does the impedance selector work on some ratio between input/output connected components with aural fine tuning later or is it all play by the ear. any suggestion on popular settings.sunil

On listening, myself and six other people all picked the '0' impedence setting in all cases. We used it with a placette/ayre/eidolon system and a CR Developments Romulus/gallo system. It was not a scientific test.

I liked it for the airy quality it lent the presentation.
The higher impedence settings did seem to lower the noise floor but also took away the airy quality.
I also tried many settings and combination settings and wound up leaving them on zero. Guess I didn't need the impedence boxes after all. But I do find the cables superb.
I too tried many settings and combinations of settings. I ended up leaving them on zero. I also guess I didn't need the impedence boxes. But I do find the cables to be very good.
Please let me, as importer of HMS, explain the impedance box settings in detail:
Not in every case you will need a different setting, although it is good to know that you are ready for the future. You will eventually change a component and suddenly you might need a different setting. With HMS you are always prepared for any system changes, the cables will grow along with your system.
The goal is to find the setting which lowers the music volume between 20% to 30% . Now use your volume control to raise the music volume to the level you like. This should be the perfect HMS TOP Match Box setting, since the sonic signal should now be far less distorted.
I too have left mine on zero. You might get some suggestions from the manufacturer if you give the output and input impedances of the items you're connecting. Excellent cables overall, give up very little to the much higher priced cables in my system.
Tekunda thanks for a new insight, but why do so many feel zero setting is fine, almost like questioning additional investment in the boxes in an otherwise good cable.
I found no changes in the sound in my system. I also have them at zero. Has anybody played with the settings on the speaker cables and heard a difference. Its hard to do alone. Do you know how hard it is to change a setting and run back to the sweet spot before the next note of music comes out.You've got to be quick.
the people responding here do not represent a true mirror of my customers. Not every HMS customer will post at A’gon. I think at least 50 to 60 percent of all HMS GF TOP Match customers use a different setting. I hardly have one customer who will buy a pair of cables and you will not hear again from him. So from emails I really feel that at least half of my customers settle on one setting other than default.
I myself use in my system setting 1 on my cdp to preamp cables and setting four from the pre to my monoblocks.
My father in Germany, who also has a full HMS cables system, uses setting 1 on the cd to pre amp also and he is not done experimenting with the cables from the pre to his four KR monoblocks. It looks like he will keep these cables on setting 2.
And according to Mr. Strassner, about 65% of all German customers use a different setting than zero.
It is also a wrong perception to think if you will not use a different setting than the default setting, the investment is wasted.
The price difference is not really huge: it is around $130. The TOP box contains also a sophisticated RFI/EMI filter, which the regular version does not contain. Even MIT have recently come out with an impedance matching system on their top interconnects, although a very crude, since they cannot copy the much more sophisticated settings of HMS, as they are protected by patents.
MIT has 3 extremely spread settings, so you cannot fine tune anything here, but the fact that they implement the impedance idea, even if it is a much more simple design, would support the whole idea about the needs of such a device, which MR. Strassner saw a long time ago
Snook2, the best way to change the settings is to have a friend, your wife or girlfriend change the settings while the music is playing and you relax in your listening chair.
If you have a helper, you can go through all settings without effort in less than 5 minutes.
how are the experiences with settings on speaker cables, are changes in sonics more finite here than interconnects.
I hope I am allowed to mention that there is a Soundstage review at:
at the equipment section coming out in 2 days, addressing these TOP Match Box questions in detail.
I absolutely notice a difference in all of the Top Match cables that I have (power, interconnect, speaker) using the different settings. Using the interconnects, you can hear the soundstage change dramatically. Having gone through a few amps since I've had these things, I have gone from one extreme setting (9) to the other (1) depending on the amplifier.

My current amp is a Wyetech Topaz 572 connected to a Silver Rock Signature C37 treated pre-amp. I use the #1 settings. Going to zero collapses the soundstage and causes the background noise to go up. You also lose image focus, and it gets louder. Going to 6 causes the volume to go down too much, and the low level detail is masked over. I haven't found these things to be subtle, but you should tune your system in the early morning hours when you have lower ambient room noise.

Tekunda's advice about about tuning the cables fits with my experince, and it's the first time I've heard it. The volume level does decrease slightly when they are tuned correctly. Regarding the speaker cables, they work pretty much the same way, but don't affect the volume as much as tuning the interconnects. The power cables are really amazing. I have rid my system of a very well respected power conditioner as a result of using the HMS power cables.

As you can tell, I'm really sold on these things. No matter what I put in my system, which changes frequently, my cables will always match whatever components I buy.
My experiences are limited to using the HMS between my dac and the preamp, although I have used different dacs and preamps. The big problem is that in all cases the volume dropped off so sharply with each higher setting that I could not get an exact constant volume setting using my pots. Since louder is generally accepted as better, I did not think this was a good test. Given the recent posts suggesting benefits, I will try again.
I spent about 2 hours with the settings on the interconnects and definitely noticed some changes. With the Piega-10 's I found the best setting was at 2. At 0 the soundstage is the biggest. When I switched to 1 and 2 the imaging was tidied up and more pinpoint and the soundstage decreased ever so slightly which I preferred. This will be interesting to play with since I am biamping and can change the bass or the treble independently with those settings.
thanks for all your responses, any idea of experimental settings between a passive pre n power amp.the soundstage review seems to favour zero settings with active pre.
If you read my post, you saw that I am using a passive pre (Silver Rock). It still depends on the equipment. The Soundstage reviewer didn't evaluate these cables properly by not substituting different components. That's the real value of these cables....being able to match different components in your system. When using my Accuphase straight in without the Silver Rock, I use the "0" setting. Different components, different settings. You'll just have to try it for yourself. The way I always start is listening to the "0" setting first, then go 1 click each way (9 and 1) to get an idea where I want to start. From there, I try to move up or down to fine tune it.