Help with amp problems

[GiLz]

Hi guys,

I did a quick search in the forums and didn't see anything specifically pertaining to this issue, but I apologize in advance if you've heard this 1000 times. Also I'm pretty new to Hi-fi so go easy on me

I have an older Sansui AU-11000 integrated amplifier (120 or 150 WPC @ 8ohm, I don't have the manual and I've seen this amp rated for both) supplying 2 Polk Audio R50's. It's nothing crazy, I mostly setup this system to get back into my vinyl collection. The R50's are 90db efficient and rated @ 150 Watts RMS with an 8ohm impedance. http://www.polkaudio.com/homeaudio/specs/r50/

The problem I'm experiencing is that at a high volume (maybe 8/10) I experience a very noticable distortion in the music (like you were talking into fan kind of noise). Obviously this is a bad thing and immediately turned the volume down. Is this a classic case of the amp "clipping"/not being able to power the speakers efficiently? If so would a more powerful amp be a solution so I wouldn't have to tax the amplifier so hard to get the same result? If this amp does infact output 120WPC then I could probably use some power in reserve.

Or could this be my speakers not being able to handle the volume. I know they aren't the BEST speakers but it was what I could afford at the time. You could definitly tell the distortion was coming from the tweeter/midrange set of speakers. The bottom end seemed to be holding up fine.

Thanks in advance.

 

[jonnythan]

I can drive my R30's to pretty painful levels without significant distortion using a 75 WPC Denon receiver.. so I don't think it's the speakers.

I can't really offer any other help, but I'd ask what kind of source you're using and what kind of cabling you have.

 

[agular]

process of elimination

If you have access to another integrated amplifier, or even a receiver try swapping them out with your Sansui integrated. Then try turning the volume up if your speaker sound fine then you probably have a problem with you Sansui. Then again if your speaker still sounds bad the problem would be with your speakers. This would be called process of elimination. GOOD LUCK.

 

[zumbo]

Sounds like a combination of a few things.

1) Room size is my very first guess. A smaller room may yield better results to what you think the level is.

2) Amp is clipping. Running out of juice for sure.

3) Speakers. Refer to #1. While a larger amp will yield better results, you are limited to what those speakers will do in your room. And, too much power will be the end for them.

Solution. Room treatment.

http://www.audioholics.com/techtips/roomacoustics/index.php

 

[GiLz]

Thanks for the feedback guys. My buddy has a 2ch power amp I'm going to sub in to see if that eliminates it. As far as cabling goes, I'm just using standard 14ga speaker wire. The longest run I have is about 12 feet.

I basically just wanted to know if there was a definitive answer to this. If not, the process of elimination begins .

Thanks again.

 

[GiLz]

Zumbo, thanks for the tips. I'll look into that for sure. The room isn't overly large, it's about 19x13 but its not 10x10 either. I'm going to also try working on speaker placement as well, just have to shuffle a few things around first.

This is a great forum and thanks again for the feedback.

 

[Josuah]

Kind of a strange thought, but since you described it like a fan, are the drivers on the speakers loose? That's what your description made me think of.