Archiac versus contemporary voice?

I think perhaps...

the answer depends on how archaic.

If you have every sentence full of prithee and zounds, ye, thou and thee, I bethinks me etc then the answer is no.

At the moment editors and publishers call that gadzookery and don't want it.

Readers hate it too.

What editors say they look for is good plain English flavoured with details of the period and no modern idioms. Generally this means that you can use, but only occasionally, words which today's reader can guess at from context but don't use today. If you're really good with words you can write your sentences with reversals and different rhythm pattern suggesting your period without gadzooks and perchance dotted every where. Means you have to read a lot of the contemporary diaries and letters!

I used some archaic language in my novel. If you want to have a look at it there's an excerpt on my website.
Linnea

Check out Naomi Novik's books for examples of writing in an early 19th-century style that nonetheless manages to be contemporary and enjoyable (and best-selling).

I wouldn't mind it--in fact, it might feel rather odd if the narrator's/main character's "voice" is too modern.

I agree that if lots of archaic LANGUAGE were used, I wouldn't be able to understand it much less enjoy it (the reason why I don't read dialect stories or Middle English!), but I think you just meant the style, not the actual language. If that's so then I think archaic voice is just fine. Warranted, in fact.

I had someone tell me that the characters in a story of mine set in ancient Egypt tended to talk in an overly formal and "stilted" manner. That was rather what I intended. These characters happen to talk in a formal, stilted manner that my more modern characters could never get away with. If I had them talk like my modern-day characters, I think it'd end up being laughable!

Perhaps let the reader know your intent in your Author's Note section.