latency problems

Optimisticly enough, I thought the latency issue would be solved once and for all, if I just fed the right value on latency correction, but it doesnt appear so any longer.
According to Help->Audio Device Info I have “High Input Latency: 0,400000” which is also the setting I got as default in Preferences->Recording->Latency->Audio to Buffer.
To help calculate the latency correction value, I recorded a click track which I recorded again on next track with overdub via a speaker and mic. With a couple of trials I came up with
-620 mS to get a perfect sync.

I thought this would be a fixed value, but not so. Today when I started it was out of sync again and I had to recalibrate and came up with -630 for perfect alignment.
Only to find that when I redid the overdub, the latency changed +58 mS, another time -15 mS, another time +46 mS
Is there anything I can do to steady the latency to a constant value?
I know there is the time shift tool, but if I cant maintain proper sync for each over-dub without having to resort to the time-shift tool each time, I doubt if it’s meaningful to pursue my project.
I use windows vista, soundcard “realtek hd” for input and “creative sb x-fi” for output
Jonas

Using the same sound card for both input and output should help. The creative sb x-fi is likely to be a lot better than the RealTek.

true, and I originally used the creative for both ways, until I discovered that I got much different levels on left and right channel when I fed the same signal to both channels. When I switched to the realtek input the problem was gone, why I suspected some kind of hardware problem with the creative. When I now try to use it again, the auto-detect of a new connector doesnt work and I cant select it as my primary input in the sound manager, it looks kind of dead. Any other suggestions? :slight_smile:

You could try uninstalling the drivers for the x-fi and reinstalling them.

yea, could be worth a try, but the “uninstall” and also the “update” driver button for that soundcard is greyed out, and no idea how to adress that.

You probably need to be logged in as an Administrator.

Ok, Ive uninstalled and reinstalled the driver which revived the line input, but just as before one of the channels seem to be broken. I do get a signal but its 20-30 db down from the good channel so its of no use for me. I still have guarantee on the pc so I guess that includes the soundcard as well, but Im not willing to let go of the whole machine. I hope that they would accept to have just the pci-card, but I have doubts that they will do that. Its probably easier for them to get the whole box so they dont have to rely on my allegations that the only problem is the creative line input.

Things to check:

  1. Check that the problem is not from the audio source -try feeding an input from something else.
  2. Check your lead - try a different lead.
  3. Make sure that you do not have a “pan”/“balance” control set to one side - they should all be central. Check this in the Windows Mixer or the sound card control panel (check this thoroughly because you will feel daft if you take it for repair and they find that you’ve just got the input panned over to one side).

If the problem persists, and if you bought the sound card with the computer from a shop, 'phone them and arrange for someone to look at the machine while you wait. It takes less than 2 minutes to replace a sound card.

1&2) I tried the same source and cord to the other soundcard (realtek) and the result was perfect in terms of signal strength. I interprete this as these parts being fault free.
3) I checked the sound card control panel and the balance control was in the neutral position (which was expected as I have never had any reason to change any of those parameters.
Yes I bought the machine from a shop, but they dont have any service of their own, but I will have to hand in the whole machine and then it’s gone for at least a month, is my guess.
Prompt service is not of any high priority for retail chains like these.

So for now, I’ll have to do with the built-in realtek. I just moved both input and output to go through the realtek, which seems to have lessened the variations of the latencies I mentioned before, when I used one card as input and the other as output.
I also browsed the on-line help some. Apparantly, if there is resource issues, one of the recommendations was to change from 32 to 16 bit.
I have raised the priority of the audacity process to “high”.
Further, I have 2 hard discs, so I just changed the temporary disc output to the non-system disc and also moved my project directories to that disc.
That might improve disc access times, right?

That’s the down side of low prices and such slim profit margins - there’s no money for customer service. I would definitely try getting them to change the sond card while you wait - if they have a sound card of the same type in stock they would not even have to install any drivers because you already have them, so it’s just a matter of taking the side off, and maybe undoing one retaining screw to get the old sound card out and replace it.

If they won’t do that and it has to go away, make sure that you back up your hard drive before it goes and securely delete any confidential information (such as banking details).