These are very little-known strings from Larsen, the makers of the most popular top-end cello strings. The fact that their top-end set (Magnacore) costs over £200, makes it a bit surprising that they also offer one of the cheapest good-quality cello sets at just £71.99 from simplystrings.com.
A similar set of strings in competition with Crown might be Kaplan or Jarger, but the Crown strings are some £30 cheaper than Jarger. It might be the case that if you’re looking for a good quality steel core string to perk up a student instrument, then these are in a niche of their own. In the past we’ve had customers who had wanted to upgrade strings for a cello for a student, but understandably without being willing to spend almost £100 for a nice set of metal core strings. So, it seems that Larsen maybe are trying to fill that niche with these Crown strings as a set.
As far as the professional payer may feel about these strings , some players are more than happy to use the A and D strings on a professional level instrument, regarding them to be similar to Kaplan, often using them in conjunction with more expensive G and C strings such as Spirocore Tungsten. To a professional player, the G and C Crown strings will seem unresponsive compared to more expensive strings such as Magnacore which are specifically constructed to mitigate the natural problems getting a thicker string to speak and be flexible and responsive.
So, the A and D strings can be used in a variety of circumstances, but the whole set represents an excellent high-quality steel-core set, which not bargain basement by any means, are excellent value and one of the cheapest good-quality sets on the market.