Resistors do make a big difference in the treble. This is most obvious on a speaker that uses a metal dome tweeter. A lot of the glare, hash, spit, and irritating sound is gotten rid of.
Just because a resistor costs $4 does not mean it will sound good. I have seen several expensive "audiophile" resistors that make things even worse.
There are not many real "audiophile" resistors. Like most things in this hobby, the upper echelon products aimed towards other industries do best in our applications. As someone who used to make the materials for the likes of Vishay, Sfernice, Holco, etc. I can tell you there are three main types of materials that go into good film thick/thin resistors:
1) 55% Palladium/45% Silver (Pd/Ag). Very low TCR (Temperature Coefficient of Resistance) and quite stable. Used in low resistance applications (0.1 Ohms to 10 or 100 Ohms - depending on the source material and company). Expensive, as both are precious metals. I believe these have the best sound.
2) Ruthenium. Less good in all respects than Pd/Ag, but provide higher resistance (>10 Ohms). Also expensive, as Ruthenium is also a precious metal, but much cheaper than Pd.
3) Carbon resistors. The most stable, and lowest cost. Can be good, but often can be poor sounding. It may depend on the source, but also the processing of the end user, as I have heard good and bad.
Personally, I prefer none of the above, and think a good wirewound resistor, such as Ohmite or NorthCreek, can sound the best, but there are just as many bad sounding ones, so many prefer film resistors.
Just because a resistor costs $4 does not mean it will sound good. I have seen several expensive "audiophile" resistors that make things even worse.
There are not many real "audiophile" resistors. Like most things in this hobby, the upper echelon products aimed towards other industries do best in our applications. As someone who used to make the materials for the likes of Vishay, Sfernice, Holco, etc. I can tell you there are three main types of materials that go into good film thick/thin resistors:
1) 55% Palladium/45% Silver (Pd/Ag). Very low TCR (Temperature Coefficient of Resistance) and quite stable. Used in low resistance applications (0.1 Ohms to 10 or 100 Ohms - depending on the source material and company). Expensive, as both are precious metals. I believe these have the best sound.
2) Ruthenium. Less good in all respects than Pd/Ag, but provide higher resistance (>10 Ohms). Also expensive, as Ruthenium is also a precious metal, but much cheaper than Pd.
3) Carbon resistors. The most stable, and lowest cost. Can be good, but often can be poor sounding. It may depend on the source, but also the processing of the end user, as I have heard good and bad.
Personally, I prefer none of the above, and think a good wirewound resistor, such as Ohmite or NorthCreek, can sound the best, but there are just as many bad sounding ones, so many prefer film resistors.