AC3 sounds like Rice Crispies

groovedude wrote on 3/30/2004, 12:29 AM
I'm getting some poping noises when I render my 16/48 wav as AC3.

The client wants it loud so I set the profiles as none, but I leave the filters in there default checked stage. I also render as 224kbps and normalize at -31dB. I really don't think it's clipping because I hear the poping in quiet areas and it's not any worse in louder areas.

It isn't loud poping its more like the poping you'd hear on an old vinyl record--and no I don't have any sound filters or plugins on the wav.

Comments

Spot|DSE wrote on 3/30/2004, 5:22 AM
Have you tried inserting wavehammer prior to output? That should remove the overdrive. AC3 that's been fed a hot signal makes distortion really ugly. Compressed distortion does sound like rice crispies over dialog.
groovedude wrote on 3/31/2004, 7:21 AM
Do you mean guitar distortion?

This is an opera, so no distortion of that nature in it.
Cheesehole wrote on 3/31/2004, 11:26 AM
Could it be the playback method / software? I've gotten my PowerDVD / Audigy into a state where it pops like crazy when playing back surround DVDs.
Spot|DSE wrote on 3/31/2004, 2:45 PM
Distortion, clipping, overdrive, squared, too hot, whatever word you wanna use, and whether distortion is intentional as with a guitar or unintentional such as in a signal that goes beyond digital zero all aggregate as the same thing. Distortion, or a change in the original signal. Compression makes distorted events much more noticeable. AC3 is a compression format, ergo if you have a distorted event, it's quite common for AC3 to make it more noticeable. or, if you have your AC3 encode set up incorrectly, it's also possible to induce distortion. Doesn't matter if it's opera, jazz, acoustic guitar, or heavy metal.
groovedude wrote on 3/31/2004, 10:55 PM
I think my brain is on vacation. When I preview my AC3 in DVDA it has a lot of pops, but when burned and played on a set top it's fine. So, its a nuisance but not a serious problem. I'll probably put a post up on the DVDA side eventually about this.
dvdude wrote on 4/1/2004, 6:13 AM
I haven't found a soundcard/driver combo yet that plays digital audio anything like as cleanly as an external device (DVD/CD etc). I have a feeling that to do so is going to cost me......

groovedude wrote on 4/1/2004, 3:23 PM
Have a look here:

http://www.tracertek.com/studio1.htm

I'm thinking about getting the Media 7.1. The Waveterminal is nice too. I don't know if I'd have better results with AC3 previewing--I just need to replace an outdated audio card in one of my computers.
stormstereo wrote on 4/2/2004, 12:17 AM
Yeah, when previewing in DVDA it's common to hear those little pops. Try making the preview window smaller. In my experience it's just a preview issue and not noticable in in the final product.
Best/Tommy