Gotta know the amp unless you are willing to change that as well.
I'm wondering why the bass integration was such a problem though? I've heard some indicate Avantgardes need to be set up correctly to get the drivers time aligned and fully coherent. Were you able to do that?
You'll likely need other high efficiency speakers to just replace the Avantgarde (not the amp) and get what you are used to. I suspect if the amp sounded good on those that it will also sound good on other high efficiency designs.
If you can afford it, speakers using field coil drivers might be able to do some of the same things with a lower power amp. Otherwise, I think you will be challenged to get what the Avantgardes deliver.
I'm wondering why the bass integration was such a problem though? I've heard some indicate Avantgardes need to be set up correctly to get the drivers time aligned and fully coherent. Were you able to do that?
You'll likely need other high efficiency speakers to just replace the Avantgarde (not the amp) and get what you are used to. I suspect if the amp sounded good on those that it will also sound good on other high efficiency designs.
If you can afford it, speakers using field coil drivers might be able to do some of the same things with a lower power amp. Otherwise, I think you will be challenged to get what the Avantgardes deliver.