Nait XS and 4 ohm speakers

The XS is well able to drive a steady 4 ohm load,  the problem is speakers are not a steady load.

Some have large swings in impedance in the bass resonance region from (e.g.) <3ohms to >48ohms.  These large swings are indicative of energy generated by the driver movement & the amp has to retain control over it - commonly known as a difficult load.  

Some speakers are less reactive & are an easy load.   

So the question is what are your proposed 4 ohm 88dB speakers  ???

Not enough information.

You also need the impedance and phase curves of the speaker and more detailed technical information about the amp to determine this.  If you can't get these then it's impossible to know.

You'll be able to get a fair indication by listening in a demo, but even then you can't be certain without using instrumentation as well.  (It's not always possible to distinguish the sound of an amp struggling from the changes in the sound of a speaker and human hearing as volume increases.)

P.S. Mike you answered while I was typing.  

The speakers are DLS R55 (swedish brand). Not very well-known in the UK, I think, but very good reputation in scandinavia (i'm danish)

There's not enough info on their website.  You'll have to try them in a demo (you should always do this anyway).

If you like the result, OK;  if you don't, then you don't:  And that's what's important.

It's unlikely that anyone will be able to give a definite answer to the technical question you asked.

Agree with Huge,  you need to try them with your amp

Looking at the various reviews & the limited info on these speakers I suspect they go lower than 4 ohms,  but I would not worry too much about that,  it depends on how reactive they are, not so much the impedance.

.........  did you know your existing Audiovector SR3's are not 8 ohms as claimed & are more like 4 ohm,  they swing between 3.7 ohm & 10 ohm (apart from bass resonance & most is between 4 & 8 ohms.

........  whats wrong with your existing Audiovector S3 Sig's,   maybe they are suffering because of the Nait XS   

Sorry, I forgot to update my profil. I don't have the Audiovector S3 anymore. But certainly not because of lach of power from the nait xs (and flatcap). They drove them pretty easily. 

I will follow both your advices about audiotion first. 

Thanks :-)

When I had my XS with speakers that had a similar load : was fine , any thing of notice was a slight hardening of high and mid high frequency pushed hard , since my speakers had a tweeter that presented a tougher load than the Woofer Believe it or not.