There are so many variables and ways components can interact with one another. I am not sure if you are talking about a receiver or an integrated amp. When you say amp and I do not know the model numbers of your equipment without looking it up I am not really sure what you have. I also do not know your sources and speakers. A receiver, integrated amp or preamp and power amp can react differently with different speakers.

I checked your profile and you have no equipment listed. The more information you provide the better answers we can give. Some speakers are hard to drive and some electronics do not have good power supplies to really drive a speaker. HK usually have good power supplies. Of course we also do not know how large a room you are trying to fill with sound and the efficiency of your speakers. Tell us more.