Have I got the wrong amp? or the wrong speakers?

With 88dB efficiency, and an older Akai, I’m guessing you are clipping, or at least driving high distortion. Maybe a new Integrated Amp?

Take a look at Parasound’s options.

A good, smooth amp with those speakers would be nice. 
Also, take a look at a powered subwoofer like Rel T Series. Their T7i is $100 off for a while. 
A little dialing in (excellent docs and videos on their site, and lifetime support. 

Kudos to everyone's input. And to Larry's note, yeah. Doin' it since this stuff was made. And to the integrated amp: yes and no. There just as many bad integrateds as there are receivers. It depends on the brand, model and year it was made. I modify older pieces to do what they never did back in the day usually because there are now better parts and / or the designers back then weren't allowed the budget to do it right.

In any case one item that comes to mind here- try a BBE processor. Unlike an equallizer, it corrects time. It's a time correction equalizer that most any mid-end system can benefit. High end system don't need this as much because there are no (or few) time base problems to solve.
Most items in your system do not process all frequecies at the same rate of speed. Amps, cables,speakers, it all adds up. Even the room plays a part in this. Time arival equals clarity and usually flater smoother response.
I keep one on my own system (often in bypass) because audio recordings themselves have no standards in which they are recorded and often have time correction problems from the invironment and equipment where they were recorded.
Best of luck on the old gear. There's probably more to it than we know. Are the surrounds on the speakers dead? Are the pot on the amp cleaned, etc?

@clearthinker
Hi Miller, Russ, SteveYou got a down on receivers.Please tell me why an amplifier coupled to a radio will have inherently poorer sound quality than a lone amplifier

I'm probably more down on the fact that it's an Akai receiver.

The receiver is still the workhorse power source in the AV space

In the 2 channel realm the receiver is considered an entry level component as you go up the food chain to separates the SQ improves

SQ and radio really don't go together very well, best done in the car for the most part - IMHO

On a similar note, why are receivers still made in any significant number? How many people actually listen to the radio at home?

I do not know anybody that does that and much less anyone who would fire up some "big gear" to listen to radio.

I have a Brio-R with the same Wharfedale EVO 4.2 speakers for my kitchen - it’s a great match. 
I tune them a little with a as schitt Loki EQ box since placement and a kitchen is not ideal for listening and it sounds really great. 
I was using a Yamaha a-s801 and switch in the brio-r was an immediate and obvious improvement. Highly recommended.