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I have a colleague who insists that it is best, when re-conditioning, to restring a grand piano with brass wound bass strings as these strings enhance the bass tone. I am sceptical about this as it seems that every manufacturer today uses copper wound strings. If brass wound strings were better, surely they would be more widely used.
Are there any views, opinions or evidence on the advantages or disadvantages in using brass wound strings?
Thank you,

Robert.

I have only found brass wound strings in guitars not in any piano.

Sometimes they are found on harpsichords but they are closer to a bronze or phosphor bronze than brass. Generally a wrapping that has a high specific density is better than lower ones and by introducing zinc into copper its sd drops from 8.96 grams/cubic cm to a range of 8.4-8.7. Aluminum is often introduced into brass for strength and resistance to season cracking and lowers these numbers even more...not exactly what piano tenor-bass strings need. Its possible that they could benefit a piano on the very lowest plain wires but I'm sure there are other reasons why we don't see them there; probably some difficulties for the string maker.
Its possible he mistakenly referred to brass instead of copper in replacing iron wrapped strings as some people make little distinction between the two.

Thank you Gadzar and Emmery for your replies. An approximately 25 year old Yamaha C7 at our school was partially rebuilt and the original copper wound bass strings were replaced by brass wound strings. Personally, I thought the result was disappointing as some of the bass notes sounded very "woolly" and muffled. I wondered if anyone had had experience with brass wound piano strings or knew something about them.

Thanks again,
Robert.

Sometime I'd like to try tungsten windings, at least for the lowest several notes of a small piano (vertical under 48", grand under 6'). Someone mentioned the density of copper as being 8.96 g/cm^3. Tungsten is approximately 19.25 g/cm^3. I understand it is used on some guitar and string bass strings.
Question... assuming the same speaking length (not rescaling the bridge) and same exposed core length, how would you calculate wrap size for tungsten vs copper assuming either A - the diameter ratio of wrap vs core is maintained or B - the core diameter size is maintained?
IMO anyone who makes pianos with a list price $20k or higher should seriously consider using gold-wound bass strings (19.3 g/cm^3). Or, isn't there something with like a 21 to 25 g/cm^3 or higher density?)
I can understand these windings being difficult to use at the upper end of the wound string range. What options would be recommended? Use a different material for the upper bass notes, or extend the plain wire notes a bit lower (my personal preference based on the tone of the Baldwin Hamilton 242 tenor vs the 243 tenor)?

Go for broke: depleted uranium!

Tungsten and most tungsten alloys are not malleable enough to be used as a winding and would likely break in the process. Gold would be good but I don't know how well it would hold up for wear. Depleted uranium Jeff...now where would we easily get that stuff these days??.....hmmm come to think of it, I'm sure there are a "few" T55's out in a certain desert which you might dig some spent (A10)30mm GAU rounds out of. Some years ago a tech applied for a patent on a new way to wind piano strings where the wrap had spaces between the coils. According to him it allowed for more gradual changes from 1 note to the next. I think the idea did not reach fruition because of the saw effect it had on the hammer felt.

U-238 (19.1 g/cm^3) is actually less dense than tungsten (19.25) or gold (19.3).
How about something like osmium (22.61 g/cm^3), iridium (22.56), or platinum (21.45)?
I think something ultra dense (and preferably not cheap) should be used in all pianos with a list price over $20k, or maybe all "tier" 2 pianos 48"+ in verticals and 7'+ in grands, and all "tier" 1 pianos (in LF's 2008-09 supplement, that is).
What element, if it isn't tungsten, is not much more expensive than copper, or at least not more than a fraction of the cost of gold, that's comparable in density? Maybe something like that could be used in less expensive and smaller pianos, or at least experimented with maybe. (I have a Baldwin Hamilton 242 I might like to try it out on, I just don't have a way to get tungsten wound bass strings, and I'm not sure how to order custom ones from a guitar / string bass maker (I know I'd need to specify wrap diameter, length, core material, diameter, etc (although if I had to I could probably make the hitch pin loop myself), and I am not aware of any companies that make bass strings for those instruments that do custom orders like that.)

I always wondered if they could plasma spray or solid deposition spray some of these alloys onto wire to give better sounding tenor notes where the highest wound strings stop? I'm not sure if the high temperatures nneeded would adversely effect the breaking point of the string.

Thank you all for these varied, interesting replies. My preference for copper is based on the premise that copper is used universally for bass string windings and if brass were better, then surely it would replace copper.

Regards,

Robert.

You’ve mentioned this before, and I can’t help but wonder if this idea could be taken a bit further. What if at each twelfth of the speaking length (at most of the nodes) the core and/or wrap was made more flexible, either by spacing or by reducing diameter, for the lowest bass strings. I would think that the iH could be lowered this way. Just another pipe dream.