I have used a TC-7115 speaker switch before. Providing the switches are decent then there is no detriment to SQ.

It has 5 switched outlets, all are switched in parallel so it is best not to have more than 2 switched in at once. If you are just using it for comparison then switch one in and one out. It is now no longer needed, so it is for sale:



One of the original knobs is missing but has an alternative fitted.



Comes with attached 60 cm tails to connect to power amp.



£35 delivered if you are interested.