near to the amp as I could, because I had noticed the benefits of shortening speaker cables and wanted to see what the benefit of shortening them to a foot would do (I think the length of the cable post x/over is less important because I believe the amp ââ'¬Å"seesââ'¬Â the speaker at the x/over.)
I started by asking Yamaha for the circuit diagram of the x/over. And saw that it was easy to cut the boards to separate each part of the x/over, which share common input and grounds, and enable tri-wiring.
Removing the crossover is easy-undoing the screws at the back and cutting the speaker wiring.
I used the x/over housing as a template and cut a piece of very thick block board to cover the hole. I passed the new cables through here, but it would have been better to have fitted speaker binding posts.
After cutting the PCB to separate each section of the x/over, and checking that no current could flow between them I replaced the internal wiring which is nothing special. This involves removing all the drive units and the level controls. This needs care, to avoid chipping the finish. Especially with the bass units which need their weight supporting as you remove them.
You need to remember to feed the wiring from the level controls to the mid and treble units through the hole left by the level controller before soldering on to it. I re-used the original gaskets, but have used draft excluder in the past!
I removed pieces slowly and made sure I was sure which wire went were before I started, but still managed to wire a tweeter out of phase. Leaving a bit of the cable at each point can help and then replacing each in turn, labelling the ends to aid identification.
So with the tri-wired x/overs near the amp I gave it a blast and discovered a huge increase in clarity. The effect was like upgrading to a much more powerful amp. The sound was more open, dynamic and totally better in all ways.
I eventually replaced the x/overs, which must now be well over 20 years old. On the advice of Les W I used the best air cored large gauge inductors I could afford and good polypropylene caps, bypassed with smaller values bringing the total value to the same as the original electrolytics. I soldered the components together and boxed them up.
I tried removing the level controls and found they had a marginal impact and were much too useful in rebalancing the speaker, I increased the mid and top controls by about 30%, which would have been harder to do on the x/over board, by measuring the resistance of the inductors and buying them with this in mind or adding resistors to the mid and top sections of the x/over.
I finally removed the fibre wool from the whole cabinet, but left the felt wadding on the insides. This gave the bass even greater depth and I never wanted to put it in again
In the time I owned them I changed the wiring several times, hearing worthwhile improvements and would love to hear a pair on the end of a silver multi core cable loop with some neutral gear.
I remember reading somewhere that the mids are intentionally wired out of phase, but I am sure I wired mine in phase.
I would recommend anyone who feels capable and patient enough, to have a go. Even keeping the original x/over and using your existing speaker cable is a significant upgrade and very cheap. But they really sing with good components."
