Hi,

My B&W 685 speakers are making a lot of noise while playing music. I can hear it from about 2 meters when I turn the volume up to quite a loud level, though not loud enough to get deaf...

When I come closer to the speakers, the noise seems to come from the tweeters, and is about the same in both speakers.

The speakers are hooked up to a Rotel RA-05 and I tested a CD player and an iMac as audio source, with different CD's and both give the noise, so I don't think that's the problem.

Does anyone know what the problem is?

Thanks!

Hi,

what kind of noise? Hissing, distortions, anything else?

It could be coming form anywhere... All "active" audio circuits generate some noise (and distortion).* And, amplifiers amplify the noise along with the signal. Better equipment generates less noise. In general, microphone preamplifiers and phono preamps are the worst** noise contributors, because you have a tiny signal and lots of gain... This makes it hard to get a good signal-to-noise ratio. There is some noise (mixed with the music) on a CD or in an MP3 file that was picked-up during the recording & production process. (It is possible to have "digital silence" on a CD or in an audio file when there is no sound.)


If you hear the noise between songs, it's not the speakers. If you hear noise from one type/model of speaker and not from another, it could be the that noisy speaker is more efficient (everything is louder) or that it has better high-frequency response.

If you hear it only when the music is playing loud, then you are overdriving the speakers and they are distorting or rattling. Or, you amplifier is clipping and generating harmonic distortion.

If the noise gets turned up when you turn up the volume (with no sound/music playing), the noise is coming before the volume control. It could be coming from the preamp inside your Rotel unit, or it could be coming from your soundcard or CD player.

Since you implied that the noise is the same with 3 different sources, I'd guess the noise is being generated inside the Rotel. You can try disconnecting the inputs, and if it gets quieter, the noise is coming from the soundcard/CD player. But, this can be deceiving, because the unconnected inputs can sometimes pick-up more noise.



* Passive circuits generate noise too, but very much less and it's usually not an issue in the audio world.
** Analog broadcasts are even worse.