Since CS4 I've always added the DeNoiser effect to some of my audio clips to take away background noise. With CS6 i noticed a slight bug. First I noticed if I don't add the DeNoiser effect as the top effect the audio sounds funny (which putting it on top is no big deal), but even with it on the top it occassionally make the audio sound low and tinny. I say occasionnaly because I can play back the clip with the effect over and over and sometimes it sounds great and others is sounds muffled and tinny. It's very inconsistant. When I export the clip it keeps that muffled tinny sound. This never happend in CS4 or CS5. I believe its a bug, but if anyone has any suggestions I would appreicte it.
Using Mac 10.7.4
You may not like it but I'd suggest not using that effect.
Start by getting better audio. Maybe you need better microphones, or different settings, or a better record deck.
But, if you just have to do something to it, you're better off cleaning up bad audio in Audition in stead of PP.
Are you trying to removing hissing caused by using too much gain during recording or editing? Or are you trying to remove background noises like AC noise or cars passing etc? If it's AC noise and Cars passing then use a highpass filter instead and set it to like something around 120-160 depending on how much you need to cut out.
Depending on exactly what "noise" you are attempting to remove, the Denoiser Effect might not be the right choice, as Jim and ComputerNovice indicate.
It is designed to remove "tape hiss" basically from old analog tape recordings, something that one does not encounter THAT often any more.
For other types of background noise, this ARTICLE, plus CompterNovice's suggestion, might be helpful. Much depends on exactly WHAT the noise is, and what Audio you wish save, in the area, where the noise appears.
Thank you for your comments. It's basically to take out the A/C noise. This effect used to work decently before CS6. I know i can take it to audtion but it's sorta a pain doing that because it's normailly about 30 seperate clips I will have to take to audtion. Thanks again.
For background AC noise, I doubt that the Denoiser Effect will do what you want, as it works on analog tape hiss.
The linked article addresses some methods of removing, or at least attenuate the AC noise.
PS - if you can get maybe a Filter, and/or Compressor to attenuate the noise in one Clip, just Rt-click on the Audio portion of the Clip, and choose Copy. Then select the other 29, Rt-click and choose Paste Attributes.
If you use Audition, you can create a Preset, to be used with each Clip, or you can Export a PCM/WAV for all of the individual Clips (make sure that all edits have been done first), work on that in Audition, Import it, and replace the individual Clips with that edited output file.