it was just a thought....but here's how I would picture it (I have limited coding skills, and this is waaaaay out of my league :( )
The software would take the audio that is sent to the wave-out or directfilter (or whatever that the breakaway software intercepts) and subtract that from the mic input, invert the result and send it back out.
Obviously it would need a very fast card (s) and a fast cpu. There are various noise cancellation circuits on the web that I thought about trying - just don't have the time to do so at the moment. The problem with the circuits is that I don't think you'd be able to what I mentioned above without some sort of processor logic programming.
just a rough idea...because I'd like to have a quiet car again without buying a new one :lol:
I would think that noise cancellation would be better done with a hardware controller somewhere closer to the amp.
As in, a processor that has its own mic input, and is programmed just to take the inverse of that mic input, and apply it to input, then output the result.
Doing it on the computer and having to do it in real time would probably be more prohibitive.
However, doing it in the last stage before the amp would be relatively easy I would think? And you could even have the mic on a lead, so you could place it up near the headrests of the seats, so as to be the most effective.
I think the biggest hurdle would be trying to avoid cancelling out the pc audio if using a hardware option. I've read that a "passive" cancellation is good for low frequencies while active is good for high...or maybe I have that backwards.
The other idea I had (and I think I'm going to try it when I get my car back) is to record a drive (without music of course) on a few different sets of pavement (smooth, rough, concrete, asphalt, etc) as well as some idle time. Then use audio software to mix and invert those recordings. Then play that back at a low volume. It wouldn't necessarily be as cool as real-time active noise cancellation...but more of a low volume playback of inverted "white noise" commonly found in the car. It should achieve some of the same effect without cancelling out the music much if any.
Actually, it would make it worse, not better.
Unless the waveform is the same shape (caveat coming up), the sound will add to the current noise levels, making the noise in the car worse.
Caveat: If the waveform is the same shape, but slightly out of phase, then it will reduce the noise level in the car, but only by a reduced amount.
So having a recording of a similar road type will not help for noise cancelling, and will in all likelihood make the road noise worse, as you aren't cancelling it, and are then adding in effect a second road noise by your recording.
it was a thought ;)
I know they use white noise in callcenters to cancel out some of the ambient noise to make the environment seem quieter (that way they can cram more people into the office while not increasing noise level)...I was hoping of a similar effect. The white noise that is played isn't very loud at all...barely noticeable, but the effect it has is very noticeable.
you must be doing something wrong. i have the alc888, and its very close of dedicated sound card quality. its not like a $100 soundcard, but its a lot better then any ipod or whatever.
Originally Posted by SoulR
I wonder if you could rip the processing hardware out of a cheap pair of ANC headphones and wire it in somehow?
I finally had the opportunity to test Breakaway in my car and could immediately notice a difference in sound quality in my music. I do have a question though. I noticed with the Breakaway Pipeline set as the default device the range from low volume to high volume has dramatically decreased. At full volume under the Breakaway control panel, the music from winamp was just above what i'd call "normal" listening volume (thats with the winamp volume maxed too). I tried a few of the different presets but didn't really find that much of a difference. Is there something i'm missing here?
I also wonder if the program exposes enough information to create a front end plugin for breakaway.
Had the same problem with the volume set to high, my way around was to increase the gain on my amp a notch.
Check the wave see if it does anything (not sure on this one)
Have a filling this is going to be a difficult one, I’ve tested Spacemonkey s cfmixer.dll on CF it aloud to control the volume level but, lost Silabs radio and phone.