You're contradicting yourself there a bit. You can't have a neutral, uncolored speaker that's also warm. It does sound like perhaps your Tannoys just can't produce the lower bass that you'd like. Are you looking for a floorstander or a standmount (bookshelf) speaker? I can't advise what matches well with that NAD. Orchestral music can require a speaker with quite a range to fully reproduce all the nuances and depth some music has.

I guess I should also ask if you're opposed to used speakers? You can sometimes get a lot more speaker for your money if you shop used and choose wisely.