2. tech-talk
  3. 1303492434

Likely culprit for harshness at higher volumes?

Hi,

I'm a newbie to higher end audio. I have a very modest system:
1) Pre-amp: Anthem AVM2
2) Amp: Adcom GFA-5400
3) Source: Sony CDP-X111ES CD player
4) Speakers: KEF C75
5) Toslink between source and pre-amp; cheap RCA cables from pre-amp to amp; 16 or 18 gauge speaker wire (Radio Shack?)

Room setup (10-ish feet x 20-ish feet rectangle):
1) 2 foot deep cabinets along one wall (20-ish foot)
2) Components stacked on top of small end table against rear wall (10 foot); centered between cabinets and opposite wall.
3) Speakers slightly in front of end table and about 2 feet from side walls and 4 feet from rear wall

Sounds good at about -45 to -25db; but higher frequencies get harsh at higher than -25db.

Appreciate your thoughts.
saru

Showing 2 responses by meiwan

meiwan
399 posts
 
You are either overdriving your speakers or your amp is clipping. Usually an amp issue, but I'd think the Adcom has lots of power - What is the Kef speaker power handling rating?

Or, your room needs treating for high frequencies - at higher volumes you be noticing harshness in your system that you don't at lower volumes (even though it's there).

You might look to upgrade your wires (speaker and interconnect), although I doubt that is the specific problem.
meiwan
399 posts
 
Sounds like (excuse the pun), it's an issue with the amplifier. Your Anthem is a pretty good pre, but Adcom power amps are not that great (having owned one). Seems like at low volume the adcom lacks detail and dynamics - you need to crank it up to get anything out of it. It may be having trouble driving the 4 ohm Kefs. You may not necessarily need more power, just a better quality power amp.
Best idea would be to borrow or try another/better power amp and see what happens. A good power amp will have lots of detail/dynamics at lower volume levels.
More to discover